Author Topic: Horsehead 28/30 Jan  (Read 520 times)

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JohnP

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Re: Horsehead 28/30 Jan
« Reply #15 on: Feb 12, 2019, 20:10:33 »
Thks Mark - Surprising clean image for a single 30 sec sub. Have to say it is amazing when you put that single sub & the final image side-by-side. Once again you need to make sure you get an A2 print of this done - John

The Thing

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Re: Horsehead 28/30 Jan
« Reply #16 on: Feb 12, 2019, 20:29:26 »
A few of years ago I'd have been happy to have that sub as a finished image!

RobertM

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Re: Horsehead 28/30 Jan
« Reply #17 on: Feb 12, 2019, 20:42:54 »
Pretty impressive skies, I’d say it would take me at least 10-20 subs to get to the same  quality as that single frame.

Robert

Carole

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Re: Horsehead 28/30 Jan
« Reply #18 on: Feb 12, 2019, 20:51:48 »
Yes, agree with all the above comments. 

Carole

Fay

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Re: Horsehead 28/30 Jan
« Reply #19 on: Feb 14, 2019, 08:25:55 »
Great image Mark, as ever
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

MarkS

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Re: Horsehead 28/30 Jan
« Reply #20 on: Feb 14, 2019, 08:50:21 »
I forgot to mention one very important benefit of using short exposures on the C11.  It completely removes the issue of star trailing caused by slight shifts in the primary mirror as the scope tracks across the sky. 

The usual way of avoiding this problem is to use an OAG (off-axis guider) but using short exposures is an excellent alternative.

Of course you need a camera with very low read noise - the Sony A7S at high ISO is perfect for this :)

Mark
« Last Edit: Feb 14, 2019, 09:21:05 by MarkS »

Carole

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Re: Horsehead 28/30 Jan
« Reply #21 on: Feb 14, 2019, 15:56:59 »
That is indeed a bonus.

Carole