Quote:
Originally Posted by Camelopardalis
Russ, looks like tilt...but I'm speculating. How do the left and right edges look about halfway down the image? The Flickr is too low res to really see.
I've got a similar issue with my 60mm scope, where two corners look like they've got wings and the other two corners are streaky, almost comatic towards the centre.
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Quote:
Originally Posted by Ryderscope
Quite opportune this Russel as I'm setting up an ASI6200 myself at the moment so we can share some stories along the way  . In my case I have an FSQ106 that I have purchased as pre loved and initial tests show a combination of tilt and possibly collimation. I won't be able to diagnose any further until these pesky clouds go away.
Nevertheless, looking at your image on Flickr. It won't let me download a copy so difficult to look too closely. If you could provide a link to a raw fits file I can have a closer look.
It is clear though from what I can see on the Flickr image that there is radial elongation on the top left and to a slightly lesser extent bottom left. If it were incorrect spacing from the reducer to the image plane on the camera I would expect concentric or radial stars in each corner so maybe tilt is worth looking at.
Did you install the ZWO tilt adjuster at the camera end or the OAG end? I'm not using the ZWO tilt adjuster so cannot comment on its use but I have seen reports that it is difficult to adjust.
A question about the M54->M48 adapter. Does this mean that you are using the TSRED379-130 Reducer/Corrector with the M48 connection on the camera side? If yes, I see from the Teleskop site that the backfocus distance is 55mm which is exactly what the ASI6200 image train delivers with the tilt adjuster included. This means that you really don't have any room for tolerance in the backfocus from the reducer to camera.
If the M54-M48 0mm adapter that comes with the camera is not doing the job then the only solution that I can think off is to remove the ZWO tilt adjuster and have an adapter made up which is M54-M48 @ 5mm length. This would give you a more robust connection which is going to be required anyway even though you will be losing the capability to adjust for tilt. Alternatively, have the adapter made to a 3mm length and purchase a couple of 48mm spacers to allow for some trial and error in the backfocus.
So thats a few thoughts from my side Russel. I will provide an update on my setup when I get back under the stars with my new camera.
Clear skies,
Rodney |
Thanks for the replies guys I appreciate it
Yes you're right - I've just rechecked and flickr struggles with the full res it seems. And it seems like tilt is the likely foe - thankyou.
I've uploaded a fit file here.
https://www42.zippyshare.com/v/2wBRgp2p/file.html - if you are using an ad block the download button is to the right of the link.
yes am using the TSRED-79 with the M48 connector. Well I should have an extra 0.6mm with the filters included
Thanks for the thoughts there Rodney, yes I have the tilt adjuster on the telescope side - I think I will be going with the first suggestion, and if I still have tilt I will go for option B.
Good luck with your tak and 6200 I hope it works out alright and it isn't collimation.
i have noticed another comment on the zwo website for the camera and someone complaining about the same M54->M48 adapter - zwo replied saying they don't have a solution for it. Frustrating everything else feels quite rock solid.
I've tried to cut out a few small sections from most of the corners (attached). (from left to right - images start; bottom left, mid left, top left, top middle, top right, middle right, bottom right).
Russ