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25% Waning Moon, 26th August


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I took 100 subs (1/500th @ ISO800) for this image at the end of quite a long night last night.  The seeing had been excellent, but I'm not really happy with the outcome here.  I think perhaps the DSLR doesn't cope very well on images which are mostly black and then a small amount of very bright illumination.  Preprocessed with PIPP, 40% stacked in AS!3, wavelets in Registax 6 and PS for the final tinkering.

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I think it could be time for a change of technique for full disc lunar imaging.  Perhaps switch to my ASI174MM and create mosaics or drop the focal length a little.  Then I could use the DSLR for wide field instead.  Needs a bit of thinking about.

James

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Hi,

nice image. regarding a different setup. Using a dedicated lunar/planetary cam instead of a dslr can for sure give better results. Making mosaics is nàt terribly difficult. Just make sure that the individual panmles have plenty of overlap. Stiching everything together can often be automated.

Wouter.

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Nice lunar image James but I think you know what needs to be done 🙂

Get that 174mm out and have a crack at it. Not sure what scope/s you have but I had a 6" SkyWatcher reflector at a focal length of 1000mm and did 2 videos, one for the top half and one for the bottom half of the moon stitched together and it came out very well in good seeing. It was at a larger resolution to what I usually do and it was one of the best lunar images I've done over the years.

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2 hours ago, Aussie Dave said:

Nice lunar image James but I think you know what needs to be done 🙂

Get that 174mm out and have a crack at it. Not sure what scope/s you have but I had a 6" SkyWatcher reflector at a focal length of 1000mm and did 2 videos, one for the top half and one for the bottom half of the moon stitched together and it came out very well in good seeing. It was at a larger resolution to what I usually do and it was one of the best lunar images I've done over the years.

Yes, I'm trying to work out how best to do it.  I have either the 127 Mak, which may actually be the easier place to start, or the C9.25.  Even the C9.25 would probably be ok if I did a 4-panel mosaic except around full moon, when I might need six.  The C9.25 might be quite handy in that arrangement for imaging small PNs, too.  I might have to swap my mounts around though.  I'm not sure the C9.25 would be happy on a HEQ5.  Or rather, I'm not sure the HEQ5 would be happy under a C9.25 :)

And it would free up the DSLR for wide field with a shorter focal length lens.

James

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Hi

I for sure would combine the C9.25 and the 174. Even would dare to add a barlow to increase focal length even more. (but then you'd need many many pics for a full moon mosaic).  But it can be done, only is a major effort to combine everything. I've done it a few times now already, with my 6000mm focal length telescope and the asi 174. 

I Think the HEQ should be able to handle it. The C9.25 is not that heavy and the camera weight is not an issue either. 

Clear skies,

Wouter.

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True enough.  The C9.25 is quoted at something like 9kg and the HEQ5 is supposed to take 11kg for imaging.  My C9.25 has a secondary focuser and motor drive and there'll probably be a filter wheel as well, but even so I reckon it should be ok, especially as the weight is fairly close to the mount rather than at the ends of a long refractor.  I might have a go at setting all that up this weekend in time for the waxing Moon to be suitably positioned for imaging.

James

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