CaLIGHTs v3.1.2.00 Released

[wols...@gmail.com]

Happy Valentines Day!

Only a few changes here...mostly focused on master FLAT compensation for astrocams

Latest Revision 3.1.2.00

-Modified how the Pedestal value is determine. The Pedestal value is defined as the value in the camera’s LIGHT frame that corresponds to total darkness. For DSLR users this value is typically the same for every photo you take. The manufacturer has programmed the camera’s firmware to use optically blacked pixels to make this happen. Astrocams don’t have this standard which introduces a problem when using master FLATs. To address this issue I have established an order of precedence for determining the Pedestal value…

When all of the masters are used, the Pedestal value will be determined by the master DARK. This is because the master DARK typically uses the same GAIN, exposure and temperature as the LIGHT frames. The Pedestal value is the mean value of the pixels in the master DARK.

If a master DARK is not used then the Pedestal value will be determined by the master BIAS for LIGHT. This is how CaLIGHTs had previously functioned. For DSLRs there is very little difference. For astrocams, I believe this was causing issues with master FLATs. The Pedestal value is the mean value of the pixels in the master BIAS for LIGHT.

If there is no master DARK or BIAS then the Pedestal will be determined by the Black ADU according to the Black ADU Usage specified via the Preferences dialog. The “Not Used” selection will cause CaLIGHTs to not allow a calibration. The “From File” selection will cause CaLIGHTs to use the Black ADU value found in the LIGHT frame to determine the Pedestal. If no Black ADU value is found, CaLIGHTs will not allow a calibration. The “Custom” selection allows the user to choose a custom value ranging from 2 to 65,535 for the Pedestal.

To give astrocam and DSLR users more control over the Pedestal value, I have given this “Custom” selection overriding precedence. When this “Custom” selection is active, the Pedestal will be determined by this custom value regardless.