M31 in 35 minutes with Altair 183M
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Please upload large images to photo sharing sites (flickr, etc) rather than trying to upload them as forum attachments.
Please share the equipment used and if possible camera settings to help others.
M31 in 35 minutes with Altair 183M
SharpCap + FITS Liberator + Nebulosity + GIMP 2.10
Focus with Bahtinov mask, unguided.
35x60s, gain=100, black level=20
35 lights, 30 darks, 30 flat, 30 bias
Session terminated by cloud bands and mist, so I processed what I had. This was first session with the camera, ideally I wanted to acquire 100 light frames and experiment with longer exposure.
I noticed some dropped frames, I think I need to increase the USB slider next time.
Dave
Re: M31 in 35 minutes with Altair 183M
SharpCap Capture screen for above image..
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Re: M31 in 35 minutes with Altair 183M
Dave,
just to confirm, the lower screenshot shows a single unstretched sub? Nice example of how stacking and stretching brings out fantastic detail. What would be seen as a screenshot if you'd used the 'autostretch' button on the mini historgam I wonder?
cheers,
Robin
just to confirm, the lower screenshot shows a single unstretched sub? Nice example of how stacking and stretching brings out fantastic detail. What would be seen as a screenshot if you'd used the 'autostretch' button on the mini historgam I wonder?
cheers,
Robin
Re: M31 in 35 minutes with Altair 183M
Robin
Yes that is an in-progress capture of a single 60s frame - progress at botton right is 20/40.
I can load up one of the frames later, stretch it and post back. It does clearly show M31 when stretched, that is how I ensure I am 'on target'. Mini histogram stretch is very useful. I can also post up what the final stack looks like.
This where it is very disconcerting for beginners because I don't have anything visible - I trust the histogram shape and LHS offset.
Dave
Yes that is an in-progress capture of a single 60s frame - progress at botton right is 20/40.
I can load up one of the frames later, stretch it and post back. It does clearly show M31 when stretched, that is how I ensure I am 'on target'. Mini histogram stretch is very useful. I can also post up what the final stack looks like.
This where it is very disconcerting for beginners because I don't have anything visible - I trust the histogram shape and LHS offset.
Dave
Re: M31 in 35 minutes with Altair 183M
Robin
One of the M31 frames loaded into SharpCap using the Test Camera 1 (Deep Sky). Display Histogram stretch applied to show object of interest, M31, at the centre. Without the stretch, the capture display looks like the image above.
Dave
One of the M31 frames loaded into SharpCap using the Test Camera 1 (Deep Sky). Display Histogram stretch applied to show object of interest, M31, at the centre. Without the stretch, the capture display looks like the image above.
Dave
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Re: M31 in 35 minutes with Altair 183M
Thanks Dave,
I'm actually rather pleased that the auto level stretch does a pretty good job on that sort of image
cheers,
Robin
I'm actually rather pleased that the auto level stretch does a pretty good job on that sort of image
cheers,
Robin
Re: M31 in 35 minutes with Altair 183M
Robin
Yes, that feature alone is worth the price of the software!
When setting up for the start of the capture, I turn the gain up to around 50%. That way, combined with the stretch, I can drop the exposure to much less than the the target (60s in this case). This allows minor positional adjustments with the hand controller, usually by being able to see a bright star and adjust using that. Adjustment with the controller at 60s would not really work.
I will capture this sequence as a set of screens next time I am imaging.
Dave
Yes, that feature alone is worth the price of the software!
When setting up for the start of the capture, I turn the gain up to around 50%. That way, combined with the stretch, I can drop the exposure to much less than the the target (60s in this case). This allows minor positional adjustments with the hand controller, usually by being able to see a bright star and adjust using that. Adjustment with the controller at 60s would not really work.
I will capture this sequence as a set of screens next time I am imaging.
Dave