Thanks very much for that, I've just been looking at the plugin. I'll give it a try. It looks like it could be be useful for what I'm trying to do, which is basically to get the detail of IR and the colour of a normal shot in the same image. I've had some success with blending images using CMYK, but can't get the colours quite right.

I just ran both images through an action I use for infrared, which swaps the red and blue channels, and they came out looking completely normal, so the red and blue channels are definitely swapped in both of these files. It looks more like a software problem than a sensor problem.

I've had a look at Imagemagick but it looks pretty complicated. Basically i want to be able to convert an sRGB file from my K5 to YcbCr, and then replace the luminance channel with the one from an infrared file. I also want to try replacing the luminance channel in a 665nm image with one from an 830nm image.
Gimp can edit YCbCr images, but I can't find any conversion tool available to convert the images in Gimp.

I don't suppose we have a member here fluent in Linux, who can tell me a simple way to do this conversion, preferably with some sort of Photoshop (or more likely Gimp) action, and then to be able to convert the image back to sRGB after editing? I understand some Linux but not enough to do this. Any advice much appreciated.

I find carrying a few spare batteries far more convenient than turning what is a great reasonably sized camera into a heavy, bulky monster. I shoot a lot in portrait, and personally don't find any problem with the controls rotating the camera. I've even been tempted to switch completely to mirrorless cameras; my IR converted Nex has the same sensor as my K5, and is half the size and less than half the weight. I do like the size and weight of the K5, though, but would not want it any bigger. I'm hoping Pentax is going to come out with a full-frame camera with the size and ergonomics of the K5. If it comes out looking and feeling like one of those bulky FF Canikons with a grip welded to it, I won't be buying one.

I agree, if the next Pentax is the same size as a K5 with grip, I doubt very much I would buy one. Personally I don't get the whole thing with grips; I just don't see the point of making a camera bigger than it needs to be to work..

Because when everyone has bought a Q7 they will come out with the Q5 which will probabbly be the same quantum leap as the K7 to K5 was....

Some really cool shots there

if they follow the naming of the K series cameras, a Q5 should be out next year....

My 4 quid Zenit E takes Pentax lenses.....though it came with a Helios 55mm.


I think I'm going to sell it on ebay with a Lomo tag on it for for 150 quid....unless of course anyone here wants to make me an offer....