While each light meter app will come with its own approach and unique set of features, there are some elements that are essential for getting the most from your photography. We need to look for apps that are:

Let’s discuss the beneficial properties of aluminum and silver, why they’re used for coating optical mirrors and which industries have found successful applications for each.

The caveat to this is that in low-light conditions the video preview may appear under-exposed. This is caused by the device attempting to maintain a stable video frame rate in poor lighting conditions.

A big part of it is software. Nowadays, a modern evaluative exposure algorithm does so much more than average a few spots of light. A modern evaluative exposure algorithm is able to assess a scene in real time to detect faces and specific skin tones, recognise backlighting, determine if the scene is indoors or outdoors and more.

Optical mirrors are used across an assortment of industries, ranging from telecommunication and aerospace industries to optics and medical applications. Depending on the application, certain metallic mirror coatings must be used. Comparing the properties of silver and aluminum, each possesses inherent properties that positively impact factors like emissivity, reflectivity and durability. However, their differences also heavily influence application. For instance, though aluminum may offer a higher rate of reflection, silver may offer lower emissivity. Before selecting a coating, you should consult surface treatment experts at Sharretts Platting Company.

Highly reflectivealuminumsheet

The two distinct aluminum alloy classifications are cast and wrought. Casting is the most widely used and is applied to products for the automotive industry. There are seven types of wrought alloys with varying limits of tensile strength and can be used for plating applications. Both the electroplating and electroless plating processes are applicable for aluminum, especially in telecommunications and energy industries.

Remember, smartphone manufacturers are at a distinct space disadvantage when compared to traditional camera manufacturers. Fundamentally, the physics of light make it impossible to achieve the same performance characteristics as bigger lenses and sensors, and yet each year smartphone cameras get better and better results. So, how do they do it?

Silver offers high performance in nearly all of its properties. It has the highest known electrical and thermal conductivity, as well as high malleability and ductility. Silver is mined throughout the world and because of its favorable properties, is used for many diverse applications including silver plating. As the least expensive precious metal, silver is used in the automotive, telecommunications, electronics and solar power industries as a substitute for other metals like gold and palladium.

It does this by using machine learning algorithms trained on millions of images to identify and recognise objects and patterns in a scene, constantly adjusting exposure to achieve a perfect balance. No easy feat.

The only problem with a digital interface so tightly aligned to its vintage inspiration is that it can interfere with its operation – the preview in the ‘classic’ mode is smaller than the app’s own logo.

From there, you can input the displayed exposure values into your camera right away. Or, with the lock still engaged, you’re free to adjust the dials to experiement with alternative exposure values – or even modes. This unique capability gives you all the flexibility of something like an old-fashioned pinwheel interface but with none of the clutter.

Enhanced protective silver coatings are being explored to provide maximum reflectivity while improving the lifespan of the silver base. One prospective process that would create stronger corrosion barriers is through plasma-enhanced atomic layer deposition, using aluminum-oxide as the top layer that acts as a barrier to help protect against corrosion and maintain reflectivity. Results of testing show that these added layers successfully protect against corrosion and moisture. These plasma-enhanced barriers can be applied to optical mirrors that require high reflectivity and absorbency.

Aluminumreflectivity vs wavelength

The differences between household mirrors and optical mirrors are key to accomplishing their intended goals. Though each of these mirrors is intended to reflect the light that is directed at its surface, their purposes are vastly different. Household mirrors are used to allow individuals to examine their appearance and may also be used as room decorations. Optical mirrors, however, must be much more versatile due to their utility in industrial and manufacturing applications. For instance, optical mirror systems have been used by NASA for the Hubble Space Telescope.

Of course, as one of the developers that works on Light Meter Ultra you’d be well within your rights to think I’m less than impartial. Luckily though, you don’t need to take my word for it. Download Light Meter Ultra today, take advantage of the free trial, and see for yourself.

The choice of coating may enhance or diminish the emissivity or reflectivity of the mirror. When choosing a coating for your optical mirror, you want to ensure the proper plating for the intended application. Determining the most applicable selection involves understanding how the properties of the various metal finishings will impact the mirror’s performance. Two crucial aspects of a mirror’s performance are its reflectivity, how much light it reflects, and emissivity, the energy radiated from its surface.

Choosing the right plating for your application can be simple when you are knowledgeable about the benefits and limitations of each coating option. SPC is here to ensure that all of our customers select the plating solution that will most effectively help them reach their business goals. We provide consulting services that will assess your operation and recommend a reliable and affordable metal finishing solution that is the ideal application to suit your needs. Call Sharretts Plating Company and receive a free quote today!

One question I’m often asked is ‘how accurate can a light meter app be anyway?’ And the answer is that a light meter app on your phone can be at least as accurate as a dedicated device – and in many ways it’s even more capable. But like anything, it’s important to understand where the relative strengths and weaknesses lie.

Though the presence of oxygen may cause aluminum to corrode, even if the aluminum does have an additional protective coating, there is hope that future optical mirrors used in an astronomic application could be positioned far enough from the Earth not to be impacted by these environmental factors. In this case, mirrors with protected aluminum coatings may be well-preserved and function without issue for long periods of time.

From maximalist to minimalist. Lightmate benefits from an edge-to-edge exposure preview that makes it easy to get a sense of your exposure. The requisite exposure values are pinned to the right side of the screen and can be adjusted by swiping to the left or right.

As helpfully explained by the app onboarding on first run, the app operates in an either aperture or shutter priority mode. Tapping the aperture value engages the aperture priority mode, locks the aperture value to your selection, and leaves the shutter speed to free float according to exposure conditions. Likewise, tapping the shutter speed value engages the shutter priority mode.

Reflectivity of metals Table

The secret to great exposures with a light meter app lies in harnessing the device’s strengths. And one of your smartphone’s biggest strengths is its exposure algorithm.

While it can be tempting to strap on an after-market diffuser or fashion one out of paper, be aware that the margin of error can be significant. Cameras vary between device models and iterations, and so without calibration to account for these differences a diffuser can’t be relied upon to produce an accurate reading.

Dominating the screen on the left hand side is a pinwheel slide which shows a combination of possible exposures for the current measurement. On the right is a small preview window with a measure button. Below that are some additional dials for setting the all important ISO and exposure compensation.

On opening myLightMeter PRO, it’s immediately apparent that a tremendous amount of care has been taken in faithfully reproducing the look and feel of a vintage pinwheel lightmeter. The luxury wood surround, the individual screws holding together the front plate – it’s a visual feast.

Like silver coating, an aluminum coating can also be used in telescope optics. The NASA Cosmic Origins Program developed aluminum coatings to maximize reflectivity for their astronomical telescopes. This coating was used particularly to help their scientists study the far ultraviolet part of the light spectrum. The durability of the aluminum coating was effective enough to enable them to achieve a far ultraviolet reflectance of up to 80 percent throughout the year without the coating succumbing to significant deterioration.

However, this doesn’t mean that the readings are unusable. In our experience, the readings will continue to be accurate at impressively low levels of light. Experiementation is recommended in order to get a feel for the limits of your particular device.

Taking a more minimalist approach in its metering interface is Photo Light & Exposure Meter. The top two-thirds of the screen are taken up by a spacious exposure preview that allows you to tap to select a point of focus. Below that sits the dials for selecting ISO, aperture and shutter speed.

Using a well-designed light meter app is notable for its simplicity. Unlike with a dedicated light meter where you have no preview of how an exposure might look, a light meter app provides a video preview interface that allows you to quickly assess overall exposure levels.

AluminumMirror thorlabs

Various coatings are used to increase the reflection properties of an optical system. The number of coating layers, as well as each layer’s thickness, directly contributes to the rate of interference it provides. The placement of these coatings is just as significant as the metal used. When coatings are applied correctly, light transmissions can combine for a greater amplitude resulting from constructive interference. However, if a coating is applied at an unintended incident angle, it creates destructive interference and can render the coating itself completely ineffective.

Reflectivity is inversely proportional to emissivity, which means that the more emissive a mirror is, the less reflective it is. A coated optical mirror can become more emissive if its coating tarnishes, oxidizes or is rough rather than smooth.

Lightme does include a continuous measurement option that allows you to see the reading change as you point it at various parts of the scene, but with so many numbers moving around it can be hard to keep track of what you’re looking at.

The aerospace industry utilizes silver coating technology as well. The Kepler Mission sought to explore the structure and diversity of planetary systems. While building spacecraft for this mission, engineers needed to design and build optical mirrors to enable them to continuously monitor and measure the brightness of stars. The large and lightweight primary mirror their team constructed needed to be sensitive enough to detect planetary movement, so they utilized an enhanced silver coating technology to increase the mirror’s responsiveness to light.

The optics system on the Hubble Space Telescope is an excellent example of the application of aluminum coatings. Known as the Optical Telescope Assembly, this telescope’s optic system collects infrared, visible and ultraviolet light through the use of two mirrors. Each of these mirrors is coated with aluminum to provide optimal reflectivity. To keep the surface of the aluminum from oxidizing, layers of magnesium fluoride coat the top aluminum layers.

At first glance, a spot-meter might seem the most similar to a light meter app, but even here there are subtle differences. A traditional spot meter will attempt to meter for middle grey, but if you attempt to do the same thing on-device, by the time your device has done its work to create the best possible on-device preview, the video output is no longer useful for extrapolating a reliable reading.

There’s room to grow too, as once your camera bag grows, Light Meter Ultra allows you to create a profile for each camera, lens and film type. This ensures you only get shown exposure values that are compatible with your current equipment selection.

Metal plating is the most common form of mirror coating. From gold and zinc to copper and platinum, many metals can be used to coat mirrors. Two of the most popular are silver and aluminum. Though each plating process has its differences, both aluminum and silver coating can offer unique benefits that improve the functionality of optical mirrors.

Taking photos with the help of Light Meter Ultra is a genuine pleasure. The big, easy-to-adjust dials on the bottom of the screen click into place as you input your exposure values. The top half of the screen is dedicated to a targeting spot and the primary reading. Switching between aperture and shutter priority modes is achieved with a swift glide of the finger across the screen.

Luckily for us, thanks to standardization, we can leverage these algorithms in order to set the exposure values for the rest of our photographic equipment. Truly, it’s the best of both worlds. The simplicity of digital, with the unassailable personality of film.

Unlike most of the other apps I’ve reviewed, Light Meter Ultra updates its exposure reading continuously. This can be really useful for quickly getting an idea about exposure variations in a scene. When you’re ready to input a reading, point the targeting circle at your subject and hit the lock button.

Aluminum is a popular choice for mirror coatings because of its reflectance. With the highest reflectance of any metal in the ultraviolet and infrared spectral ranges, aluminum only falls behind silver in the visible light and near-infrared ranges. Bare aluminum can be used in optical mirrors for telescopes in space to achieve larger bandwidths of light. Unfortunately, the natural creation of aluminum oxide can reduce the reflectiveness of the aluminum coating. To counteract this, additional protective coatings can be applied over the aluminum.

Silver is an excellent metal to use for plating. Though tin is often assumed to be a low-cost substitute, its properties do not give it an advantage in tensile strength, heat absorption, corrosion resistance or conductivity. Silver is also used a more affordable alternative to gold plating. In astronomical optical mirror application, silver coatings provide benefits to primary, secondary and tertiary mirrors because of its high reflectance and lasting durability.

A natural barrier oxide layer can form over aluminum mirrors, protecting it from further corrosion. Unfortunately, this barrier is not easy to clean and can be altered based upon other environmental factors. Because of this unreliability, protective coatings are often placed over the bare aluminum. This usually involves a dielectric coating that successfully protects the surface from damage. However, this could potentially reduce the reflectance of the aluminum. An atomic layer deposition technique or another deposition method could potentially improve protection while limitedly effecting mirror reflectance.

Specializing in metal finishing solutions, SPC is ready to lend our knowledge and expertise to help you determine the best plating for your optical mirrors. We’re able to efficiently coat metals, plastics, ceramics and glass. With hundreds of years of combined plating experience, we’re equipped to meet the needs of nearly any industry. SPC is the proud plating business leader and innovator that you can count on to satisfy even the most demanding technical requirements.

The defining difference between optical mirrors and household mirrors is the location of their coating. Household mirrors are coated on the back while mirrors used in optical applications feature front-surface mirrors. Metals are the most commonly used mirror coatings. Because of their reflectivity, layers of aluminum and silver are often used. Silver is the most reflective across the visible spectrum, reflecting 95 percent of light. Aluminum is slightly less reflective yet still can reflect 90 percent of light. Both coatings are excellent for use in many applications.

For the most part, the following apps fulfil the above criteria, and where exceptions arise I mention them in the review:

Reflectivealuminumsigns

Generally, if you can see detail in the in-app preview, you should find that you can capture that detail in the final exposure too.

It took me some time to work out how to actually take a reading with this app. At first I felt I had unwittingly entered a game of whack-a-mole as I found myself moving dials into position and locking them, only to have them unlock again when I attempted to input another value. Tapping the ‘pause’ icon helped keep things stable long enough for me to take a reading – but it does take some getting used to.

Moving into the ‘pro’ mode and you’re presented with an interface that, while similarly styled, no longer bears any resemblance to a traditional light meter. Here, the preview is similarly miniaturised, but now permits tapping into a larger preview to select a point of focus. There’s also the addition of a hyper focus scale.

As a coating for optical mirrors, silver may outperform traditional aluminum coatings. Researchers studying the Gemini telescopes have determined that a silver mirror coating is effective for observing infrared and visible spectrum wavelengths, however, the properties of silver may tend to over-absorb ultraviolet light. Although aluminum may be a better solution, hybrid coatings that combine silver and aluminum are being explored.

In addition to the device’s natural reflective metering mode, the app offers an incidental mode. Typically, smartphones adapted to being incidental meters suffer with significant accuracy problems for reasons that I go into above. Unfortunately, myLightMeter PRO is no exception. This is tacitly acknowledged by the developer in their manual with a recommendation to ‘make your own tests’.

Despite my struggles with the interface, once I was up and running the meter performed well, faithfully relaying suitable exposure values for the scene.

The first thing that strikes you about Lightme is its user interface. Much like myLightMeter PRO, Lightme has approached its interface by replicating the look and feel of a vintage light meter.

There’s an incredible amount of choice when it comes to light meter apps for photography, and it’s fair to say that some choices are better than others. So which should you choose?

Depending on the application in which your optical mirror will function, you’ll want to select a plating that provides the most benefits. To help you feel confident in your decision, we have identified the advantages of each coating so that you can determine which is best for you.

Though bare silver is considered a poor solution due to its ability to tarnish and its inability to reliably adhere to surfaces like glass, a protected silver mirror coating can be applied. These coatings can be highly reflective dielectric layers that resist tarnishing and improve adhesion. Although it is possible that these protected silver coatings may be susceptible to damage from ultraviolet light, choosing specific dielectric overcoats of higher thicknesses may prevent this degradation.

Aluminum reflectionapp

Lightmate peforms well as a light meter just as long as your equipment marries to its particular setup; there’s no option here for increments other than half-stops, and there’s no way to constrain your values to minima and maxima other then the defaults.

Compared to other plated metals, silver has the most applications and is found throughout nearly every common industry. Classified as a noble metal, silver possesses many inherent benefits that make it a versatile plating material. For years, the process of silvering was applied to coat the surface of glass to create mirrors. Silver coatings are ideal for observing all wavelengths of light, offering high reflectivity and low emissivity that is especially useful for an infrared application.

Nor is it possible to take incidental readings with any great accuracy. For one thing, your device’s lens is designed to take reflective readings.

Aluminummirror vs glass mirror

Researchers believe that, as new mirror-coating technologies are developed, they can provide increasing positive benefits when applied to optical mirrors in new telescopes. They even suggest that current telescopes could see a dramatic increase in efficiency and reflectiveness by switching from an aluminum coating to these new silver coatings. This could potentially offer a cost-effective way to allow existing telescopes to reflect more light and increase their application limitations.

Unlike the rest of the apps in this round-up, myLightMeter PRO doesn’t offer a free tier, so even if you just want to try you’ll need to pay outright.

A good light meter app should be a trusted companion: with you at all times, helping you to get the shot. Image: Alexander Andrews

Sharretts Plating Company is recognized around the world as a leader and innovator in the metal plating industry. As full-service plating business, we dedicate our skill and expertise to enhancing our customer’s competitive positions. Our scientists, engineers and production staff continue to develop new ways of enhancing our production process to improve quality, lower costs and reduce lead times. SPC is focused on helping your manufacturing or industrial operation reach new levels of success with our ISO certified metal coating and plating services.

In my experiments, these methods can result in errors of two or more stops. Therefore, take any readings from apps which offer these metering modes with caution.

Reflectivealuminumpanels

Silver coated mirrors can be used in telescopes. For example, the Gemini Observatory has switched from using an aluminum coating on their telescopes to a silver coating. This resulted in a direct improvement in lowering the emissivity of their primary and secondary mirrors and increasing the telescope’s sensitivity. As one of the only telescopes to use silver mirrors, the Gemini Observatory is achieving significant infrared optimization. Though environmental factors do lead to the silver tarnishing, they employ an annual multi-layer coating process to protect the surface from tarnishing.

To answer that question, first we’ll explore if a smartphone is capable of metering light accurately at all. Then, we’ll take a look at how it compares to using a dedicated meter. And finally, we’ll apply what we’ve learnt to assess each light meter app individually.

The optics and computing power available on today’s smartphones are nothing short of phenomenal. You already hold in your hand a device that the technology giants have invested billions of research and development dollars into – you may as well make the most of it!

As a resource that can be found throughout the globe, the properties of aluminum have made it one of the most versatile non-ferrous metals that can be used in a variety of applications. Though in pure form it can be weak, chemical treating and alloying processes drastically increase its strength. These increased mechanical properties have made it a valuable resource throughout various applications in industries including aerospace, medicine, optics and defense.

Lightme also boasts a spot-metering mode that can be accessed by tapping on the preview window. Unfortunately, in my testing of version 2.5.4, the reading suffered from up to 2-stop deviations from middle grey which makes this unsuitable for typical spot-metering applications.

Likewise, the incident mode suffers from the same limitations as myLightMeter PRO and so I would avoid these functions completely.

For example, a Light Meter app can’t replicate the functionality of a Flash Meter – the latency of the optical sensor makes it impossible to get a usable reading in the short window of time the photons of a flash gun remain in-flight.

Not only is Light Meter Ultra the most intuitive and easy-to-use light meter, but it also packs an incredible amount of power. Its interface delivers all the flexibility of a pinwheel interface, but with none of the visual overwhelm. Its large exposure preview makes assesing a scene a cinch, and its large dials and quick-swipe mode changes mean you’re less likely to miss a shot.

At SPC, we understand that the unique needs of your industry dictate that the optical mirrors you use need to deliver optimal performance. To meet the technical demands of your requirements, we use several different plating techniques including autocatalytic, electroplating and electroless methods. Our variety of precious and non-precious metals can be plated for applications ranging from power generation and optics to the medical, oil, gas and aerospace industries. For nearly 100 years, we’ve provided our clients with innovative metal finishing solutions to suit their specific needs. As one of the leading plating companies in the industry, SPC is ready to provide you with reliable and affordable silver coating and aluminum plating for your optical mirrors.