What you see above is an enhanced representation of what I had to routinely subtract from my DSRL astrophotography images through last season. It’s obviously not a defect in the optical train, nor a feature of the night sky. The only explanation I’ve been able to produce is that the image sort of maps areas of different sensitivity on the CMOS chip.
Naturally this kind of defect doesn’t affect daylight photography, but stretching the histogram to the limit while shooting extremely faint objects can show things like this on a camera that was not intended to be used for this purpose.
Tags: astrophotography, Canon450D
yeah thats interesting.
Just wondering if you’d investigated or found a way to desensitise a chip so that you could do 2 hour daylight exposures?
I was thinking of a resistor on the power line into the chip or maybe a software alteration afterwards?
Robin
Hi. You can use Neutral Density filters to do long exposure with daylight. Or why wouldn’t you want to (permantently?!?) desensitize your chip instead of putting a filter in the optical train?