Scopes for permanent pier

[koputai]

Hi All,

I'm after recommendations on a new scope. Having just built a permanent pier with EQ6 Pro, I've discovered the scopes I already have aren't really compatible......

At the moment I have 3 Newts/Dobs (2x 8", 1x 12") but when mounted on the pier getting to the eyepiece is terrible. I also have an ED80, which is ok to use as far as eyepiece access goes, but it lacks aperture for visual use. Of course, the ED80 will be great for wide-ish field astrophotography.

So, I'm thinking I need something shorter than the Newts, and with the eyepiece at the back, something like an SCT, RC etc. I'd really like decent aperture for visual, plus the ability to use it for astrophotography as well.

I'm considering the following:
10 inch Meade LX200-ACF
10 inch GSO RC
11 inch Celestron (C11)
12 inch Meade LX200-ACF

What experience do you guys have with the above? I think 8 inch is too small for visual, so haven't included them. Are there other options in this size reange I haven't considered?

As I said, I want to use it for visual, as well as astrophotography.

Cheers,
Jason.

[Terry B]

I'm sure there are other scopes. One that comes to mind is the vixen VMC260L

[Waxing_Gibbous]

The 10" Meade or C11 are probably about the limit once you add imaging gear. While the mount can take more, its best to have a little 'in reserve' as it were.
Either are perfectly good for A-P or visual and without camera, filter wheel motofucus etc, are well within the EQ6s capabilities.
Others with more experience are welcome to dispute! :)

[icytailmark]

120mm refractor if you wanna do astrophotography for DSOs or if you wanna do mostly planetary astrophotography go for C14 or C11. Both scopes would be great for visual work too.

[g__day]

Your maximum aperature range for quality astrophotography using a SCT (which will probably have to be off axis guided at that focal range) is likely 9.25" - 11".

That is presuming that your site with a pier is very well shaded for wind (like an astrolab) or you live in a place where wind won't affect your tracking.

So your OTA (and hopefully well matched to it camera or CCD) choice will be affected by target preferences and typical seeing quality at your locality. For that size SCT you also have to add in focusers, filters, OAG, two cameras, focal reducers if required and sturdy mounting bars - like Losmandy D series. All this adds weight and limits the maximum sized OTA you can put on your mount.

As you are mentioning 10" - 12" SCTs - I infer your targets are small, faint nebulae (not planets nor open clusters). If you can specify what targets you wish to eventually image - so we know how dim they are and what your exposure times will be - gives us a better idea of how excellent tracking and focus control you will need - and therefore what maximum load you can put on your mount and hope it will all work out.

Your choices listed seem reasonable - but better information about what you wish to image and the maximum lenght exposure you hope to take, and whether its at full SCT focal length - or if you intend to use a focal reducer (and what your cameras and focusers will be) will likely greatly improve the advice folk here can give you. Otherwise we are shooting a bit blind offering advice.

[gregbradley]

Meade ACF or Edge HD or the Vixen VMC260 as Terry recommended.

Standard SCTs are not the best for imaging although I have seen some stunning C8 images and also great C9.25 images. Mirror flop, dew on the corrector, image shift when focusing, tube currents all conspire to make them awkward.

RCs are not the best for visual as they usually have a large central obstruction. They are among the best for for imaging though.

Overall though I think you are on the wrong track here.

Unless you are experienced at imaging you will find imaging much more fruitful if you start off with short focal length imaging like your ED80 or something similar. Aperture is less important for imaging than it is for visual.


Getting round stars in a 10 minute image is your first target. You won't get it with the equipment you have listed nor with these super long focal length scopes. You are likely to have a loss.

My recommendation is 2 scopes. Image with your ED80 and get everything working with 10 minute round stars in images as your target and use an SCT for visual or something similar.

Once you've got some runs on the board with the shorter focal length try it out with the longer focal length.

The Vixen would be good here as it would probably be good for both purposes although I am not sure how it is as a visual instrument as I thought it was slanted more towards imaging (the 2 have conflicting requirements).

The only few instruments that excel as both imaging and visual are APO refractors or corrected Dall Kirkhams and perhaps Newts (but they tend to be short focal length).

Large aperture APOs are super expensive but there is a large amount of choice and value in the 100mm band. You want a triplet with a decent focuser and around 100mm aperture and accessories like a flattener if you are using a DSLR or larger sensor.

Greg.

[Poita]

You are welcome to try my Meade 10" ACF for a week or two if you want. I could meet you with it halfway to Sydney, in the Blue Mountains. It already has a Vixen dovetail on it.

Personally, I'd get two scopes, an ED80 or 127mm refractor for standard imaging, and a C11 Edge for planetary and visual work. You could then later add a Hyperstar to the C11 for fast imaging at F1.9, the mount isn't such an issue then as the subs are so fast. Then you get the best of both worlds.

[koputai]

Thanks for all the suggestions guys, much appreciated. Maybe I will just image with the ED80 for a while and look for something purely for visual.

Peter, thanks for your kind offer, but getting out to pick it up is a bit difficult for a while. Thanks again.

Cheers,
Jason.

[Poita]

I'm in the mountains every two weeks or so, so if you ever want to borrow it, just give me a hoy.