Lodestar non square pixels

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Pogo
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Joined: Sun Aug 19, 2018 8:13 pm

Lodestar non square pixels

#1

Post by Pogo »

Hi all,

I just downloaded SharpCap mainly for polaralignment purposes. I have an older Lodestar camera which I use for guiding. I noticed it is supported by SharpCap, from what I understand either directly or via Ascom.
Now I read in the documentation that for platesolving you need a camera with square pixels, which the Lodestar does not have. I believe it is 8.6x8.3 um if I am not mistaken. Now the Ascom driver has a box you can tick to square the pixels.
My question is, can I use the Lodestar succesfuly to polar align with the program and if so, what settings shoul I use?
I have a 60mm guidescope to use with it. Also have a first generation QHY5 to use if that would be better.

Thanks very much,


Peter
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Re: Lodestar non square pixels

#2

Post by admin »

Hi Peter,

I do have a recollection of making some changes to the polar alignment to try to help deal with slightly non-square pixels, but it was long enough ago that I can't quite remember what I did :( It's certainly worth a try with the lodestar - the most likely outcome if there is going to be a problem is that the plate solving in the polar alignment won't work because of this, which will show up fairly quickly (and you can test that part without paying for SharpCap Pro). If you do have problems with the plate solving then save a few frames in different rotation positions and send them to me and I can most likely fix the problem.

Depending on just how 'first generation' your QHY camera is, it might be a better bet. QHY5LII cameras will work fine in SharpCap - older QHY5 / QHY5V cameras have to be used with the corresponding ASCOM driver.

cheers,

Robin
Pogo
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Re: Lodestar non square pixels

#3

Post by Pogo »

Hi Robin,

Thanks for your fast response.
I have noticed that other users are using the Lodestar, so appears to they got it working.
When using ascom for the Lodestar you can actually tic a box to square the pixel, which also changes the aspect ratio somewhat. Maybe better to use it that way .
If not and plate solving g does work, would that than influence the result do you think?

Thanks,

Peter
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Re: Lodestar non square pixels

#4

Post by admin »

Hi,

I think the *biggest* effect it could have would be to make the adjustment distance out by up to the % difference in pixel ratio - ie (8.6-8.3)/8.3 =~3.6%. Running the PA routine a second time after completing the first time would show whether there was such an issue and allow you to close further in on correct PA if necessary.

cheers,

Robin
Pogo
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Joined: Sun Aug 19, 2018 8:13 pm

Re: Lodestar non square pixels

#5

Post by Pogo »

Thanks Robin. I will give it a shot and compare results with the qhy5.
Will post here.
groberts
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Joined: Thu Jul 26, 2018 1:13 pm

Re: Lodestar non square pixels

#6

Post by groberts »

I'm interested to know what the outcome of this was, as I'm looking to use Sharpcap for Polar Alignment with a Lodestar X2 mono camera.

From what I can see the FOV meets the Sharpcap requirements and it works fine with PHD2 using 8.3nm, as the pixel size at 8.6 x 8.3 nm is not square.

Furthermore, I've obviously already installed a suitable ASCOM driver for this camera + PHD2, will this be OK with Sharpcap too or do I need something else?

Thanks, Graham
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