@duartix It's pretty light, huh? ;) If you look at the "usable", not heavily distorted part of the de-fished image then I wouldn't say it's any wider. However, if distortions and loss of resolution is acceptable then it's obviously a lot wider.. Very good for it's price, nonetheless!

@RRRR That's the thing about using a Panini projection when defishing. The "Usable" part of the image is massively wider than with a Rectilinear projection. Here's an example at 120º: http://vedutismo.net/Pannini/FdeS-120x90.html

The example won't tell you one very important thing though: the wider the original image is, the bigger the issue with distortion becomes. When going full Rectilinear, each corner pixel gets distorted to 5x-10x, while with the Panini projection it's more likely 1x-2x, which ends up holding quality and requiring a lot less cropping. The price to pay is distorted (non radial) horizontals. The horizontals that cross the center of the frame will still hold straight. In the end it's mostly a matter of careful composition that you'll soon master.

I've only bought two lenses beyond kit: the 45mm F1.8 (a price/performance champ) and the 7.5mm as for other uses I've got plenty of legacy options. I can say that from a price/performance view, the Samyang is as good as the 45mm. It's really a no-brainer.

@duartix is your 7.5mm a Samyang? What brand/model is your 45mm 1.8? I looked at the link you posted, and the top-left (Rectilinear) image is closest to what I want to achieve. A slight distortion is okey, because that's how we humans view things - wide angle, while our brain slightly "distotrs/smudges" the edges because our attention is at the center. So which lens can I use to achieve that kind of top-left image with a GH13?

@RRRR I don't mind using CCTV lenses. Actually, I have Fujian 35mm F1.7 and loving it. Also have a Pentax 8-48mm F1.0, which awaits modification as soon as I have a spare $125 - I'd be able to use it with GH13 in crop mode (albeit with significant loss of resolution), and it should give me a 32-192mm range. When I get a GH2, I heard I can use it without loss of resolution. I searched for Rainbow 3.5mm because that would give me exactly 14mm in crop mode. And I found this:

I like the perspective look of Rainbow 3.5mm, but the texture is too soft. The modified Pentax 6mm gives a lot sharper image, which I like. Does Rainbow 3.5mm readily fit into a C-mount adapter, or does it need modification?

@RRRR: You already have everything you need here: http://www.personal-view.com/talks/discussion/comment/66342#Comment_66342

I've massively built upon that script though!!!

It is now near complete with ~100 lines of batch code and what it does is ask for the image dimensions (4:3, 3:2, 16:9, FullHD or Auto), ask for the projection to be applied (Rectilinear or Panini), auto detect file types to be processed (JPEG, TIF or PNG) and finally clean up sources and conform generated file names in the end.

It just needs another pair of hours of testing and tuning. I'll publish it soon if I don't get carried away on batch programming again...

@duartix thanks! I don't know how I managed to miss that.. I'd be a whale on shore until someone manages to make it mac-able though. (At least until autumn when I plan to invest in a heavy editing station)

The nice thing about using a lens like the Panasonic 7-14mm or a Canon 10-22mm (on an APS-C body) is the usable field of view available without having to do any post-processing.

If you look at a lot of the stabilizer tests shot with a Panasonic 7-14 mm, you will notice that exaggerated distances/sizes towards the edges of the frame are a lot more noticeable than any barrel distortion. Notice how moving the camera forward and backward draws a lot less attention than panning left or right. This is especially noticeable with people in the frame.

I have only used the 7-14mm once or twice but I have used the Canon 10-22mm on APS-C a lot at the 10mm end (16mm FOV compared to the 35mm equivalent). It is a LOT easier to use than a fisheye, at least if you aren't trying to make the effect of the lens really obvious. I have not had a chance to compare the barrel distortion on the two lenses, but the 7-14 should perform very well given the in-camera correction that the GH2 will automatically apply during recording.

If anything should happen to me in the very shorty term, the beast of a script that has grown from those lines is here. I got carried away again so it took some more developing, testing & debugging. I could add a few more stuff like execution time statistics and detecting the Hugin folder (right now you need to set that manually in the 4th line of the script), but I feel it's the moment for prime time.

I'll include the script and document my findings with defished video in the proper thread, but right now it's up for everybody's use!

So, change that 4th line of defish.bat, put it in a folder with unprocessed images from the GH2 and defish away!!!

@Duartix 20 minutes!? You have no idea how much I suck at this.. Even if I find instructions, it usually takes a lot of time to get something done in the terminal!

Give me DOS! ;) Thanks though!

Do you have any video examples with movement in the frame (like things crossing the frame) – I'd be very interested to see how it looks!

@duartix that would be awesome..

If the settings are adaptable then one could easily make it work for other lenses as well..

@DirkVoorhoeve : Lightroom and some other RAW developers will correct lens distortions but I suspect they will not fully defish. And even if they do, the best you end up with is a Rectilinear projection which for the reasons already discussed is almost useless for a 180º fisheye. I've done quite a bit of research and Hugin was the best candidate around: it's cross platform, among it's 20 different projections it has got an Equirectangle Panini option, and best of all it's free!!!

This guy here: http://m43photo.blogspot.pt/2012/03/defishing-fisheye-images.html has found a video processing app that does a Panini Projection. It's called kdenlive but I never heard of it and the last thing I need now is to learn another video processing tool and include it in my workflow. :(

The way I figured it it's pretty simple and straightforward. You load your video in AE, export as image sequence, defish with my script, and reimport as image sequence.

@RRRR Looking at the script lines that do the defishing ( http://www.personal-view.com/talks/discussion/comment/68826#Comment_68826 ), the hugin project file is amazingly simple:

• p f16 w1920 h1080 v140 n"TIFF"

• o w1920 h1080 f2 v140 y0 p0 r0 n"testfile.tif"

• m i0

where the 1st line f16 says it's Panini (f0 for Rectilinear), w1920 & h1080 is the size

on the 2nd line I understand y0 p0 r0 must be yaw, pitch and roll, I don't know what f2 stands for

on the 3rd line there is a i0 which I don't understand either

My guess is that there is little if any parametrization for the Samyang, however it still works wonders... I really have to get some video results to post, you'd all be surprised at how good this gem of a lens really is!

There were serious bugs in the Rectilinear Projection part of the script (it was defishing to Panini and the crop was totally off). So, this post is totally off: http://www.personal-view.com/talks/discussion/comment/68826#Comment_68826 because the Hugin project parameters are indeed different after all... There's a very distinct crop parameter on the second line.

Anyway here's the right one.

The comparison video is near complete but I need to put some text over it. I'll be uploading to youtube soon...

Cheers @DirkVoorhoeve

The wider the better because you'll need less pictures or end up with bigger overlap which eases the software's work. In this case there is little to choose from between a 7.5mm or a 8mm because you can probably get away with either one by taking 4 horizontally panned pictures, one extra for the sky and another one for the ground (to make your legs or the tripod's disappear).

This guy has got some incredibly useful tutorials:

In the end I would get the Samyang 7.5mm but that's because the lens is simply stunning. It's got top notch centre and corner sharpness, almost 0 chromatic aberration, stellar flare resistance, great build and amazingly small size. It's easily the best lens I own.