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 !

[Martyn87]

Sorry to drag this one back from the dead, but I've been looking at a couple of options that are reasonably priced and was looking for others opinions...

Celestron AVX - Available cheap, around £500 ish with decent rated payload (30lbs). Celestron sell them bundled with the 11" SCT so must be half decent!? Reviews seem mixed though...

iOptron GEM 28 - Around £700, seems a much nicer mount, belt driven, much quieter, but iOptrons quality seems to be hit and miss, and from some review, it seems the payload rating is... optimistic at best? 

Anyone got any opinions on these 2? The AVX is tempting me at the minute due to the price, but if I can get a "forever mount" for a few hundred more, it seems a no brainer to avoid...

[Elp]

1 hour ago, Martyn87 said:

iOptron GEM 28

Don't know why the negatives, mine was bought used and it's been exemplary. Polar alignment is a joy, guiding is good, even the in built tracking usually keeps a target near dead centre after an hour. They're also incredibly quiet.

Liked it so much my first HD mount was a hem15.

[Martyn87]

Thanks Elp, we're you using it with your C6 too? 

[Elp]

Yes, please reread my previous posts above.

[bosun21]

I would rather have an HEM 15 as opposed to the AVX.

[Martyn87]

3 minutes ago, bosun21 said:

I would rather have an HEM 15 as opposed to the AVX.

As would I, but they're quite a bit pricier. 

Funnily enough, I've just picked up an AVX yesterday, for the pricey sum of £475 basically brand new. Hopefully it'll arrive in the next couple of days and I can get it set up. 

This means I've spend £735 on a goto mount and 6" SCT. Leaves a bit left over for an OAG and guide camera. Not bad considering Celestron sell the same setup for £1899. 

I know it's not the best, but for what I've spent, I'm hoping I cans till get some decent images, and maybe upgrade in the future. 

[bosun21]

12 minutes ago, Martyn87 said:

As would I, but they're quite a bit pricier. 

Funnily enough, I've just picked up an AVX yesterday, for the pricey sum of £475 basically brand new. Hopefully it'll arrive in the next couple of days and I can get it set up. 

This means I've spend £735 on a goto mount and 6" SCT. Leaves a bit left over for an OAG and guide camera. Not bad considering Celestron sell the same setup for £1899. 

I know it's not the best, but for what I've spent, I'm hoping I cans till get some decent images, and maybe upgrade in the future. 

You have landed yourself a bargain there. Your AVX will be great paired with the 6" SCT. If imaging is the route you are taking then you will likely need a 0.63x reducer. Good luck on your journey.

Edited July 11 by bosun21
Typo

[Martyn87]

6 minutes ago, bosun21 said:

You have landed yourself a bargain there. Your AVX will be great paired with the 6" SCT. If imaging is the route you are taking then you will likely need a 0.63x reducer. Good luck on your journey.

Thanks bosun, I've already picked up the reducer, so once I have guiding sorted (I'm going to get the hang of using the mount first), pretty much the last step for now will be a better camera, at least something I can control through software rather than an intervalometer

[Martyn87]

Well, it's been a hassle (and is still sort of a work in progress...) but the mount is here! 

I've seen various complaints about stiff axis on the AVX but it seems to move pretty well, I've had no issues getting it balanced, but the dovetail is a bit short so I'm trying to find a way to get some extra length at the back. The alternative is probably just to stump up the cash for the aluminium dew shield I suppose... 

[RT65CB-SWL]

Hi @Martyn87 and a belated welcome to SGL. 

I was going to say to go and purchase the Vixen GP or SP. I have dabbled with various GEM/EQ mounts in the past and found the GP was the one that worked for me. I have since sold my GP to fund other topics and/or hobbies and do regret it. I now use Alt-Az mounts as I like use a dual mount/side-by-side setup. The GP could manage it… just! [images below].

Since you now have your chosen mount and you mention a few shield, the Astro-Zap ones are good quality and lightweight. They do heated or un-heated. Not sure where you are in the world, but I use the un-heated. Also they store flat, so no worry about getting a dent or two in use or in storage.

[Martyn87]

Thanks @RT65CB-SWL! 

That wooden tripod is beautiful... I had my eye on one at the beginning of the week when the tripod I bought we'd missing on the way (thanks ParcelForce...), the StellaLyra ones on FLO are actually not too badly priced. 

Dew shields... I had looked at the AstroZap ones, as well as Astro Essentials and Lynx Astro ones, but even though it's more expensive, I'm still leaning towards the Celestron aluminium dew shield and eventually one of their corrector plate heaters. I'm not paying the obscene price for one of their controllers though, so it might depends on if I can come up with a solution for that. 

[RT65CB-SWL]

Thank you @Martyn87.

The wooden tripod is/was the original Vixen one. Saving up for a couple of Berlebach or surveyors tripods for these two… 

[left] AOK-AYO  [right] Tele-Optic Giro.

Edited July 17 by RT65CB-SWL

[LandyJon]

2 hours ago, Martyn87 said:

I'm not paying the obscene price for one of their controllers though, so it might depends on if I can come up with a solution for that. 

Just plug 12v in to the 1 lead, it'll run at full power but that's only an issue if you're trying to run on a battery pack, if you're on mains power it's no problem to leave it on max.

[Martyn87]

Just now, LandyJon said:

Just plug 12v in to the 1 lead, it'll run at full power but that's only an issue if you're trying to run on a battery pack, if you're on mains power it's no problem to leave it on max.

Thanks Jon. I know this will work, but I've read that it can cause issues with flexing in the corrector plate if it gets too hot? I was looking at putting together one of these: HBG3

[Elp]

Get the right tool for the job, the Celestron dew ring which actually sits on the corrector plate, the best place for conductivity.

You might find you don't even need it, the flexible dew shied for example is very long. I only installed the dew ring on my C6 because I'm imaging for hours, enough for any dew on the OTA to usually freeze over when it's winter.

[Martyn87]

Thanks @Elp. Surprisingly they're actually not that expensive, makes a change in this hobby! 

[Elp]

I know, the aluminium dew shield which is ideal for taking flat images is one such high price example, especially when you go up in sizes.

[LandyJon]

8 hours ago, Martyn87 said:

corrector plate heaters

Sorry I thought we were talking about the heater ring

5 hours ago, Martyn87 said:

not that expensive

Relative to a wrap around band they probably are, but as Elp said, it's the better option and relative to other asto gear it's not a fortune

 

6 hours ago, Martyn87 said:

I was looking at putting together one of these: HBG3

Just had a quick look, I know it says heater control but how it'd connect I don't know.

[Martyn87]

18 minutes ago, LandyJon said:

 

Just had a quick look, I know it says heater control but how it'd connect I don't know.

It's a bit hidden on the website, but it is in there. A bit more here over on the "other" forum... 

https://www.cloudynights.com/topic/848895-homebrew-celestron-compatible-dew-heater-control/page-7#entry13177277

 

The guy that's built this whole thing has mostly reverse engineered the Celestron accessories, GPS, WiFi, heater controller etc so that it send the same commands as the official accessories do. They even work correctly on the hand controller. 

Edited July 17 by Martyn87

[Martyn87]

Well unfortunately, I've just had to start the return process for the AVX, it's not working. Dec axis doesn't move at all (mechanically it's fine, electronically not so much), and the RA axis just spins and spins. I contacted Celestron on the off chance it was an easy fix, but they say that the RA issue is likely to be the encoder, so it's going back.

The search continues!