Fish eye lenses are almost more fun than is permitted by US law!
A rectilinear lens preserves straight lines, while a fish eye distort them. This means if you have a straight line in your photograph that does NOT go through the very center of the lens, then it will be bent by the fisheye, but not by the rectilinear.
the fish will distort facial features - you may not want to use this on da laydeez....
There's some serious truth there! Although some can be good sports.
My GF at a wedding. Canon DRebel w/ Sigma 8mm circular fish, cropped..
I have another great one of her and her uncle next to each other w/ the same lens, however it is not cropped and shows the full reach of the lens. Unfortunately I don't have it online.
No, seriously, I have a question that should definitely be answered here. What is the difference between a diagonal and circular fisheye? Sigma has both, the 8mm is circular and the 15mm is diagonal.
I have used both the Sigma 8mm circular and the Canon 15mm fish, which is functionaly similar to the Sigma of the same focal length. The difference has nothing to do w/ the distortion, but instead the coverage of the lens. The 8mm circular has a 180 degree field of view in both the horizontal AND the vertical. Obviously this means vignetting, especially in the corners and on the horizontal. The 15mm 'diagonal' fish covers 180 degrees in the diagonal of the frame, from corner to opposite corner.
..Remember all of that is on a 1x crop frame though. I shoot w/ a DRebel, so I've got a 1.6x crop to deal w/. The Sigma 8mm covers just a touch over 180 degrees in the horizontal w/ a 1.6x crop. Again, there is vignetting in the corners and touch on the horizontal edges, but none on the top or bottom. I've never done the math to figure the vertical FOV, but it is obviously far less than the full 180 degrees the lens is capable of covering. I find this lens to be just about perfect for full 360x360 panoramas. 6 shots gets you full coverage and PLENTY of overlap for stitching. Technically I think it could be done w/ as little as 4 shots. But remember, fish eyes have poor resolution near the edges by definition, so it's best to overlap this and use the centers of each shot to maximize resolution and sharpness.
I've never bothered to measure the actual FOV of the Canon 15mm fish, although it is far less than 180 degree in all dimensions, due to the crop. It's basically like a really wide angle lens w/ some serious disortion. Of course it can be de-fished in software fairly easy. I think the 15 f/2.8 lens (either Canon or Sigma) is a great candidate for such use. It gives you a really wide angle, fast lens w/ great sharpness for a reasonable bargian..
I someday hope to own both the 8 and the 15.. and maybe a cropped version that delivers a full circular coverage as the 8 does for full frame..
I took this shot with the Sigma 8mm at PMA 2004 on my 1Ds, add this lens to the reasons to want a FF camera. It is a cool lens. I would not mind owning one.
I took this shot with the Sigma 8mm at PMA 2004 on my 1Ds, add this lens to the reasons to want a FF camera. It is a cool lens. I would not mind owning one.
I took this shot with the Sigma 8mm at PMA 2004 on my 1Ds, add this lens to the reasons to want a FF camera. It is a cool lens. I would not mind owning one.
Agreed. However my friend who owns the Sigma 8 and I were speculating that a full circular fish eye for cropped cameras will probably be offered sometime in the near future. W/ all Nikon dSLRs at 1.5x and the Canon 1.6x cameras being so popular Sigma could probably sell more than a couple such lenses. I know I'd want one.. if I could afford it is another subject..
I have since picked up and tried the Canon 10-22 rectilinear. What a WEIRD lens! I guess that I'm just so used to seeing things THAT wide w/ the fish-eye distortion that the lens completely weirds me out. I snapped a shot of the back of my truck out in the lot and can't get over it..
Werid no?!
I've got nearly similar shots w/ the Sigma 8mm fish and the Canon 10-22. Pardon the crappy exposure. Clearly wide angle shots require more attention to get the exposure right, particularly when involving so much contrast!
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thanks doc,
i really love this pic - -looks great on my 30" monitor as desktop
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A rectilinear lens preserves straight lines, while a fish eye distort them. This means if you have a straight line in your photograph that does NOT go through the very center of the lens, then it will be bent by the fisheye, but not by the rectilinear. There's some serious truth there! Although some can be good sports.
My GF at a wedding. Canon DRebel w/ Sigma 8mm circular fish, cropped..
..Remember all of that is on a 1x crop frame though. I shoot w/ a DRebel, so I've got a 1.6x crop to deal w/. The Sigma 8mm covers just a touch over 180 degrees in the horizontal w/ a 1.6x crop. Again, there is vignetting in the corners and touch on the horizontal edges, but none on the top or bottom. I've never done the math to figure the vertical FOV, but it is obviously far less than the full 180 degrees the lens is capable of covering. I find this lens to be just about perfect for full 360x360 panoramas. 6 shots gets you full coverage and PLENTY of overlap for stitching. Technically I think it could be done w/ as little as 4 shots. But remember, fish eyes have poor resolution near the edges by definition, so it's best to overlap this and use the centers of each shot to maximize resolution and sharpness.
I've never bothered to measure the actual FOV of the Canon 15mm fish, although it is far less than 180 degree in all dimensions, due to the crop. It's basically like a really wide angle lens w/ some serious disortion. Of course it can be de-fished in software fairly easy. I think the 15 f/2.8 lens (either Canon or Sigma) is a great candidate for such use. It gives you a really wide angle, fast lens w/ great sharpness for a reasonable bargian..
I someday hope to own both the 8 and the 15.. and maybe a cropped version that delivers a full circular coverage as the 8 does for full frame..
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very cool patch!
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I have since picked up and tried the Canon 10-22 rectilinear. What a WEIRD lens! I guess that I'm just so used to seeing things THAT wide w/ the fish-eye distortion that the lens completely weirds me out. I snapped a shot of the back of my truck out in the lot and can't get over it..
Werid no?!
I've got nearly similar shots w/ the Sigma 8mm fish and the Canon 10-22. Pardon the crappy exposure. Clearly wide angle shots require more attention to get the exposure right, particularly when involving so much contrast!
Canon 10-22 @ 10mm on DRebel