Autoguiders

[PCH (Paul)]

Greetings Guys and Gals,

I'm going to try and get my ETX125 rigged up for imaging. I know at F15 it's hardly 'fast', yet people do use SCTs and the likes for imaging very successfully. So I thought that if I can get the gear without blowing a gasket budgetwise, I would give it a go.

So, can anyone recommend a guidescope and autoguider suitable for a beginner. Re the autoguider, I see Bintel have the DSI (and Pro) on special although they don't have stock yet. The basic DSI at reduced price of $149 seems good value and it claims to be a good simple autoguider.

Any & all comments appreciated - as long as they're polite

Cheers,
Paul

[Tamtarn]

Hi Paul

Will be interested in the feedback you receive as we will be going down this track as soon as we organize our new mount.

I know that Eric ( Ezystyles ) uses a DSI with great success.

David

[Doug]

G'day Paul, I think your ETX would best be left as a planetary/luner imaging scope; f15 is a bit extreme for DSO imaging. And for lunar/planetary work a guide scope/autoguider is not required. On the otherhand, if you intend mounting your ETX on a wedge,then by all means get the DSI, but rather than a guide scope, you might consider something like the Lumicon easy guider. Bit more expensive, but a much better set up.

cheers,
Doug

[JohnH]

Paul,

Have you checked this site?

http://www.weasner.com/etx/menu.html

I used an ETX90 for imaging, best results were mounting a camera piggy back - other than that the DSI would be an option - with a focal reducer.

[Alchemy (Clive)]

I dont know how you would manage this with your setup but on mine i use the following.ED80 guidescope and a modified 840k webcam. The ed80 is available anywhere for $600 up, the Modified webcam i purchased from an internet vendor in Adelaide $300??? cant remember , he has someone who does the modifying for him and onsells you may have a wait depending on his supply. (AUS Google Modified webcam you should find him.)for the program i use Guidedog FREE available (again WORLD google ).My mount probably uses a different pulse system to yours but i use an adaptor available through shoestring astronomy in US about $65.00 i think .they have list of adaptors on their website. I could name the supplier in adelaide but not sure if OK with this forum, (let me know).This setup works flawlessy on my system finding guidestars with 2 second interval generally easy.Hope this helps although i have no idea how you would mount a guidescope on your setup.

[[1ponders] (Paul)]

I could name the supplier in adelaide but not sure if OK with this forum, (let me know).

That's not a problem. Most of the members who have been here for some time are aware of Matthew at Telescope-Astronomy selling the long exposure mods. I think he is probably the only one in Aust selling them commercially atm.

[Lee]

Originally Posted by Doug

G'day Paul, I think your ETX would best be left as a planetary/luner imaging scope; f15 is a bit extreme for DSO imaging.

Can you use focal reducers with these? They are Maks right?

[Doug]

Yes they are Maks, I'm not sure what is available in focal reducers for these scopes.
Looking at Meade reducers made for their SCTs, (f10), a 6.3 reducer with a Mac would tend to give f 9.45 or thereabouts, still too long for all but the best setups for DSOs. An f3.3 at f10 (33%) reducer would give around f4.95, however the problems are or could be legion.
The actual reduction ratio depends on the back focus distances which with SCTs and Macs, varies greatly when focusing due to mirror movement. An F3.3 (33%) reducer might well also have significant vignetting too.

We really would need to hear from a MAC user, I'm only raising issues that might be detrimental to pleasing DSO imaging and suggesting alternative pathways.

Doug

[[1ponders] (Paul)]

Don't quote me on this...but...I'm not sure how effective FR designed for SCTs will be when used with Maks. Sure they will reduce the focal ratio but the corrector/primary/secondary design for a Mak is considerably different to an SCT. You may find that the image is unusable. I don't know this, but it is something to consider.

[Karls48 (Karl)]

I have tried Mogg FR with Meade ETX-105. No problem with focus, sharp image – but I was getting really bad reflections on brighter stars.

[g__day (Matthew)]

I use a 80mm with a DSI and PHD v1.6 from http://www.stark-labs.com/phdguiding.html connected via a 6 pin cable from my mount to the parallel port converting via a shoestring astronomy adapter.

I guess with a wedge the ETX might get you going. PHD certainly performs its function well once you learn its ins and outs!

[Zenton (Rodney)]

I have also been using a Mogg focal reducer with the DSI-C with the EXT-125 and have had lots of success. I dont use a guide scope because the DSI software is good enough to take out any errors. You can check out some of my images on the WSAAG website in the photo gallery http://wsaag.org/photos/index.php