Rectilinear vs fisheye wide angle question

PentaxPoke · 08-30-2008, 06:09 PM

I thought I would take my discussion about how I am going to spend my DA*16-50 refund off of the 16-50 thread. So here is the question:

I have opinions from people suggesting the Pentax 10-17, the Pentax 12-24, and the Sigma 10-20. I don't do a lot of wide angle, but I think I might enjoy it. Wouldn't the most versatile choice be the 10-17? That way I can enjoy fisheye if desired, but also by using software like DXO, I can correct to very wide rectilinear? I really like the idea of being able to get almost 180 FOV in tight spaces.

I have searched every thread on this subject on Pentax Forums, but they didn't help me make the decision.

I would appreciate opinions if you have time.

*troyz* · 08-30-2008, 06:58 PM

This subject came up a little while in the postprocessing/software forum; although nobody with the 10-17 zoom posted a response, you might find the discussion useful:

10-17 de-fishing resolution loss?

It's mathematically impossible to have a rectilinear image with 180 degree FOV (the corners of the image would be infinitely stretched out); other projections can give you the 180 degree FOV; these generally straighten only vertical elements and produce very interesting geometric effects.

You could do a rectilinear projection of a zoom-ed in image from the 10-17; you would get about a 90 degree horizontal FOV. Image quality may be adequate for your purposes but won't be as good as an image from a rectilinear lens (particularly in the corners).

My advice: if you like fisheye look (I assume you have found the Fisheye Fever thread by now), and you think it would work for your subjects, get the fisheye.
Otherwise, go for the ultrawide rectilinear.

BTW, the Pentax 12-24 and Sigma 10-20 both zoom in to a pretty useful ordinary-wide-angle focal length; this would be quite useful when you're trying to minimize lens changes.

** EDIT -- I just noticed from your signature that you already have the DA14! In this case I suggest getting whatever you want and skipping this rectilinear conversion stuff entirely!

NaClH2O · 08-30-2008, 07:19 PM

My suggestion would be to go with the zenitar 16mm fisheye. That way you'd know if the FE distortion bothers you (I love it myself). Yes it's not as good as either the 10-17 or the 12-24, but it's also a lot less expensive. There is always a used market for the lens, so if you then decide to go for the 10-17 you can always sell the Z.

NaCl(a big "Z" fan)H2O

stevebrot · 08-30-2008, 10:49 PM

Originally Posted by NaClH2O

My suggestion would be to go with the zenitar 16mm fisheye. That way you'd know if the FE distortion bothers you (I love it myself). Yes it's not as good as either the 10-17 or the 12-24, but it's also a lot less expensive. There is always a used market for the lens, so if you then decide to go for the 10-17 you can always sell the Z.

NaCl(a big "Z" fan)H2O

I can't say about the performance of the 10-17 or 12-24, but I do have some time in with the Zenitar and think that Salty's suggestion is a good one for anyone wanting an inexpensive introduction to the fishy stuff.

Steve

Imagination4 · 08-31-2008, 02:29 AM

Originally Posted by PentaxPoke

I have opinions from people suggesting the Pentax 10-17, the Pentax 12-24, and the Sigma 10-20. I don't do a lot of wide angle, but I think I might enjoy it.

If you want to try out wide-angle, I think that the DA 12-24 is a much better choice and more versatile than the DA 10-17 Fish-Eye. You would likely find yourself using the 12-24 more often than going to the Fish-Eye (unless you already have the WA covered by some other lenses). The Fish-Eye lens is more of a special use/effects lens. That said, I do have a DA 10-17 and find occasion to use it.

*k100d* · 08-31-2008, 08:03 AM

remember there is still some perspective distortion when going ultra wide

ryan s · 08-31-2008, 01:56 PM

If framed correctly, the Zenitar produces very little "bending" of trees, posts, etc.

Plus it's about $150, how can you argue with that?

PentaxPoke · 08-31-2008, 02:12 PM

So what about this strategy: I have down to 17mm (78deg AOV) with my Tamron. My Pentax 14mm gives me 90 deg FOV. The 12-24 would overlap my Tamron from 17-24, and only give me 9 deg more FOV than the 14mm. If I go with the 10-17 I get a 180deg-100deg FOV. At the 17 end, the distortion is not that great, and could easily be made rectilinear if desired, and still be around the same as the widest end of the 12-24. The fisheye is also less expensive. If I go with the Sigma, the max FOV is about the same as the min FOV on the 10-17.

Thoughts?

*troyz* · 08-31-2008, 02:40 PM

Originally Posted by PentaxPoke

So what about this strategy: I have down to 17mm (78deg AOV) with my Tamron. My Pentax 14mm gives me 90 deg FOV. The 12-24 would overlap my Tamron from 17-24, and only give me 9 deg more FOV than the 14mm. If I go with the 10-17 I get a 180deg-100deg FOV. At the 17 end, the distortion is not that great, and could easily be made rectilinear if desired, and still be around the same as the widest end of the 12-24. The fisheye is also less expensive. If I go with the Sigma, the max FOV is about the same as the min FOV on the 10-17.

Thoughts?

Makes sense to me -- if you need better results than defishing can provide you can always go back to the DA14.

danielchtong · 09-01-2008, 06:18 AM

Originally Posted by PentaxPoke

I thought I would take my discussion about how I am going to spend my DA*16-50 refund off of the 16-50 thread. So here is the question:

I have opinions from people suggesting the Pentax 10-17, the Pentax 12-24, and the Sigma 10-20. I don't do a lot of wide angle, but I think I might enjoy it. Wouldn't the most versatile choice be the 10-17? That way I can enjoy fisheye if desired, but also by using software like DXO, I can correct to very wide rectilinear? I really like the idea of being able to get almost 180 FOV in tight spaces.

I have searched every thread on this subject on Pentax Forums, but they didn't help me make the decision.

I would appreciate opinions if you have time.
PENTAX K20D, PENTAX K10D, PENTAX DA* 50-135 f/2.8, PENTAX SMCP-FA 50mm f/1.4, PENTAX SMCP-FA 35mm f/2, PENTAX SMCP-DA 18-250mm f/3.5-6.3, PENTAX SMCP-DA 14mm f/2.8, TAMRON AF 90mm f/2.8 Di SP macro, TAMRON SP AF 17-50mm f/2.8 XR Di-II, PENTAX AF360FGZ flash, PENTAX BG2 grip.

Why bother? Your DA14mm is a very capable WA. And you do not have any serious longer range tele. Get either the DA*200mm or 300mm.

Daniel

PentaxPoke · 09-01-2008, 10:09 AM

Originally Posted by danielchtong

Why bother? Your DA14mm is a very capable WA. And you do not have any serious longer range tele. Get either the DA*200mm or 300mm.

Daniel

I really spend very little time at the tele end. I am very happy with the results I get at the 250 end of my 18-250. Most of my tele shots are handheld, of planes at low altitude. 250mm is about all I can handle, and is often even too much zoom. Even if I did get the 200 or 300, I think that I wouldn't notice the difference in the tele shots I usually take. They are usually more limited in sharpness by motion of the subject than the lens.

I find that the 14 is not as wide as I want to go relative to the 17 on my Tamron. I mainly bought the fixed 14 for the high-altitude balloon flights as an upgrade to the 18-55 II kit I used last time.

koper · 09-01-2008, 11:49 AM

i have sigma fishey 15mm-i use this lensess very rarely(i louded yesterday a photo in section of landscape )
i make a lot of wide angle photos with sigma 10-20 mm.
i use rarely pentax 10-17mm for panoramic photography
i think the best advice is to bay sigma 10-20 mm
look for may photos in israelian site

???????? ????? ?????? ???????? - ????? ????? - ????? ????? - ????? ?????? - ????? ?????? ?? ???? - ????? ????? - ????? ?????? - ????? ?????? -

most of the photos are done with sigma 10-20 mm+panoramic software
koper

PentaxPoke · 09-01-2008, 12:30 PM

Thanks koper. You have some beautiful shots there. Ironically, I think I like the shots you took with the Pentax 10-17 best! The more pictures I see, the more I think that the constant-angle projection (conformal mapping) of a fisheye is a bit more pleasing to my eye than the rectilinear projection that results in stretching.

Am I just odd, or does anyone else think the same way?

timk · 09-01-2008, 12:47 PM

Originally Posted by PentaxPoke

Am I just odd, or does anyone else think the same way?

nope i agree,just ordered my 10-17

*J.Scott* · 09-01-2008, 01:28 PM

I have a DA 10-17mm and really do like the images it produces. However, be prepared for a lot of PF (purple fringing) under the 'right' conditions. Below is an example. In fact, it should be described as torture testing the poor lens!

I produced the image on a very bright winter afternoon by deliberately including some sun flare. The crop is a 500% blow up of a small area on the image. Under less strenuous conditions it performs admirably. (In this case I just wanted to bend lamp posts in the sun - it's lots of fun.

But just thought it fair to warn you that PF will happen with this lens.

500% crop