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NGC 2392 - The Eskimo


centroid

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This is a 'first' for me, as me and the Eskimo hadn't met before :D

Didn't realise what a little chap he was. :D

He was imaged at f/10, while being guided at f/15 (ED80 + x2 Barlow), which was quite difficult to achieve. Tried the ED80 at f/7.5 but the guiding just wasn't 'tight' enough for an f/10 image. It probably would have been ok at f/7.5 if the 'seeing' had been a bit steadier.

Given the guiding difficulty, and the 'seeing', I am actually quite pleased to get what I have.

12" LX200R at f/10, ED80 + x2 Barlow (f/15), SXVF-H9C 36x90 sec subs, processed in AA4.

post-13389-133877337216_thumb.jpg

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Very nice capture Dave :D

He is a small fellow !!

Fortunately he's also quite bright. I found 90 seconds to be an achievable time to guide for at F10.

I used a slightly shorter FL with the guidescope but when I imaged mine the seeing was rock solid, not like last night!

Cheers

Rob

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Yeah, I did struggle with the guiding Rob, and have certainly never guided at f/15 before. Its not very forgiving :D

Fortunately, I spent some time with Pempro, refining the Mount's PE, which is now below 5 arc secs, and this certainly helps matters.

I found that 90secs, was just about the right exposure, to balance getting enough on his 'fur hood', and not burning out his nose. :D

Am actually out in the obs now, and the 'seeing' looks a bit better than last night.

Dave

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I'm out too Dave, going widefield on the Pliedes as I haven't managed to get anything decent on them yet this year. This will be my last chance as I go away for a month from tomorrow.

Seeing is a bit better for sure.

Exactly what I found with the exposure time. Tricky balance, getting the hood without burning out the core.

Haven't tried Pempro.

Cheers

Rob

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Pempro is expensive for a 'one trick horse' piece of software, but its good at what it does.

Ok on a w/field of M45, I'm just coming to the end of an hour on M1. Really just to pass the time until Leo, and all his content, climb high enough.

Plus the fact, we just can't afford to waste a clear night. :D

Dave

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Dave,

What is pempro? I looked on search engines only to find something about the menopause!!

John

Hi John, it might help with the menopause as well, but that's not what it was designed for. :D

Pempro is a piece of software that can analyse the Periodic Errors of a mount by carrying out a Fourier Analysis. Fourier analysis, can look at a set of data, and recognise true periodic (repeating) errors.

Pempro will then calculate a set of correction data, that you can then download to the mount, which will then attempt to 'iron out' the Periodic Errors. It costs around £75.

Of course, its essential that the mount has a Periodic Error Correction ability.

HTH.

Dave

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saw this object for the first time tonight... very cool. tried to capture it on the lpi (I know its not meant for this.. but worth a try) anyhow was just too dim for the poor little ccd :D .. ooh well, will have to wait a couple of months till I can afford to get some better kit for proper imaging of DSO's.

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Great Eskimo Dave, whatever problems you had you've overcome them. A tough image for bad seeing conditions!! What are you using for guiding? If the seeing is bad I would have thought upping the focal length of the guide scope would have made things worse. Maxim does a fantastic job on sub pixel guiding accuracy. It actually reports a centroid to 3 decimal places - 1/1000 of a pixel. Don't know how accurate this is.

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