Budget EQ mount for 6" SCT?

[Martyn87]

15 minutes ago, LandyJon said:

I started out with a 6SE and the reducer is a must, don't remove it until you're up to speed on everything else, the narrower FoV is good for smaller targets but introduces much greater need for accuracy in pa, guiding etc. and needs much longer total exposure times.

With the reducer I was happy with what I was getting after 4.5 hrs, at F10 it'd take days worth.

On PA I can't fault Sharpcap, the routine is simple, expose at park position, rotate 90° and expose again, then it guides you to adjust the bolts.  I can get down to 5 arcsec on the EQ6 in <2 mins provided the laptop is in view from the mount (often it's in the kitchen and going back n forth makes it harder).

It's a premium feature on Sharpcap, but the £10 ish per year is a small price to pay for the PA alone.  I find the software great for capture and the focus aids and calibration frame routines all work with ease.

I had a guide scope on mine which worked fine, since upgrading to 9.25 the OAG is invaluable but more to learn and unnecessary at 6" I'd say especially starting out.

The other thing I'd mention is look at the field of view differences the camera sensor size makes. I started with a very small 183 sensor which made things more difficult, stick with larger sensors if you can, to keep that FoV wide and minimise the headaches.

 

 

Thanks Jon, all really useful info! Out of interest, which guide scope were you using? I was planning on going OAG, but if I ever end up buying a Hyperstar, then I'd have to switch again. 

I think for the time being I'll be sticking with a DSLR, so obviously much larger sensor. I had been looking at the imx585 but I think that would be asking for trouble! 

[GrumpiusMaximus]

@Martyn87 Firstly, this is definitely not a mount recommendation for what you're trying to do as it will be inadequate - but just experience-sharing in reference to you looking at an AL-55.

I have an AZ-GTI that I use with my 70mm Altair ED Refractor.  A very different telescope to a C6 (but I do also own a C5).  Whilst the smartphone control is fine I really dislike the lack of tactile feedback.  This is mainly a problem with visual observing, as I'm having to look at my phone screen the whole time to adjust the view and as a result what little dark adaptation I have gets partially lost each time, even with the brightness turned down and in night mode.  When I can justify it to myself (and when I get back from my Swedish holiday in a month, having forked out for a very expensive sleeper train...) I'm going to buy a handset controller for the AZ-GTI to make life easier.

The Sky-Watcher Synscan Pro app is pretty decent but I think having to look at a screen during visual sessions is an inherent flaw with the idea.

This is absolutely not an issue if you're imaging, I grant you!

Edited June 15 by GrumpiusMaximus

[LandyJon]

4 hours ago, Martyn87 said:

Thanks Jon, all really useful info! Out of interest, which guide scope were you using? I was planning on going OAG, but if I ever end up buying a Hyperstar, then I'd have to switch again. 

I think for the time being I'll be sticking with a DSLR, so obviously much larger sensor. I had been looking at the imx585 but I think that would be asking for trouble! 

I had a William Optics I got 2nd hand from a nearby members advert on here, but any 200mm would suffice, as long as it's fixed securely.  There's a golden ratio between pixel scale of imaging to guiding, about 4 if I remember and I seem to remember with the tiny 183 and a 385 I had in the guide, I was about on the limits of recommended, but it worked, I got some good pics, I'll try find on the NAS and post a couple.

Hyperstar is a whole different ball game, I'm only just getting in to.  You don't need guiding, you don't even need an equatorial mount apparently, f2 is that quick you get good subs in seconds rather than minutes and at super wide FoV field rotation is negligible.

I've wondered about putting the guide scope back on but the couple times I've had it out I'm not sure it's worth guiding at all.

Yeah that was my point, stick with the DSLR for now but when you start thinking about a dedicated camera, bear in mind the tiny 183 I had just emphasised the problems you're already starting with with these long focal length optics.

Personally I love them, the 3 scopes in 1, add in a Barlow and put the guide cam in, you've got a planetary imager you can try, again it's on my long list for few clear sky opportunities lol

 

Edited June 15 by LandyJon

[Elp]

I autoguide with my Hyperstar, if you want reliable good quality images it's the only way to do it. I normally do 30-60s exposures, when trying to get very faint signal I'll go up to 3 minutes at least. RGB you're kind of limited to 10-30s in a LP environment. If doing EAA type imaging you don't really need to guide, just sidereal.

For F6.3 you really need an OAG, I couldn't get my gem28 to guide accurately with a 200mm GS, even with the OAG it's sometimes awkward. At F6.3 you also have to expose for longer as target signal is spread out across more pixels, even more so if using a small pixel camera like the 183.

Edited June 15 by Elp

[LandyJon]

I've had very little practical time with my hyperstar since getting it collimated (more by fluke I think!).  I was going to fit the guide scope but read it didn't need it, although the longer guided exposure makes sense I'd have come to that conclusion eventually I guess, need to figure out a detachable clamp so the OTA still fits in it's bag.

Totally agree with you on the f6.3, I was exposing 3-5 mins with 200mm guiding.  To be clear those pics were 4.5 hrs imaging time unfiltered OSC (one shot colour sensor if OP isn't sure as opposed to mono) it was at a dark sky site and 1 pic is about 3 hrs of the data, the other about 2 hrs ... and I'm sure I could process it better these days but I've still a lot to learn on that side, I enjoy the capturing and tinkering more than the learning how to use editing software lol, I'll get round to it !