10 Super Wide Lenses for DSLRsJuly 1, 2008
By Michael Stewart
Wide Angle photography has been revolutionized by technology. One sure way to make a unique image is to do something that wasn’t possible before. It wasn’t possible to shoot a good sharp flare-free 120-degree image in the past, and now it is. Along with the availability of good wide angle lenses, there are now many new ways to produce and present wide angle photography. Roll-fed inkjet printers can make extremely wide prints and Virtual Reality Photography (VR) can utilize a full 360-degree image.
With the ability to stitch images together using software tools like Photoshop’s Photomerge field of view is now essentially limitless, but this doesn’t exclude the need for good wide glass.
Today’s full frame rectilinear lenses are reaching 120-degrees and fisheye lenses are seeing as wide as 185-degrees. I’m using the term Super Wide to mean “very good ultra wide lens”. The term came from a Hasselblad camera with a 72-degree FOV, not very wide at all by today’s standards. “Super Wide” lenses were once rare, extremely expensive, and not very good. Today there are many choices; they are reasonably priced; and many of the sharpness and flare problems have been solved. In addition to better lens design, software like DXO can be used to correct undesirable lens characteristics like chromatic aberrations, vignetting, and distortion.
Full frame sensors offer a serious advantage to wide angle photography. Engineering wide lenses with enough resolving power for small sensors is very difficult. Also, the focal length and angle of view have to make up for a multiplier factor of 1.5 or 1.6 on an APS-C sized sensor. For example: The very good Canon EF-S 10-22mm is made for a sensor with a crop factor of 1.6; this is a 10mm lens, yet it only has a 107-degree angle of view. On a full frame camera, a 16mm lens can accomplish the same angle of view without the added distortion. A 10mm lens has most of the same properties regardless of the sensor size, only the FOV and some of the cropped edge characteristics of the lens are different. It’s desirable to have the widest FOV with the longest focal length possible.
Rectilinear lenses are designed to have as little barrel distortion as possible, so straight lines appear straight. This creates a design limitation that makes it difficult to go beyond the 120-degree mark. Fisheye lenses on the other hand make no attempt to correct this distortion and can therefore be much wider, some as wide as 185-degrees. That last 5-degrees is very important because it provides overlap for stitching a full 360-degree VR (Virtual Reality) image out of just two exposures.
Wide angle images often have wide scene contrast. Because of this, gradated neutral density filters are very useful for wide angle photography, but it’s difficult to get a large enough filter to cover the front of one of these lenses. Using filters on Super Wide lenses is also difficult because of mounting issues. Some lenses accept rear mount filters which are difficult to install and it’s hard to set polarizers and gradients. Cokin’s X-Pro Series of large filters (170mm x 130mm) are some of the only filters large enough to cover the front element and the FOV of these Super Wides. When using a polarizer with a wide angle lens, be aware that very uneven skies may result because the polarization angle is not consistent across such a wide angle of view.
Here’s a Guide to some of the more interesting Super Wide Lenses for DSLR’s:
AF-S Nikkor14-24mm f2.8G ED (114°)
Nikon has made fascinating super wide lenses for many years, and now they have made one that I feel is revolutionary, the 14-24 2.8. It’s not only the best lens in its class; it’s really the only one. In conjunction with a full frame Nikon D3, this lens is a super star! It will be unquestionably revolutionary when the rumored and long awaited 24.4 Megapixel Nikon D3X is available. Nikon uses its Super Integrated Coating in conjunction with Nano Crystal Coating to create a very low flare lens. It’s a 2.8 lens that is rectilinear and full frame which makes it very unique. Unfortunately it’s a G series lens, which means it does not have manual aperture settings, so it cannot be used with an adapter on a Canon camera body.
Sigma 12 - 24 mm F4.5-5.6 EX DG HSM (122°)
The Sigma 12-24 is a real sleeper in the super wide category. It's the only rectilinear lens that's 122-degrees wide and it's actually very sharp at 12MM. I tested this lens against a Canon EF 14MM f2.8L and a Canon 16-35 f2.8L II; the Sigma outperformed both in sharpness, distortion, and chromatic aberrations. I'm a big fan of this lens for a Super Wide. Be aware, however, that this model varies tremendously from one lens to the next and some have real problems. I had two for awhile and one of them had a small area that was not sharp. As with many wide lenses, the Sigma 12-24 is sharpest in the center and the outer corners are softer and darker (vignetting). I use software corrections to account for this vignetting and sharpness fall off. A simple technique for correcting these in Photoshop is to make a correction layer with a circular gradated layer mask. The gradated mask allows corrections for sharpness, brightness, and chromatic aberrations to have more effect at the edges of the image.
The Fisheyes (Wikipedia):
I love fisheye distortion when it's used creatively and judiciously. Fisheyes are really fascinating, especially in combination with digital "defishing" and VR software. The fisheye distortion can be removed using software like PT Lens or ImageAlign, but this greatly reduces the angle of view and corner sharpness. Full Frame is a term used to describe an SLR camera with a sensor that is roughly the size of a 35mm film frame; but when applied to fisheyes, full frame also refers to the fact that the circle of illumination covers the entire frame (distinct from a circular fisheye). Many fisheyes suffer from poor image quality and just don't have what it takes, especially if your intent is to make big prints.
Canon EF 15mm f/2.8 Fisheye vs Sigma 15mm F2.8 EX DG Fisheye
These closely matched lenses cover 180-degrees, but that's the corner-to-corner field of view. The horizontal FOV is actually 142-degrees and the vertical FOV is 92-degrees on a full frame camera. These are full frame fisheye lenses that cover a full frame DSLR sensor. The Canon has slightly better auto focus, though this is not critical on a fisheye. Sigma has 7 shutter blades instead of Canon's 5, once again not that important on a fisheye.
Full Frame (180 Diagonal FOV) Fisheyes for APS-C Sized Sensors
Tokina 10-17 3.5-4.5 Fisheye
Tokina makes a 180-degree -100-degree fisheye zoom. A zoom fisheye, now that's unique and cool! I'm not sure how well it performs, but it's the first fisheye zoom and I'm hoping others will follow. I think there should be more funky lenses to choose from.
NIKON 10.5 DX Fisheye vs Sigma 10MM 2.8 DC Fisheye
Too close to call! Both are excellent lenses on APS-C sized cameras and they are especially well suited for VR photography. I used the Nikon 10.5 on a D2x for several years and loved it.
Circular Fisheyes (180-185 round image)
Circular fisheyes make no attempt to cover the whole frame; they produce an image that is a circle with a black border. Most of them cover 180-degrees, but a few have stretched it to 185-degrees, which allows two images to be stitched together.
Sigma 8mm 3.5 and Sigma 4.5mm 2.8
Sigma's 8mm lens, which produces an uncropped circle on a full frame camera, has been out for some time, but its little brother the 4.5mm 2.8 for APC-S sensors is brand new. A 180-degree lens will sacrifice image quality somewhat, but with the ability to correct for this in software, it's really not that bad.
It's fitting that the last lens in this interesting group of Super Wides is the widest. The Sunex's claim to fame is its 185-degree FOV. It's a sharp little lens designed for doing VR photography on an APS-C sized sensor. The fixed 5.6 aperture is somewhat limiting, but not such a problem for a specialty lens like this. If 360-degree VRs are your thing, this is your lens.
Sunex 5.6MM Fixed F5.6
I haven't provided an abundance of technical details or included any MTF (Modulation Transfer Function) charts in this article. These are valuable if you have choices to make, but with these Super Wide Lenses there just aren't any additional options. A potential alternative to consider when possible is stitching images together. Stitching multiple images will yield a larger file size and, when working with a sharper lens, this may yield a better result.
NASA Runway on Wallops Island, VA. Shot with a 10.5mm Nikkor Fisheye on a Nikon D2x
© 2006 Michael Stewart
Michael Stewart is a digital photography expert with more than 20 years of experience. He runs a busy commercial studio in Northern Virginia, just outside of Washington DC. Technical skill and a sharp eye for creating artistic work are the bases of his studio's success. When he isn’t shooting assignments, Stewart enthusiastically writes books and articles on photography. He is the Tech Editor of UPDIG and the DAM book. He is also currently writing a new book based on his popular photography technologies blog.
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