The SMC + 47 Tuc.

[Retrograde (Pete)]

Hi all,

thought I'd throw up another of my SPSP wide-field shots.

Really struggled with the processing of this as I have in the past with the LMC.
I find it really hard to get the colour balance right. Open to suggestions

20 x 90 second subs using a Samyang 135mm f2 lens (at f2.8) and ISO 400 using the modded Pentax K-5iis

Larger view: http://www.astrobin.com/full/305459/0/

Thanks for looking,
Pete

[gregbradley]

Lot of detail there Pete. Some red still remains in the background and Tuc
glob core is blown.

I would use levels or curves or the colour balance tool to pull back the red background (its also a gradient as not everywhere has it so really it would be better to use a gradient removal technique).

Shadows and highlights will pull back the Tuc core.

Greg.

[Atmos (Colin)]

Nice detail Pete
It is showing the upper portion of the tidal tail nicely. As Greg mentions, there is some tweaks that can be made but the data looks good

[Retrograde (Pete)]

Originally Posted by gregbradley

Lot of detail there Pete. Some red still remains in the background and Tuc
glob core is blown.

I would use levels or curves or the colour balance tool to pull back the red background (its also a gradient as not everywhere has it so really it would be better to use a gradient removal technique).

Shadows and highlights will pull back the Tuc core.

Greg.

Thanks for the feedback Greg.
I rather rushed the processing on this as I'm heading off to the USA very soon for the eclipse. I should be able to sort out 47 Tuc reasonably easily when I get time (although I don't think it was resolved to the core on the original subs as it's only 135mm).
The gradient might be a different matter as I haven't had to deal with this before. I suspect it might even be light leakage in the camera from a red torch.
A friend told me to be careful of this with a modded camera but it's not till it actually happens that you take it seriously.

Originally Posted by Atmos

Nice detail Pete
It is showing the upper portion of the tidal tail nicely. As Greg mentions, there is some tweaks that can be made but the data looks good

Thanks Colin - I think the image has potential if I can just get the processing right. Will probably have to wait until I get back from O/S however.

[atalas]

Always nice seeing a wider shot of SMC Pete....good work

As Greg mentioned, get your gradient under control and when having trouble with colour balance go back to basics....things tend to go amiss when you push to hard....work with a colour wheel.

Tip. remember as far as your software knows It's working with brightness levels for each channel.

ps. have a good trip.

[avandonk]

Pete light pollution and gradients are the bane of wide field imagers. Especially with fast optics.

The best invention ever is DynamicBackgroundExtraction in PixInsight.

I used PI DBE on your large image. Here is the result.800k

http://d1355990.i49.quadrahosting.co...07/PeteSMC.jpg

This was done at eight bits and stretched so not ideal.

DBE works much better on 16bit and unstretched data. If you want give me the data and I will use DBE on it for you.



Bert

[Retrograde (Pete)]

Originally Posted by atalas

Always nice seeing a wider shot of SMC Pete....good work

As Greg mentioned, get your gradient under control and when having trouble with colour balance go back to basics....things tend to go amiss when you push to hard....work with a colour wheel.

Tip. remember as far as your software knows It's working with brightness levels for each channel.

ps. have a good trip.

Thanks Louie - appreciate the advice.

Originally Posted by avandonk

Pete light pollution and gradients are the bane of wide field imagers. Especially with fast optics.

The best invention ever is DynamicBackgroundExtraction in PixInsight.

I used PI DBE on your large image. Here is the result.800k

http://d1355990.i49.quadrahosting.co...07/PeteSMC.jpg

This was done at eight bits and stretched so not ideal.

DBE works much better on 16bit and unstretched data. If you want give me the data and I will use DBE on it for you.



Bert

Thanks Bert - that's an awesome job!

Unfortunately I haven't made the jump to PixInsight as yet (although I realise it's probably inevitable). I appreciate the offer to do it on the 16bit data but I need to try and work out how to do it myself as part of my self-improvement as an astrophotographer.

Apologies for not commenting on the many other fine images posted here lately (including your excellent SMC mosaaic Bert) - just doing frantic last minute travel stuff as I leave in less than 24 hours!

[Paul Haese]

I really like the field of view and composition. Puts that small galaxy into perspective.

[RickS (Rick)]

Look forward to the repro, Pete. Have a good trip!

[Retrograde (Pete)]

Appreciate your comments Paul and Rick.