Quote:
Originally Posted by Terry B
This is not quite correct but it certainly makes it much more difficult. ABG chips become less linear as they reach over 1/2 full well. This complicates differential photometry but doesn't preclude it. There is a very good article at http://www.aavso.org/publications/ejaavso/v33n1/1.shtml
that discusses using a consumer grade ST7 for detection of planetary transits. They discuss the difficulty with the ABG type of chips. |
Hi Terry
Good article you refer to.
I guess this is why I wrote good and scientific in quotation marks.
The article states.
1.The major challenge was to achieve long exposures.
2.Diminished well capacity does not help achieve long exposures
3.Differential photometry requires a large dynamic range which is enhanced by deep wells
4.Reduced well capacity and non linearity are definately problematic
5.Anti blooming reduces well capacity and introduces non linearity
6.Both these attribute are undesirable for photometry.
Any work around to these problems can only introduce more uncertainty and hence my statement regarding "good" and "science"
Regards
Steve
PS There is a subtle difference between differential photometry and searching for planetary transits.