I have been on this site for a few months and am posting images using a 70 mm scope with a reducer @ f4.9. My imaging experience is limited to about a year.
I have a standard stock Canon 60D with a pixel size of 4.3uM. The seeing that I normally shoot my images is OK, not exceptional. I am using unguided rig and am working on putting together auto guiding.
My thoughts are generated from the sampling of targets. For nebulae, this combination and sampling isn't such a bad thing as I can smooth the result and deemphasize the stars with processing. The issue is in star cloud images… with added luminance/noise reduction, comes the loss of detail. My camera has rather large pixels for the naturally wide field capability of my little scope, and thus I am always and forever under-sampling (pixel scale of ~2.61), especially when I reduce my effective focal length with a 0.8x reducer.
This was a useful page to get a handle on this issue: https://astronomy.tools/calculators/ccd_suitability
With OK seeing, I can walk the edge of acceptable resolution I think 🙂. Nontheless the other issue is that with no auto guiding, I am unable to use a computer to dither my lights. I guess these two realities conspire to require me to run the processing gauntlet… do I try for maximum sharpness (not likely the best plan - too much noise) or should I try to "smooth the result" thus taking me in a direction that may deviate from the raw subs eg, reality in representation?
So, this is an ongoing obstacle, and something I am working on. I also am building my autoguiding capability (ASIAIR Pro, 290mm mini camera, 60 mm guide scope), and am waiting for ZWO to send me the camera. Perhaps I can improve my raw data, and I am excited to try it.
Otherwise (by fiddling with the scope itself) I can try dropping the focal reducer, gaining back some focal length, and slightly improving my pixel scale. Or buy a camera with a chip using tiny pixels, like the 183.
This has turned into a long-winded discussion, but I thought I might post these thoughts to stir some discussion about the problem.
I welcome input… thank you for reading to the bottom.
Ian
I have a standard stock Canon 60D with a pixel size of 4.3uM. The seeing that I normally shoot my images is OK, not exceptional. I am using unguided rig and am working on putting together auto guiding.
My thoughts are generated from the sampling of targets. For nebulae, this combination and sampling isn't such a bad thing as I can smooth the result and deemphasize the stars with processing. The issue is in star cloud images… with added luminance/noise reduction, comes the loss of detail. My camera has rather large pixels for the naturally wide field capability of my little scope, and thus I am always and forever under-sampling (pixel scale of ~2.61), especially when I reduce my effective focal length with a 0.8x reducer.
This was a useful page to get a handle on this issue: https://astronomy.tools/calculators/ccd_suitability
With OK seeing, I can walk the edge of acceptable resolution I think 🙂. Nontheless the other issue is that with no auto guiding, I am unable to use a computer to dither my lights. I guess these two realities conspire to require me to run the processing gauntlet… do I try for maximum sharpness (not likely the best plan - too much noise) or should I try to "smooth the result" thus taking me in a direction that may deviate from the raw subs eg, reality in representation?
So, this is an ongoing obstacle, and something I am working on. I also am building my autoguiding capability (ASIAIR Pro, 290mm mini camera, 60 mm guide scope), and am waiting for ZWO to send me the camera. Perhaps I can improve my raw data, and I am excited to try it.
Otherwise (by fiddling with the scope itself) I can try dropping the focal reducer, gaining back some focal length, and slightly improving my pixel scale. Or buy a camera with a chip using tiny pixels, like the 183.
This has turned into a long-winded discussion, but I thought I might post these thoughts to stir some discussion about the problem.
I welcome input… thank you for reading to the bottom.
Ian
