Help with flat frames
Posted: Tue Feb 23, 2021 1:28 pm
HI all,
I'm relatively new to EAA and would appreciate assistance with SharpCap flat frames. I had some early positive results with flats, however, I recently attempted to image IC2024 with a new filter (Baader UHC-S/L Booster) and got poor results: dust halos, vignetting and color abnormalities. I'm stumped because outside of the new filter, I used same equipment and followed same approach for producing the flats. Below is my equipment:
ES102 APO FCD100
Stellarvue flattener/reducer (SFFR102-25)
ASI294 MC Pro (cooled between -15 to -20)
AVX mount[/list]
My approach and settings for flats
White t-shirt method
LED tracing light box (set to lowest illumination)
Per SharpCap instructions, I take care to ensure there are no changes to the imaging train
Exposure 2.5s
Gain 120 - 125
My histogram shows white channel peak @ ~50%...red, blue and green channels are between 40% and 80%
It never occurred to me to inspect my master flats when I produced decent images (prior to attempting flats with the new filter). Unfortunately, I did not save those flat files and am left with questions re what may be happening with my recent attempts. I've included a link below to a master flat I produced during a test last evening. You'll note many dust halos. This makes sense as I do know my filter needs to be cleaned; possible my camera sensor also needs to be cleaned. I'm uncertain how to interpret the balance of the master flat file. Appreciate any thoughts and insights. Happy to provide additional info as needed.
Link to master flat file: https://drive.google.com/file/d/1fi9Mvt ... sp=sharing
Thanks
Sam
I'm relatively new to EAA and would appreciate assistance with SharpCap flat frames. I had some early positive results with flats, however, I recently attempted to image IC2024 with a new filter (Baader UHC-S/L Booster) and got poor results: dust halos, vignetting and color abnormalities. I'm stumped because outside of the new filter, I used same equipment and followed same approach for producing the flats. Below is my equipment:
ES102 APO FCD100
Stellarvue flattener/reducer (SFFR102-25)
ASI294 MC Pro (cooled between -15 to -20)
AVX mount[/list]
My approach and settings for flats
White t-shirt method
LED tracing light box (set to lowest illumination)
Per SharpCap instructions, I take care to ensure there are no changes to the imaging train
Exposure 2.5s
Gain 120 - 125
My histogram shows white channel peak @ ~50%...red, blue and green channels are between 40% and 80%
It never occurred to me to inspect my master flats when I produced decent images (prior to attempting flats with the new filter). Unfortunately, I did not save those flat files and am left with questions re what may be happening with my recent attempts. I've included a link below to a master flat I produced during a test last evening. You'll note many dust halos. This makes sense as I do know my filter needs to be cleaned; possible my camera sensor also needs to be cleaned. I'm uncertain how to interpret the balance of the master flat file. Appreciate any thoughts and insights. Happy to provide additional info as needed.
Link to master flat file: https://drive.google.com/file/d/1fi9Mvt ... sp=sharing
Thanks
Sam