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Two "Quickies" from last night - NGC7635 and IC1805

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Hi all

Later this year I have been planning to do some 30 minute sub frames to see how deep I can go with some of the emission nebula so last night I thought it was about time that I tweaked my polar alignment and gave it a go. Using TPoint I managed to get the polar alignment to 6 arc seconds beyond which you can't measurably adjust the Paramount by the alt/az adjusters. I was using the Starlight Xpress H9 camera as its quick 1 second downloads make TPoint mapping a breeze. I had planned to use the H9 anyway and had taken a series of 30 minute darks a couple of evenings ago albeit at a different temperature as they were taken indoors.

My main target for the evening was the centre of IC1805 but as I had to wait about 2 hours for it to clear my neighbours tree it gave me time to do some work on the bubble nebula. Both of these targets I tried last year with the BRC-250 and H9 but I was plagued by halo problems, these efforts can be seen on the Nebulae 2 page of the image gallery on my website http://www.imagingtheheavens.co.uk the difference is like the difference between chalk and cheese.

Equipment for last night was

Paramount ME

Takahashi FSQ106ED at f5

Starlight Xpress SXVF H9

Auto guided by Lodestar and OAG using 2 second guiding exposures and dithering

Exposures were 4x30 minutes for NGC7635 and 10x30 minutes for IC1805, the "Quickie" comment wasn't in relation to the exposure length but more in relation to the processing time taken which was about 10-15 minutes each including callibration and stacking.

Each frame was callibrated with dark subtracted flats (32 of each), bias frames (32) and dark frames (15x30 minutes)

The only processing was a combination of levels, curves and contrast and shadows and highlights adjustment. No noise reduction was used in either image

I will be adding to both of these next outing to eventually complete a HST rendering of each

Here are links to the full size high resolution images on my pbase site

http://www.pbase.com/imaging_the_heavens/image/128347428/original

http://www.pbase.com/imaging_the_heavens/image/128347432/original

Thanks for looking

Best wishes

Gordon

ngc7635hah9max.jpg

ic1805hah9max.jpg

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Two astounding photos Gordon, well done!

do some 30 minute sub frames

My Canon can't take the heat after 10min. Way too noisy!

Thanks for sharing those, Tim.

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Two astounding photos Gordon, well done!

My Canon can't take the heat after 10min. Way too noisy!

Thanks for sharing those, Tim.[/quote

The H9 uses a sony chip and even after 30 minutes the noise level is incredibly low

Gordon

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