What is Spherical Aberration?

Spherical Aberration is an optical problem that occurs when all incoming light rays end up focusing at different points after passing through a spherical surface. Light rays passing through a lens near its horizontal axis are refracted less than rays closer to the edge or “periphery” of the lens and as a result, end up in different spots across the optical axis. In other words, the parallel light rays of incoming light do not converge at the same point after passing through the lens. Because of this, Spherical Aberration can affect resolution and clarity, making it hard to obtain sharp images. Here is an illustration that shows Spherical Aberration:

Spherical Aberration

As shown above, light rays refract or change their angle when passing through the lens. The ones closer to the top and the bottom of the illustration end up converging at a shorter distance along the optical axis (black/red dotted line), while the ones closer to the optical axis converge at a longer distance, creating different focal points along the same axis. The point of best focus with the “circle of least confusion” is illustrated as the thick green line. Spherical Aberration is not just caused by lens design, but also by the quality of the lens material. Lenses made of poor quality material and large bubbles can drastically impact light refraction.

[Read more...]

Sigma 50mm f/1.4 Review

« »

This is an in-depth review of the Sigma 50mm f/1.4 EX DG HSM prime lens that was announced on March 18, 2008 for Sigma, Canon, Nikon, Pentax, Sony and FourThirds DSLR cameras. The Sigma 50mm f/1.4 EX DG HSM is a professional-grade lens for enthusiasts and pros that need a high quality lens for portraiture and everyday photography. Its large aperture of f/1.4 is great for low-light photography and the shallow depth of field helps isolate subjects from the background, beautifully rendering background highlights, also known as bokeh. Unlike cheaper DX lenses, the Sigma 50mm f/1.4 is designed to work on both APS-C / DX and full-frame / FX sensors from many current DSLR manufacturers, including Nikon and Canon.

Sigma 50mm f/1.4 EX DG HSM

[Read more...]

Nikon Quality Control Issues

Like any manufactured product, Nikon’s products are also prone to quality assurance / quality control issues. While Nikon has a very extensive and comprehensive quality control process, some defective products can slip through and make it to the market. Other times, the pressure to increase the production output on Nikon’s manufacturing plants is so high, that the initial shipments of a newly introduced product can be defective or could have other problems not discovered during the initial testing of the product. Unless the defect is of physical nature, the latter is typically addressed through firmware updates later, which Nikon is pretty good about.

Nikon D700 Rubber Issue

Nikon D700 Rubber Issue

In this article, I would like to point out some of the recent quality control issues I have seen in Nikon products. Specifically, on the latest generation DSLRs like Nikon D700/D5100 and some of the newer lenses, like the Nikon 24-70mm f/2.8G. Why am I doing this? Because first, I want to make our readers aware of potential QA (Quality Assurance) issues they might encounter and second, I want to provide some information on how to react to such problems. Please bear in mind that the purpose of this article is not to scare existing or potential Nikon customers. In fact, every manufacturer, including Canon and Sony occasionally have issues with defective parts and products, so this article could apply to other brands as well.

[Read more...]

Nikon 50mm f/1.8G Review

« »

This is an in-depth review of the new, much anticipated Nikon 50mm f/1.8G prime lens that was announced in April of 2011. The Nikon 50mm f/1.8G is a consumer-grade lens for enthusiasts and seasonal pros that need quality optics of a fixed portrait lens at an affordable price point. Its large aperture of f/1.8 is great for low-light photography and the shallow depth of field helps isolate subjects from the background, beautifully rendering the background highlights, also known as bokeh.

Nikon 50mm f/1.8G

[Read more...]

Nikon 24mm PC-E Review

« »

This is an in-depth review of the Nikon 24mm f/3.5D PC-E, a special purpose wide-angle “Perspective Control” lens designed for architectural, commercial and nature photography, also known as PC-E Nikkor 24mm f/3.5D ED. The Nikon 24mm f/3.5D PC-E is a very specialized wide-angle lens specifically targeted at three groups of photographers – architecture photographers, landscape photographers and macro/product photographers. Architectural photographers often work with a lot of straight, often converging lines both indoors and outdoors and the “Perspective Control” or “Tilt-Shift” lenses (from this point on I will refer to them only as “tilt-shift”) give the ability to avoid the convergence of parallel lines by shifting the lens upwards or downwards. Landscape photographers need to be able to get everything in focus – from the closest foreground object to distant landscapes. While proper lens and camera techniques, along with good post-processing skills can help in getting sharp images for both foreground and background objects, normal lenses have certain limits landscape photographers have to work around with.

Nikon 24mm f/3.5D PC-E

For example, stopping down lenses beyond f/11 results in diffraction, which can impact the sharpness and overall quality of an image. With perspective control/tilt-shift lenses, landscape photographers can change the angle of the focus plane without having to increase aperture, putting both closest and furthest objects in focus. The same goes for commercial/product photographers that photograph jewelry and other items for product showcases – everything from the front to the rear of the object must often be in perfect focus. Again, stopping down does not always work and unless angles are changed and subject is on the same plane, there is no easy way to get everything sharp without focus-stacking images in post-processing software like Photoshop. By using tilt-shift lenses, photographers do not have to worry about lens aperture limitations and can achieve the desired effect with minimum effort. One other use that has been gaining popularity lately is to use tilt-shift lenses for portrait photography. Due to the ability to apply selective focus on a particular part of the image via lens tilting (also known as “anti-Scheimpflug“), portraits can appear more interesting and creative. Distant subjects can even appear “miniaturized”, although the effect can be easily reproduced in Photoshop through various plugins.

Sample #10

[Read more...]

Our Gear Page

You might have noticed that the secondary navigation menu of our site now contains “Our Gear” page. I created it for four reasons: a) our readers constantly ask both Lola and I about what camera gear we use, b) I want to centralize all questions regarding camera gear to one single page, because replying to comments in many different articles is becoming unmanageable, c) some readers just want to see a quick review of a product rather than reading my long full camera and lens reviews and d) I can receive and test more gear when you buy through affiliate links on our site and “Our Gear” page contains links to our affiliates. Please bear in mind that the amount of money we receive from our affiliate program is very little – we typically give it back to our readers through our giveaways and various contests. That’s because we do not run any advertising and post very few links to external websites to not annoy our readers. Perhaps in the future, if the revenue from the links on our site grows, we might be able to use that money to pay for hosting and other expenses. As for now, I am just asking you guys to buy from our links to be able to keep the partnership with our affiliates and sponsors like B&H.

As for “Our Gear” page, while it has been there for several months now, I only had some text links to what we use, without much info on the gear. Today I updated the page with some short reviews of the camera gear we are using and finished the “Cameras”, “Camera Accessories”, “Lenses” and “Teleconverters” sections. I will soon update the page with a lot more content and provide more information and links to other tools we use, so please check back the page later.

If you have any questions about camera or computer gear, please ask them in the gear page rather than other articles. I will be checking this page more often and replying to your comments as soon as I can. Also, if you have been sending some case studies to me, please be patient, as I just have not had much time to work on them.

I am currently finishing up with the Nikon 24mm f/3.5D PC-E lens review and will soon start working on reviewing the new Nikon 50mm f/1.8G lens, along with the Nikon D5100 DSLR. Stay tuned!

Nikon TC-20E III Review

« »

This is an in-depth review of the new Nikon TC-20E III teleconverter that was released in December of 2009, along with an updated version of the Nikon 300mm f/2.8G VR II lens. The Nikon TC-20E III is a major update to the existing Nikon TC-20E II teleconverter, sporting a brand new optical design with an aspherical element, which delivers better performance with many specialty telephoto lenses. The purpose of teleconverters is to increase the focal length of lenses, in other words to get closer to subjects, and the TC-20E III is the biggest and the longest teleconverter manufactured by Nikon – it doubles the focal length of a lens. While this teleconverter works with any professional Nikon lens that can take teleconverters, it is specifically designed to work with fast prime lenses with an aperture of f/2.8 and larger. The Nikon TC-20E III is targeted at sports, wildlife and other types of telephoto photography where the photographer cannot physically approach subjects.

Nikon TC-20E III

It was not easy to obtain the Nikon TC-20E III because of high demand/short supply and after waiting for a few weeks, I decided to just rent it for a couple of weeks instead. My objective was to try the Nikon TC-20E III specifically with the Nikon 300mm f/2.8G VR II and with the Nikon 70-200mm f/2.8G VR II to see how it truly performs in an outdoor environment when photographing nature. It is one thing to shoot test charts with a lens sitting on a tripod, and another to get out and do some real shooting. Some lenses look great on paper and on test charts, but cannot perform equally well when used in an outdoor environment, especially with fast-moving subjects like birds. The primary reason is autofocus, the performance of which depends on many different factors. Teleconverters generally negatively impact autofocus performance, due to a considerable loss of light and contrast and the 2x TC is the worst in this regard. Adding a teleconverter slows down lenses and the Nikon TC-20E III slows down by two full stops. What this means, is that when the teleconverter is mounted on an f/2.8 lens, it slows down to f/5.6 and as you may know, autofocus performance on small apertures beyond f/5.6 is unreliable even in broad daylight conditions. Nikon clearly points out that autofocus does not work beyond f/5.6, so if you have an f/4.0 lens, forget about autofocus – you will have to resort to manual focus.

[Read more...]

Testing Nikkor PC-E Lenses

I am currently in the process of testing all three Nikon PC-E Lenses – Nikkor 24mm f/3.5D PC-E, Nikkor 45mm f/2.8D PC-E and Nikkor 85mm f/2.8D PC-E:

Nikon PC-E Lenses

Have been having too much fun with these gems, so full reviews will be published within the next few weeks.

Zeiss Distagon T* 35mm f/2.0 ZF.2 Review

« »

This is an in-depth review of the manual focus Zeiss Distagon T* 35mm f/2.0 ZF.2, a second generation 35mm f/2 prime lens from Zeiss for Nikon and Canon mounts. The lens sample I tested was for the Nikon F mount, although you can get the same lens for the Canon EF mount. The Zeiss 35mm f/2.0 ZF.2 is a professional-grade fixed wide-angle lens targeted at enthusiasts and professionals that need high quality optics for different types of photography, including landscape, architecture, portrait and astrophotography. Similar to other Zeiss prime lenses, the lens is designed to work on both FX and DX sensor cameras (equivalent of approx 52.5mm on DX) and yields amazing clarity and contrast throughout the frame.

Zeiss Distagon T* 35mm f/2.0 ZF.2

The all-metal Zeiss 35mm has a very tough and high quality build and is sealed against dust and tough weather conditions. When compared to the latest generation Nikon AF-S lenses like Nikon 35mm f/1.4G with plastic exterior, it feels much more solid in hands – even the lens hood is made of metal. The focal length of 35mm is a good compromise between ultra-wide angle lenses and standard lenses. Thanks to the 9-blade diaphragm, the Zeiss Distagon 35mm f/2.0 ZF.2 renders background highlights in round, circular shapes, making it a good candidate for portraiture and street photography.

Zeiss 35mm Sample #10

[Read more...]

Nikon 50mm f/1.8G Lens Announcement

NOTE: A full review of this lens can be found in my Nikon 50mm f/1.8G Review article.

Nikon has recently released the Nikon 50mm f/1.8G AF-S lens, an upgrade to the existing Nikon 50mm f/1.8D lens. This long overdue upgrade is great news for all current and future owners of entry-level DSLRs without focus motors. Finally, there is now an affordable 50mm portrait lens that will autofocus on Nikon D3000, D3100, D5000, D5100 and older cameras like Nikon D40/D40x and D60. In addition, unlike DX lenses that are designed to work only on crop-factor sensors, the Nikon 50mm f/1.8G works great on both DX and FX sensors.

Nikon 50mm f/1.8G

Nikon 50mm f/1.8G

The Nikon 50mm f/1.8G is a great lens for portrait and everyday photography and is designed to render beautiful bokeh (background blur).

[Read more...]