Bison Bud

I probably should know this, but is there any real difference other than the focal length in a wide angle lens that does not distort the image and one that gives the "fisheye" effect? If focal length is the primary difference, at what point does the image begin to distort. In other words how low of a focal length can I shoot and not get the fisheye effect? Also curious as to how a crop sensor body effects the fisheye effect. Any productive discussion on this subject would be really appreciated! Good luck and good shooting to all.

BboH Loc: s of 2/21, Ellicott City, MD

I'm also interested

rmalarz Loc: Tempe, Arizona

https://www.quora.com/What-is-the-difference-between-a-wide-angle-lens-and-a-fish-eye-lens
http://thefuturephotographer.com/wide-angle-vs-fisheye-lens-guide/
https://www.dpreview.com/forums/thread/3134442

for starters. Yes, the focal length is a factor.
--Bob

gvarner Loc: Central Oregon Coast

I've read that 15mm full frame (10mm crop) is the cutoff point. I have a 10-20mm Sigma for my crop sensor D7000 and it pushes vertical in or out if you don't have it pretty level. I noticed this on the hoodoos in Bryce Canyon. You're on top looking down and strong verticals are pushed out a bit. But it was not distracting. It added to the scene dynamic.

LWW Loc: Banana Republic of America

Any lens will distort every image to some degree.

ToBoldlyGo Loc: London U.K.

There are fisheye lenses for crop sensor cameras. Mine gives a nice image, though you cannot see a complete circle around the image. I love the way it works. Incidentally, I used it for some video today in 4K. Using the central portion and outputting in say 720, the image had no fisheye effect, but had the benefit of being nice and wide. Great for my uses.

Bison Bud

There is some good info. in the links above, but it's still somewhat difficult to fully understand. It does seem that the focal length is the primary difference in wide angle and ultra wide angle (with fisheye distortion). However, if I understand correctly, it also appears to make a big difference in how the resulting image is projected on the sensor as to how much barrel distortion is created. Apparently, the shorter the focal length, the more circular the image becomes and if it is set up for only the corners of the sensor to reach the circumference of the image, then far less barrel distortion is created (rectilinear verses curvilinear). It would also appear that around 15 mm, on a full frame sensor, is the point where the image reaches a 180 degree view and possibly where the barrel distortion really becomes excessive.

This possibly flawed new understanding makes me wonder if wide angle lenses of longer than 15 mm can also be made to be fisheye lenses and whether a 15 mm crop sensor lens would show the barrel distortion on a crop sensor camera body? Can anyone out there clarify this concept further or is it best to just consider 15 mm and less as Ultrawide/Fisheye and just let it go at that? Thanks to all who have contributed!

ToBoldlyGo Loc: London U.K.

I have a 10-20 which is an ultra wide, not a fisheye. It's made for a crop sensor camera, I have never mounted it on a film or full frame camera. It shows distortion, but not the fish bowl kind of effect.

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

Terms, such as rectilinear (straight lines rendered as straight lines) but with perspective distortion, or fisheye (barrel distortion - straight lines rendered as curves) would be good to Google.

Blurryeyed Loc: NC Mountains.

I am not sure that I understand your question, fisheye lenses give a much wider view at the same focal length, for instance, my 17mm fisheye lens gives a 180 degree angle of view where as at 16mm my rectilinear lens gives about 108 degree angle of view. The fisheye has much more distortion that is more complex than my zoom lens, it would never be a good lens for let's say real estate photography, though it can be a fun lens.

BboH Loc: s of 2/21, Ellicott City, MD

Another thing about the fisheye - it allow a vary close focus distance; up to 1/2" or closer.

DirtFarmer Loc: Escaped from the NYC area, back to MA

Fisheye lenses are generally very short focal length, but I believe the thing that makes it a fisheye is a lot of barrel distortion. Barrel distortion can be corrected in the design of a lens but it's tough to do.

Fisheye lenses also have an extremely wide field of view. In an extreme case, the field of view can be wider than 180 degrees. Lenses like that are used in meterology and auroral studies. They produce a circular image in which you can see the horizon in all directions.

E.L.. Shapiro Loc: Ottawa, Ontario Canada

"Regular" general purpose wide angle lenses come in three ranges; moderate, medium and extreme (super) wide. For a full frame body, the focal length range goes from 36mm down to 15mm respectively providing a field angle form about 60 to 110 degrees. Most modern wide angle lenses of high quality are RECTILINEAR, meaning, simply stated, the yield images of straight features such as wall of buildings as straight lines as opposed to curved lines. Although the use of regular wide angle lenses can entail some distortion such a foreshortening, exaggerated foreground elements and certain perspective issues, they do not usually exhibit extreme curvature of field and barrel distortion. Fish eye lenses in order to provide hemispherical, panoramic and extremely wide fields of view yield hemispherical images which are the result of barrel distortion (or radial distortion) and curvature of field, especially at the edges of the frame. There are full frame (not to be confused with a full frame sensor) fisheye lenses fill the rectangular format and others that produce a round circular image within the rectangular frame. Theses lenses are usually in the 8mm to 10mm range. The are made for astronomical photography.

Im my opinion theses lenses usually help the creative photographer produce a variety of specialized effects that are very dynamic but not traditional and therefore limit their application for general photography. Some time ago, at a professional trade show exhibit, I had an opportunity to peer through the viewfinder of a Nikon camera with their 6mm f/2.8 fisheye. I saw the ceiling directly above and my feet in the same frame. You can have this monster for a mere $160,000.

The only fisheye I own is a 30mm Distagon for my Hasselblad medium format cameras. I picked it up from the rental stock of my local dealer at the time- the price was right at $600. I used at a few weddings in churches. It makes rectangular doorways look like archways and small chapels appear like massive cathedrals. I have done a few cool shots of ethnic and folk dancing- kind of aerial views and use it for the odd commercial job for one or two novel shots.
I even use if for an environmental portrait of an architect who wanted to be pictured in the interior in a domed church that he had deigned. I kept him in the center of the frame and did not show his legs- he was standing behind the altar. There was no distortion or curvature in the center of the frame. I have had this lens for some 20 years and it still looks like new!

If you use theses lenses on smaller formats or sensors than they are designed to cover, you just won't see the total effect of the curvature and will reduce the angle of field but I don't see this application as a substitute for a general purpose wide angle optic in that I am not sure if enough of the distorted area would be negated.

I hope this helps.

ToBoldlyGo Loc: London U.K.

No, that's dependant on the individual lens.

Architect1776 Loc: In my mind

The difference is the fisheye look and a rectilinear look.
You can have a 15mm fisheye and a 10mm rectilinear wide angle.