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No alignment found!

Posted: Tue Sep 25, 2018 9:00 pm
by remyastro
Hi,

I am a new user of Sharpcap.
Everything is working well but I still have problems with stacking the frames.
I always get the following status:" Frame not stacked because no alignment found".
What does it mean, as stars are normally detected.
What's wrong with me?

I am using Sharpcap with my Atik 314L camera on my NEQ6 mount.
Thank you for your help.

Kind Regards.
Remyastro

Re: No alignment found!

Posted: Tue Sep 25, 2018 9:19 pm
by admin
Hi,

check out the documentation for the alignment tab - https://docs.sharpcap.co.uk/3.2/#Alignment%20Tab - and make sure that you have 10 or more stars being detected by the application in both the frame being added and the stack. If still no luck then turn on the option to highlight stars and make sure that the stars are fairly well spread out and that they are really stars, not hot pixels.

If the higlighted stars are all in the top half of the frame then that means you have too many stars being detected - in that case adjust some settings to make it harder to find stars - usually turn up the minimum star size to reduce the number found until they are spread evenly over the frame.

Hope this helps,

Robin

Re: No alignment found!

Posted: Tue Oct 02, 2018 9:49 pm
by remyastro
Hi Robin,

I have tried again imaging M57, but with the same problem that is no alignment.

As you can see on the attached screen shots, stars are actually detected, but with no stacking.

I hope that the attached screen shots would help you finding the reason why I still have this problem.

Thank you.
Remyastro
20181002.docx
No alignment
(572.5 KiB) Downloaded 53 times

Re: No alignment found!

Posted: Tue Oct 02, 2018 11:26 pm
by turfpit
Robin - I could try this out using my Atik 314E on M27 ( I need the live stack practice). 60s exposure is plenty for this object. Next decent weather window for me seems to be at the weekend.

Remy - what type of telescope are you using? Suggest you post as pdf rather than docx by using File > Export. Some mail systems are picky about native Word files because of macros. Also not everyone has Word.

Dave

Re: No alignment found!

Posted: Wed Oct 03, 2018 6:17 am
by admin
Hi Remy,

there are no stars actually within the star detection highlight boxes which is a worry - each box should be around a clearly visible star. There are clearaly visible stars in the field of view that should be detected. I would suggest turning off the 'Digital Gain', setting the 'black level threshold' back to 20% and the 'minimin star width' back to 1 in the star detection settings to see if that helps as your settings are a bit odd (probably as a result of you trying to get things working).

If that doesn't help, please use the 'snapshot' button to save 2 or 3 individual frames as FITS or PNG and then share those with me by email and I will investigate further.

Dave - feel free to have a test :)

cheers,

Robin

Re: No alignment found!

Posted: Wed Oct 03, 2018 8:05 am
by remyastro
Hi Robin, Hi Dave,

I was using my 102/714 ED refractor (I also used my C8 telescope but with same alignment problem).

Clear coming nights are forecast in the Alps where I live, so I will imaging again according to the settings Robin have advised.
I' ll provide more pictures including individual snapshots.

Thanks.
Remy

Re: No alignment found!

Posted: Wed Oct 03, 2018 1:43 pm
by turfpit
Remy

I have a C8, so will try with that. My other scope is an Altair 66ED refractor. I can dump the screens for the various settings. Saturday will be my first chance according to the forecast.

Do you use a reducer on the C8 ( I have an f6.3)?

Do you want M27 or M57 or both?

Dave

Re: No alignment found!

Posted: Thu Oct 04, 2018 5:55 am
by remyastro
Hi Dave,

I would be really interested to 'grasp' your settings if you could imagine any of M27 or M57.
I didn't use my reducer 6.3 on the C8 when I first tried imaging with sharpcap.
I don't think this would have changed the alignment problem I am encountering.

Thank you.
Remy

Re: No alignment found!

Posted: Thu Oct 04, 2018 7:13 am
by turfpit
Remy

It will be interesting for me as well, I haven't used Live Stack since creating the example in the 2.9 docs ;)

The reducer isn't needed for M57/M27, I was just trying to match equipment. The cameras we are using have different pixel sizes but I don't see that making any difference to settings.

The 314E I have just purchased so this is a good excuse to do some real work with it.

Dave

Re: No alignment found!

Posted: Sat Oct 06, 2018 8:25 pm
by admin
Hi,

just an update on this. As far as I can see this is a bug in SharpCap 3.1 that occurs under some circumstances when the image width is an odd number. It is already fixed in SharpCap 3.2.

cheers,

Robin