Dark Frame Comparison
We compared the dark frame shots of unmodified camera and cooling modified camera and the models are EOS 1100D(= Rebel T3, Kiss X50 ) and CDS-1100D / EOS 600D (=Rebel T3i, Kiss X5) and CDS-600D / EOS 60D and Astro60D.The images were taken at indoor dark room and the exposure time was 450sec ( 7.5 minutes).We croped 224×224 pixels in center area of original images and not resized.
In order to distinguish the deferance of each shots more easily we stretched the tone levels in Photoshop program. The default value of highlight Levels is 255 and we stretched this to 100 and 30Levels.
1.Original Images ( ISO1600, 450sec, RAW file center croped)
2.Levels stretched 255 to 100 in Photoshop ( ISO1600, 450sec, RAW file center croped)
3.Levels stretched 255 to 30 in Photoshop ( ISO1600, 450sec, RAW file center croped)
The noise patterns of unmodified EOS models are quit different. Unmodified EOS 1100D(Rebel T3)’s Dark Frame shot is worst. But After modification the cooled images of these 3 cameras are absolutely clear without noise and almost equal to each other. We guess the image sensor technologies of these 3 cameras are same. The differences of inner fever or EMI shield , electric grounding condition are the difference of the amount of noise.