Here is a recent image from data I acquired with the Aluma AC4040 Camera on a CDK20. 25 Hrs of LRGB + Ha data Data acquired in HighStack Pro mode, 60 Second frames stacked on Camera. 180s LRGB frames, 300s Ha Frames. Frames acquired at 0 Deg C. Sky fats acquired at 10 deg C to an average ADU of 400, 10 flats for each filter/rotator combination. Other details at https://www.astrobin.com/70k4pn/ These camera setting reduce the fixed pattern noise from the sensor. There are polishing marks visible in the image from the residual bulk image effects of this sensor (buries in the background near the black point of this image. I used a Pixinsight MMT filter to reduce this type of noise.
Greg, that is a nice image, congratulations. By the way, I've been configuring ACP to work with my observatory to present its simple web interface for students to use. A couple days ago I took 15 one-minute Bin2 luminance images of M51 from humid Tennessee during the test. I found a picture of the Mt. Palomar Hale telescope M51 poster that I had on my wall in college decades ago, and put the new 15 minute image next to the Hale 200" image of that era. Pretty interesting how the technology has changed .
Greg, I'm not clear on your data acquisition description. Does your reference to '60 Second frames stacked on Camera' followed by the 180s LRGB and 300S Ha mean that you had your HSP settings in DL Config set to 60s in 'Stacking Sub-Exposure'? That would mean you were forcing internal stacking of 3 images for your LRGB data and 5 for Ha? Thanks, Mark
Mark, thanks for the comments. and that image comparison is cool. I am working on acquiring Abell's planetary nebula list which originated from a Palomar survey on film in the 50s I believe I remember reading. This camera will really catch the light! I have had ACP running to 10 months now and it works well with this setup. I don't use the scheduler even though I purchased it. I need to take some time and implement it so I can let it plan multiple targets every night instead of me doing it manually. Mark, you are correct on acquisition mode settings. I am forcing 3 and 5 on camera stacks (HighStack Pro) respectively for 180sec and 300sec frames. This gives me a high dynamic range image so I don't have any blown out stars. 12 bits of data for High mode runs out in a hurry for a bright object. I have been very impressed with the low light sensitivity that this configuration gives. In High mode acquisition, I was seeing blown out stars for Lum channel after 120 sec, and RGB after 180 sec, so I was interested in getting rid of this issue. 60 second subs already have high signal to noise and I decided to try stacking on-camera and it works well. I have also found that the sensor residual bulk image issues (RBI-afterglow) are better in this mode at 60 seconds. I have virtually eliminated the fixed pattern noise in my calibrated and stacked frames, as long as I acquire at 0 deg C (colder gives more pattern noise because, I believe, the RBI half life is longer as lower sensor temperatures). I acquire flats and flat-darks at 10 dec C and targeted to 400ADU. And of course darks match the time and HighStack Pro mode used for lights. I am now able to use a dark library for flat darks and darks (earlier I was acquiring nightly thinking that would help pattern noise.) PS, I use ACP's sky flats routine. It works great. Good luck, it looks like you have progress. We just hit monsoon season here in the Valley. We need the rain, but my productivity may fall off for a while. PS, my Planewave Images on Astrobin since April are all in this same mode. Greg
