Feb 2010 Update: Newer wide angle lenses to consider for the 5D Mark II:
This article is over 3 years old, but still gets a lot of visits. I upgraded in early 2009 to the Canon 5D Mark II, which pushes the resolution limits of Canon's wide angle zooms even more. Neither the 17-40mm f/4L or 16-35mm f/2.8L II lens is acceptable in the corners on this 21 megapixel camera. The 5D II is also pushing the limits of the Olympus OM Zuiko 21mm f/3.5 lens. Don't panic. There are some great wide angle options for Canon full frame digital SLRs:
- Zeiss Distagon 21mm f/2.8 ZE -- if 21mm is your focal length of choice, and you have the budget, then look no further. Solid metal build, sharp as a knife, with that magic Zeiss 3D pop. Would make a nice companion to the 24-70/2.8L. Downsides? No autofocus, not as fast as the 24mm f/1.4L II, moustache distortion. I'm trying to decide between the 24mm f/1.4L II and this lens, and I'm leaning towards the Zeiss.
- Canon 24mm f/3.5L TS-E II -- Very sharp at f/5.6, even when shifted. Sharp in the corners. In a different league than the poor performing version I of this lens. A great lens for architecture and landscape photography. Downsides? You may have to wait to get one, and they're $2200. I owned this lens for a few months, and found I wasn't using the movements very much.
- Canon 24mm f/1.4L II -- The same price as the Zeiss 21mm, and 2 stops faster with autofocus. Again much better than the version 1 predecessor. Downsides? Price, and Canon lens quality control (i.e., sample variation).
The choice boils down to focal length preference, and whether you need tilt-shift. Hard to go wrong with any of these options.
Wide angle options
The image above is 11 minutes, f/16, ISO 50 with in camera noise reduction, using an Olympus Zuiko 21mm f/3.5 lens on the 5D with a Cameraquest adapter. The center sharpness of this tiny prime lens is on par with Canon's wide angle zooms, but the Zuiko walks all over the Canon 17-40/4L and 16-35/2.8L in the corners of the frame. The only significantly sharper lens at this focal length is the fabled Contax Zeiss 21mm Distagon, which currently runs $2500-3500 on the used market.Some people have also resorted to using the Nikon 17-35mm zoom on their EOS cameras with an adapter. Blasphemy!
If you use a 20D, 30D, 40D, 50D or other Canon dSLR with a smaller sensor, don't throw your zoom on the junk heap quite yet. This problem is with the edges of the frame, which are not utilized by 1.6x crop cameras. But if you are a 5D, 5D II, or 1DS series owner who has looked at your wide angle images at 50% or 100% in Photoshop, you'll know what I'm talking about. Canon wide angle zooms show a loss of sharpness and smearing of detail near the edges of the frame, even when stopped down at f/8 or f/11. I would like to thank Mark over at 16-9.net for his extensive lens testing and comparisons. His site is a great resource.
Olympus Zuiko 21mm
Using aftermarket lenses on Canon EOS cameras can be an expensive and time consuming rabbit hole to go down. Fortunately, the Zuiko lenses made for the Olympus OM system are quite small, light, and reasonably priced in most cases. The Olympus 21/3.5 usually sells in the $300-500 range. There is also a Zuiko 21mm f/2 lens that will give you a brighter viewfinder image, and has an additional lens element for close focusing. This lens is usually $800-1000. Extensive specs and technical information on Olympus OM lenses can be found on the MIR website. The Olympus 18/3.5 and 24mm shift lens are both stunning performers that do not fall into the "reasonably priced" range.
The Zuiko lenses are manual focus, and the aperture needs to be stopped down manually. Manual focus lenses are great for night photography -- unlike modern zooms and even high end prime lenses, most manual lenses have a decent manual focusing scale. Before shooting anything critical with manual focus lenses, I recommend taking test shots at different focus settings and analyzing the results.
Do not focus by only using the markings on the lens, or with an online depth of field calculator. The old trick of setting infinity on the focus scale one aperture wider than you are shooting may or may not work. You'll get the best results by taking test shots at different focus settings to calibrate how the lens focuses on your camera.
For night photography exposure calculation, it's easiest to pick an aperture and stick with it. I usually like to shoot at f/8, both for sharpness and exposure time.
Perhaps the night photographer's addendum to the "f/8 and be there" axiom is "f/8 and be there for 10 minutes."
I tested the Olympus 21/3.5 in the daytime at 5 or 6 different focus settings and made notes about where the focus ring was set. After analyzing the results in Photoshop, I determined I get the best results by shooting at f/8 with the focus set at 3 meters.
Night photographers, do you see where I'm going with this line of thinking? No more fumbling with a flashlight and praying that your wide angle zoom focuses where you want it to. No more having someone stand in the photo holding a cell phone so you have something to focus on. No more taking 4 test shots at high ISO to gauge your focus accuracy before shooting. I just set the lens to the 3 meter mark, stop the aperture down to f/8, and take the shot.
This focus setting also works just fine at f/11 and f/16, which is useful if you need a longer exposure. I wanted longer star trails in the above image -- due to strong tungsten street lighting, I stopped down to f/16 to get an 11 minute exposure. I realize after finishing this article that it really could be entitled "in praise of the Olympus 21mm lens." It really is the full frame wide angle shooter's most economical choice for sharp, wide angle shooting.