Affiliation
American Association of Variable Star Observers (AAVSO)
Thu, 11/25/2021 - 02:37
I am thinking of buying a CCD camera that says the following: Typical Readout Noise 9 e- at 500 kHz; 14 e- at 2 MHz
What is the best trade-off between clock speed and readout noise for exoplanet work in which exposures range from 1 second to 30 seconds, and hundreds of images are taken over 5 hours are so? I know I need to minimize readout noise, but what exactly would I be giving up by running at a lower speed of 500 kHz?
What trade-off would be appropriate for exoplanet work?
A second question.. I have is, can I control whether the camera runs at 500 kHz or 2 MHz? Is there a way I can adjust this? Or does this have to be set at the factory?
Thanks,
Ed
Wow! Who makes the CCD camera that runs at 2 MHz?
Best way to optimize anything from exoplanet imaging to LPV imaging is to start doing it.
If money is tight, buy a less expensive camera, fully characterize it, and put it to work.
Ray
From another of your posts, I see that you mean that the down-load clock can run at 2 MHz, rather than taking 2 million exposures per second. ( 2 BILLION "exposures" per second is possible with few "pixels" and that is my next project )
Then you need to know how many bits each clock cycle sends. is it 8 bits? 16 bits? If it is 8 bits, per clock cycle and the word is 16 bits long (16 bit ADC ) then the download would take twice as long as the number of pixels divided by the clock speed. Plus overhead. Many comm links are 8N1.
Ray
Ed
Thanks Ray,
Ed