Canon EF 15mm f/2.8 Fisheye Lens

You must be careful of using autofocus on this and other wideangle lenses. The fuzzy logic "brains" will actually focus somewhere between three to ten feet when you are focusing on something at "infinity", relying on hyperfocus to give apparent sharpness at infinity. Much better to focus manually. Beware!

I'd like to emphasise that the above comment about autofocus is absolutely right, and very easy to forget. Using my Sigma 8mm circular fisheye and Canon EOS, the autofocus is completely useless but merrily beeps away thinking it's working.

Also, when using very wide angle lenses for (semi-)scientific purposes, it can be beneficial to use software to brighten the outside of the image slightly. The brightness drops off imperceptibly away from the centre (with circular fisheyes, at least), and can lead to problems in applications that depend on a consistent rendition of brightness. The image shows an example of this problem.

Sigma do an 8mm f4 full circular fisheye (180 deg), it's in their EX series and lists for £600 (US$900) ... sigma - http://www.sigma-photo.com ... fish-eye - http://www.sigma-photo.com/html/fixed_ultrawide.htm (confusingly the photo on this page is not a circular one - the page lists their ultra-wide lenses 8-24mm)

Obviously not the same quality, but surprisingly good is the Nikon FC-E8 fisheye attachment for the Coolpix series of cameras. It takes in a 183 degree angle of view and sells new for just under $200. Great for playing around with!

Fairchild Oak

A large 800-year-old tree near Daytona Beach, Florida is difficult to capture because of the width of the branches, one trailing along the ground. I tried a multi-frame capture and stitching, but didn't like the results. This is the best so far and was taken with the 15mm.

I have used this lens with two Canon SLR's, the original Digital Rebel and the D5, for a total of roughly 5 years. The point that several of you have made about the failure of the auto-focus to give a proper setting beyond 10 feet is very interesting, because I haven't seen the results of this. Odd, huh?

I guess the lens is almost acting like a fixed focus unit on a simple box camera. So I've been playing point-and-shoot with $3500 worth of camera and lens. But because the lens is so short, the hyperfocal distance serves very well for almost all distances WHEN THE APERTURE IS SMALL. Right? From now on, just to be get the best possible result, I will switch to manual.

Two other points. First, I find the lens is tricky to use in terms of achieving the exaggerated foreshortening one sometimes desires, as in creating a sense of great depth or distance from front to back. The effect is great sometimes, but other times what I get is a flattening rather than an elongating. My guess is that the foreshortening works on just a short range, after which EVERYTHING just seems very tiny, and thus "far away". In other words, there is a not much difference between something that is 20 feet away and something that's behind it at 200 feet.

Second, I get quite variable results when I use a program that can pull the bulge out of the picture so that the image looks rectilinear. Some images come out well, while others are just hopeless. Is there a particular piece of software that anyone is using that handles these images especially well?

Thanks for any help and comments. Great forum!

Filmdog

I've just acquired one of these, and would be appreciative of any tips from previous users...