[multiweb (Marc)]

Originally Posted by gregbradley

Superb Marc.

Greg.

Thanks Greg. Glad you liked it.

Originally Posted by Bassnut

whoa, epic Marc, nice (relatively ) to view.

Thanks Fred. Not too shabby for WF BS hey?

Originally Posted by renormalised

Great shot there, Marc. Great colour, excellent detail. Well done

Only one thing....what happened up in the top right hand corner of the big piccie??

Thanks Carl. Yeah it's me being greedy. If I crop that corner I loose another 2 strips of stars. ?!

Originally Posted by Octane

Marc,

Fabulous image!

That's pretty much the same field of view the FSQ/STL combination gives. : )

H

Thanks H. Go on. You know you want to do it!

Originally Posted by desler

That really is Something Marc, Thanks for sharing!



Darren

Thanks for the kind comment Darren.

Originally Posted by DavidU

Just fabulous Marc. Very tidy work.

Thanks a lot David.

Originally Posted by strongmanmike

Lovely work Marc, the colours look good...what's that nebula on the right though, not seen that one before

Mike

Thanks Mike. Yeah... on the right...ermmm, let me get back to you on that one. Waiting on the plate solving results.

Originally Posted by TheAstroGuy

Marc,

That's a winner, great shot mate i really like how well you've got so much out of the Trifid, loads of blue O2 around the edges.

Good shot indeed

Regards

Shane

Thanks for looking Shane. Yes the blue cloud is fairly extended around M20. If you go deeper I think it even goes further in the field.

Originally Posted by sheeny

Excellent Marc!

Al.

Thanks a lot Al.

Originally Posted by rcheshire

As usual Marc, a beautiful shot. Scintillating nail polish...

Thanks - too kind mate.

Originally Posted by philiphart

lovely.. a very nice result!

Thanks Phil - glad you enjoyed it.

Originally Posted by kinetic

Beautiful Marc!

Steve

Thanks Steve.

Originally Posted by batema

I agree with everything said above. I'd love to know how to do a mosaic as well as a lot of other things. Fantasic colours and what camera were you using for this as well as exposures. The weather has been fantastic on the sunshine coast for the last week so we put on an astronomy night at school last night and it rained all day but today is superb Typical. What prohram did you stich the panels together with.

Mark

Thank you Mark. Here's my work flow for this one:

Camera is an older model QHY8 (square body) at prime focus on a Celestron SLT 130. Although I did modify the scope a bit. Flocked the OTA with protostar as well as a 30cm dewshield, changed the focuser to a GSO 10:1 and also shimmed the mirror in its cell. Collimation is also razor sharp.

I have to point out this data was taken in more than optimal conditions. I was by myself at the house. No lights (at all) and no wind which makes a hell of a difference.

The subs are approx. 15x5min each. I calibrated them all in CCDStack, flat fielding (20k ADU - 80 of them) and bias (100 of them). Then I debayered in separate directories to Red, Green and Blue.

Once this is done I indentify the sub with the best FWHM in CCD Inspector and use it for registration. I then align them using Nearest Neighbourg in CCD Stack. Then normalisation by picking the darkest background area and the brightest nebula in the field. Next I run a quick Hot/Cold pixel removal and a STD reject at 2% top to paint all noise and outliers then use mean combine.

Next saved all the master channels and ran 30 iterations of deconvolution positive constraint. Then did a bit of pixel math to balance the colors and push the blues. Blues are always a problem to capture and push in with small aperture scopes in my experience. Once you have all your master colors for each panels you do a color combine in CCDStack and look carefully at the histogram while tweaking the levels then save as a scaled 16bit TIFF file.

Then that's where the fun begins. Load all those TIFF files in registar and align all of them to one central overlapping sub then use union to make the master scaffold frame. Combine using mean/median then save as combine.TIFF. Next load that frame again and register all the masters to it using union again but this time save all the registered masters to TIFF files. So you end up with 5 TIFF files with a big black background and a small square which is the position of the sub in the mosaic.

Next load all the frames in PS as individual layers and delete the black background in each layer. You don't have to align anything as they already match. Order them from top to bottom as Best to worse then select them all and use PS blending function. That will work out all the seams and gradients if any.

From there on you can go on with normal PS processing. HTH.