Dear fellow astrophotographers
Along my journey to better images, where progress goes hand in hand with increased expectations and discoveries of new imperfections, I am wondering what is wrong with my stars and in particular whether the grey aura around medium sized stars is a consequence of i) bad seeing (ok, no action required), bad processing (then I am willing to learn) or dirty mirrors (then I will clean everything but only after confirmation that this is the issue).
On these images, medium stars have an aura that I would like to get ride of.
https://www.astrobin.com/g3nvbk/B/
https://www.astrobin.com/ps27ua/D/
Here is a concrete example from pic #1 above :
Interestingly, I did not identify the same issue on some older images of mine, even after reprocessing with the workflow used of the above images. Here is an example:
https://www.astrobin.com/full/95geuq/D/
My processing goes always the following general lines : extract Ha and Oiii from DNB data to prepare a starless using either pixelmath or a foraxx script, after crop, DBE, PMCC, BlurX, noiseX, GHS. The stars are prepared using RGB data, with crop, DBE, PMCC, blurX, noiseX, gentle GHS, starnet+, stretch and intergration with the following expression : Pixelmath expression: RGB/K: ~((~starless)*(~stars)).
Up to now, I considered that my mirrors are note in terrible conditions. I have some dirt on the main mirror and also some dew droplets that fall from the OTA onto the primary because the scope parked in home position after hitting the ascom limits instead of parking, as it should do, on the side at ALT=0 AZ=270 for drying in the morning (in that position no droplet can fall on a mirror). That episode left some very discreet and faint staints on the main, nothing more. But my recent images make me wonder.
Any hint most welcome !
Clear skies,
Patrice
Along my journey to better images, where progress goes hand in hand with increased expectations and discoveries of new imperfections, I am wondering what is wrong with my stars and in particular whether the grey aura around medium sized stars is a consequence of i) bad seeing (ok, no action required), bad processing (then I am willing to learn) or dirty mirrors (then I will clean everything but only after confirmation that this is the issue).
On these images, medium stars have an aura that I would like to get ride of.
https://www.astrobin.com/g3nvbk/B/
https://www.astrobin.com/ps27ua/D/
Here is a concrete example from pic #1 above :
Interestingly, I did not identify the same issue on some older images of mine, even after reprocessing with the workflow used of the above images. Here is an example:
https://www.astrobin.com/full/95geuq/D/
My processing goes always the following general lines : extract Ha and Oiii from DNB data to prepare a starless using either pixelmath or a foraxx script, after crop, DBE, PMCC, BlurX, noiseX, GHS. The stars are prepared using RGB data, with crop, DBE, PMCC, blurX, noiseX, gentle GHS, starnet+, stretch and intergration with the following expression : Pixelmath expression: RGB/K: ~((~starless)*(~stars)).
Up to now, I considered that my mirrors are note in terrible conditions. I have some dirt on the main mirror and also some dew droplets that fall from the OTA onto the primary because the scope parked in home position after hitting the ascom limits instead of parking, as it should do, on the side at ALT=0 AZ=270 for drying in the morning (in that position no droplet can fall on a mirror). That episode left some very discreet and faint staints on the main, nothing more. But my recent images make me wonder.
Any hint most welcome !
Clear skies,
Patrice
