Software To DeFish The 10-17mm Pentax Lense?

[C.W Tsorotes]

Any suggestions for the best program to use?

[WheresWaldo]

I have and still use Proxel Lens Corrector. I do not think it is still being actively developed, but I can't find anything that it won't defish. Besides this they include a utility to create your own lens configuration that allows multiple focal lengths for zooms. It is fairly straight forward to use and works very well. It also does not arbitrarily shrink the image size in order to accomplish its magic.

I have also tried PTLens and others but I found Proxel the easiest to use.

Proxel Lens Corrector

[troyz]

I occasionally use Hugin for de-fishing:
Hugin - Panorama photo stitcher

It's actually a stand-alone pano stitcher but it de-fishes just fine and lets you correct perspective distortion at the same time (if you're going to bother making all those lines straight you'll often find yourself wanting to make them parallel).

It's quite powerful but perhaps hard to use:
- load the image
- select "fisheye" lens type
- go to the stitcher tab, select rectilinear projection
- click calculate FOV, click calculate optimal size
- output as remapped images
- look at the preview
- maybe play with pitch and roll to correct perspective distortion, repeat FOV/size
- click "stitch now".

BTW, at 17mm you should be able to straighten all the bent lines (a rectilinear projection), but at 10mm this is essentially impossible (the corners get infinitely stretched out). You can do a cylindrical projection on a 10mm image, straightening the vertical lines only.

You might also want to try the Fisheye-Hemi plugin:

Image Trends - Digital Imaging Products - Fisheye-Hemi Plug-in - Specifications

Fisheye-hemi isn't very flexible (only three settings, essentially 8mm, 10mm, and 17mm-ish) but others really like it.

[stevebrot]

PTLens:

PTLens Web Site

I have used it for de-fishing my Zenitar 16/2.8 FE and for distortion correction with the Pentax-DA 18-55 kit and have been very happy with the results. Here is my take on the advantages:

• Flexible
• Does a good job
• Integrates with Lightroom
• Inexpensive

Here is an example from the Zenitar fisheye:

Before:


After:


Steve

[audiobomber]

Originally Posted by C.W Tsorotes

Any suggestions for the best program to use?

And are there any freeware programs?

[WheresWaldo]

Originally Posted by audiobomber

And are there any freeware programs?

Most of these programs use Panorama Tools, PT is free but the gui slapped on to it is what you are paying for with these applications. A google search on Panorama Tools will reveal some command line and gui applications that are free and will work with varying degrees of ease.

[troyz]

Originally Posted by audiobomber

And are there any freeware programs?

Hugin is free, open source, and runs on Linux, OS X, and Windows.

[Damn Brit]

Moved, this is about post processing, not lenses.

[mysticcowboy]

Not free but it's a great tool. It not only will correct for barrel distortion but will get rid of chromatic aberration (fringing) too. It's calibrated for camera/lens combos so can work with just a click, unlike the free options.

I've gotten great support from the developer, too.

[oshua]

I downloaded the trial version of PTLens and it looks like it works great but I am wondering if there is any program that can work with DNG files or that can batch correct the files.