Guide scope Vs OAG

[Rodd]

49 minutes ago, Jkulin said:

Rodd, if you are going the Guidescope route can I make a suggestion?

Although I am going OAG on my RC, for my Refractors I will probably continue with a Guidescope until such time as I am comfortable with OAG. I use a couple of these: -

https://www.firstlightoptics.com/guide-cameras/skywatcher-guidescope-mount.html

Absolutely brilliant and rock solid and not expensive, probably about $130 over your side of the pond, I hated flimsy constantly moving guide rings and these have really improved my guiding.

Thanks--Astrophysics makes something similar--the AP Vario guider is actually the Baader Vario Finder fitted with an Astrophysics non flexive bracket and a base and connection similar to what you use.  probably not identical, but Astro Physics is well regarded and the Vario Guider is supposed to be very, very stable.

[vlaiv]

29 minutes ago, Rodd said:

So you use the ASI 1600--great.  I was told that the filter wheel is inaccurate to the point that the filters will not precisely line up so that flats will not be accurate enough.  Is that true?  Is calibrating the ASI 1600 subs difficult?  I am used to the self guiding wheel of the stt-8300, which purports a micron level accuracy of filter placement.  Anything to this? 

Unfortunately can't help with that. I've got no frills version of ASI1600 and I use filter drawer instead of filter wheel. No permanent setup yet, so setting up each time (a bit tedious but ... ). This also means flats each time, but that is not such a big deal, it takes less than 15 mins to get a set of flats (x256 flats, x256 flat darks), and if I manage to do different filters in a night, then I usually aim for same exposure for both filters - this way I reuse flat darks.

On calibration - I find that ASI1600 calibrates perfectly. I'm using 60s exposures (probably going to bump that up to 2-4mins for narrowband, still did not manage to try out everything, this winter has been awful so far, 5th month with no decent night), and I shoot x256 darks as well (don't use bias frames).

[Rodd]

6 minutes ago, vlaiv said:

Unfortunately can't help with that. I've got no frills version of ASI1600 and I use filter drawer instead of filter wheel. No permanent setup yet, so setting up each time (a bit tedious but ... ). This also means flats each time, but that is not such a big deal, it takes less than 15 mins to get a set of flats (x256 flats, x256 flat darks), and if I manage to do different filters in a night, then I usually aim for same exposure for both filters - this way I reuse flat darks.

On calibration - I find that ASI1600 calibrates perfectly. I'm using 60s exposures (probably going to bump that up to 2-4mins for narrowband, still did not manage to try out everything, this winter has been awful so far, 5th month with no decent night), and I shoot x256 darks as well (don't use bias frames).

Well your filter drawers would be even less accurate than a filter wheel, so if you do not have a problem then it is probably fine.  Thanks--Can't wait to snap some subs.

[Andyb90]

1 hour ago, Rodd said:

So you use the ASI 1600--great.  I was told that the filter wheel is inaccurate to the point that the filters will not precisely line up so that flats will not be accurate enough.  Is that true?  Is calibrating the ASI 1600 subs difficult?  I am used to the self guiding wheel of the stt-8300, which purports a micron level accuracy of filter placement.  Anything to this? 

I also use the 1600 together with zwo wheel and oag. I haven't had any issues with the filters lining up.

Andy.

[Rodd]

4 minutes ago, Andyb90 said:

I also use the 1600 together with zwo wheel and oag. I haven't had any issues with the filters lining up.

Andy.

Yay! the tide is turning....that's good news.  As long as I can calibrate my data it will work well I am sure.  I was able to take a 20 sec sub of M63 and the scale is obviously different than the 5.4 pixel KAF 8300.  Basically it reverses the resolution loss with the .7x reducer.  You get all the advantages of a shorter FL and wider FOV but maintain the pixel scale of the unreduced scope.  that's pretty cool

[r3i]

13 hours ago, Andyb90 said:

I also use the 1600 together with zwo wheel and oag. I haven't had any issues with the filters lining up.

Andy.

I also run an ASI1600 with the ZWO 8 position EFW - all has worked fine so far.