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View Full Version here: : M1 "The Crab Nebula" closeup in HST palette


Paramount
26-11-2008, 09:59 AM
Hi All
It was very clear last night but also very cold and windy, I thought I'd have a go at M1 in the HST palette, I had planned on 9x10 minutes Ha and 12x10 minutes each for OIII and SII, giving a bit more time to OIII and SII as they have a tendency to need more help than Ha. What was surprising was the amount of OIII and SII evident in the subframes (for me anyway as this is my first attempt at this subject in NB). Unfortunately things didn't go to plan as when the SII subframes were being done at 4am onwards the subject was getting very low in the sky and after 5 subframes a tree got in the way, so the SII master frame had quite a bit of noise in it.
I took the image with the TMB 115 and H36 which gave a very small image of M1 in a large widefield so the image I have posted here is a cropped closeup of the 100% zoomed widefield so please excuse the quality. The full widefield is on my website http://www.imagingtheheavens.co.uk (http://www.imagingtheheavens.co.uk/) in the nebulae section of the image gallery, thanks for looking
Best wishes
Gordon

http://www.imagingtheheavens.co.uk/USERIMAGES/M1crop.jpg

jase
26-11-2008, 06:04 PM
Gordon, will be honest - I've seen much better work from you. I think a reprocess on this target would deliver a richer result and perhaps something a little less "electrifying". I'd say you've got the data, you just need to make it work for you. i.e. know how far you can push each emission line master (clipping masks may assist). Hope to see more of your work soon. Keep at it.

Paramount
26-11-2008, 07:16 PM
Hi Jase
I agree it certainly isn't my best. Some of the data was good but the OIII was starting to get noisy towards the end of its run and the SII was all noisy, 2 of the subframes affected by wind gusts. None of the master frames was pre-processed, as soon as they were combined the 3 were colour combined using a standard 1:1:1 weighting and the end result was then processed in CS2. This is very much how I do all my processing with exception to the weightings which I vary depending on the results I am looking for. I haven't got into clipping masks, etc as I am still very much in the early learning stages of processing at the moment, but this will come as I progress
Best wishes
Gordon

peeb61
26-11-2008, 07:55 PM
Nice image Gordon,
M1 is a bit on the low side for me to image, it looks great, I'm not by any means an expert but Jase has nailed it. I still love the composition.

It would be nice to see some stars, been cloudy on and off here for the past weeks and I'm growing tired of it. Withdrawals are setting in.

Thanks for sharing.
Paul

Garyh
27-11-2008, 07:35 AM
Hi Gordon,
Pitty you couldn`t get all the data you desired to complete the image but well done on what you have done so far with it.

I hope you don`t mind but I did a bit of selective clipping and a bit of red channel stretching to help with dark noise and to lift the red channel in the crab a little more..just a quick 5 minutes of play in PS.
If you can get another night on it, it shall make alot of difference!..:thumbsup:
cheers Gary

Paramount
27-11-2008, 07:51 AM
Hi Gary
Thanks for that and for the tip, I don't ever mind others tinkering around with my images as it helps me to develop my basic skills further. regarding getting adequate data, in the UK we have to be grateful for what we get and quite often this means one clear night and then no more imaging for over a month, it is very hit and miss. Sometimes it makes renting remote scopes a tempting prospect but the thought of spending anything up to $300+ for one night of imaging brings me back to Earth with a bump :lol:
Best wishes
Gordon