What is Vignetting?

Vignetting, also known as “light fall-off” (sometimes spelled “light falloff”) is common in optics and photography, which in simple terms means darkening of image corners when compared to the center. Vignetting is either caused by optics, or is purposefully added in post-processing in order to draw the viewer’s eye away from the distractions in the corner, towards the center of the image. Depending on the type and cause of vignetting, it can be gradual or abrupt. There are a number of causes of optical vignetting – it can naturally occur in all lenses, or can be caused or increased/intensified due to use of external tools such as filters, filter holders and lens hoods. In this article, I will talk about each type of vignetting and also discuss ways to reduce or increase the amount of vignetting in photographs using post-processing software like Lightroom and Photoshop.

1) Types of Vignetting

As I have already pointed out in the introduction of this article, there are different types of vignetting that one might encounter when taking pictures or viewing images. Some types of vignetting are naturally caused by the optical design of lenses, others can occur when using third party accessories such as filters and extended hoods and some are artificially added by the photographer in post-production. Let’s take a look at each type in detail.

1.1) Optical Vignetting

Optical vignetting naturally occurs in all lenses. Depending on the optical design and construction of the lens, it can be quite strong on some lenses, while being barely noticeable on others. Still, vignetting occurs on most modern lenses, especially on prime / fixed lenses with very large apertures. There are two causes for this. First, at the widest apertures, the light than enters the lens is partially blocked by the lens barrel, as indicated by the below diagram:

Optical Vignetting

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The Future of Optics Could Change Significantly

How would you like the future, if a lens like the Nikkor 800mm f/5.6 VR weighed a kilo / couple of pounds and cost 10 times less? Or perhaps a wide angle lens as big as a pancake that delivers the same quality images as your favorite 24mm f/1.4 prime? Sounds like a dream, doesn’t it? Well, we might not be that far away from this dream, since the researchers from the University of British Columbia and the University of Siegen might change the way modern optics work. Their current research on using a single lens element in a lens and correcting lens aberrations looks promising – a method called “deconvolution”, which is based on analysis and reconstruction of the image via software. Instead of using physical elements within a lens to correct for lens aberrations such as distortion, spherical aberration, chromatic aberration and coma, the idea is to use a lens with a single (or more) lens elements and correct such aberrations via computational photography techniques and software algorithms that are applied after the image is captured. This obviously results in lenses with very few lens elements, making them both lighter and cheaper to manufacture.

Complex to Simple Lens

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What we have been doing with your donations

Our readers frequently ask us about the performance of classic Nikkor lenses, some of which were kept from the film days, some inherited and others acquired at an auction or a garage sale. Considering the high cost of modern Nikkor lenses, older lenses can be of great value, especially AF-D and Ai-S manual focus models that could be snatched for 3-4 times less than their modern counterparts. Unfortunately, due to the fact that I never owned those older classics or had any access to them, I have never been able to test and review them. While building our lens database, I realized that it was very difficult to obtain information on older lenses and almost impossible to find product images. So I decided to look at local product listings and auction sites like eBay to find old lenses of good value. Not the hard to find / rare items, but the ones that are commonly found everywhere. Thanks to the gracious support of our readers, I was able to find a few good deals and use some of the money to fund this project.

Classic Nikkor Lenses

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Sigma 120-300mm f/2.8 DG OS HSM Review

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This is an in-depth review of the Sigma 120-300mm f/2.8 DG OS HSM Sport, a high-end super telephoto lens with a versatile zoom range and a wide constant aperture of f/2.8, designed for wildlife, sports and portrait photographers. This is the third iteration of the lens. Its predecessor, the Sigma 120-300mm f/2.8 EX DG OS APO HSM was released back in 2005 with identical optical design. What has changed, is the exterior make and appearance of the lens (along with the tripod collar and tripod foot), the new rigorous quality control that Sigma has implemented on its new lines of high quality lenses, and the ability to attach a USB dock for fine tuning the autofocus operation of the lens. In this review, I will go over the technical specifications of the lens, talk about its optical features and performance with and without teleconverters, and compare it to other super telephoto lenses like Nikon 200-400mm f/4G VR and Nikon 300mm f/2.8G VR II.

Sigma 120-300mm f/2.8 DG OS HSM

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Sigma 2.0x Teleconverter Review

This is a detailed review of the Sigma 2.0x Teleconverter EX APO DG for the Nikon mount. I had a chance to test out this teleconverter, along with the 1.4x Sigma teleconverter when working with the Sigma 120-300mm f/2.8 lens, so I wanted to share some of my findings and compare the teleconverter to its Nikon counterpart, the Nikkor TC-20E III. In this review, I will go over the optical characteristics of the Sigma 2.0x teleconverter and talk about its performance when using both Sigma and Nikon super telephoto lenses.

Sigma 2x EX DG Tele Converter

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Nikon 800mm f/5.6 VR Review

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This is an in-depth review of the Nikon 800mm f/5.6E FL ED VR, an exotic super telephoto lens designed for wildlife and sports photographers. Nikon first teased us with its plans to release an 800mm lens in July of 2012, with an official announcement that followed in January of 2013 (along with the Nikon 18-35mm f/3.5-4.5G ED lens). Nikon has not updated its manual focus 800mm f/5.6 ED-IF lens for over 25 years, so it was about time to introduce an autofocus version of the lens to the market. The Nikon 800mm f/5.6 VR is a significant milestone for the Nikkor line, because this is the first lens to have the letters “FL” on the lens name, which indicate that fluorite elements are used in its optical design. Although Canon has been using fluorite elements in its exotic super telephoto lenses for a while now, Nikon historically has only used fluorite elements in its medical / microscope lenses. So in a way, this is the first lens of its kind for Nikon.

Nikon 800mm f/5.6E FL ED VR

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Do Filters Affect the Resolution of Lenses?

Just like the old “film vs digital” or the “Nikon vs Canon” debates, lens filters often create endless discussions on the Internet. Some people argue that one should never use protective filters, since it is another piece of glass in front of the lens that reduces resolution and emphasizes other optical problems such as ghosting / flare, while others argue that filters make it easier to protect the front element of the lens and make it easier to clean that element. I personally have been recommending use of protective filters for years, as long as they are of high quality. The filters that I have been using do not seem to affect the resolving power of lenses they are mounted on and mostly do not seem to heavily affect ghosting / flare either. Having spent the last couple of weeks in a lab testing many lenses, I wondered if I could actually measure the resolution of a lens with and without a filter. I recently purchased a used lens that came with a crappy plastic filter, so I decided to run two separate scenarios – one without a filter, one with a high quality B+W filter (more on B+W products below) and one with a cheap plastic filter. The results of the study came out very interesting!

Filters to Use or Not to Use

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Sigma 1.4x Teleconverter Review

This is a detailed review of the Sigma 1.4x Teleconverter EX APO DG for the Nikon mount. I had a chance to test out this teleconverter, along with the 2x Sigma teleconverter when working with the Sigma 120-300mm f/2.8 lens (review to be published within the next week), so I wanted to share some of my findings and compare the teleconverter to its Nikon counterpart, the Nikkor TC-14E II. In this review, I will go over the optical characteristics of the Sigma 1.4x teleconverter and talk about its performance when using both Sigma and Nikon super telephoto lenses.

Sigma 1.4x EX DG Tele Converter

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What is Distortion?

In photography, there are two types of distortions: optical and perspective. Both result in some kind of deformation of images – some lightly and others very noticeably. While optical distortion is caused by the optical design of lenses (and is therefore often called “lens distortion”), perspective distortion is caused by the position of the camera relative to the subject or by the position of the subject within the image frame. And it is certainly important to distinguish between these types of distortions and identify them, since you will see them all quite a bit in photography. The goal of this article is to explain each distortion type in detail, with illustrations and image samples.

1) Optical Distortion

In photography, distortion is generally referred to an optical aberration that deforms and bends physically straight lines and makes them appear curvy in images, which is why such distortion is also commonly referred to as “curvilinear” (more on this below). Optical distortion occurs as a result of optical design, when special lens elements are used to reduce spherical and other aberrations. In short, optical distortion is a lens error.

There are three known types of optical distortion – barrel, pincushion and mustache / moustache (also known as wavy and complex). Let’s examine each in more detail, but before we do that, let’s take a look at a lens with zero distortion:

No Distortion

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Nikon 18-140mm f/3.5-5.6G VR Announcement

Nikon has just announced a brand new lens, the Nikon AF-S DX 18-140mm f/3.5-5.6G ED VR to expand its line of APS-C / DX lenses. This lens is meant to be an update to the existing Nikon 18-135mm f/3.5-5.6G lens that was produced back in 2006 and discontinued in 2009. Interestingly, the Nikon 18-135mm was a kit lens for mid-range DSLRs like Nikon D80, which means that we should be seeing an announcement for at least one DX camera later this year (probably at the end of September). And since the Nikon DSLR entry and mid-range lines are fairly recent (D3200, D5200 and D7100), this lens might ship as a kit lens for the upcoming Nikon D400.

Nikon AF-S DX NIKKOR 18-140mm f/3.5-5.6G ED VR

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