Page 1 of 1

Is this flexture or something else?

Posted: Sun Sep 15, 2019 9:13 am
by rottielover
Hi all,

While I was watching the "Hangout with Hamza" (TM)-lol last night I was also trying to grab some narrowband data. After slewing around (see what I did there) for a while I finally decided to start grabbing data on the Witches Broom. But my 10 min subs came out with some wonky oblong stars. The guiding looked really good last night and was sub-pixel guiding...

I've never had this issue crop up before now. I have had to move my mount between front and backyards a couple of times in recent days, but I doubled checked this morning and everything is tightened down well. I'm using a piggy backed guidescope a 60mm Stellavue with my ES127ed that has a flattener reducer on it giving me a final Focal Length of 667mm on the main scope.

Any suggestions on recovery of this data? Any suggestions as to what the issue with my data could be (as I said it would appear to be a hardware issue for me, but I'm not sure).

Help very much appreciated. Here are the RAW fits files: ... qbQra?dl=0

Re: Is this flexture or something else?

Posted: Mon Sep 16, 2019 7:22 am
by rottielover
I ran a cloudy nights thread as well just to get a bit more exposure (ha!) anyway... I think the general consensus at this point is that it's definitely some flexture.

Considering I have the ZWO 290 mono mini, which is supposed to be an excellent guide cam, I'm thinking about going to an OAG.

I would love to hear some experiences others have had with this!

In my case I think it might make a lot of sense because I swap out my flattener/reducer for a flattner only sometimes to change my focal length from 667 to 957mm. I usually struggle a bit at the longer focal length when guiding with my current setup. Perhapse an OAG is the way for me to go?

Re: Is this flexture or something else?

Posted: Mon Sep 16, 2019 9:51 am
by rottielover
A quick update...

For the price I went forward with ordering the ZWO OAG and their non-rotating focuser for it, figured I could always sell it or send it back if it doesn't work out. However after talking to a couple folks at my local club and doing more internet reading I think this is going to work out for me and the equipment I have.

Re: Is this flexture or something else?

Posted: Wed Sep 18, 2019 12:32 am
by jason
I just picked up a 90mm skywatcher maksutov 1250mm fl and added a 6.3 antares reducer (not actually a corrector?)... it's still clocking in at 940mm FL (I figured I should be having it at 790) but damn good guidescope from what I can tell. 290 mm with it, images look alot better than the 60mm and 90mm refractor guidescopes, even though the scope is slower, the optics just compensated I guess. - all tests with the 290mm.

I have a celestron oag and while it has a relatively huge prism there just was never a star in the fov.

The best I could fathom is that you don't have guiding working but I'm a little lost as to why things are fat in the middle.