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Old 05-03-2013, 04:39 PM
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PRejto (Peter)
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Join Date: Jan 2011
Location: Rylstone, NSW, Australia
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Originally Posted by Shiraz View Post
Hi Peter. Put the two options into the model. Looks like your scope would be a good match for either chip for hi res imaging down to about 2 arc sec seeing.
  • The 8300 will give you a much larger field of view.
  • The system broadband sensitivity will be about the same with either camera (the bigger pixels of the 8300 help with sensitivity, but lose resolution).
  • The 694 will have much better SNR (maybe 2x) at low signal levels in Ha narrow band due to the low noise of the 694.
  • The 694 will give you significantly better resolution (if you have a target that covers 100 pixels on the 8300, the 694 will put 140 pixels on it). that would be a noticeable advantage in good seeing
  • The 694 has a somewhat better dynamic range than the 8300, and the very low read noise of the 694 gives you more flexibility in exposure strategy.
Not sure if you want an opinion, but if it was me, I would push the 8300 as far as I could before deciding if I needed a replacement - but that is entirely your call, based on what you want to do. And of course you also need to consider the ancillary mechanical issues.

hope this is helpful. regards Ray
Thanks Ray, and, yes, I always value an opinion!

May I ask another? What about well depth vs light pollution? Is it true that light pollution will have a greater effect on a chip with a smaller well depth? For example if I compared the KAI4022 to the ICX694 the KAI chip well is 2x the well size ICX694. If LP in a given subframe took up say 5000 that would be 25% of the ICX694 but only 12.5% of the KAI. Would that then give a better dynamic range to the KAI chip? If so, imaging in a light polluted environment, would it be better to trade higher QE for greater dynamic range?

I ask because I struggle with background noise imaging as I do from Sydney, and I'm wondering if what I really need is greater dynamic range rather than another camera with a small well. Or, have I got this wrong and the greater SNR of the ICX694 would make a big difference?


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