Log in

View Full Version here: : Dual Scope Advice


PKay
13-01-2018, 09:05 AM
Hi All

I need some advice if duel scope setup is the way to go.
Thanks in advance for any help.

Currently I am running an Orion EON 85mm Triplet (see equipment setup below).
This is my first ASTRO photography setup and it has enabled me to take some great images.
I like the FOV and the scope setup.
The 85mm scope has an aperture area of 0.02m^2 ( A=πr^2)

Now I want to move on to narrow band using filter wheel and mono camera.

The idea I have is to get another 85mm scope (exact same) and piggy back it on top.
The tube rings would make this very easy with no flex.
It would be well under the weight loading of the mount.

Scope 1 has the OSC, and scope 2 has the filter wheel & Mono.
Having 2 scopes would double the light gathering area ie: 0.02 + 0.02 = 0.04m^2

The other option was to get a 130mm triplet (0.05m^2)
There is not much to be gained in light gathering area and I can’t get RGB and Luminance, Ha etc at the same time.

xelasnave
13-01-2018, 09:53 AM
I would like to think having two scopes would work.
I dont know if they would but given the dragon fly group now run many scopes it appears doable.
I would love to double or tripple my capture time and multiple scopes I find most appealing.
In Sydney I have a window of an hour for any object so narrow band is really nit an option unless I had multiple scopes.
Alex

xelasnave
13-01-2018, 09:56 AM
I have purchased a 80 mm espirt triple but I need another six I guess.One scope one filter would be nice.And then there will be many cameras...
Alex

Camelopardalis
13-01-2018, 11:07 AM
Peter, you certainly seem to be getting results :thumbsup:

Given the price of the EON 85, I’d save a few $$$ and get the Esprit 80...the main reason being that it is almost a f-stop faster. Speed is king when it comes to narrowband, so that would help keep the exposure times manageable.

AstroApprentice
13-01-2018, 01:34 PM
Hi Peter, a dual setup can work well - see Sarah Wagner's site where she discusses the pros and cons of her dual Tak FSQ85 setup
https://www.swagastro.com/dual-imaging-set-up.html
There's plenty of interesting reading & great images there.

Wavytone
13-01-2018, 03:27 PM
IMHO aperture rules (a larger scope) over two small scopes.

If I was seriously into imaging I'd probably opt for one of these:

http://www.apm-telescopes.de/en/telescopes/reflecting-telescopes-ota/maksutov-newtonian/intes-micro-alter-mn73-ccd-photo-russ.-standard-delivery.html

There's a 12" f/4 available too, if you have a spare $30k. A spare million buys a 75 cm Mak.

PRejto
14-01-2018, 08:41 AM
Hi Peter,

I have done this but with two TEC APOs (TEC140 and TEC180) on an MEII mount. At first the issue may seem simple enough but there are a huge number of issues you will need to solve! A cover article was published on my setup by Astronomy Technology Today last year.

Briefly you need to:

1. Synchronise camera exposures if you plan on dithering.
2. You need to aim both scopes exactly. The ability to do this will add differential flexure. There is no escape! Perhaps with a wide FOV, low resolution setup this may go unnoticed.
3. Using a single computer to deal with multiple cameras is very complicated.
4. Focusing two scopes automated requires consideration. FocusMax V4 comes to the rescue.

For more gory details you can read the article. Sadly neither Sky and Telescope or AT could successfully print my Antennae Galaxy photo...

https://drive.google.com/open?id=0BwREpRcqsuvzM2QtSGZ3RjlOMT Bjd3l6djM1azdtUlZmSEdZ

Peter

PKay
14-01-2018, 03:05 PM
Thanks for all the advice.

I will have to think long and hard about this.

It appears there is more to setting up dual scopes than I first thought.

And maybe I am not ready for it...yet.