To evaluate whether the numerical aperture significantly changes the measured value of the surface parameters, a Bayesian Multi-factor ANOVA was applied. This method computes the amount of variances that can be attributed to a single factor or a combination of two factors using Bayesian inference.

International Organization for Standardization. ISO 4288 – Geometrical product specifications (GPS) – Surface texture: Profile method – Rules and procedures for the assessment of surface texture (1996).

All descriptive analyses (summary statistics and scatter plots) were performed in the open-source software R v. 3.5.1 (ref.29) through RStudio (v. 1.1.456; RStudio Inc., Boston, USA) for Microsoft Windows 10. The following packages were used: doBy v. 4.6-1 (ref.30), ggplot2 v. 3.0.0 (ref.31), openxlsx v. 4.1.0 (ref.32), R.utils v. 2.7.0 (ref.33). Reports of the analyses in HTML format, created with knitr v. 1.20 (refs34,35,36) and rmarkdown v. 1.10 (ref.37), as well as raw data, scripts and RStudio project, are available as Supplementary Material 3.

The resulting 3D surface data were processed in batch with templates in ConfoMap v7.4.8633 (a derivative of MountainsMap Imaging Topography developed by Digital Surf, Besançon, France).

ICArEHB, Interdisciplinary Center for Archaeology and Evolution of Human Behaviour, University of Algarve, Campus de Gambelas, 8005-139, Faro, Portugal

In this study, we tested whether using objectives with different numerical apertures affects the results of quantitative 3D surface texture analysis. It appears that the surfaces of experimental flint and quartzite tools, as well as those of a roughness standard, are significantly different when acquired with different objectives and analyzed quantitatively. The numerical aperture is only one of the many acquisition and analysis settings that could influence the results of use-wear analyses.

Stemp, W. J., Braswell, G. E., Helmke, C. G. B. & Awe, J. J. An ancient Maya ritual cache at Pook’s Hill, Belize: Technological and functional analyses of the obsidian blades. Journal of Archaeological Science: Reports 18, 889–901 (2018).

The polarization diagrams discussed above refer to the case where the anode reaction is that of a metal changing to its ion and the release of electrons, and ...

Whenever you buy any kind of serious OM-D body, this lens will be one of the bundle options. It's kept the same design for years, but that's not because it's some kind of low-cost throwback that's just used for lens bundles – it's because the company got everything right with this lens from day one. Its 24-80mm effective zoom range is just a tad longer than the 'standard' 24-70mm on other cameras, and its optical performance is consistent right across the zoom range. It can also focus very close for a standard zoom lens too, so it's very versatile. If you had to choose one standard zoom lens for your Olympus, this is the one to get. Also, note that there is a newer rebadged OM System version of this lens – the OM System M.Zuiko 12-40mm f/2.8 Pro II is virtually the same, but has added weather-sealing.

Microscopes are useful tools for visualizing small structures in great detail. There are two common types of microscopes used in laboratories when studying ...

Kruschke, J. K. Bayesian estimation supersedes the t test. Journal of Experimental Psychology: General 142, 573–603 (2013).

The template for the roughness standard (Supplementary Material 2) followed the ISO 4287/4288 norms, in order to compute values that are comparable to the nominal value: (1) level by least squares plane subtraction (Fig. 5c,d), (2) extract a 4.56 mm-long profile, (3) apply a Gaussian microroughness low-pass filter (λs = 2.5 μm) to filter out the noise and keep the primary profile, (4) apply a Gaussian roughness high-pass filter (λc = 0.8 mm, end effects not managed) to filter out the waviness and keep the roughness profile, and (5) compute ISO 4287 Ra (Supplementary Table S1).

Covering an equivalent range of 16-50mm, this deceptively capable zoom goes from a wide field of view to standard. It's great for street shooting.

In order to check for a significant effect, the unknown parameters β0, β1, β2 and M must be inferred from the data and the prior knowledge on the measurement process. The detailed model is chosen as

Almost impossibly slim and portable, the Olympus M.Zuiko 14-42mm f/3.5-5.6 EZ is an ideal take-everywhere standard zoom for street shooting, travel and more.

Odell, G. H. Stone Tool Research at the End of the Millennium: Classification, Function, and Behavior. Journal of Archaeological Research 9, 45–100 (2001).

Calandra, I., Schunk, L., Bob, K. et al. The effect of numerical aperture on quantitative use-wear studies and its implication on reproducibility. Sci Rep 9, 6313 (2019). https://doi.org/10.1038/s41598-019-42713-w

Artigas, R. Imaging Confocal Microscopy. In Optical Measurement of Surface Topography (ed. Leach, R.) 237–286, https://doi.org/10.1007/978-3-642-12012-1_11 (Springer Berlin Heidelberg, 2011).

Stemp, W. J., Lerner, H. J. & Kristant, E. H. Testing Area-Scale Fractal Complexity (Asfc) and Laser Scanning Confocal Microscopy (LSCM) to Document and Discriminate Microwear on Experimental Quartzite Scrapers. Archaeometry 60, 660–677 (2018).

Hereafter, following Leach21, the term surface topography will be used to describe the overall surface structure, while surface form is defined as the shape of the object, and surface texture is what remains when the form is removed from the topography. These definitions differ from Evans et al6., where texture describes the roughness and topography the waviness (both included in Leach’s21 texture), the distinction between roughness and waviness being based on wavelength filters (see below).

Right from the moment you pick this lens up you can feel the Olympus Pro lens quality in its design and operation – and our lab tests have shown that its optical quality does not disappoint, either. This is another unique lens, this time because of the focal lengths it straddles: you could see it as an ultra-wide zoom that goes right up to a standard zoom range, or as a standard zoom that also goes ultra-wide. Either way, this one lens could replace two lenses for many travel, street and architectural photographers. It's not particularly small, to be fair, but the focal range it covers is quite impressive

There are a few too many M.Zuiko lenses to cram into a single guide, and they cater for a multitude of purposes and user types, so we've split our guide into four sections:

And while Panasonic lenses autofocus as you would expect on OM cameras, they are tuned for Panasonic's own DFD contrast-detect AF system – and some notable examples (such as the Panasonic 20mm f/1.7) focus incredibly slowly on non-Panasonic bodies. Overall, we think that OM System lenses are just that bit snappier on OM System cameras.

While we're still finishing our lab tests of this lens, it's looking safe to say that it's shaping up to be one of the best macro lenses on the market for the MFT system.

OM System now offers a few 40-150mm telephoto zooms: this one is tiny, light and… well, let's not pretend, more adequate than spectacular. But you can forgive a lot in a telephoto zoom that's this small and this cheap. It's equivalent to an 80-300m lens in full frame terms, but a fraction of the size and price – it's a reminder of the advantages of the Micro Four Thirds format over APS-C and full frame systems. Yes, the sensor is smaller, but so are the lenses – often spectacularly so. Some may prefer to get the newer OM System M.Zuiko 40-150mm f/4 Pro for its IP53 weather-sealing; however, we think the incredibly low price of the Olympus M.Zuiko 40-150mm f/4-5.6 R means it merits inclusion in this guide.

Scatter (a) and contrast (b) plots of ISO 4287 Ra calculated on the surfaces from each objective on the roughness standard. The dotted line in (a) highlights the nominal Ra value of the roughness standard (0.40 µm). Note that values in (b) are given in units of 0.01 µm. See Fig. 1 for details on symbols.

We test lenses using a mix of both real world sample images and lab tests. Our lab tests are carried out scientifically in controlled conditions using the Imatest testing suite, which consists of custom charts and analysis software that measures resolution in line widths/picture height, a measurement widely used in lens and camera testing. We find the combination of lab and real-word testing works best, as each reveals different qualities and characteristics.

Xie, Y. knitr: A General-Purpose Package for Dynamic Report Generation in R. R package version 1.20.(2018). Available at: https://yihui.name/knitr/ (Accessed: 27th September 2018).

This lens delivers an impressive 114-degree viewing angle, which is no mean feat on a Micro Four Thirds camera. Its contrast and sharpness are utterly sublime.

A cosmetic refresh of one of the oldest lenses on the Olympus books, this gorgeous zoom is still one of the best. Its pocketable dimensions make it ideal for travel.

One of the best pancake lenses, when fitted to something like the Olympus PEN E-P7 you can slide your camera into a jacket pocket or a handbag and take it anywhere. We've all had to accept cameras and lenses getting bigger and bigger and bigger over the past few years, but this lens, on a compact PEN body, takes carry-round cameras right back to the size they ought to be! Read our full Olympus M.Zuiko 14-42mm f/3.5-5.6 EZ review here.

Even though the objective with the highest NA should yield the results closest to reality, the real, expected results for these rock samples are unknown. Therefore, a roughness standard with nominal Ra = 0.40 ± 0.05 μm was measured with each of the two objectives. The measured Ra values were then compared to the nominal value.

While the crop factor of MFT format cameras boosts the telephoto abilities of lenses, it makes the design of ultra-wide optics more of a challenge. The M.Zuiko 7-14mm f/2.8 Pro is a remarkable wide zoom lens with a minimum focal length of just 7mm, delivering an astonishing 114-degree viewing angle, similar to using a 14mm lens on full-frame cameras. Like other lenses in the Pro line-up, it’s immaculately turned out, with fabulous build quality. Contrast and sharpness are outstanding, while color fringing and distortions are negligible. As with many ultra-wide lenses, however, the hood is built-in so there’s no filter attachment thread.

While the influence of at least some of these settings is critical when quantifying use-wear, their influence on qualitative use-wear has not been considered. However, a conservative approach would be to be as cautious about acquisition and analysis settings in qualitative studies as in quantitative ones.

Locations 2 and replicas 1 on all three samples: (left) FLT1-7, (middle) QTFU2–10 and (right) roughness standard 0.4 µm. (a) Stitched 3 × 3 overview image acquired with the C Epiplan-Apochromat 5×/0.20 objective. (b) Stitched 2 × 2 (FLT1–7 and QTFU2–10) or 8 × 2 (roughness standard) wide field image acquired with the 50×/0.95 objective. (c-d) S-L surfaces (FLT1–7 and QTFU2–10) or leveled surfaces (roughness standard, stitched 4 × 1) acquired with the 50×/0.75 and 50×/0.95 objectives, respectively.

The samples have been cleaned thoroughly previously (see refs24,25). The measured areas (around the edge) were cleaned again with 2-propanol 70%v/v and lens cleaning tissues just before acquisition.

Salvatier, J., Wiecki, T. V. & Fonnesbeck, C. Probabilistic programming in Python using PyMC3. PeerJ Comput. Sci. 2, e55 (2016).

Nevertheless, the results demonstrate that the NA of an objective influences the way the surface topography is acquired on both quartzite and flint (Figs 1 and 2), two of the most common raw materials in the archeological record. This, in turn, implies that quantitative use-wear analyses have the potential to produce different results depending on the objective used on most archeological samples. Previous research in microscopy19,20, and the role of NA on resolution in general (see Supplementary Material 1), have shown that this influence of the objective’s NA was to be expected. However, this effect had not been measured before in archeological use-wear studies. Unfortunately, this property is not always reported in quantitative use-wear research.

Stemp, W. J., Watson, A. S. & Evans, A. A. Surface analysis of stone and bone tools. Surf. Topogr.: Metrol. Prop. 4, 013001 (2016).

Both objectives used here yield data within the certified tolerance of the roughness standard, although they are significantly different from each other (Fig. 3). The values calculated on surfaces acquired with the 50×/0.75 objective are closer to the nominal Ra value than those acquired with the 50×/0.95 objective. This is surprising, as the higher numerical aperture (NA) objective should theoretically produce the most accurate results. The real Ra value of the roughness standard is unknown, though; it could be that the real Ra value is closer to 0.42 µm than to the nominal Ra value 0.40 µm.

International Organization for Standardization. ISO 25178-2 – Geometrical product specifications (GPS) – Surface texture: Areal – Part 2: Terms, definitions and surface texture parameters (2012).

With a whopping 200-800mm equivalent focal range, this telephoto zoom lens packs a wallop, and can even be extended further with teleconverters.

TraCEr, Laboratory for Traceology and Controlled Experiments at MONREPOS Archaeological Research Centre and Museum for Human Behavioural Evolution, RGZM, Schloss Monrepos, 56567, Neuwied, Germany

Evans, A. A., Macdonald, D. A., Giusca, C. L. & Leach, R. K. New method development in prehistoric stone tool research: Evaluating use duration and data analysis protocols. Micron 65, 69–75 (2014).

There are several advantages to this approach compared to the traditional null hypothesis testing procedure38. First, this method does not rely on assumptions other than the ones stated below and is therefore more transparent. Second, by using the full posterior distribution for the significance testing, the certainty of the results can also be assessed. Finally, regarding the practical component of the analysis, the availability of steadily increasing computational power and user friendly software libraries makes the greater complexity of the computation not a serious drawback compared to the gain in insight.

Sheppard, C. J. R. & Larkin, K. G. Effect of numerical aperture on interference fringe spacing. Appl. Opt., AO 34, 4731–4734 (1995).

We selected two experimental tools displaying use-wear. The first tool (FLT1–7; Fig. 4a) is a blade knapped from flint from the French Pyrenees (Narbonne-Sigean Basin). It was used in mechanical bi-directional linear (cutting-like) action on dry wood (Pinus sp.) boards. It performed 250 strokes of 2 × 30 cm at 0.5 m.s−1 with a 4.5 kg load applied onto the tool (Pereira et al. in prep.). The second tool (QTFU2–10; Fig. 4b) is an unretouched metaquartzite flake manually used to cut a Giant cane’s stem (Arundo donax) for 2 × 15 min (see ref.24 for details).

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As well as making very compact and portable f/1.8 and f/2 primes, OM System makes a series of whopping f/1.2 Pro primes too, and this is one of the most useful. Its 45mm focal length equate to 90mm in full frame terms, so this makes a superb portrait lens for OM cameras. Now we need to come clean about the MFT format and point out that the smaller format means you don't get the shallow depth of field of a full frame lens with this aperture, or an APS-C camera – its closer in its effect to f/2.3 on APS-C and f/3.5 on full frame. Even so, at f/1.2 the depth of field is extremely shallow and it's easy to blur backgrounds in portraits – and this lens has been designed to produce super-smooth bokeh too. OM's f/1.2 primes are pretty hefty brutes, but they are optically superb.

Xie, Y. knitr: A Comprehensive Tool for Reproducible Research in R. In Implementing Reproducible Computational Research (eds Stodden, V., Leisch, F. & Peng, R. D.) (Chapman and Hall/CRC 2014).

All data generated and/or analyzed during the current study are included in this published article and its Supplementary Information files, or are available on Zenodo (see Supplementary Materials 2, 3 and 4).

The 180mm equivalent focal length gives you plenty of telephoto reach, and if it's not enough, you can pair it with OM System’s M.Zuiko MC series teleconverters to double it to 360mm. If you're looking to photograph macro subjects that won't let you get too close like flighty insects, this is a fantastic asset – though naturally, you'll need a good deal of precision and potentially some quick reflexes to get them in the frame.

Allaire, J. J. et al. rmarkdown: Dynamic Documents for R. R package version 1.10. (2018). Available at https://CRAN.R-project.org/package=rmarkdown. (Accessed: 27th September 2018).

Zupancich, A. et al. Early evidence of stone tool use in bone working activities at Qesem Cave, Israel. Scientific Reports 6, 37686 (2016).

Evans, A. A., Lerner, H., Macdonald, D. A., Stemp, W. J. & Anderson, P. C. Standardization, calibration and innovation: a special issue on lithic microwear method. Journal of Archaeological Science 48, 1–4 (2014).

Key, A. J. M., Stemp, W. J., Morozov, M., Proffitt, T. & de la Torre, I. Is Loading a Significantly Influential Factor in the Development of Lithic Microwear? An Experimental Test Using LSCM on Basalt from Olduvai Gorge. J Archaeol Method Theory 22, 1193–1214 (2015).

Walker, A. openxlsx: Read, Write and Edit XLSX Files. R package version 4.1.0.(2018). Available at: https://CRAN.R-project.org/package=openxlsx. (Accessed: 27th September 2018).

There are so many good M.Zuiko standard zoom lenses that we had to leave some out! That's not because we don't rate them, but because we wanted to offer a balance spread of favorite choices. So even though they're not listed below, we still want to mention the original retracting M.Zuiko 14-42mm f/3.5-5.6 II R kit lens (plasticky feel, but rather good), Olympus M.Zuiko 12-45mm f/4 Pro (a slightly smaller alternative to the 12-40mm F2.8), the incredible Olympus M.Zuiko 12-100mm f/4 IS Pro (with a big zoom range and its own stabilizer) and the M.Zuiko 14-150mm f/4‑5.6 II superzoom (yes, a superzoom, but optically better than 9 out of 10 examples of its type).

Højsgaard, S. & Halekoh, U. doBy: Groupwise Statistics, LSmeans, Linear Contrasts, Utilities. R package version 4.6-1.(2018). Available at https://CRAN.R-project.org/package=doBy. (Accessed: 27th September 2018).

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Table 1 and Supplementary Material 2 list all hardware and software settings related to both acquisition and analysis used here. Nevertheless, there might be settings that are not accessible in this system and/or software packages but that are still relevant to data acquisition and analysis. Furthermore, other systems might have different settings and it is likely that some have different names.

OM System makes so many excellent prime lens that picking just three to represent the whole spread was VERY difficult. With that in mind, we have to mention some lenses that aren't on the list but deserve maximum respect. They include the M.Zuiko 8mm f/1.8 Fisheye Pro (how is an f/1.8 fisheye even possible?), the compact and classy 35mm equivalent M.Zuiko 17mm f/1.8, the big but tasty M.Zuiko 25mm f/1.2 Pro, the dinky little M.Zuiko 30mm f/3.5 Macro, the equally dinky and ridiculously cheap M.Zuiko 45mm f/1.8 portrait lens, the amazing 150mm equivalent M.Zuiko 75mm f/1.8 and the remarkable M.Zuiko 300mm f/4 IS Pro telephoto prime. Phew.

If you're doing a project but don't have high resolution photos, use our photos. Each person in the photo have signed a Rotary International Photo Release, ...

All relevant information and acquisition settings are listed in Table 1. On the flint and quartzite samples, the field of view (FOV) was 255.6 × 255.6 µm. The pixel size was calculated following as closely as possible the ISO 4287/4288 norms26,27: L = FOV/2 = 127.8 µm, S1 = L/300 = 0.426 µm, and pixel size = S1/5 = 0.0852 µm. The frame size was then defined as the field of view divided by the pixel size, i.e. 3000 × 3000 pixels. The field of view on the roughness standard was set to 945.62 × 255.56 μm, with a 4 × 1 stitched image, representing a frame size of 7578 × 2048 px. In doing so, evaluation length (4.56 mm ≥ 4 mm), sampling length (0.927 ≥ 0.8 mm), and point spacing (0.125 ≤ 0.5 μm) are according to ISO 4287/4288, so that the measured values can be compared to the nominal value. The pinhole diameter was adjusted so that it corresponds to 1 Airy Unit for each objective: 54 µm for the 50×/0.95 objective and 73 µm for the 50×/0.75 objective. This means that the optical lateral resolution of the objectives was kept constant throughout the experiment. The Shannon-Nyquist criterion (pixel size less than half the optical lateral resolution; see Supplementary Material 1) is met on all samples.

Feb 1, 2023 — ... regeneration. Increased cell volume and ... wave plate (AHWP10M-980, Thorlabs) was app ... Regenerative 922. medicine 3, 1-13 (2018) ...

for the priors, where ‘~’ means ‘is distributed as’ and N(a, b) denotes a normal distribution with mean a and standard deviation b and U(a, b) a uniform distribution between a and b.

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After having computed the samples from the posterior, the so-called contrast, i.e. the distribution of the differences between β1,0 and β1,1, can be analyzed. To decide whether there is a significant effect in changing the numerical aperture, the 95% high probability density interval of 2.5% to 97.5% cumulated probability of the contrast is considered. If zero effect strength is not within that interval, the effect is considered significant.

The template for flint and quartzite samples performs the following procedure on each 3D surface (Supplementary Material 2): (1) apply a Gaussian low-pass S-filter (S1 nesting index = 0.425 µm, end effects managed) to remove noise and keep the primary surface, (2) apply an F operator (polynomial of degree 3) to remove the form and keep the SF surface, (3) apply a Gaussian high-pass L-filter (L nesting index = 127 µm, end effects managed) to filter out the waviness and keep the SL surface (Fig. 5c,d), and (4) compute 29 ISO 25178-2 parameters28 (Supplementary Table S1). This template follows Digital Surf’s Metrology Guide (accessible at https://guide.digitalsurf.com/en/guide.html) as closely as possible, but it should not be expected that lithic tool surfaces require the exact same processing as dictated by the ISO norms defined for industrial applications. We therefore adapted the cut-off values for the filters based on field of view, frame size and pixel size, as detailed above. Much more work is needed to define the most appropriate way to analyze surfaces of archeological tools but this task is beyond the scope of the present study. The processing workflow was performed consistently to enable the comparison, which was the goal. It is not intended as a general recommendation on how to measure surfaces of experimental or archeological samples.

With its short telephoto focal length and wide f/1.2 maximum aperture, this sumptuous (and hefty) professional lens is ideally placed for portraiture.

Pedergnana, A. & Ollé, A. Monitoring and interpreting the use-wear formation processes on quartzite flakes through sequential experiments. Quaternary International 427, 35–65 (2017).

Bengtsson, H. R. utils: Various Programming Utilities. R package version 2.7.0.(2018). Available at: https://CRAN.R-project.org/package=R.utils. (Accessed: 27th September 2018).

Leach, R. Introduction to Surface Topography. In Characterisation of Areal Surface Texture (ed. Leach, R.) 1–13 (Springer Berlin Heidelberg, 2013) https://doi.org/10.1007/978-3-642-36458-7_1.

The change in numerical aperture is considered here as the first factor, x1. The combination of the two other settings, the type of raw material (quartzite or flint) and the location on the sample, is considered as the second factor, x2. For every single measured surface parameter, the measurement outcome y is related to the factors by a linear model:

Many archeologists are skeptical about the capabilities of use-wear analysis to infer on the function of archeological tools, mainly because the method is seen as subjective, not standardized and not reproducible. Quantitative methods in particular have been developed and applied to address these issues. However, the importance of equipment, acquisition and analysis settings remains underestimated. One of those settings, the numerical aperture of the objective, has the potential to be one of the major factors leading to reproducibility issues. Here, experimental flint and quartzite tools were imaged using laser-scanning confocal microscopy with two objectives having the same magnification but different numerical apertures. The results demonstrate that 3D surface texture ISO 25178 parameters differ significantly when the same surface is measured with objectives having different numerical apertures. It is, however, unknown whether this property would blur or mask information related to use of the tools. Other acquisition and analyses settings are also discussed. We argue that to move use-wear analysis toward standardization, repeatability and reproducibility, the first step is to report all acquisition and analysis settings. This will allow the reproduction of use-wear studies, as well as tracing the differences between studies to given settings.

May 24, 2024 — Infrared is radiation with a wavelength between 780 nanometres and one millimetre on the electromagnetic spectrum. This IR radiation cannot be ...

In the context of an experiment, repeatability measures the variation in measurements taken by a single instrument or person under the same conditions, while reproducibility measures whether a study or experiment can be reproduced in its entirety. Preproducibility is a neologism that Philip B. Stark defined as follows (p. 613): “An experiment or analysis is preproducible if it has been described in adequate detail for others to undertake it. Preproducibility is a prerequisite for reproducibility”16.

The same focal range as the previous lens – but its polar opposite in just about all other ways. This is a gorgeous, high-quality pro lens, at a pro price.

To gain a better representation of the imaged areas, wide field overview and extended depth of focus (EDF) images were also acquired at each location. The overview images (Fig. 5a) were acquired with the following settings: C Epiplan-Apochromat 5×/0.20 objective and 3 × 3 tile region. The EDF images (Fig. 5b) were acquired with the following settings: the 50×/0.95 objective described above, step size = 1 µm, 2 × 2 tile regions for flint and quartzite, and 8 × 2 tile regions for the roughness standard in order to cover the same area.

Creath, K. Calibration of numerical aperture effects in interferometric microscope objectives. Appl. Opt., AO 28, 3333–3338 (1989).

continuous wave laserFQCW266-1000 ... FQCW266-1000 - 1 W cw laser at 266 nm The DPSS-CW-DUV laser FQCW266-1000 delivers an output power of 1000 mW in single-mode ...

R Core Team. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. Version 3.5.1. (2018). Available at https://www.R-project.org/ (Accessed: 27th September 2018).

• Best camera lenses to buy • Best Micro Four Thirds lenses • Best Olympus cameras • Best wide-angle lenses • Best standard zoom lenses • Best telephoto lenses

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Leach, R. Some Common Terms and Definitions. in Optical Measurement of Surface Topography (ed. Leach, R.) 15–22, https://doi.org/10.1007/978-3-642-12012-1_2 (Springer Berlin Heidelberg, 2011).

Watson, A. S. & Gleason, M. A. A comparative assessment of texture analysis techniques applied to bone tool use-wear. Surf. Topogr.: Metrol. Prop. 4, 024002 (2016).

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We pick the best Olympus lenses (OM System) to get right now, from compact primes to professional constant aperture zooms

When you're looking for the best Olympus lenses, you're also looking for the best OM System lenses, as the range is undergoing a transition from one name to the other. You're also working with the Micro Four Thirds mound, meaning you can also use Panasonic lenses – however, as we'll see, there are plenty of reasons why users of Olympus or OM System cameras might want to stick with lenses by the same brand.

The last lens you'll ever need? Not quite, but with an equivalent range of 24-400mm and sharpness to die for, this superzoom lens is pretty darn close.

In the present study, we list and discuss the relevant hardware and software settings that should be reported if the research is to be preproducible. This list is by no means exhaustive, but it represents a solid starting point. As an example of such settings, we tested whether the numerical aperture (NA) of the objective can and does influence the results of archeological quantitative use-wear analyses.

While it carries the OM System badge, this is really just a minor refresh of one of Olympus' oldest Micro Four Thirds lenses – however, it's still one of the most desirable. It arrived alongside the company's first PEN cameras and the standard kit lens back then, another retracting design, this one a 14-42mm. The Olympus 9-18mm doesn't go as wide as other, more recent Olympus ultra-wides, the f/4-5.6 maximum aperture is a tad restrictive and the retracting mechanism is not a deal breaker but it is a bit of a faff. Even allowing for all that, though, this lens's size, light weight and ultra-wide angle of view make it a unique proposition for travel photography and interiors, and dated as it might look, there's still nothing like it today.

CaF2 Window. Calcium fluoride is often used in spectroscopic windows and lenses due to its high transmission from 250nm to 7μm. Its low absorption and high ...

IDS Imaging uEye+ GigE Cameras are used in a variety of applications such as automation, automotive, medical technology, and logistics.

Scatter plots of the selected ISO 25178 parameters: Sa, Sq, Sxp, Sku, Str, Std, Sdr and Vmc. For each plot, the left y-axis relates to FLT1-7 (flint) and the right y-axis corresponds to QTFU2-10 (quartzite). Symbols differentiate the three locations on each sample (○ = location 1, Δ = location 2 and □ = location 3), empty symbols represent data acquired with the 50×/0.75 objective, and filled symbols correspond to data from the 50×/0.95 objective. See Supplementary Table S1 for details on parameters.

There are significant differences for 25 parameters (all but Sku) between the height maps acquired with objectives having different NA values (Figs 1 and 2, Supplementary Materials 3, 4 and Table S3). The standard deviations are more often larger with the 50×/0.75 than with the 50×/0.95 objective, but this depends a lot on the parameter considered (Supplementary Table S3).

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We also until recently had the M.Zuiko 60mm f/2.8 Macro on this list – unquestionably a fine lens, but one that has had to step aside in favour of the mighty M.Zuiko 90mm f/3.5 Macro (see below).

Hoffman, M. D. & Gelman, A. The No-U-Turn Sampler: Adaptively Setting Path Lengths in Hamiltonian Monte Carlo. Journal of Machine Learning Research 15, 1593–1623 (2014).

If you're a fan of ultra-wideangle photography then you're in luck, because OM System makes three rather good ultra-wide zooms and we've included them all. These lenses are great for travel, architecture, interiors and dramatic landscape shots.

Twenty nine ISO 25178-2 parameters were calculated on each surface of the flint and quartzite samples (Supplementary Material 2 and Table S1). Three of them (Spq, Svq and Smq) could not be calculated on most surfaces (Supplementary Table S2) so they were not included in the inferential statistics. Out of the 26 analyzed (Supplementary Materials 3, 4 and Table S3), eight parameters, spanning the different categories of field parameters, were selected for figures (Figs 1 and 2). The Sa and Sq parameters are different measures of surface roughness22. Sxp is the height difference between the average height of the surface (p = 50% material ratio) and the highest peak, excluding the 2.5% highest points (q = 97.5% material ratio). Sku is the kurtosis of the height distribution of the surface texture. Str is a measure of isotropy; it varies between 0 (anisotropic surface) and 1 (isotropic surface). Std calculates the main direction of the surface, but is obviously only relevant for anisotropic surfaces (Str < 0.5). Vmc is the volume of material (i.e. below the surface), excluding the 10% lowest (p = 10%) and 20% highest (q = 80%) points. Sdr is a measure of surface complexity.

The 3D images referred to below are representations of the surface topography, form and texture of the samples. These 3D images, or 3D surface data, can be processed so that the surface topography and/or texture are measured quantitatively. Many parameters describe specific attributes of the topography and/or texture.

Objective manufacturers offer a wide range of objectives, with different combinations of magnification, numerical aperture and working distance, to cover numerous applications. To our knowledge, however, the 50×/0.95 objective is the only 50× objective produced by all manufacturers. This is likely because 0.95 is the highest numerical aperture for non-immersion (i.e. air) objectives. Therefore, this objective appears to be the best candidate for standardization in use-wear studies. Nevertheless, having the highest possible numerical aperture also means that this objective has the smallest working distance. This could be problematic for samples made of coarse-grained materials, such as quartzite. Indeed, the sample used here (QTFU2-10) proved challenging to image with this objective (working distance = 0.22 mm): the sample had to be very precisely oriented and only the highest locations could be imaged without the objective touching the sample. Still, 0.22 mm is a minute distance that is challenging even to the experienced user.

100–200 µm ceramic beads were adhered onto the samples with epoxy resin to provide reference points for the coordinate system (see ref.25 for details). This allows us to find the same spot again for future analyses.

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We thank Sigmund Lindner GmbH for providing us the ceramic beads used for the coordinate system. We also thank Telmo Pereira (ICArEHB, University of Algarve, Faro, Portugal) for his help in the mechanical experiments that used the flint blade analyzed here. This research has been supported within the Römisch-Germanisches Zentralmuseum – Leibniz Research Institute for Archaeology by German Federal and Rhineland Palatinate funding (Sondertatbestand “Spurenlabor”) and is publication no. 2 of the TraCEr laboratory.

The M.Zuiko 100-400mm f/5.0-6.3 IS perfectly illustrates some of the key advantages of the Micro Four Thirds format. Namely a compact and light weight lens that offers an incredible amount of reach for its size. With a focal length equivalent to 800mm at the long end, the M.Zuiko 100-400mm f/5.0-6.3 IS is also compatible with the Olympus M.Zuiko Digital 2x Teleconverter MC-20 and 1.4x Teleconverter MC-14 – which means that you can extend the maximum focal length to an enormous 1600mm if you want or need to. The downside is it's not at its sharpest when shooting at its maximum focal length, while you can't expect an f/6.3 lens to achieve the same results as faster and more expensive optics. If you're prepared to make a few sacrifices though, this is a decent lens if you're looking for a portable lens that'll hit 800mm.

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These results are highly relevant in the growing field of quantitative use-wear analyses. Indeed, using quantitative methods is often seen as a way to improve standardization and, in turn, repeatability and reproducibility1. It was demonstrated here that this is only true if the same acquisition parameters are used. The objective used (magnification and numerical aperture) is a critical component of a microscope, but it is not the only one. Different types of imaging equipment are known to produce results that are not quantitatively comparable5. Furthermore, resolution, which is based on the objective’s NA, on the light source and on the size of camera/detector (see Supplementary Material 1), surely plays a role in the way wear features are measured. As this was beyond the scope of this paper, it was not tested. Other acquisition settings, concerning both hardware and software, might also have an impact on the measurement of surface textures.

Calandra, I. et al. Back to the edge: relative coordinate system for use-wear analysis. Archaeol Anthropol Sci. https://doi.org/10.1007/s12520-019-00801-y (2019).

Arman, S. D. et al. Minimizing inter-microscope variability in dental microwear texture analysis. Surf. Topogr.: Metrol. Prop. 4, 024007 (2016).

The terms of the equation can be understood as follows: β0 is a real number that indicates the overall order of magnitude of the measured values. β1 is a vector of length 2 that contains the effect strengths of choosing the numerical aperture, while x1 is a vector that indicates the level of factor 1, i.e. x1 is [1, 0] when choosing the first level of factor 1 and [0,1] in the other case. The same applies to β2 and x2, but here with 6 different levels (2 levels for raw material × 3 levels for location). M is a matrix where the entry Mi,j indicates the effect strength of the particular combination of the two factors.

Blateyron, F. The Areal Feature Parameters. In Characterisation of Areal Surface Texture (ed. Leach, R.) 45–65, https://doi.org/10.1007/978-3-642-36458-7_3 (Springer Berlin Heidelberg, 2013).

It is currently still unknown how to best define these settings for use-wear analyses on experimental and archeological samples (lithics made of different raw materials, bone, antler, shells…), so it is currently impossible to define standards. In the meantime, we therefore recommend that every use-wear study reports all the settings used so that, at least, the studies are preproducible and the source of variation between studies can be traced to one or several acquisition settings.

The samples were positioned with the measured area as horizontal as possible to minimize the vertical (z-axis) measuring range. Temperature and humidity were measured constantly. Three locations were measured on each sample. Each location was scanned three times (i.e. technical replicas) with each objective. In order to compensate for unknown confounding factors that could influence the results, we randomized the acquisition as follows:

Every professional photographer keeps a 70-200mm f/2.8 lens in their kitbag to combine telephoto capability with a constant f/2.8 maximum aperture and controllable background blur for everything from wildlife to wedding portraits. The M.Zuiko f/2.8 Pro is the OM System equivalent... except that it goes further. Its effective zoom range is actually 80-300mm, so it offers 50% more reach than a regular 70-200mm. (You might also want to check out what it would cost to get a 300mm f/2.8 lens for other formats.) Better still, the 40-150mm f/2.8 Pro works with Olympus / OM Systems' 1.4x and 2x teleconverters to offer the equivalent of a 112-420mm f/4 or a 160-600mm f/5.6. It's like not one lens, but three (potentially)!

Index of Refraction Ranges for Several Types of Glasses. Glass. Index of Refraction. Headlight glass. 1.47-1.49. Television glass. 1.49-1.51. Window glass. 1.51 ...

OM System is simply the rebadged name for Olympus, following the sale of the Olympus imaging division to OM Digital Solutions. The new owners have been refreshing the line with new cameras and lenses, while also retaining everything that made Olympus so popular among its hardcore fanbase. You don't need to worry about compatibility – everything OM System will work completely seamlessly with everything Olympus, and vice-versa.

The hyperparameter are chosen as follows: m denotes the estimated mean of the measured data and s the estimated standard deviation. σ1 and σ2 are calculated as the maximum observed effect strength when varying factor 1 or 2, respectively. σM is computed as 5% of the combined effect strength \(\sqrt{{\sigma }_{1}^{2}+{\sigma }_{2}^{2}}\) as, from a priori knowledge, there is no interaction between the numerical aperture and the location and sample type. ErrorMax, which is a strict upper bound on the measurement error for stabilization of the computation, is chosen as 20% of the minimum of σ1 and σ2, although the measurement process itself is far more precise. Lastly the likelihood is modeled as y ~ N(µ,ε).

Olympus makes five telephoto zooms and we only have space for three – but we still want to give a mention to the other two. The M.Zuiko 75-300mm f/4.8-6.7 II looks amazing, with its 150-600mm effective focal length, but the truth is it's not the sharpest knife (or lens) in the box. And while the M.Zuiko 150-400mm f/4.5 TC1.25X IS Pro is a spectacular 300-800mm f/4.5 ultra-telephoto, it is a massive lump of a thing, with a price to match. For sports and wildlife pros it's a must-have dream lens, but probably not for anyone else.

Martisius, N. L. et al. Time wears on: Assessing how bone wears using 3D surface texture analysis. PLOS ONE 13, e0206078 (2018).

If you have old Olympus lenses from the film SLR days, you may be wondering if you can use them on new Olympus and OM System cameras in the digital realm. The short answer is yes, as long as you have an adapter – they won't mount natively to Micro Four Thirds, but there are a number of affordable and good-quality adapters available (Urth makes a good Olympus OM to MFT mount adapter). Just remember that you'll only be able to use manual focus.

Contrast plots between the two objectives of the selected ISO 25178 parameters: Sa, Sq, Sxp, Sku, Str, Std, Sdr and Vmc. The green vertical line marks the 0 effect strength, while the black horizontal line and the values given on each side represent the 95% high probability density interval.

I.C. and J.M. designed the study. A.P. and E.P. performed the experiments in which the flint and quartzite tools were used, and W.G. cleaned and prepared them. I.C. and L.S. acquired the data and wrote the manuscript. I.C., K.B. and A.H. analyzed the data. All authors commented on and approved the manuscript.

Institute for Prehistoric and Protohistoric Archaeology, Johannes Gutenberg University, Schönborner Hof, Schillerstraße 11, 55116, Mainz, Germany

Numericalapertureand resolution

For people who don't know this lens, it would be easy to dismiss it as a cheap and cheerful – but inferior – alternative to a 'proper' standard zoom lens. But not so fast! Optically, this little lens is a lot better than you might expect, and while its 28-84mm zoom range and f/3.5-5.6 maximum aperture are about as ordinary as kit lenses get, its sheer size – or lack of it – makes it incredibly useful.

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With a 2:1 reproduction ratio and a long 180mm equivalent focal length, this powerful macro is ideal for photographing tiny wildlife and plants.

A Fresnel lens is a type of compact, multi-faceted lens originally developed by French physicist Augustin-Jean Fresnel for lighthouses.

Kubo, M. O., Yamada, E., Kubo, T. & Kohno, N. Dental microwear texture analysis of extant sika deer with considerations on inter-microscope variability and surface preparation protocols. Biosurface and Biotribology 3, 155–165 (2017).

International Organization for Standardization. ISO 4287 – Geometrical product specifications (GPS) – Surface texture: Profile method – Terms, definitions and surface texture parameters (1997).

The brand may have changed, but the quality, integrity and heritage of the M.Zuiko line remains. You can rest assured that these lenses are as great as they always were,

While it takes time to master, the images you can capture with this powerful macro lens are simply unreal. The OM System M.Zuiko 90mm f/3.5 Macro offers a maximum reproduction ratio of 2:1 – which in 35mm terms (due to the smaller MFT sensor) is equivalent to 4:1. So, as we put it in our review, you could capture an image of a 5mm insect and reproduce it at 20mm, which is actually wider than the 17.5mm MFT sensor. It's the first autofocus lens to offer this reproduction ratio (the others are all manual focus).

The posterior distribution is now accessed by sampling using a special variant of Markov Chain Monte Carlo, the Hamiltonian Monte Carlo algorithm40 in the implementation by Salvatier et al.39. When performing the sampling, the results have to be checked for consistency based on the trace plots and on the energy plots of Hamiltonian Monte Carlo (see Supplementary Material 4 for details).

Measuring a mere 58x42mm and tipping the scales at just 137g, this diminutive lens feels right at home on even the most compact MFT format body. Like the Olympus 17mm that we favor for street photography, this one is available in either a silver or black finish, and the hood is sold separately. Naturally, the 2x crop factor of MFT cameras gives this lens an effective 50mm focal length, delivering a classic ‘standard’ viewing angle with a fairly fast f/1.8 aperture rating. Image quality is impressive in all respects. Considering the prices of Canon and Nikon 50mm f/1.8 lenses for full-frame cameras, the M.Zuiko doesn’t look terrific value. However, its performance fully justifies the price tag.

However, while you can fit Panasonic lenses on OM System bodies without any obvious issues, Panasonic's lens stabilization doesn't always play nicely with OM's in-body stabilization, and you get better results from switching off the lens O.I.S.

Investigating how artifacts were produced and used in the past by humans is one of the key research areas in the study of human behavioral evolution. Although use-wear analysis has the clear potential to significantly contribute, a lot of criticism has been raised against it, mainly due to a lack of standardization during experiments and analyses, compromising in turn its repeatability and reproducibility1,2,3.

If you're looking for just one standard lens for your Olympus / OM System camera, this pro-spec zoom is the best buy. It covers an equivalent range of 24-80mm.

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The present results have implications on how to move use-wear analysis toward a reproducible science. This goal can only be achieved if all relevant acquisition and analysis settings are standardized. As it is still unknown which settings are relevant and which values should be used for these settings, this ultimate goal remains out of reach. Nevertheless, a first step would be to report all hardware and software settings that can vary between studies and that can be adjusted by the users of the piece(s) of equipment. Listing all these parameters can be done very quickly and easily; for example, Table 1 was prepared in a few minutes and Supplementary Material 2 was created automatically in batch. The potential benefit of doing this is significant and therefore largely exceeds the minimal costs. Eventually, standardization will help us in exchanging data as well as comparing, reproducing and replicating use-wear studies1, lending more weight to our archeological interpretations.

From a theoretical point of view, the NA should have an impact on the way an image is acquired, because it dictates the optical lateral and axial resolutions, as well as the steepest slopes that can be measured (see e.g. refs17,18 and Supplementary Material 1). The NA has already been shown to have an effect on the image acquired19,20, but, to our knowledge, this effect has not been measured on surface topographies acquired with confocal microscopy. Furthermore, it is currently unknown how variations in NA would affect the results of quantitative use-wear analysis. Therefore, we acquired quantitative surface texture data of experimental tools at high magnification with two objectives having different numerical apertures. This represents one of the first steps toward comparability, repeatability and reproducibility in use-wear analyses.

In these discussions, the importance of equipment and analysis settings is often overlooked and underestimated. For example, different pieces of equipment, objectives (see Supplementary Material 1 for definitions and details), as well as light and analysis settings have been shown or are expected to yield different results4,5. Quantitative use-wear analyses6,7,8,9,10 are likely to be more sensitive to such acquisition and analysis settings. As more emphasis has been put on quantitative analyses in recent years, it is now important to define which settings play a role and should therefore be standardized, if possible.

Scientific Computing and Bioinformatics, Institute of Computer Science, Johannes Gutenberg University, Staudingerweg 9, 55128, Mainz, Germany

Numericalapertureformula with refractive index

In each section in this guide we've picked out what we think are the stand-out candidates and we explain why. It's worth bearing in mind that these categories are not set in stone – you can capture fantastic landscapes with telephoto lenses, just as it's possible to capture a characterful portrait with a wide-angle. However, these categories are a good starting point for thinking about the kinds of lenses you want to use.

Of course, the best Micro Four Thirds lenses all fit and work on MFT cameras from all manufacturers – thanks to the fact that it is an open mount, so anybody can develop optics (or indeed cameras) for it.

Rod is an independent photography journalist and editor, and a long-standing Digital Camera World contributor, having previously worked as DCW's Group Reviews editor. Before that he has been technique editor on N-Photo, Head of Testing for the photography division and Camera Channel editor on TechRadar, as well as contributing to many other publications. He has been writing about photography technique, photo editing and digital cameras since they first appeared, and before that began his career writing about film photography. He has used and reviewed practically every interchangeable lens camera launched in the past 20 years, from entry-level DSLRs to medium format cameras, together with lenses, tripods, gimbals, light meters, camera bags and more. Rod has his own camera gear blog at fotovolo.com but also writes about photo-editing applications and techniques at lifeafterphotoshop.com

We acquired 3D surface data on the samples (Fig. 5c,d) with an upright light microscope Axio Imager.Z2 Vario coupled to laser-scanning confocal microscope (LSCM) LSM 800 MAT, manufactured by Carl Zeiss Microscopy GmbH. The system was turned on at least one hour before starting acquisition, so that all components were warmed up to limit thermic drift. The LSCM was equipped with an EC Epiplan 50×/0.75 (Fig. 5c) objective and a C Epiplan-Apochromat 50×/0.95 objective (Fig. 5d) on a motorized revolver (Carl Zeiss Microscopy GmbH). The numerical apertures of the objectives are 0.75 and 0.95, respectively, as written after the slash in the description of the objectives above.

Amazingly affordable, this lens is ideal for anyone who wants to cover a telezoom range on a budget – and it's also incredibly small and lightweight, too.

Both objectives produced results within the tolerance range of the nominal Ra value of the roughness standard (Ra = 0.40 ± 0.05 µm; Fig. 3a, Supplementary Material 3 and Tables S2 and S3). However, it should be stressed that the values from each objective are significantly different (Fig. 3b, Supplementary Material 4), the 50×/0.75 objective producing values closer to the nominal value (Supplementary Table S3).

Feidenhans’l, N. A. et al. Comparison of optical methods for surface roughness characterization. Meas. Sci. Technol. 26, 085208 (2015).

Equivalent to a nifty-fifty in full-frame terms, this is the quintessential walkabout lens, perfect for photographing a range of subjects and scenarios.

Furthermore, it is well known that a surface –be it from an engineered tool, an animal tooth or an archeological artifact– appears differently when observing it at different scales, or magnifications11. The application of both high and low power approaches to use-wear analyses12,13,14,15 demonstrates that traceologists recognize the importance of scale. Yet, the magnification and resolution of acquisition and analysis (see Supplementary Material 1 for definitions and details) are rarely unambiguously reported in archeological studies. We argue that this is, at least partly, due to the recent developments in digital microscopy.

Sick of changing lenses? Want an all-in-one solution? OM System reckons it has cracked it with this impressive 16x optic, covering everything in between a wide 12mm (24mm equivalent) perspective to a telephoto 200mm (400mm equivalent). And, by and large, they've done it! The lens is great to use, delivering impressive results from a body that's not only lightweight and easy to carry, but is also weather-sealed and hardy. It's not perfect of course, with a narrow-ish maximum aperture and a few sharpness issues (all but unavoidable with a lens of this type), but it's a hugely impressive achievement of optical engineering and one that any Micro Four Thirds user will get a great deal of value out of.

The processing workflow and filter cut-off values are likely to have a major influence on the topography of the surface that will be quantified, although the magnitude has not been measured yet on archeological samples (but see refs4,23 for a discussion of analysis protocols in dental microwear texture analysis). This post-processing can also be used to compare surface data produced by different types of equipment4,23. Therefore, analysis settings should also be reported as exhaustively as possible. As surfaces can be processed many times with different settings by different researchers, we urge all archeologists to provide access to the unprocessed data, for example by using repositories. The present raw data, including the acquired surfaces and the whole processing workflow, are available as *.mnt (MountainsMap) files on Zenodo (https://doi.org/10.5281/zenodo.1479117).

As mentioned, the camera brand is officially called OM System, but you'll find both names on this list. We've kept this list manageable as there are simply too many for it to be comprehensive, so have stuck to simply including the lenses that have impressed us most. There's a range of options here, including some outrageously cheap lenses, so you should definitely be able to find a great lens for your Olympus or OM System camera.

Photos of the two experimental tools used in this study, FLT1-7 (a) and QTFU2–10 (b). Photos were taken with a Nikon DSLR camera D610 with a Nikon AF-S VR Micro-Nikkor 105 mm f/2.8G IF-ED lens.

Rod is an independent photography journalist and editor, and a long-standing Digital Camera World contributor, having previously worked as DCW's Group Reviews editor. He has used and reviewed practically every interchangeable lens camera launched in the past 20 years, from entry-level DSLRs to medium format cameras, together with lenses, tripods, gimbals, light meters, camera bags and more.