IC1396 - HST palette (final part)

[GordonH]

Hi

I was lucky with the weather last night as, despite the forecast being for cloud it stayed clear long enough to get 3 hours of SII data to go with the Ha and OIII I had already got from previous nights. This is the first colour image where I have used full calibration which were as follows

16 bias frames

10x20 minute dark frames

16 dark subtracted flat field frames per filter with an average ADU count of 42-45,000

All the frames were calibrated and then stacked using sigma clip in Maxim DL. I colour combined in Maxim using a weighting of 7:1:3 for SII:Ha:OIII before gamma stretching and saving to 16 bit tiff.

In photoshop I did one aggressive curves stretch followed by a milder curves stretch with levels adjustments in between

Any gradient was taken care of with gradient xterminator

Several small contrast curves adjustments with levels in between to bring out more detail

To get the colours out better I used selective colour and finally I cropped the image to remove stacking artefacts

I estimated that the total processing time including calibration was about 2.5 hours

It was taken over 3 nights in June and July with a Takahashi FSQ106ED at f5, Starlight Xpress SXVF H36 autoguided by a SX Lodestar and OAG on a Paramount ME with 2 second guiding exposures with dithering invoked

Exposures were 12x20 minutes for Ha, 9x20 minutes for OIII, 9x20 minutes for SII with 5nm narrow band filters

Previous versions of this subject with different equipment can be see on the Nebulae and Nebulae 2 page in the image gallery of my website http://www.imagingtheheavens.co.uk

There is a full size high resolution version at the following link, it is over 11mb in size so it may take a while to download but I think it is worth the wait

IC1396 - Elephants Trunk Nebula in HST palette photo - Gordon Haynes photos at pbase.com

Thanks for looking and following the progress on this image

Best wishes and clear skies

Gordon

[MikeD]

Very. very nice work.

I love the scale and detail in the full size image, like you say well worth the download time.

Mike.

[Erwin Kats]

holy smokes what a perfect image Gordon !!

[RobH]

An image to be very proud of Gordon.

Excellent capture and processing....really 3D and a great example of the Hubble pallette executed properly.

Lovely control of the stars too....what approach did you take to them?

It doesn't look like you did the 'select all the stars and desaturate' trick!!

Cheers

Rob

[GordonH]

An image to be very proud of Gordon.

Excellent capture and processing....really 3D and a great example of the Hubble pallette executed properly.

Lovely control of the stars too....what approach did you take to them?

It doesn't look like you did the 'select all the stars and desaturate' trick!!

Cheers

Rob

Actually apart from using the reduce colour noise filter prior to selective colour I did absolutely nothing to the stars not even reduce large or small blue/violet halos. The workflow that I am using at the moment from image acquisition to end product works really well for me. When I have had a bit of sleep (haven't been to bed for over two days) I will put it down in detail as a post

Best wishes

Gordon

[narrowbandpaul]

very nice gordon...good colour balance!

[ollypenrice]

This whole project has been a treat...

Olly

PS regarding hidden monkeys etc, Rorschach test?

[Deneb]

You've summed up the whole project. Just Brilliant..

Nadeem.

[NickH]

Truly exceptional

[barkis]

What a wonderful piece of work Gordon.

Narrowband filtering certainly reveals the complexities embedded in these vast nebulous regions.

You've earned some sleep for sure.

Ron.

[Coco]

This is outstanding... what a fantastic image..

Professional result..

Guy

[GordonH]

This whole project has been a treat...

Olly

PS regarding hidden monkeys etc, Rorschach test?

That's it Olly, "Rorschach Test", just rolls off the tongue doesn't it?

Thanks for the comments everyone, this ended up being a very pleasing result, all the files including sub frames and calibration frames came to about 4.5 GB (glad I haven't got a bigger camera:D)

Best wishes

Gordon

[msinclairinork]

A true work of art! very inspiring work! WELL done!!!

Michael