Will my wide angle adapter give me a fisheye effect?

Question

I use a Canon T2i with Canon FD lenses. My 28mm is not very wide since the camera has a 1.6 crop and the adapter to use the FD len on an EOS mount basically turns my 28mm lens in to a 50mm lens. I figured I would try a .43x wide angle adapter on the end to help me get closer to the original 28mm look I am going for. Will this adapter give my footage a fisheye look? What about if I put it on my 50mm lens which is essentially a 100mm lens after all the cropping.

Answer 1

The 0.43 tells you, just multiply your lenses focal length with this number. So your 28mm becomes a 28 * 0.43 = 12.04mm, on your 50mm lens it's 50 * 0.43 = 21.5mm you still have to multiply by the crop factor. So your 28mm with adapter and crop factor (1.6) has the field of view of a 28 * 0.43 * 1.6 = 19.264mm lens hardly fisheye though there might be some barrel distortion it will be minimal.



To get the fisheye effect you need a genuine fisheye lens around 10mm with a crop sensor, not all 10mm lenses are fisheye most are rectilinear which corrects the distortion and reduces the field of view whilst doing the correction.



I have a Pentax 10 - 17mm fisheye lens, by the 17mm end the fisheye effect has virtually disappeared. At the 10mm end I get almost a 180° field of view. It's by far my least used lens, the only time I use it is when photographing cars very close. Depth of field is huge, basically everything from touching the lens to the horizon is in focus at f16.



You won't get that from an adapter, put it on a wide lens and you may just get a circular image, you'll get vignetting on most lenses, adapters are not the same as a dedicated lens.



Here are a couple of examples, Notice the lack of flare, you won't get that with an adapter, they will flare as well as vignette.



http://www.flickr.com/photos/chris-judge/2946928132/in/photostream



http://www.flickr.com/photos/chris-judge/3328805784/in/photostream



Using FD lenses on an EOS camera is not a good idea as your adapter will have to have a corrective lens in it so you get infinity focus and bang goes the best of any image quality. I use FD lenses all the time on my Micro 4/3 cameras and they are very good and cheap which is a rare combination, but on an EOS camera you loose that advantage. Though you may find an FD fisheye lens, they are rare, but were made.



Chris

Answer 2

My advice is to throw out the FD lens, nix the idea of an adapter lens, and buy a bona-fide lens. I am sure you have discovered already that the FD lens will not focus to infinity, as is usually the case with those adapters.



A good camera and bad lens = a bad photo.

Answer 3

What effect the adapter will give will depend on the exact adapter used. Such adapters are little more than toys, and you are likely to get some sort of distortion, and probably even color seperation. I use something similar with my lens-baby kit, but then again that is "toy" kit.