The highest-power microscope objective available is the immersion objective. When this type of objective is used, a drop of oil must be placed between the object on the microscope slide and the objective. The oil used has an R.I. that matches that of the glass in the first component of the objective.

The N.A. and the complexity of the objective increase as the magnification increases. Low-power objectives, of order 2–5×, are generally two-element lenses. Ordinary crown glass and flint glass (optical glasses with, respectively, relatively low and high R.I.’s) can be used to correct for spherical and chromatic aberration.

Water-immersion lenses are also available. These use water as an immersion liquid and allow biologists to examine specimens in a watery medium without the burden of a cover slip confining the living organisms.

2 waysto adjust lighton microscope

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which of the three factors affecting image quality is altered by thelightsource?

Manufacturers provide objective lenses with standard magnifications usually ranging from 2 to 100×. The focal length of the objective is inversely proportional to the magnification and, in the majority of modern microscopes, equals the tube length (usually 160 mm [6.3 inches]) divided by the magnification. The field of view of the eyepiece is usually set to be a standard size of about 20 mm (0.8 inch) diameter. The field of view of the objective is then set to range from 10 mm (0.4 inch) for an objective with a magnifying power of 2× to 0.2 mm (0.008 inch) for an objective with a magnification of 100×. As a result, the angular field of view is about 7° for all objectives.

Expected behavior So my question is, do I have to install different drivers while switching cti files? I'm using a GigE Vision Camera. You already wrote in ticket #91: "If you use JAI then you'd use JAI's driver. If you go with MV, then you'd use their dirver." But does that only apply to USB3 Vision or also GigE Vision Cameras?

Increases or decreases thelightintensity microscope

Or is this wrong and could lead into my problems? You linked this page (http://static.matrix-vision.com/mvIMPACT_Acquire/2.29.0/) in your installation manual. But I was not sure what to download and install for Windows 10 (64 bit). Would it be mvGenTL_Acquire-x86_64-2.29.0.msi ?

@12Patrick Hi, thank you for the update. Please excuse me, I had thought that you were also working with a U3V camera having read the following sentence:

In general, you should just install MV's GenTL Producer and the file name should look like mvGenTL_Acquire-x86_64-n.nn.n.msi .

If I open the programm wxPropView(x64), I get images from the Allied Vision Camera without consciously installing new drivers. So it seems that it works in this programm with the Allied Vision driver.

As I run afterwards also in a kind of same problem as #92, maybe you can put the following in the FAQ. The reason why I have not posted it directly under #92 is that he wanted to have the ChunkModeActive to be true. But for me, it seems as I don't need it until now. SO the following could be helpful for others: => If you are getting the error "Invalid layout of buffer attached to chunk parser! RuntimeException..." (happens especially on Allied Vision Cameras) and you don't need the chunk mode, try the following workaround: Disabling chunk mode stops the raising of the exception. It is a workaround if you do not need Chunk data. In order to implement this workaround, you have to add this line to your code: ia.device.node_map.ChunkModeActive.value = False

It's working now. It was a stupid issue. The \ in the path string led to problems. It was just luck that in the path string of vimba it was a big B and in the path of matrix vision a small b. And "\b" changes the string in a way I don't wanted it. (I think Byte String is the right word.)

Hi @kazunarikudo, Thanks for your great work to provide harvesters and your support! I started a new project and run into problems.

I uninstalled Vimba and also all Matrix Vision Software. Afterwards, I installed mvGenTL_Acquire x86_64 2.37.1.exe again. Is this the correct software? I downloaded it from this website https://www.matrix-vision.com/software-drivers-en.html and selected mvBlueCOUGAR (Gigabit Ethernet / Dual Gigabit Ethernet) in the drop down menu.

Platform that supports a microscope slide

Apart from condensers that are matched to specialized objectives (such as phase-contrast systems), others are available for specific applications. Thus, the dark-ground, or dark-field, condenser illuminates specimens against a black background and is eminently applicable to the observation of structures such as bacteria and flagellated cells in water. The use of colour filters, pioneered in the closing years of the 19th century by British microscopist Julius Rheinberg and now known as Rheinberg illumination, allows one to practice a form of dark-ground microscopy in which the background and the specimen are in contrasting colours. Although this technique is of no diagnostic benefit, the results can be spectacularly beautiful.

The first component of immersion objectives is generally a hyper-hemisphere (a small optical surface shaped like a hemisphere but with a boundary curve exceeding 180°), which acts as an aplanatic coupler between the slide and the rest of the microscope objective. An immersion objective with a high N.A. typically consists of a hyper-hemisphere followed by one or two aplanatic collectors and then two or more sets of doublets. Such objectives are made with magnifying powers greater than 50×, the extreme being about 100×.

Conventional objectives do not produce a flat image surface. The field curvature is generally of little importance in the visual use of the microscope because the eye has a reasonable accommodative capability when examining the image. Field curvature is a problem for imaging systems, however. Special objectives with flat-field lenses have been designed for these systems.

High-power objectives pose several design problems. Because the focal length of an objective decreases as the N.A. and magnifying power increase, the working distance, or distance from the front of the objective to the top of the slide, is shorter for higher-power objectives. The need to use additional elements in the lens system for high magnifications further shortens the working distance to only 10 to 20 percent of the focal length. Thus, a 40× objective of 4-mm (0.2-inch) focal length may have a working distance of less than 0.4 mm (0.02 inch), so objectives with an increased working distance have been designed. These use a negative lens element between the object and the eyepiece, which has the added attraction of providing some field flattening as well. These objectives are especially of value in use with video systems.

For objectives with magnifying powers of 10×, the required N.A. increases to 0.25, and a more complex type of lens is required. Most microscope objectives of this magnification use a separated pair of doublets that share the refractive power. The correction of spherical aberration is readily achieved, but residual chromatic aberration is obtained when normal optical glasses are used for the lens elements. For most optical applications this is not important, but for critical high-magnification objectives (magnifications greater than 25×) this aberration is visible as chromatic blur. The correction of this residual aberration is achieved through the use of special optical glasses whose dispersion properties vary from normal glasses. There are only a few such glasses or crystalline materials that are useful for this purpose. Objectives that use these special glasses are called apochromats and were first produced commercially by Abbe in the 1870s.

Early microscopes had as their condenser a single lens, which was fixed in the end of the instrument facing the lamp (as in barrel microscopes) or mounted below the stage (as in the Bancks microscopes used by Robert Brown, Charles Darwin, and others). More-complex designs followed, their development driven by the peculiarly English obsession of observing fine details on diatom frustules. Achromatic condensers followed, but they are more troublesome to use because they need precise focusing, and the working distance is short.

Concentrateslightonto the specimen

Additional context I have not added more code. Because I ran into some other problems. That is why I wanted to switch to the GenTL Producer of Matrix Vision as often recommended by you to exclude that problems are coming from the Vimba GenTL Producer.

The illumination system of the standard optical microscope is designed to transmit light through a translucent object for viewing. In a modern microscope it consists of a light source, such as an electric lamp or a light-emitting diode, and a lens system forming the condenser.

The condenser is placed below the stage and concentrates the light, providing bright, uniform illumination in the region of the object under observation. Typically, the condenser focuses the image of the light source directly onto the plane of the specimen, a technique called critical illumination. Alternatively, the image of the source is focused onto the condenser, which is in turn focused onto the entrance pupil of the microscope objective, a system known as Köhler illumination. The advantage of the latter approach is that nonuniformities in the source are averaged in the imaging process. To obtain optimal use of the microscope, it is important that the light from the source both covers the object and fills the entrance aperture of the objective of the microscope with light.

Optimal lighting levelon microscope

Increasingly prevalent today is the use of an electronic detector such as a complementary metal-oxide semiconductor (CMOS) or charge-coupled device (CCD) chip to capture the magnified image as a digital signal. This signal can be transmitted to a computer and translated into an image on the monitor. Software allows the user to take single pictures, moving video sequences, or time-lapse sequences at the click of a mouse. These may be saved for conventional viewing, and image processing can be used to enhance the result. Analysis of area and particle size and distribution is easily done by conventional analytical means once the images have been digitally captured. The production of computer presentations, transmission via e-mail, and ease of printing are benefits that digital imaging brings to the modern microscopist.

@12Patrick As I described recently, you should be able to detect GEV cameras without any GEV filter driver, unlike U3V GenTLProducers require you to install its proprietary U3V driver; a GEV filter driver is used to boost the performance in general and a typical GEV application software can at least detect GEV cameras without any GEV filter driver. Anyway, I believe this issue should not involve the mvBlueCOUGER driver you tried. So you should forget about the installer. However, I do not have any idea that tells you why MV's GenTL Producer can't detect your Allied Vision camera. I'm sorry but I guess there are people who have got Allied VIsion camera working with MV's GenTL Producer. One thing I can tell you is MV's GenTL Producer should accept any GenICam compliant camera in principle.

The optics of the microscope objective are defined by the focal length, N.A., and field of view. Objectives that have been corrected for aberrations are further defined by the wavelength requirements and the tube length of the microscope.

Describe the bug If I use the cti file of Allied Vision, the device is recognized and create_image_aquirer(0) works. If I change to the cti file of Matrix Vision (without changing anything else, no driver change), the device is not recognized and the device_info_list is empty.

Brightness adjustment microscope

However, no matter what the principle is, I also feel strange you can't enumerate GEV devices though a GenTL Producer from MV.

Anything else I could check? What could I have done wrong? If I open the program wxPropView(x64), I am able to acquire images in this program.

The eyepiece is selected to examine the relayed image under conditions that are comfortable for the viewer. The magnifying power of the eyepiece generally does not exceed 10×. The field of view is then about 40° total, a convenient value for a relatively simple optical design. The observer places the eye at the exit pupil of the eyepiece, the point at which the light rays leaving the eyepiece come together. In most cases an eye relief (or distance from the exit pupil to the last element of the eyepiece) of about 1 cm is desirable. Too short an eye relief makes viewing difficult for observers who wear corrective eyeglasses.

@12Patrick Hi, thank you for trying out Harvester. In general, you should use the driver that its GenTL Producer manufacture shipped with because if it worked by a chance such as the driver is based on an open source software but it does not mean it’s a case where the manufacturer can support any issue based on the unauthorized driver software. Feel free to update if the issue cannot be resolved by the suggestion. /Kazunari

Can you confirm that the following is correct: I downloaded the GenTL producer from Matrix Vision from this website https://www.matrix-vision.com/software-drivers-en.html and selected mvBlueCOUGAR (Gigabit Ethernet / Dual Gigabit Ethernet) in the drop down menu. Then I downloaded the file mvGenTL_Acquire x86_64 2.37.1.exe (login needed to see all files).

In objectives with magnifying powers of 25× or greater, meniscus-shaped aplanatic elements are designed into the microscope objective in the space between the object and the pairs of doublets that carry out the relayed imaging. These aplanatic components have the property of converging the light without adding spherical aberration to the image and provide an increase in the N.A. without introducing significant aberration.

The objectives described above are usually intended to project an image through an eyepiece for direct viewing by an observer. The use of a photographic recording method permits the capture of a real image in a film holder or digital imaging system without an eyepiece lens. One approach is to remove the eyepiece and place the film holder or digital camera in the focal plane of the eyepiece, thus intercepting the image from the objective directly. A better approach is to use a specifically designed projection eyepiece, which can be adjusted to provide the appropriate magnification coupling the image to the film. Such an eyepiece can incorporate a change in the chromatic aberration correction to accommodate the requirements of the image-capture system.

The large N.A. of a microscope objective restricts the focusing requirements of the objective. The depth of focus is shown in the table as the accuracy with which the focal plane must be located in a direction along the axis of the microscope optics in order that the highest possible resolution can be obtained.

Lightswitch microscope function

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Thanks again for your support and patience! I hope I haven't taken up too much of your time with this problem. But even that I had a problem which was not related to harvesters maybe it could help somebody. So maybe it's better to put my problem with the backslash in the FAQ as it is not a bug of harvesters.