New Feature : Moon Mosaic Planner

[Jean-Francois]

Hello Robin,

OK and yes, please save all the files in the same directory ... it will simplify the batch processing with a stacking program.
But maybe not, if the file format is FITS.

Good evening,
Jean-Francois

[admin]

Hi Jean-Francois,

if you can get the mosaic tool to capture to FITS then I have done something wrong... It's supposed to be video formats only (SER, AVI, etc).

I supposed I had better go check now that this is actually enforced!

cheers,

Robin

[admin]

Hi,

just a quick update on what changes are in the mosaic capture side of things this week

* Autoexposure - option to autoexpose every panel removed, but SharpCap will try to work out which panel is the brightest and use that for autoexposure at the start of the mosaic. For a solar mosaic, it is the panel nearest the center of the solar disc. For Lunar it is based on the preview image shown. If autoexposure is not available it most likely means that your camera does not have a 'calibrated' gain control (ie SharpCap does not know what brightness change will result from a given gain change).

* Current telescope co-ordinates now marked on the mosaic graphic with a magenta cross (once alignment is complete)

* Additiion of the ability to run the mosiac for multiple filters. Note that it will run all panels for the first filter, then all for the second, etc. You need to have set up focus offsets for your filters for this to be workable so that the focus is automatically adjusted on filter changes

* Fix a small offset in the calculated co-ordinates of each panel from the desired co-ordinates

* Adjusted the trial (no SharpCap Pro license) for mosiacs to capture images, but limit each panel to capturing 5 frames only.

* Previous alignments are remembered and can be re-used for up to 3 hours

* Many small bug fixes and tweaks.


Looking through my notes, I still want to add a few more changes

* Ability to remove planned panels if you only want to capture a part of the moon or sun (perhaps the active regions on the sun)

* Tidy up the 'Mosaic Panel Capture Settings' page - it's all a bit messy at the moment

* Some things don't work quite right if you go back to previous pages and change things

cheers,

Robin

[Jean-Francois]

Hello Robin,

I tested yesterday the new feature.

Here below the result of 23 positions.
My setup: Newton FD4 with 2.7x APM barlow, camera QHY-200.
Processing with Autostakkert! and the mosaic of the "Autostakkert sharpened images" with iMerge.
Image rotation and crop with PaintShopPro (7!) ... nothing else.

It is a little bit tricky to adjust the starting position in the "Manual" mosaic.
I tried the "Guided", but the first GOTO was completely off.

One shock ... one time the mosaic start to move the telescope completely wrong ... it was necessary to "jump" to telescope and switch-off the mount before the tube collide with the tripod. I guess it is a question of the meridian-flip.
Can you try with the moon very near the meridian, but with the telescope from the "down" position ?

Good evening,
Jean-Francois

Here a reduced image to fit the 1 MB condition.

Moon_mosaic_SharpCap_reduced.jpg (980.48 KiB) Viewed 5186 times

[admin]

Hi Jean-Francois,

great image - glad that it worked with just a small number of glitches for you

I will look into the problem of the mosaic running when near the meridian. I suspect I should block the run if it is not clear of the meridian, as it is hard to be sure what the behaviour of the mount will be (some work past, some freeze, some make crazy GOTOs by the sound of it!)

I find the best thing for the manual alignment is to pick one of the cusps of the moon as the alignment point, as you can judge that with even a small field of view. As the notes say for the manual alignment you must not judge on the position of craters/seas, since the display in SharpCap is an 'average' moon without the effects of libration included.

cheers,

Robin

[admin]

Hi folks,

I also had a good go testing the moon mosaic tool a couple of nights back, but have only just managed to find some time to process the videos.

The video shows the mosaic alignment and capture process in action with the latest SharpCap 4.1 Beta



Because the latest version saves all the videos into a single folder, working with them is easier. The easiest approach is to drag all the SER files into Planetary System Stacker (https://github.com/Rolf-Hempel/PlanetarySystemStacker). All you really have to do is to choose the % of frames to keep and then tick the 'Automatic' check box and tell it to continue - it will process all the videos for you and create stacked images from each with no further intervention.

Next stitching - I use Affinity Photo 2 'Panorama Mode'. Really easy, select the still images into the panorama tool and everything is automatic. So far I haven't seen it trip up, but maybe things get trickier with a lot of panels

Capture.JPG (30.54 KiB) Viewed 5161 times

Next step was to fill in the missing background areas and save as PNG to allow sharpening in IMGPP (https://github.com/GreatAttractor/imppg)

Once Sharpened, back to Affinity Photo for a little final tweaking to give the result below.

cheers,

Robin

download/file.php?id=8130 (Use this link to see full resolution version)

mosaic_lr.jpg (987.97 KiB) Viewed 5161 times

[Jean-Francois]

Hello Robin,

For the GOTO near the meridian ... yes, some mount driver perform or not a meridian flip.
That can be set in some more developed driver. ... For example to start with a "telescope down" near the meridian if the object is not too distant from the meridian. The advantage is that the observation can continue if the object cross the meridian.

One point for your tool ... I do not remember if the telescope buttons were activated, but it could be good to have a large "emergency" stop button in the window of the tool. It was possible to switch-off my mount ... while I was 2 meter away. It could be necessary for a remote observation to have s stop button. (It should stop the mount immediately, but it could ask if the mosaic tool shall be close or not).

I was interested to know how good the position of the telescope was on the moon ... so I did today the following:
- open each image and crop it to the camera detector size
- add a white frame around the images
- redo (manually) the mosaic

Here the result ... note with the moon not rotated ... that is here the image orientation during the capture with SharpCap.

SharpCap_Mosaic_reduced.jpg (916.7 KiB) Viewed 5145 times

The image "3" is off. The other images are good.
The line distance between the image "5" to "23" are good regular.
The line with "1" and "2" are a little bit off.

For the "manual" centering process ... your method relies on the estimation of the clocking of the moon and one point.
The problem of the clocking is ... it is relatively easy with a mosaic with 3 or 4 images. You can see a large part of the moon.
With more than 10 images ... in my case with 23, then it was more difficult to estimate the clocking on the small part of the moon surface.

SharpCap_Mosaic_reference.jpg (145.69 KiB) Viewed 5145 times

Maybe a "2 points" method could be more precise.

Regards,
Jean-Francois

[admin]

Hi Jean-Francois,

thanks for the feedback - an emergency stop button is a good idea... I will add one

I know that there are drivers that can pass the meridian by various amounts under some circumstances, but there is no standard way to find out about those capabilities via the ASCOM interface, so I think I will initially work on a 'no meridian crossing' approach for safety.

For the panel being out of place, I suspect that it may be possibly some backlash (probably in the DEC direction, since SharpCap is already configured to try to take up RA backlash), although I'm not even sure if that makes sense, since the RA/Dec axes are probably rotated quite a bit relative to the field of view. If it happens again in another mosaic then please send me the log (which should have all the planned panel locations in) and I can confirm whether it's a mechanical backlash effect or some bug with the planning/implementation.

I totally agree that the manual alignment is tricky when the field of view is much smaller than the disc (and getting the rotation wrong by more than about 5 to 10 degrees may cause gaps in the mosaic). Similarly the plate solving option is unlikely to work well at such small fields of view. However, I can't quite see how a two point option as you are suggesting would help set the rotation - can you explain a bit more?

thanks,

Robin

[Jean-Francois]

Hello Robin,

Yes, I think that the start was "delayed" by the backlash in my mount.

For the "2 points" calibration ...

Monn_Mosaic_planner.jpg (783.97 KiB) Viewed 5114 times

One possibility is to move the telescope to 2 different points on the moon.
So ... movement to the first position, reticle on the live view (maybe do not need to be centered, if the plate scale is known), the user click on the full moon image (here generated with Virtual Moon Atlas software) where the telescope is pointing (so the libration calculation necessary, but not for the image shown in the tool).
For the second point ... simple repeat the same steps.
So ... SharpCap can combine the mount coordinates of the two points with the moon coordinates.

Regards,
Jean-Francois

[admin]

Hi,

I will have to think about that - I suspect that without a true display including libration it may be difficult for people to click relative to the lighted area rather than the features, just the same as it is for the single point manual align. Then, if you do that you end up with the rotation being out by the magnitude of any libration effects.

I did consider putting libration into the view in SharpCap, but it would basically mean building a 3D display of the moon in the code, which is quite a significant amount of work, so decided that 60 pre-rendered phase images would be easier.

cheers,

Robin