Lunar Imaging - Help With Quality of Frames

[gnomus]

I have been trying to put together a lunar mosaic but have run into some strange issues that I don't understand.  I'm using my ZWO ASI174 attached to my C8 Edge.  I used a Bahtinov Mask to get precise focus on a nearby star (Regulus).  I have a Moonlite focusser so I get rough focus with the main knob, lock down the mirror and do fine focus with the Moonlight (attached to a motorised unit).

The videos themselves looked great - sharp, contrasty and not overexposed.  I shot 2000 frames.  I took 12 videos for the mosaic (I probably overdid the 'overlapping', but didn't want to miss out anything - ..... like I have done before !!!!)

I decided to load all 12 AVIs into PIPP and asked it to select the 200 best frames.  I assumed (given what I was seeing in the 'raw' video) file that these would be fairly good quality.  However, when I went to AS2 to stack the 200 frames it was reporting pretty indifferent quality.  Here are my PIPP settings:

Does this seem correct?

Here is the AS2 window:

Any ideas what might be going on? 

After processing 9 videos, PIPP produced an AVI that seemed to be only 1 frame long!!

It's been a while since I tried lunar imaging so please be gentle if I am missing something obvious.

 

[David Smith]

I tend to just let AS!2 do the quality sorting rather than PIPP. Seems to work.

[gnomus]

9 minutes ago, David Smith said:

I tend to just let AS!2 do the quality sorting rather than PIPP. Seems to work.

That has been my usual practice too Dave.  I was trying to save time ............  

[PhotoGav]

I guess that AS!2 is only giving you relative quality of your 200 frames, so the poorest quality might still be really good, if that makes sense. I have used PiPP followed by AS!2 for lunar mosaics, just as you are, and have been delighted with the results.

[cgarry]

5 minutes ago, PhotoGav said:

I guess that AS!2 is only giving you relative quality of your 200 frames, so the poorest quality might still be really good, if that makes sense. I have used PiPP followed by AS!2 for lunar mosaics, just as you are, and have been delighted with the results.

I think that this is probably the case.  I suspect that if you gave AS!2 all of the frames but sorted into quality order by PIPP, then the AS!2 graph would largely agree with PIPP's quality ordering.

Cheers,
Chris

[gnomus]

Ah... so AS2 calculates RELATIVE quality not absolute?  

[Bizibilder]

Yes - the "best" frame in AS2 is 100 and the "worst" is zero.  I would put your whole avi into AS2 and select maybe the best 200 frames (10% of them).  Fiddle about with the Ap size (40-60) to give about 700-1000 alignment points.  Set the Min bright to 10 (or 20) to force some of the AP's into the darker areas of the picture - you want AP's all over all of the "data".  Don't get AP's on any black background sky.  Hit stack and see what you get.  

[gnomus]

30 minutes ago, Bizibilder said:

Yes - the "best" frame in AS2 is 100 and the "worst" is zero.  I would put your whole avi into AS2 and select maybe the best 200 frames (10% of them).  Fiddle about with the Ap size (40-60) to give about 700-1000 alignment points.  Set the Min bright to 10 (or 20) to force some of the AP's into the darker areas of the picture - you want AP's all over all of the "data".  Don't get AP's on any black background sky.  Hit stack and see what you get.  

I did exactly that for the last three videos.  I then tried stitching them together.............  argh

PS's 'Photomerge' didn't really work at all.  It left two panels out of the mosaic - plunking them below the moon for some reason.  Perhaps I didn't use the correct settings  - 'Auto'.  Then I remembered that I had a copy of PT GUI from my old landscape photography days.  First attempt was no good - one edge of the moon had a visible overlap.  I had another go with different settings (chosen almost randomly) and the photo below popped out (I have reduced the size for posting here).  What do other folks use for photo stitching lunar (and I suppose solar) images?

I tried doing the Lucy-Richardson deconvolution thing I normally do in Astra Image 3.0 (free).  It was having none of it - kept crashing.  Maybe the size of the file (~3600 pixels square)?  Is there any way round this?  L-R does seem to work quite well on my lunar images.

[PhotoGav]

Looking good! I have used PS photomerge in the past and it has worked very well.

[gnomus]

3 minutes ago, PhotoGav said:

Looking good! I have used PS photomerge in the past and it has worked very well.

I probably used the wrong setting.

[David Smith]

End result looks good anyway.

[gnomus]

I was quite pleased with it.  This is my first completed mosaic.  I always leave a bit out or have some other issue when I try one.  Someone once mentioned some software that would take care of all this mosaic capturing for me ... but I can't remember who, when or where....

[Bizibilder]

Photomerge can fail and often the cause is either too little overlap of the adjacent panes (you need at least 10-15% on all edges - more is better) or it may be that the edges of your panes are not "dead sharp".  By that I mean do you carefully crop all your panes after stacking?  If not the merge software will pick up any edge defects and try and "merge" them - It will, of course, fail as the adjacent pane will not have a matching defect.

Oops! Nearly forgot - Nice mosaic, focus, exposure and processing seem spot-on! 

[gnomus]

8 minutes ago, Bizibilder said:

Photomerge can fail and often the cause is either too little overlap of the adjacent panes (you need at least 10-15% on all edges - more is better) or it may be that the edges of your panes are not "dead sharp".  By that I mean do you carefully crop all your panes after stacking?  If not the merge software will pick up any edge defects and try and "merge" them - It will, of course, fail as the adjacent pane will not have a matching defect.

Oops! Nearly forgot - Nice mosaic, focus, exposure and processing seem spot-on! 

Thanks Roger.  I did crop the frames prior to stitching - a lucky guess.