Wide Angle or Fish Eyes?

Rowmac · 2010-08-17T13:53:27+0100

Having very recently bought a K-x (very pleased with it), in the mountains of reading and research I've done I've come across wide angles and fish-eye lenses. My questions are these: Are wide angle lenses the same thing as a fish eye? Does a wide angle gradually become a fish eye the shorter the focal length and if so, roughly at what point? Ideally, I'd like to get a wide angle lense for landscapes et al. If someone can recommend one (hopefully not too expensive) I'd be very grateful. I don't know if my next question falls into a similar category or not but I'll ask anyway: I've seen some 50mm fast f1.8, f1.4, f2.8 lenses about as well. Is it to say that you cannot zoom with these lenses? Is it right to think that they have a very big aperture, as such allow lots of light in and thus for fast(er) shutter speeds? Thanks in advance

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Don Don

6213 posts
20 years
Winterpeg Manitoba Canada

Posted 20/08/2010 - 22:13 Link

petrochemist wrote:

Dangermouse wrote:

Wide angle does eventually become fisheye, although I'm not sure at what point.

Actually this is wrong.
Wide angles are rectilinear. Fisheyes use different designs (4 basic types - orthogonal, equidistant and two others I cant remember) which give much greater field of view.
From the online field of view calculators I've played with even with an impossibly short focal length of 0.1mm you don't get close to 180° FOV with rectilinear.
Pentax's 10-17 fisheye manages 180 on the diagonal, & Sigma do one thats 180 all round.

Mike

There are some canikon brand wide angles that have soo much barrel distortion you might be inclined to believe it was a fisheye.....

Fired many shots. Didn't kill anything.

MrCynical MrCynical

965 posts
17 years
Glasgow

Posted 20/08/2010 - 23:29 Link

Don wrote:
There are some canikon brand wide angles that have soo much barrel distortion you might be inclined to believe it was a fisheye.....

If any landscape shooter ever needs an advert for APS-C, please compare the barrel distortion of the Sigma 10-20 f4-5.6 with the Nikon 16-35 f4, which isn't even as wide