Platesolving issues - Ekos / Skymax 127

[Matt S]

Would anyone be able to offer me any advice on this? 
 

I had the chance last night to get everything running for the first time, and whilst it took me a good hour to figure out my focus was way off before seeing any stars, I couldn’t get a plate solve to work.

Equipment:

• EQ3-2 mount (Goto)
• Skymax 127
• Raspberrry Pi / Astroberry
• ASI678mc

So Ekos/Kstars is running fine on the Pi, and I’ve added my mount, camera details and scope to Ekos. Slewing to a rough target works fine, but is obviously off. 
I’d seen others have been able to plate solve with the Skymax 127 - so thought I’d give it a go. Unfortunately I keep getting told there aren’t, sufficient stars. 
 

I’ve downloaded the recommended index files (although haven’t downloaded all the LARGE optional ones), but I’d like to get any advice on what I could/should try?

Upping the gain more? Downloading all the optional index files?

 

 

[Cosmic Geoff]

I have found that platesolving needs at least 7 stars in order to work. I can only see 4 in your sample image. Possible solutions: lengthen the exposure, or jab an up/down or L/R button to shift the scope to an adjoining bit of sky, hopefully with more stars in it. Check you have entered the focal length of the scope in the relevant field(s)

[alacant]

Hi

What do the logs say?

At that image scale you're likely going to need the larger maps.

Before you download, other stuff to try:
- make sure 'Use scale' is unchecked (it's under 'Options')
- up the settle time
- ensure focus is better than perfect
- make certain the mount is tracking
- bin 1
- a rich star field high in the sky
- unity gain (I think on a 678 it's 100) 
- a shorter exposure
- a longer exposure

If still no go, download

If it still doesn't work, go with ASTAP.

Cheers and HTH

[StevieDvd]

The screenshot shows the answers to the other questions.

Your fov is correct, the index files are the ones needed.  And it also says you don't have enough stars.

Could it be you are using bin 2x2 otherwise the usual suspects will be gain & exposure times?

 

 

[Matt S]

Thanks all, some of those tips certainly helped.

I found a slightly better star field of view to begin with and then spent some time with gain/focus to try and get a good starting shot.

For some reason I’m struggling to find the focus unless I add the camera to the diagonal, but that may just be luck. Live/video made seemed useless to me here.

Solving worked this time until a third hop where it simply couldn’t see enough stars again, but at this point M81 was in the frame so that was good enough for now .

Still need to process my data, and I only shot lights (I’ve only been shooting plants so far) but this seems like a good starting point.

 

 

I was finding it hard to tell if things were focused correctly, if anyone uses a similar setup and has some advice on that side of things I’d love to hear your advice. 

[StevieDvd]

If you get better results using a diagonal that would indicate you may need to use the focus extender that should have come with the scope.  Which is the opposite of what I thought would be your problem.

The 130P & 200P had issues in getting a dslr to focus and needed them to be closer to the tube, which is why they brought out the 130PDS & 200PDS for astroimaging.

A quick google for 200PDS with cameras is a bit sparse in results but from some of the images with a DSLR and ASI cameras they do seem to be connected without extenders or diagonals.  Perhaps a picture of the connection and how you are achieving the 55mm focus would assist someone spotting the problem.

 

 

 

[Dazzyt66]

On 08/04/2023 at 09:20, Matt S said:

I was finding it hard to tell if things were focused correctly, if anyone uses a similar setup and has some advice on that side of things I’d love to hear your advice. 

I use a Bahtinov mask to get initial focus and then use the Ekos autofocus to keep things going if I’m moving between targets (you’ll need an auto focuser for this though). I struggled for ages for a good focus but a Bahtinov solves that immediately - you can Google how to make one yourself before buying one - a sharp knife and a cereal box works! Once you’ve focussed you’re pretty much done for a whole session. 😊

Edited March 26 by Dazzyt66