[kmurphy220]

Is it possible to use a fisheye lens for its ultrawide view and then in post fix the fisheye without losing too much quality?

[blackcloudbrew]

Not really, you can correct some of it but I think its images quality would not compare to a non-fishey wide angle.

[Paul the Sunman]

Yes, with a little work. See the various methods in

You Tube

You Tube

.

[kmurphy220]

Yes, with a little work. See the various methods in this video.

Thanks. I find fisheye lenses to be cheaper than actual UWA lenses. Especially if I see them on CL and ebay. Thanks!

[SpecialK]

You stretch the pixels quite a bit so image quality will not be really good. You might consider one of the Bower/Samyang/Whoever manual-focus wide angles that will provide better results.

[kh1234567890]

You stretch the pixels quite a bit so image quality will not be really good.

Actually it is not too bad in practice ...

[stevebrot]

I own a Zenitar 16/2.8 Fisheye (a 180 degree fisheye on FF 35mm) as a general-purpose ultrawide and while I have the means to correct in PP, I very seldom do so. The methods to de-fish fall into two main categories, those that sacrifice a large portion of the image resulting in modestly wide final image and those that replicate and/or remove pixels to normalize the view at the expense of detail.

Below is a link to photos from my Flickr stream taken with the Zenitar. Most were done on APS-C and the rest on 35mm film. Only one was corrected in PP. I have found that for landscape work, the eye is remarkably insensitive to a bent line. That may be because the eye itself is not a rectilinear lens. What's more, a fisheye does not distort or "smear" proportions at the edges. As a result, some subjects appear more natural even if a little bent*

https://www.flickr.com/search/?user_id=28796087%40N02&sort=date-taken-desc&t...tar&view_all=1

For those who prefer to not click through:

Here is a framing that would be impossible with the subject and a rectilinear projection...




Here is a fairly conventional landscape...




A little architectural work. This one would defish with little loss and with quality comparable to a properly "corrected" image from more expensive rectilinear lenses at similar focal length and field of view.




And just to prove that the Zenitar truly is a fisheye.




Steve

* Fishiness is related to the position of the lens axis relative to the straight lines within the frame. For many subjects there is no discernible bending at all.

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Last edited by stevebrot; 08-02-2015 at 08:28 PM.

[stevebrot]

In case you are interested in a true 180 degree diagonal on APS-C, here is a link to a few from the Rokinon 8/3.5 Fisheye:

https://www.flickr.com/search/?user_id=28796087%40N02&sort=date-taken-desc&t...non&view_all=1


All have 180 degree FOV, but not all look fishy.


Steve

[Sandy Hancock]

As luck would have it, I just tested this.

The first shot is with the Sigma 8-16mm @ 8mm, the second with the DA10-17 @ 10mm and de-fished in Lightroom. You will note that the fisheye is wider even after the barrel distortion is corrected, and the loss of sharpness is not great.

All taken on tripod without moving the camera.





And here's the fisheye before correction. Now *that's* wide.

[interested_observer]

Evening,

Take a look at this thread. Depending on the scene and how you set it up, a fisheye can have a more natural look that a wide angle. It depends on keeping the lens level with the horizon, and thus the fisheye curve falls to the bottom of the frame - and potentially hidden.

• https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/235102-uwa-...omparison.html

[Tony Belding]

You stretch the pixels quite a bit so image quality will not be really good. You might consider one of the Bower/Samyang/Whoever manual-focus wide angles that will provide better results.

I actually tested and compared defished images from a Samyang fisheye with images from the Samyang ultra-wide 10mm lens. And the result...

Almost identical. It seemed to me that optical correction and digital correction both produced similar kinds and amounts of image degradation. However, the fisheye lens was a lot smaller and lighter -- and, of course, can take actual fisheye images too. Seems to me like an easy choice.

[lesmore49]

I have a Pentax 10-17 fisheye. At 17 mm...with some up and down movement I can get passable, IMO...wide angle shots.

[Sandy Hancock]

And while we're at it, the DA10-17@ 17mm and corrected matches the DA15's field of view almost exactly.

[jimr-pdx]

I used the Sigma 15 and Pentax' SMC 17 for wide landscapes and to me they worked great without any correction. I would put the horizon dead center, then crop higher or lower to get the composition I liked best. And occasionally I'd point it up or down, just let it be its bendy self!

I never tried de-fishing to see how it would do, and now I have a DA15 so those days are (presumably?) over. As Sandy noted I found the 17FE was just between the DA14 and DA15 in field of view.

[stevebrot]

Thanks. I find fisheye lenses to be cheaper than actual UWA lenses. Especially if I see them on CL and ebay. Thanks!

It depends on the fisheye and also on the rectilinear UWA.

There are several ways to cook the circular fisheye projection. My Zenitar 16/2.8 projects a very different image to the 35mm FF frame than my Rokinon 8/3.5 to APS-C, despite both having the same FOV. The Rokinon differs from most fisheyes in having a so-called orthographic projection while the Zenitar is more typical. Notice too that the conventional notion of crop factor in regards to FOV does not apply to the Rokinon when compared to the Zenitar.

Likewise, two rectilinear UWA lenses will differ in terms of how their distortion is crafted or how well chromatic and other aberrations are handled. Few (none?) are distortion free and how the distortion is distributed varies.

The better fisheyes (say Sigma 15/2.8 or Pentax DA 10-17) are in the same price range as the better rectilinears (say DA 15/4).


Steve