Vela Supernova remnant mosaic repro

gregbradley · #1 22-03-2011, 08:40 AM

Here is one I took at New Years but being a mosaic I had to learn more processing techniques to put it together.

I only just finished that learning curve (or at least enough technique to put one together) recently.

This one is 2 panels of 4:40 hours each of O111, Ha and LRGB so its 9 hours worth.

FSQ106ED and reducer and FLI Proline 16803.

http://upload.pbase.com/gregbradley/...33323023/large regular

and Panel 1 by itself is the better of the 2:

http://www.pbase.com/gregbradley/image/133366534

There are a number of objects in the field of view.

Greg.

Stevec35 (Steve) · #2 22-03-2011, 09:08 AM

Hi Greg

A pleasing image with lots of detail. I'm not sure I like the colour though. Hard to put my finger on it but it seems too red.

Cheers

Steve

strongmanmike (Michael) · #3 22-03-2011, 09:09 AM

Good on you Greg, you are becoming a mosaic convert

There is a lot of green (OIII?) in this field though that I don't see here..? You look to have used plenty of OIII data so perhaps the Ha has dominated a bit too much in your processsing..?

It really is an amazing field well done.

Mike

multiweb (Marc) · #4 22-03-2011, 09:24 AM

Huge field Greg but TBH the processing is letting it a bit down. Stitching's great but the stars and details look a bit harsh, over burnt. I reckon a sid is in order and you'll have a corker coz it's a really nice vista altogether.

mswhin63 (Malcolm) · #5 22-03-2011, 09:51 AM

Well done lovely image, also see you've got pencil nebula there as well.

telecasterguru (Frank) · #6 22-03-2011, 10:51 AM

Looks pretty good to me.

Frank

gregbradley · #7 22-03-2011, 12:40 PM

Quote:

Originally Posted by Stevec35

Hi Greg

A pleasing image with lots of detail. I'm not sure I like the colour though. Hard to put my finger on it but it seems too red.

Cheers

Steve

Yes the colours are pushed and its resulted in a heavy contrast. Red is pulled back a fair bit as there is a lot of Ha here including general background Ha.

Quote:

Originally Posted by strongmanmike

Good on you Greg, you are becoming a mosaic convert

There is a lot of green (OIII?) in this field though that I don't see here..? You look to have used plenty of OIII data so perhaps the Ha has dominated a bit too much in your processsing..?

It really is an amazing field well done.

Mike

Thanks Mike. Funnily enough Ha seemed to have more data in it this time. O111 is not pushed very hard in this image at all.

Quote:

Originally Posted by multiweb

Huge field Greg but TBH the processing is letting it a bit down. Stitching's great but the stars and details look a bit harsh, over burnt. I reckon a sid is in order and you'll have a corker coz it's a really nice vista altogether.

The colour is pushed for sure but then the nebula tendrils are hard to see unless pushed. Perhaps a better compromise can be achieved. I wasn't going to post this one as I thought it could be better.

The reducer with the Tak does seem to cause larger star sizes compared to the object imaged. The Tak without the reducer may be the way to go as the reducer seems to enlarge the star sizes relative to the object too much sometimes. The bane of too short a focal length and not enough aperture. Mikes 12 inch aperture at 3.8 is a good way around this phenomena.

Greg.

Quote:

Originally Posted by telecasterguru

Looks pretty good to me.

Frank

Thanks Frank.

gregbradley · #8 22-03-2011, 07:49 PM

I did a repro of this one. The green from the O111 comes out much better and emphasises the tendrils more.

Same link.

Greg.

marco (Marco Lorenzi) · #9 22-03-2011, 09:21 PM

Quote:

Originally Posted by gregbradley

I did a repro of this one. The green from the O111 comes out much better and emphasises the tendrils more.

Same link.

Greg.

Hi Greg, this one is better. I believe however that with the data you have you may be able to get out more details from both Ha and OIII. Pay attention also that in some parts the nebulosity is lacking midtones and become totally flat..

Clear Skies
Marco

Stevec35 (Steve) · #10 23-03-2011, 11:02 AM

Hi Greg

I like this a lot better. The colour is much improved and it doesn't have the slightly over processed appearance of the first one.

Cheers

Steve

multiweb (Marc) · #11 23-03-2011, 11:04 AM

Looks heaps better Greg. Colours are coming up a treat now. Agreed with Marco though. Check your dynamic range, especially in the blue channel. Mid-range is dead flat.

gregbradley · #12 23-03-2011, 04:50 PM

It looks best really as a single panel.

Panel 1 is the better of the 2:

http://www.pbase.com/gregbradley/image/133366534

Greg.

jjjnettie (Jeanette) · #13 23-03-2011, 05:10 PM

A beautiful region of the sky, thanks for sharing it with us.

John Hothersall · #14 24-03-2011, 06:38 PM

Gosh that is such a rich area, thanks for sharing.

John.

richardo (Rich) · #15 26-03-2011, 02:31 AM

Quote:

Originally Posted by gregbradley

It looks best really as a single panel.

Panel 1 is the better of the 2:

http://www.pbase.com/gregbradley/image/133366534

Greg.

Ah yes this is the one Greg

Very nicely put together and the colours are far better than the original..
Lots of twirls and bubbles in a cauldron of galactic soup.

All the best
Rich

gregbradley · #16 26-03-2011, 12:07 PM

Thanks Rich. I agree, that panel I like but the mosaic didn't quite work out. There was a slight difference between the 2 in that the 2nd had less Ha. I wouldn't have thought it would have made that much difference but perhaps it did.

Greg.

Hagar (Doug) · #17 26-03-2011, 10:40 PM

Very nice Greg. Such a busy field. Takes quite a while to look around and absorb it all.
Mosaics , I've only ever tried a mono one and that was hard enough to get correct. Colour must be a bugger.

Well done.

gregbradley · #18 27-03-2011, 11:21 AM

Hi Dougie,

I have done a few mosaics so far including a larger one finished but not posted yet.

Yes they are a lot of work in blending in the panels so they are not obvious.

There are a number of techniques around. I studied up on them and then ended up creating my own routine which seems to work fairly well. It got down to not taking too much time at all. I have a 16 panel mosaic I took well over a year ago waiting on my processing skills to come up to a level where I could tackle it.

One rainy week I'll do that.

One lesson from that also is to keep a written map of which panel goes where. Some panels are very nondescript slices of the sky in a large mosaic and its like a jigsaw puzzle trying to work out where it goes. Fortunately I kept a map! That mosaic could be cool but no doubt a few weeks work of processing. It'd be about 3.5 billion megapixels. I took it when I had a fabulous run of clear nights, night after night was clear all night and as I took it from home it was no bother to do 6-8 hours per night and 2 panels each night.

If I were to do a masterpiece I would probably do a slightly different approach to get it perfect.

Rob Gendler is the master. Jase on this site produced a few that were as seamless as I have seen but they were not as deeply coloured as Robs which makes it harder.

Some make the image quite dark to hide the imperfections. A bit like a guitarist short on competency who relies on heavy fuzz to hide the flubs!
Whilst darker images have their appeal I wonder if the main appeal is to hide the imperfections!

Greg.