 Cindy L. Ferguson |
How do I eliminate the fisheye effect when shootin
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robert G. Fately |
Cindy, what you're describing is not really the "fisheye effect", but rather the expected result of perspective distortion when one subject (e.g. the bride) is close and others are farther away from the camera. This has to do with the ratio of their distances - say a line of people are standing only 5 feet from your camera. Well, the person in the center (the bride, in this case, I presume) may be 5 feet from you, but the folks at the ends of the line are more like 10-12 feet from you. So the natural perspective makes the B look much bigger than the outlying people. Kind of the same when you use that 10MM lens to shoot a person with their hand outstretched and their fingertips 3 inches away from the lens - their hand looks huge in coparison to their head. Frankly, I'm not aware of any Photoshop "fix" for this, as it's not, technically, as distortion. If you were to stretch the sides of the image vertically, no doubt the people will become even more distorted. COmpare this to using, say, an 80MM lens on the same group. Obviously, you need to stand further back to get them all in the shot (which I realize you couldn't do in the room this time). So say you step back to 25 feet away from the bride - now the folks at the ends of the line are 30 or so feet from your lens - and the ration of 30 to 25 is not so severe as to cause this kind of perspective. Fisheye, on the other hand, is the bowing out of lines not in the center of the frame - basically a huge mount of barrel distortion - and that's something altogether different. In fact, I think Nikon software can "undistort" their fisheye's bowed effect, but that's not going to help you here.
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John P. Sandstedt |
If you truly used a 10-20 mm focal length lens, you were using a lens considered to a fish-eye. While I don't dispute Bob's comments, I'd think twice about using a lens for this purpose shorter than 24-mm.
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robert G. Fately |
Not to pick nits here, John, but you are technically incorrect. "Fisheye" refers to a lens with, as I stated above, uncorected barrel distortion. There are a number of non-fisheye (called "rectilinear" - because they keep straight lines in the subject matter as straight in the image) lenses under 24MM - the so-called Ultra-wide angle family. Where the exotica of this group were the 20MM, then 18MM and then 14MM lenses, today there are 12-24MM zooms (including Sigmas, which works for both film and digital) and even a 10-20MM zoom designed for digital SLR only (it will vignette on a 35MM film format). That said, you are right about being very careful when using one of these ultra-wides due to this unavoidable perspective distortion. But if you are stuck in a small space with no way to "move back" sometimes they are the only way to go.
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BetterPhoto Member |
The other day, I was turned on to a program called photofiltre. Tonight, I was downloading the plugins for this program and noticed that it had a fisheye correction plugin. This is a free program that you can download by going to www.photofiltre.com. I hope it helps in your dilemma. Have a great night and keep shooting.
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BetterPhoto Member |
And Bob, when I was studying with NYIP, we called this the dognose effect for short. It's technically called perspective distortion. Sorry to stick my nose (ha, ha) in again.
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Craig m. Zacarelli |
i use photshop cs2 and there is a filter in there to correct any lens faults. I like the fisheye effect for landscapes and buildings (i have the sigma 10-20mm) but as you have said, not to good for crowds! Craig-
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Deborah Liperote |
sorry to ask a stupid question but what is the difference between a fisheye and a superwide angle lens? I want to get the 10-22mm efs lens "someday" but I don't want the fisheye effect. I just want a larger expanse. I hope I'm understanding this thread right. that a fisheye is optically different than a superwide angle zoom. Yes?
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Deborah Liperote |
By the way I'm sure Cindy you have moved on from this subject by now but Craig is right you can fix this in Pcs2. p.s. does any one have a recommendation for a superwide angle fixed lens(canon 30d). Just for natural landscapes. wider than 18mm
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robert G. Fately |
Deborah, a fisheye lens is basically an ultra-wide angle lens that has not been optically corrected for barrel distortion. This means, for example that straight lines bow outward, increasingly so as they get to the edges of the frame. If you are shooting architecture or people - things that folks know what they should look like - then this type of distortion is quite noticeable. True fisheye's have a 180 degree angle of view, which means they project a circular image on the film (or chip). So-called "full frame" fisheyes hav a 180 degree angle of view along the diagonal only, so there is no vignetting. These lenses can be a lot of fun under the right circumstances, but aren't recommended for portaiture, for example. The 10-20MM lens is not a fisheye - it is a true rectilinear lens. That is, straight lines remain straight whrever they appear in the frame. That said, there is now software for some fisheye shots that can "de-fisheye" the image - dXo optics has one for the Nikon 10.5MM ffisheye that's supposedly pretty neeat ( plan on trying it sometime). Hope that helps!
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Craig m. Zacarelli |
As Bob said, A fisheye produces a "Round" image and anything in the shot will also have a curve to it along the outside of the frame and whatever is in the center will look as if its coming out twords you. A Fullframe fisheye or rectanguler fisheye or Ultra wide or diagonal fisheye ( I have heard it called all of these ) is a very wide lens that retains its rectanguler Image so anything in the shot, such as a building, will look as if its getting smaller as it goes up to the top of the frame and the items at the bottom will curve across the bottom of the frame getting higer as it reaches the corners. I have the sigma 10-20 and love it but really not good for large groups unless you have no choice and you have the softwaer to fix it.
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Deborah Liperote |
no the wide angle im looking for would totally be for landscapes ya know. just for beautiful scenic shots. so with that in mind do you guys recommend a a fixed lens or do you suggest the zoom?
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John P. Sandstedt |
Bob/Craig - from the internet encyclopedia:Wikipedia - In photography, a fisheye lens is a wide-angle lens that projects deliberately distorted images. All ultra-wide angle lenses suffer from some amount of distortion. While this can easily be corrected for moderately wide angles of view, rectilinear ultra-wide angle lenses with angles of view greater than 90 degrees are difficult to design. Fisheye lenses achieve extremely wide angles of view by foregoing a rectilinear image, opting instead for a special mapping (for example: equisolid angle), which gives images a characteristic convex appearance. A panorama by rotating lens or stitching images (cylindrical perspective) is not a fisheye photo. A special kind of fisheye lens, called circular fisheye lens, projects a circular image fully contained inside the frame, typically with an angle of view of 180 degrees. The focal lengths of fisheye lenses depend on the film format. For the popular 35 mm film format, typical focal lengths of fisheye lenses range from 6 mm to 16 mm. Deborah - Be careful of how wide a wide-angle lens you use for landscapes. You don't want the fish-eye effect so you will need to consider something no shorter than 24 mm [on the 35 mm film side.] Canon's standard lens for the 20D or 30D is 18-55 mm. With the 1.6 multiplier, this lens is equivalent to 28-85 mm [traditional.] If you want to go wider, however, check: http://consumer.usa.canon.com/ir/controller?act=ModelDetailAct&
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Craig m. Zacarelli |
lol john, good old Wikipedia! A good full frame fisheye for land scapes huh? yeah, I agree with John, unless you can correct an image in PS id say 24MM. Id have to risk saying a zoom would be better, just for the fact that you can leave it on the camera and go wide and or far. but I guess it would be user preference on that one.
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Todd Bennett |
Hey Mark, That's a pretty nice program for it to be free ware, thanks for sharing that. Todd
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Christopher A. Vedros |
Deb, The 10-20mm Sigma is not a fisheye lens. On your 30D, it will be the equivalent of a 16-32mm lens. It has aspherical elements to correct for any barrel distortion. It should not give you distorted landscapes. When used at close ranges, though, you will run the risk of getting perspective distortion like Bob explained to Cindy above. Chris
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BetterPhoto Member |
It's free and good. Two words you don't hear in a sentence too ofter. You're welcome, Todd.
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