Astrophotography: Deep Sky Objects

[Fishperson]

Weather generally moves to East

The best conditions are dry, stable air, and as cold as possible... this time of year can be good for imaging as the night time temperatures start dropping it makes the thermo electric cooling on the camera perform that much better. This image was taken with the camera set to -30 Celsius.

I knew that... (Not really)

That's interesting. Does that mean that certain parts of the camera were actually -30 degrees?

 

[fort384]

Yes, the CCD chip itself has a thermo electric cooler coupled to it.

When you do long exposure photography with either a CCD or CMOS (standard DSLR chip), the warmer it is, the more the image is subjected to thermal noise. By cooling the chip it helps to eliminate much of this thermal noise resulting in more "good" signal showing on the image. Another way to reduce the noise and increase the signal is to stack multiple exposures of the same image. Noise is somewhat random where as the good signal of what you want to see is not... so by stacking images on top of each other with software, you can eliminate even more noise and make the resultant good signal that much stronger. This particular image of M33 is composed of 18 individual pictures of 10 minute exposure each. Not sure if that makes sense..........

 

[Fishperson]

Yes, the CCD chip itself has a thermo electric cooler coupled to it.

When you do long exposure photography with either a CCD or CMOS (standard DSLR chip), the warmer it is, the more the image is subjected to thermal noise. By cooling the chip it helps to eliminate much of this thermal noise resulting in more "good" signal showing on the image. Another way to reduce the noise and increase the signal is to stack multiple exposures of the same image. Noise is somewhat random where as the good signal of what you want to see is not... so by stacking images on top of each other with software, you can eliminate even more noise and make the resultant good signal that much stronger. This particular image of M33 is composed of 18 individual pictures of 10 minute exposure each. Not sure if that makes sense..........

No, that mostly makes sense. Thank you!