Orion 2020-02-03
Orion might be my target for a while. I find that I can move my Losmandy GM-8 with Canon EOS D60a/50mm lens very easily in one piece, and capture the full constellation in a single frame.
I feel strongly enough about it to reiterate, that wide field photography is a great place for an astrophotographer to begin learning this craft. At 55mm focal length in this case, I polar aligned with a polar alignment scope - no fancy devices or software here. Not only could I not discern elongated stars in my subs, I could detect no movement of Orion within the frame over the last two hours of imaging! As precise polar alignment can be a vexing issue for a beginner, short focal lengths are very forgiving and can allow the photographer to concentrate on learning to collet photons, and set polar alignment aside as a problem to solve another day.
My setup is perfect for our weather of late, because it presents a slim profile that reduces the wind's effect, and I can align and be back indoors in just a few minutes. This is my second time on this target in a week, and more visits will, I hope, permit me to track my skill progression.
This image is derived from a stack of 196 35-second subs at ISO 100. I set the BYE histogram peak at about 25% in BYE thinking that anymore of than that would render the frames over exposed. But when I checked the histogram in PixInsight, I found the peak at about 10%. Next time I will go longer with my exposure to see what happens.
I calibrated with 55 dark frames and 55 bias frames. I did not use flats.
The stars seem bloated in both individual subs and in the final image, which really highlights the bright stars that define the constellation. But of course we strive for pinpoint stars. I attribute the bloatedness to gusty surface winds, below average seeing, and poor focus. Focus was good when I started out, but in PixInsight's SubframeSelector measurements, I could see a distinct jump in FWHM in the frames taken after the meridian flip. Lesson learned, of course, is to refocus the camera after the flip.
I see some noise in the final image that I have not seen before, and is not present my subframes. It consists of squiggly lines sweeping sharply up and to the right. Perhaps dithering is required to address this.
Bloated stars and noise aside, I am very happy with the colors in this image.
Canon EOS 60Da (f/2.8, ISO 100, 60s)
Losmandy GM-8
PixInsight (196 lights, 55 darks, 55 bias)
Orion 2020-02-03
Orion might be my target for a while. I find that I can move my Losmandy GM-8 with Canon EOS D60a/50mm lens very easily in one piece, and capture the full constellation in a single frame.
I feel strongly enough about it to reiterate, that wide field photography is a great place for an astrophotographer to begin learning this craft. At 55mm focal length in this case, I polar aligned with a polar alignment scope - no fancy devices or software here. Not only could I not discern elongated stars in my subs, I could detect no movement of Orion within the frame over the last two hours of imaging! As precise polar alignment can be a vexing issue for a beginner, short focal lengths are very forgiving and can allow the photographer to concentrate on learning to collet photons, and set polar alignment aside as a problem to solve another day.
My setup is perfect for our weather of late, because it presents a slim profile that reduces the wind's effect, and I can align and be back indoors in just a few minutes. This is my second time on this target in a week, and more visits will, I hope, permit me to track my skill progression.
This image is derived from a stack of 196 35-second subs at ISO 100. I set the BYE histogram peak at about 25% in BYE thinking that anymore of than that would render the frames over exposed. But when I checked the histogram in PixInsight, I found the peak at about 10%. Next time I will go longer with my exposure to see what happens.
I calibrated with 55 dark frames and 55 bias frames. I did not use flats.
The stars seem bloated in both individual subs and in the final image, which really highlights the bright stars that define the constellation. But of course we strive for pinpoint stars. I attribute the bloatedness to gusty surface winds, below average seeing, and poor focus. Focus was good when I started out, but in PixInsight's SubframeSelector measurements, I could see a distinct jump in FWHM in the frames taken after the meridian flip. Lesson learned, of course, is to refocus the camera after the flip.
I see some noise in the final image that I have not seen before, and is not present my subframes. It consists of squiggly lines sweeping sharply up and to the right. Perhaps dithering is required to address this.
Bloated stars and noise aside, I am very happy with the colors in this image.
Canon EOS 60Da (f/2.8, ISO 100, 60s)
Losmandy GM-8
PixInsight (196 lights, 55 darks, 55 bias)