Montes Apenninus

[Averton (P and C)]

This image was taken on 26/5 around 5am using a 130mm F5 scope, Skywatcher x2 Barlow and a Prostar LP-Guide-C2 camera with an IR cut filter. The image is a stack of 150 subs stacked with AutoStakkert, sharpened in Registax, then cropped and adjusted in GIMP. We particularly liked how the sun caught the steep slopes of the Montes Apenninus.



For this image, instead of using our Celestron moon filter to cut the intensity, we left the scope cover on with the small hole only open. Is this an acceptable practice or should you use the full aperture and the filter? BTW our filter plays havoc with colours.
Clare & Peter

[Outcast (Carlton)]

I think the answer to your question lies in the result of your picture.. which IMHO is lovely...

Great detail & contrast &, I agree, the sunlight on the mountain range is a particularly lovely effect... sharpness/focus needs some minor tweaking but, still a very nice picture

[Averton (P and C)]

Hi Carlton, Thanks for the feedback. For this image we used the Bahtinov mask as you suggested. We used it and focused with the mask on a nearby star which looked spot on with the spikes exactly centred and then moved back to the moon to take the subs. We're not sure if this is the correct procedure. If it is, then we're not sure how to improve our focus more. Maybe there are other issues affecting the sharpness. The collimation was checked and its as good as we can get it.
Clare & Peter

[Outcast (Carlton)]

Originally Posted by Averton

Hi Carlton, Thanks for the feedback. For this image we used the Bahtinov mask as you suggested. We used it and focused with the mask on a nearby star which looked spot on with the spikes exactly centred and then moved back to the moon to take the subs. We're not sure if this is the correct procedure. If it is, then we're not sure how to improve our focus more. Maybe there are other issues affecting the sharpness. The collimation was checked and its as good as we can get it.
Clare & Peter

No worries, the moon, like many planets can be a fickle target that is particularly dependant upon seeing conditions contributing to image sharpness. I'm sure you have seen visually how the image can flutter in and out of focus.

Did you take stills for the shot? If so, I recommend you try video then use either Registax or Autostakkert to do your stacking. 2 - 5 minutes of video can get you literally, thousands of frames & you can then look at the quality graphs provided in either program to determine the percentage of frames to stack. In most cases this will result in much sharper images as you will stack a greater quality of frame rather than just all the frames you have.

If you did use video as described above, it may pay to reduce the number of frames stacked to ensure you are getting the highest quality of frames for stacking... sometimes though, there is no answer if the seeing is poor..

Nevertheless, I think it is a wonderful image, the sharpness is only a hair off & I don't feel it detracts from the beauty of the image at all

Cheers

[Saturnine (Jeff)]

Good for you for having a go at imaging, it can be fun and rewarding. The focus looks a little soft in your image but getting better focus will come with experience and maybe using an Bahtinov mask. As far as your set up goes, I wouldn't bother with the moon filter and would use the full aperture of the scope. This would allow more light onto the camera sensor so that you can then increase the frame rate and reduce the gain setting if you are using a capture program like SharpCap. This in turn would help to produce sharper frames for stacking.
The only filter I would recommend using would be an UV / IR filter and by not masking down the aperture you will gain resolution, as in finer detail.
The main thing is to experiment and see what works better for you.

[Averton (P and C)]

Thanks Jeff & Carlton for the encouragement and suggestions. We have plenty more ideas to try next time. We are currently writing down the settings we use each time but with so many combinations it is going to take many attempts to test them all. Unfortunately presently in Melbourne the weather is atrocious and looks set to continue that way. Very frustrating for budding astrophotographers.
Clare & Peter

[bojan]

Telescope resolution is determined by its aperture - see here.
I suggest you use Moon filter if you must, but I think you will be better of with shorter exposures.

[Averton (P and C)]

Hi Bojan, Thanks for the link. We are aware that our limited equipment and budget will place restrictions on what we can achieve but there is great satisfaction in trying to push the limits within these constraints.

P&C