The images were taken at indoor dark room (Temperature : 20C~22C) 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 30Levels. Read more
We tested 8set of camera cooling modules to get the temperature curves/ time.
Below chart is the output.
In the period of 0~3minutes the drop down curves are almost similar to straight line and reached to about 70% of maximum cooling temperature. Read more
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.
▣ Dark Frame comparison [EOS 350D(Rebel XT), EOS 5D , ASTRO 350D]
These were exposed continuously with 3min rest interval, 300sec -> 600sec ->900sec,and cropped from center of full size images.
▣ The rise of the temperature of image sensor according to exposure time [unmodified original 350D(Rebel XT)]
data: Canon 20-35L lens,
EOS 350D(Rebel XT)
ambient air temperature:75℉ (24 ℃)
ASA1600, 15min exposure &
3min rest & 5min exposure
We have checked temperature change with B shutter exposure by attaching thermometer on the back surface of CMOS Sensor.