Multi-FOV for photometry
Posted: Tue May 15, 2018 10:15 pm
Hello,
I want to request a SharpCap feature about capturing multiple FOV from one frame. Let me explain how would this look like and why it would be very useful (at least for photometry).
The program records a FOV area that was chosen under settings. When we are capturing frames for photometry, we need some comparison stars. There starts to appear a problem, when they are very far (in pixels) and we are about to make short exposures (because targets are relatively bright). So, we have a lot of frames with large resolution, giving many gigabytes of data, so photometric programs won't be able to handle them all.
The thing is, we only need small parts from the frame. Most of frame (90-99%) is just useless background sky. If we could click multiple areas (for example 128x128 pixels sized) on all stars of interest and capture only those data, we would save a lot of space and time!
Here's an image of the concept for IMX178 sensor:
https://www.aavso.org/sites/default/files/concept.png
At the top, there's a single frame (what normally shows) with squares - fields of interest, that contain stars. At the bottom is a final .fits single image, which is a sequence of all chosen areas. All areas should be possible to be saved and they cannot move (no guiding, we should do it ourselves with mount).
Why would this work & why would this be useful:
- all distances between stars in single sequence frame are the same, no problems with matching
- we can still see the whole frame, where squares are perfect reference points for corrections etc. (if no guiding)
- we are able to make calibration frames with the same FOV set (flats, darks, etc.)
- it is understandable that we capture a large frame first, so despite small FOVs, it won't increase FPS value (because there are squares on it, this is what we would see), but the current FPS value (which is reachable with USB 3.0) is high enough for this purpose
- this feature would be highly important in high cadence photometry with CMOS (also below 1 second of exposure), which never appeared before on any capturing software (this program would be even more recommended by AAVSO members then?)
- other possible astrophotography purposes (capturing Jupiter moons individually?), but as you can see, mostly scientific ones
- not to mention again how much data and work time this would reduce
Regards,
Gabriel
I want to request a SharpCap feature about capturing multiple FOV from one frame. Let me explain how would this look like and why it would be very useful (at least for photometry).
The program records a FOV area that was chosen under settings. When we are capturing frames for photometry, we need some comparison stars. There starts to appear a problem, when they are very far (in pixels) and we are about to make short exposures (because targets are relatively bright). So, we have a lot of frames with large resolution, giving many gigabytes of data, so photometric programs won't be able to handle them all.
The thing is, we only need small parts from the frame. Most of frame (90-99%) is just useless background sky. If we could click multiple areas (for example 128x128 pixels sized) on all stars of interest and capture only those data, we would save a lot of space and time!
Here's an image of the concept for IMX178 sensor:
https://www.aavso.org/sites/default/files/concept.png
At the top, there's a single frame (what normally shows) with squares - fields of interest, that contain stars. At the bottom is a final .fits single image, which is a sequence of all chosen areas. All areas should be possible to be saved and they cannot move (no guiding, we should do it ourselves with mount).
Why would this work & why would this be useful:
- all distances between stars in single sequence frame are the same, no problems with matching
- we can still see the whole frame, where squares are perfect reference points for corrections etc. (if no guiding)
- we are able to make calibration frames with the same FOV set (flats, darks, etc.)
- it is understandable that we capture a large frame first, so despite small FOVs, it won't increase FPS value (because there are squares on it, this is what we would see), but the current FPS value (which is reachable with USB 3.0) is high enough for this purpose
- this feature would be highly important in high cadence photometry with CMOS (also below 1 second of exposure), which never appeared before on any capturing software (this program would be even more recommended by AAVSO members then?)
- other possible astrophotography purposes (capturing Jupiter moons individually?), but as you can see, mostly scientific ones
- not to mention again how much data and work time this would reduce
Regards,
Gabriel