"red" cameras
The Sigma SD10 ( SD-10 ) is unique as it uses a combined dust-protector/IR-cut filter that can be removed by the user. This allows for fascinating IR pics. Eric from www.evolvingbeauty.com/ used an SD-10 before switching to a modded Nikon. He was so kind to give me one of his testing images with the SD-10. It shows the achievable contrast and the "wood-efect" (white foliage) nicely and thus I use it here, although the camera and Eric are both capable of much nicer shots ;) The Sigma SD-10 only shoots RAW - may be a nuisance for snapshots, but it is ok for IR. When using an almost opaque filter (720nm), autofocus becomes a problem and manual focus evenmoreso. You might get away with a dark red filter, especially if narrow apertures conceal focusing errors.
What I had already learned from the Sigma forum at dpreview is that the Sigma's IR response is mainly red, with quite some blue and only a little green.
Indeed it showed that the green channel is not noteworthy - at least I could not get it to contribute nicely to the overall IR image. I normally use the free RAW->JPEG converter Pixmantec Raw Shooter | essentials. However, this fine software does not support the different algorithms needed for the Foveon sensor of the Sigma. I downloaded the Sigma Software "PhotoPro". When post-processing my IR shots with the Pentax *ist DS, I use the eye-dropper white-balance tool of RSE - sadly PhotoPro does not offer this.
Instead I manually adjusted the colour balance until
the red and blue channels use much of the full range:
A simple conversion by desaturation to greyscale (B&W) yields the usual, flat image:
But adjusting curves and levels in your favourite editor really gets the shot to life!
Levels:
Now desaturation:
and finally curves:
Doesn't look so ordinary now, right?
Thanks again to Eric from www.evolvingbeauty.com/ for providing not only the X3F RAW file, but also some hints about the SD-10. Visit his site for some seriously good IR shots.
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