Solar Stacking Problem - AS!3

[Mandy D]

@Laurieast I can't get Autostakkert to properly stack my solar images from this morning. I've uploaded the best image from the camera and a stack sample for reference. It doesn't seem to be aligning the solar disc properly, yet there is noticeable improvement in the sharpness of the sunspots. I have around a hundred frames acquired and have tried stacks of 30% and 10 images. I've tried with alignment point sizes from 24 to 200 but nothing seems to work. The camera files were auto-cropped in PIPP.

Any ideas what is going wrong? I've been on this for a couple of hours now and getting nowhere.

[Steve Ward]

Looking at that stack I'd ask if PIPP was set to Crop and Centre each frame first , the misalignment looks too big to me for this to have been done ?

I find it can have hissy fits sometimes when I try to stack just a few percent of the AVI I feed it.

Try going back to PIPP and getting it to output just around 15% or so of the frames added then get AS!3 to stack all 100%.

Another trick to try is using Planet mode not Surface and setting your initial boxes on the features on show before Analysing.

This is one reason I painstakingly go through my captures by eye first ( using Reg5 for a close-up preview) and select only the very best , crispest detailed frames.

There's no point in stacking hundreds of frames of frames of lesser quality , the last few days I've stacked 16 frames maximum 

Edited August 19, 2022 by Steve Ward

[Laurieast]

1 hour ago, Mandy D said:

Any ideas what is going wrong?

Try this the other way than you did it? Make an initial alignment point  around that large sun spot?

I think you have Gimp, does that have a sharpen and sharpen more filter, and make it brighter with curves. Do that to 10 or so and try Autostakkert again. 

 

 

Edited August 19, 2022 by Laurieast

[Steve Ward]

And it won't help trying to stack frames that are so out of focus as the one you posted first.

This is one of the 16 frames I stacked today ... not touched just converted to TIFF before feeding to PIPP ... 😉

 

 

 

Edited August 19, 2022 by Steve Ward

[Mandy D]

5 minutes ago, Steve Ward said:

And it won't help trying to stack frames that are so out of focus as the one you posted first.

This is one of the 16 frames I stacked today ... not touched just converted to TIFF before feeding to PIPP ... 😉

Thanks! I'm struggling to focus at the mo and have to let auto-focus do it's best as my telescope eye is currently out of action.

I've just re-run my PIPP process and then imported and stacked the 10 best images and got the final result below. If I import 100% and stack the best 30% it still does the same as before. I think it's a PIPP problem, like you say. I had set PIPP to crop and centre, but now I've got it set to Object/Planetary.

[Mandy D]

50 minutes ago, Laurieast said:

Try this the other way than you did it? Make an initial alignment point  around that large sun spot?

Thank you! Yes, this, too, has worked. Progress!

[Laurieast]

26 minutes ago, Mandy D said:

Progress!

Good to hear it, It can be done! 

Is that last one above now stacked and how many?

Are you focusing using the camera auto focus? That BackyardNikon would let you see it more easily and has focus tools.

 

Edited August 19, 2022 by Laurieast

[Steve Ward]

There's still one frame at least woefully out of alignment which is unusual from PIPP after "Crop and centre".

Have a look at your AVI output from PIPP , if there's a frame out of alignment from the rest you could put the AVI back in PIPP and get it to recentre , just reduce the Crop sizes a bit first though.

Or you could just remove that offending frame from the initial set and start over.

Edited August 19, 2022 by Steve Ward

[Mandy D]

1 hour ago, Steve Ward said:

There's still one frame at least woefully out of alignment which is unusual from PIPP after "Crop and centre".

Have a look at your AVI output from PIPP , if there's a frame out of alignment from the rest you could put the AVI back in PIPP and get it to recentre , just reduce the Crop sizes a bit first though.

Or you could just remove that offending frame from the initial set and start over.

Yes, you are quite right about frames out of alignment. There were two runs of photography taken this morning with a half hour gap between them and the solar disc had obviously rotated noticeably between the two sessions. On some attempts with PIPP, I was remembering to ignore those frames and others I completely forgot. I have now moved the offending images elsewhere.

[Steve Ward]

I generally shoot 5 or 6 sets of 120 frames ( unless I'm aiming for tiny gaps like yesterday.) takes about 4 minutes to shoot each set.

I would never stack frames from more than three consecutive sets , especially if there are features right on the limb. 

When there are tiny feature on show mixing frames from each end of a session just kills them as everything is changing so fast relatively , not obvious at first glance doing full discs .

So 1-2-3 or 2-3-4 or 3-4-5 etc , never 1-2-6 .

And certainly never from either end of sessions half an hour apart.

[Mandy D]

1 hour ago, Laurieast said:

Good to hear it, It can be done! 

Is that last one above now stacked and how many?

Are you focusing using the camera auto focus? That BackyardNikon would let you see it more easily and has focus tools.

Yes that last one was stacked. Probably 30%, so about 40 frames.

Here is another version where I've removed the offending frames (see my reply to Steve) and taken 30% of the best frames selected by PIPP for final stacking, so about 10.

The camera is currently on auto-focus, due to my eye problem and the laptop being at home along with the fact I still do not have Backyard Nikon. I am currently trying to get to grips with Digicam Control, but it does not look like it can focus the camera.

[Steve Ward]

One more question .... your AZ/EQ  is running in EQ mode I  assume ... ?

[Mandy D]

2 minutes ago, Steve Ward said:

I would never stack frames from more than three consecutive sets , especially if there are features right on the limb. 

When there are tiny feature on show mixing frames from each end of a session just kills them as everything is changing so fast relatively , not obvious at first glance doing full discs .

So 1-2-3 or 2-3-4 or 3-4-5 etc , never 1-2-6 .

And certainly never from either end of sessions half an hour apart.

Yes, this is exactly what I have realised. A part of the problem this morning is that I was shooting from work and had forgotten to bring my remote for the camera, so was using the five second timer in the camera to avoid shake, so long time to capture 120 frames.

[Mandy D]

7 minutes ago, Steve Ward said:

One more question .... your AZ/EQ  is running in EQ mode I  assume ... ?

Nope! I am not using the AZ-HEQ5 at the mo. I am walking everywhere right now and that is a bit of a monster to carry along with the D800 and a 300mm prime lens and teleconverter. Yes, EQ mode would deal nicely with field-rotation for me, if only I could ...

Edited August 19, 2022 by Mandy D

[Laurieast]

Hope you don't mind, but could not resist giving a go 😁

[Mandy D]

3 minutes ago, Laurieast said:

Hope you don't mind, but could not resist giving a go 😁

If that is my image, what did you do to it to get that result?

Am I under-exposing my solar images? I never find that I pick up the sunsposts properly when I get the disc bright yellow like that.

Thank you. 😊

[Steve Ward]

Never try and get a disc that looks like that at capture , you always want to 'under expose' , you will have no room to maneouvre in post processing as far as levels and contrast are concerned. 

Once you've saturated a pixel white by 'over exposing' there's no going back , but you can always stretch an 'under exposed' shot , a necessary step when trying to reveal details , especially when trying to show the plage.

 

[Laurieast]

I have Photoshop not Gimp, but same idea...

Copied your colour pic
Made into 16 bit
Adjust the colour balance

Adjust the Curves

Took the brightness up a little. Taking up the Exposure seemed to wash it out. 

 

[Mandy D]

2 minutes ago, Steve Ward said:

Never try and get a disc that looks like that at capture , you always want to 'under expose' , you will have no room to maneouvre in post processing as far as levels and contrast are concerned. 

Once you've saturated a pixel white by 'over exposing' there's no going back , but you can always stretch an 'under exposed' shot , a necessary step when trying to reveal details , especially when trying to show the plage.

 

Yes, I understand this from regular photography, which is why I questioned the "uber-bright" image Laurieast just posted. I watch my exposure very carefully to avoid washing out.

Who'd have thought the Sun has beaches, huh? 😃

Thanks for the explanations.

[Steve Ward]

The word I meant to use was 'Faculae' , too many ciders out under the Sun fogged my brain there ... 🙃

[Laurieast]

What filter was it? How did it get so red.

 

[Steve Ward]

There's a gentle darkening of the disc towards the limb that needs a gentle hand to avoid an overblown centre.

Personally I concentrate on all the detail work as in Unsharp Mask , Blurring etc first then adjust the disc using 'Levels' and maybe a touch of 'Contrast/Brightness'.

'Curves' are a lot harder to control and replicate on a daily basis I find when trying to maintain consistency day to day.

[Steve Ward]

I should have mentioned that I capture with the camera set to "Monochrome"  and simply add my false colour at the end using the "Colorify" filter in Gimp.

Again this is in order to try and have consistent results day to day.

 

Edited August 19, 2022 by Steve Ward

[Mandy D]

2 minutes ago, Laurieast said:

What filter was it? How did it get so red.

 

It's a standard Syemour Solar glass filter. Just under-exposure, I guess. I can make it as yellow as you have it straight from the camera, but then I lose all the sun spots and detail. As @Steve Ward says, you can recover detail in under-exposure, but over-exposure: it's lost for good.

[Steve Ward]

2 minutes ago, Mandy D said:

It's a standard Syemour Solar glass filter. Just under-exposure, I guess. I can make it as yellow as you have it straight from the camera, but then I lose all the sun spots and detail. As @Steve Ward says, you can recover detail in under-exposure, but over-exposure: it's lost for good.

Well if you don't mind me saying ... therein lies half the problem.

I highly recommend you buying a filter that uses Baader Astrosolar film , no glass filter will give you the fine structure and detail as Baader film , the glass used in the filters is not optically flat and is a poor substitute for the film.

I've started with a glass filter on my ETX105 about ten years ago and was looking for something better after about a week ... 😄