This spreadsheet is (c) 2009 Michael Fulbright and may not be distributed without my permission and definitely cannot be sold. Feel free to modify for your personal use.
Not responsible for any inaccuracies in this spreadsheet.
CCD Compare is a spreadsheet I wrote to help me compare the optical sensitivity of various combinations of imaging CCDs and telescopes. I offer it as a investigative tool but do not propose it is a authoritative technical document. I am not responsible for inaccuracies in the tabular data or the calculated results.
There are Excel and OpenOffice Calc 2.4.2 versions of the spreadsheet.
There are several sheets in the spreadsheet which are experiments at this point and you are welcome to look at them but I can't vouch for their accuracy.
Its easy to add a new telescope or ccd using the "Telescopes" or "CCDs" sheet.
My primary metric for each setup is something I just call "power". It's defined as:
Power = (Aperture)^2 * (plate scale)^2 * QE
I believe it is comparable between different OTA/CCD setups as long as the optics of the telescope do not add significant vignetting/light loss. Also it is only meaningful for extended objects - these numbers will not be applicable for stellar photometry, for example.
Here is an example:
Comparison
Bin OTA FOV (deg) Scale Ap FL P(L) T for S/N P(Ha) T for S/N (Ha)
ICX-285 1 Canon200mm @ f/3.5 2.55 6.6 57 200 77850.86 1.00 77850.86 1.15
KAF-8300 1 Sky90 @f/4.5 2.54 2.75 90 405 27569.32 2.82 27569.32 3.25
KAF-6303e 1 FSQ106 2.99 3.5 106 530 75815.64 1.03 89600.3 1
Here:
In this example I chose some OTAs that would give me similar FOV for these different CCD chips. This causes a different pixel scale for each since the various CCDs are different sizes. That said you can see the KAF-6303e is clearly preferable (if money is not an issue) due to a larger FOV and yet a reasonable pixel scale, and the collecting power of the larger OTA (the FSQ-106) and larger pixels (9 micron) really makes a difference compared to the smaller pixels on the KAF-8300.
However if you decide to bin the KAF-8300 2x2 then you see a different picture:
Comparison
Bin OTA FOV (deg) Scale Ap FL P(L) T for S/N P(Ha) T for S/N (Ha)
ICX-285 1 Canon200mm @ f/3.5 2.55 6.6 57 200 77850.86 1.42 77850.86 1.4
KAF-8300 2 Sky90 @f/4.5 2.54 5.5 90 405 110277.29 1.00 122530.32 1.0
KAF-6303e 1 FSQ106 2.99 3.5 106 530 75815.64 1.23 89600.3 1.78
If you are willing to give up some detail by a lower plate scale with the KAF-8300 it actually is good for collecting alot of light per pixel and using a telescope instead of a camera lens to achieve a large FOV.
One caveat: the KAF-8300 does not have wide enough output registers to handle binning 2x2 w/o overflowing if the individual pixels are too full. So the solution is to bin AFTER readout, but this increases the effective read noise per binned pixel to twice the read noise of if you had binned the pixels on chip.