How to remove distortion on a Fisheye image

IMG_1284

I recently bought the Canon 15mm f2.8 Fisheye for my new 5D Mark II. It’s extremely wide angle and gives the characteristic fisheye distortion.

Here’s a gallery of images shot with that lens:
http://www.flickr.com/apps/slideshow/show.swf?v=63961

In some images you want the fisheye distortion, but in other images you might want to remove it.

15mm Fisheye Original

And there are several applications that can help you with that. Regardless of what fisheye you’re using.

ptlens

The most common way to remove the distortion is to squeeze the image in the middle. Something like what PTlens will do for you. In addition you can adjust perspective, rotation and a couple of other settings.

But this leaves you with an image that has to be cropped and if there are people along the edges of the image they will look very distorted.

Another program called Fisheye Hemi aim to fix that problem. And will try to remove the fisheye distortion using advanced algorithms to keep as much as possible and do the adjustments but keeping people and other details in the image without distortion.

I’ve made a simple flash animation to show the different images. Click the buttons below the image to change from original, to the one corrected with fisheye hemi to the one corrected with PTlens.

[kml_flashembed movie=”http://eirikso2.com/flashfiles/FisheyeTest.swf” height=”400″ width=”500″ /]

There are a lot of programs that is made to help you adjust lens distortions. I’ve also tried DxO, but simply found it too difficult to use. For people using Windows I’ve heard positive remarks of RectFish.

Please leave a comment if you have a favourite that I haven’t mentioned.

How to remove distortion on a Fisheye image

Test clips from Canon HF10

Filming those trees in full HD

People that have been following me for a while know that I bought a Panasonic HDC-SD5 and returned it because of too much noise in the audio.

So, I’ve been patient and waited for the Canon HF10 Solid State AVCHD camera. It arrived about a week ago and unfortunately I haven’t had the chance to test it in detail yet. So far it looks very good. Small, but more sturdy and solid than the Panasonic. No noise on the audio and a very nice progressive recording mode. Way better performance in low light and a built in 16 GB of memory in addition to the SD-slot.

It works very well with both iMovie and Final Cut Express.

Update:
Here’s a detailed review with tech specs on Camcorderinfo.

I have published some very short test videos and will add more later.

25p-960×540.mov 18-May-2008 01:22 43M
= recorded in 25p and scaled down to half size

25p-testclip-canon-h..> 18-May-2008 02:21 177M
= original recording in 25p, Apple intermediate file

50i-testclip-canon-h..> 18-May-2008 02:11 126M
= original recording in 50i, Apple intermediate file

50p-960×540.mov 18-May-2008 01:52 55M
= recording in 50i and converted to 960×540 50p

For the converting from 50i full size to 50p half size I’ve used the free and excellent JES Deinterlacer. I set it up with the following parameters under “Project”:
Standards Conversion
Custom
Minimal Blend
Settings: Height: 540 Width: 960 Frame rate: 50.000
Movie speed: 1.000

Here’s another quick clip. Something I did to demonstrate Shazam ID on my phone. The video is slightly edited in iMovie, transcoded and uploaded to Brightcove. The recording was done in 25p, saving the hassle of deinterlacing. If you’re reading this in an email update or RSS reader you might want to click through to the article on eirikso.com to view the video.

http://services.brightcove.com/services/viewer/federated_f8/376819422

And here are two stills from the same camera. It’s snapping decent 3 megapixel stills as well.

Still image from Canon HF10

Test clips from Canon HF10