webcam - modified vs unmodified stacked

CCD vs Film? Lots of time vs no patience? Alright, this is your place to discuss all the astrophotography what's and what's not. You can discuss about techniques, accessories, cameras, whatever....just make sure you also post some nice photos here too!
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starfield
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Joined: Thu Jul 21, 2005 4:20 pm

webcam - modified vs unmodified stacked

Post by starfield »

What is the benefit to modify webcam to do long exposure. Shouldnt stacking 100x5s do exactly what a 500s long exposure and better?

Found the following link to support my thoughts.
http://www.skyinsight.net/wiki/index.php/Image_Stacking

Any comments or advise?
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river
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Post by river »

which is better 500x1s, 25x20s, 10x50s........1x500s?

Signal to Noise ratio (Noise from heat and the CCD) and desired detail of the chosen target captured per exposure are the major consideration.

then you continue to 100 x 500s x L,R,G,B,Ha,darkframe,flatframe,testframe.... :mrgreen:
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Meng Lee
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Location: NTU, Woodlands

Post by Meng Lee »

The short answer is that 100x5 does not give you the signal to noise ratio of a 500s exposure because readout noise will be stacked also. Meaning 100x5 gives the readout out noise 100 times more than the 500s exposure.

But you may say the 500s exposure has too many hot pixels, well, that can be resolved by a matching dark frame.

webcam sensors are very noisy compared to StarShoot, DSI or Atik, so I will say that if you buy starshoot, DSI or Atik, you will surely get much better pictures than a modified webcam and with less effort also.
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