Solar Mosaic tool/sequencer Output files Won't Stitch?

[chuck666]

Whoa.......... No flats were done!!!!!!! This was done with the auto solar mosiac sequencer......... How and when would that be done? I wondered how to that when the full disk content is NOT on the screen at the same time? I'm missing something simple aren't I?????

Oops, that's not an issue the flats are my image screen and it remains constaint thru short periods of time. OMG, I just had another DUH, momment!!

Thanks so much for following thru.......... I will do better tomorrow...

Chuck

[admin]

Hi Chuck,

I do flats before capturing the mosaic - put the center of the sun in view and then put something like translucent plastic sheet over the telescope, capture a flat and then run the mosaic. That helps keep the corners from dimming due to vignetting and also deals with any 'lumpy' illumination due to the solar filter (quarks are notorious for this).

Without a flat, I'm still a bit puzzled about the 'over exposed but mid grey' look of the left hand of the two frames - definitely some detail missing in the brighter portions on the right of that image.

cheers,

Robin

[chuck666]

Robin,
Good morning. Been redoing since about 5am. I knew I should have read your post before I started! Just finshed after about 3 hours. Focusing was a moving target today. Again, very new to solar. Been DSO for 4 yrs....
After reading your email above, I see I did NOT do the flats correctly, three consecutive times. LOL. Since I cannot see a full disk, one of my other Quark issue; I just put an edge in view did the flats. As I was doing things, I keep noticing the one edge was always brighter. Now, I have the DUH momment thank you. I will shoot flats with a best guess of its center tomorrow.. I've made a mask with two thicknesses of cereal liner on a cottage cheese tub to fit my scope. Don't you adjust exposure for a centered histogram before you capture? And, is there a centering function in SCPro?
Also, when does one redo his session flats? Read different opinions??????
I definitely think I have a "lumpy" quark. Good discription. And since my flats were edge centered, all my images have edge issue; I'm sure? I ran the solar mosaic twice with differ flats and different focuses,.... I'll post later; I'm mentally exhausted..... At 81, I need a brain break........ HA>.

Again, thanks for the support. Sorry, for all the questions? YT is a good thing for us Newbees. But, can cause confusion, also.
Chuck

[chuck666]

Back again.
We almost made with my last try. I think better flats by me and maybe better focus will get a full disk...........

When you see the attchments, you'll understand my thoughts. Either I can't read the proposed mosaic image in the sequencer or you have some clever trickery going on? The proposed 8 panel mosaic looks to me to be drawn very symmetrical. Or, I have had my brain fill in the blanks wrongly.
It's a 2 column, 4 row mosaic. I think I'm seeing simple rectangles panels in an overlap fashion with an safety margin all around?
Or is there some staggering going on for stitching reasons that I'm not seeing on screen.
Because edges don't line up in the panels and that has been always true since my day 1 with the algorithm?
See attached images Two halves got knitted; one with 4 panels, yea; and one with only 3 penels. I think the 3 panel would have been fine with better flats....
Also, I added my processed panel 6 for reference this morning Jul 4th..

Chuck

[admin]

Hi,

that's definitely progress this time around - good to see that you are nearly there.

In theory the panels should make a accurate vertical alignment than you have here (although the top and bottom rows might squeeze the panels closer horizontally as the disc is less wide at the top/bottom. There are a couple of things that can happen that can lead to the sort of offset effect you are seeing.

1) Alignment isn't perfect - in particular SharpCap needs to work out the rotation of the camera relative to the sky, and that being out by maybe 5 or 10 degrees could lead to the stepped effect that you are seeing. You can check this by using the 'Goto Top/Bottom/Left/Right Edge' buttons on the page after the alignment has completed. Those buttons use the calculated alignment to try to put the appropriate edge of the sun into the center of view. By seeing how far off the result is, you can judge whether the alignment is good or not and potentially retry if the results are a long way out.

2) Drift of the sun during the mosaic capture process due to imperfect polar alignment (EQ mount), imperfect horizontal alignment (AZ mount) or other issues. In particular, poor polar alignment (hard during the day) on an EQ mount tends to lead to declination drift over time. If declination happens to be roughly horizontal in your images due to the orientation of the camera then the mount may be drifting as the panels are being captured, and by the time it gets to the last two at the bottom, the drift may have built up. You can test for drift by capturing a very small number of frames at each panel (say 10) - that will make the whole mosaic run faster, and if you see less misalignment in the mosaic that runs quickly than the slower one then drift may be the issue.

In either case, you can opt to try to cure the underlying problem, or just bump up the overlap/safety margin to make sure that you get enough images anyway.

cheers,

Robin

[chuck666]

Great answer, thank you.
I wondered how those go to worked. TY.
How about the flat centering question
Chuck

[admin]

Hi Chuck,

sorry, missed the first of your two posts...

Yes, the use of an edge of the sun for flats causes issues as you get ones that are not even across the frame, as you spotted. I hit that problem myself the first time out with the quark...

There is a bit of a trick to get to the center of the sun that should work - do a mosaic alignment, which lets SharpCap work out the exact position/orientation/size of the sun. Then press the 'Goto Sun' button in the mosiac window and it should use the alignment data to point right at the center of the sun (correcting for any mount pointing offset, etc). You can then close the mosaic window and capture flats. Once done, re-open the mosaic window and you will have the option to re-use the saved alignment that you did earlier.

hope this helps,

Robin

[chuck666]

Thank you,
How easy is that. Perhaps that should be in the manual for Quark users. Just saying.
Chuck

[chuck666]

Robin,'

Just a note, I thought the "go to Sun" didn't work and I did some other things. At the end of my session, I went back the mosaic tool and at the appropriate screen, tried again. And discovered what I had done or what you had NOT done, ha. I "missed hitting the button" because it is half NOT exposed due to NOT enough real estate for the bottom. We have all seen this. Propably the graphic to the right bottom's edge is a few pixels low. I just couldn't resist explaining. LOLLLLLLLLLLLLLLLLLLLLLLLLLLL Bi focals can get ya.

I thought I got a better flat; seeing was great. Then it got a little worse, then, the wind. Etc. So, I got some more panels and will post later.

More later.

Joker,
Chuck

Edit: This batch of 8 panels yielded one half panel and 2 quarter panels. HA And they were much better aligned, edge wise. I widened the overlap.
Still poor quality and uniformity. And I thought they looked better. NOT....... There were a couple of random flat questions riddled in the above posts that didn't get answered. Please clarify some issues. After I find center and put my homemade flat cap on the scope, I go to exposure and increase it until I get a histogram centered around 50%, correct. Then I run the flat capture tool with default settings? After that, my live screen images should look more uniform? Should they look darker over all or slightly lighter with the Quark lumpiness gone?
Another run tomorrow.
Chuck

[admin]

Hi Chuck,

for the flats, the correct procedure is to set up the exposure at about 50 to 70% peak - the most important bit is to avoid any pixels/areas being either saturated (above 95%) or below about 20%. Then you need to use the 'Capture Flat' tool from the Capture menu - that will automate the process of capturing multiple flat frames, averaging them and setting up SharpCap to use them (see https://docs.sharpcap.co.uk/4.1/#Creati ... t%20Frames).

Can you send me some more details on the 'Goto Sun' button not being fully visible? Was it off the bottom of the mosaic window, or was the mosaic window a bit low on the screen so that the button was off the bottom of the screen? Perhaps a screenshot would help me understand if there's anything I need to fix.

cheers,

Robin