Dual imaging setup - would this be a possibility?

[Paul Haese]

I'm with Mike. If you are gonna do it use two mono camera's You could also do narrow band and RGB at the same time. Using two 40D is a waste of money. Yes they are good but you will get more out of two mono's in the end.

[strongmanmike (Michael)]

Originally Posted by h0ughy

thanks for confirming my temporary insanity Dr Ward

Hey! I was the first to point out that you are a blithering idiot

[rally]

Sounds like a good idea in theory - but . . .

2 different sets of Master Darks and the complete Darks library to go with it
2 different sets of Flats to take each night
2 sets of equipment to manage focus between frames

So thats a lot of extra data, processes and potential problems to juggle with and more time taken per night getting the calibration data you need.
More problems on pier flips managing your image data orientations.
If you have your processing down pat and never ever get mixed up - Maybe, just maybe - if not, I wouldn't.

There is always going to be flexure and misalignment - no big deal, but when the two cameras are rotated its another misalignment step to deal with.
Guiding with three scopes to manage now - double the flexure problems on longer exposures.

At the end of the day it sounds like you are trying to get better results by having more data but in reality you are not improving the quality of any particular system - guiding, tracking, acquisition, image quality, focussing.
Potentially even reducing some of those.
Given the extra time doing flats etc you aren't necessarily going to get double the exposure time anyway.

As Peter says
. . . just get the CDK17

Rally

[h0ughy (David)]

Originally Posted by strongmanmike

Hey! I was the first to point out that you are a blithering idiot

thanks for your support Mike

well if we cant dream we are dead - Eh?

I might trial the idea with the 127 and the ED80 (larger field of view) and see how that works - no money spent LOL

[Barrykgerdes]

Yes two identical telescopes on the same mount could be interesting as long as they are separated by a couple of feet. Get the video in phase and process it the right way and get the resolution of a two foot aperture.
For those who don't understand feet substitute 30 CM for each foot of separation.

Barry

[Peter Ward]

..... it is cool however to have different focal length scopes hanging off the same mount.

Side by side plates keep the centre of gravity low, reducing the need for extra counterweights.

[multiweb (Marc)]

Originally Posted by h0ughy

thanks for confirming my temporary insanity Dr Ward

just sounded a good idea

Well, while it's true that one scope of larger aperture will do a better job than two scopes of smaller aperture I still don't think it's a bad idea. You have two scopes, whether they are the same FL or not and two cameras that can do two different things. RGB on one NB on the other or Lum, etc... So yes you double your production. There are multiple softwares now doing good registration between pictures with different image scale and orientations so processing is not an issue anymore. That is no different than mixing old data with newer subs.

[gregbradley]

When the weather is stable and there are a reasonable number of clear nights all that extra work may not be that valuable.

But when you hit a patch of wettish, cloudy weather like Sydney has had for nearly a year now then 2 scopes to double production makes a lot of sense.

Tom Davis has been doing that for ages with his ASA12N for luminance and a Televue NP127 for colour (one shot STL11) with fabulous results.

I am planning to do the same except in my case I am using 2 setups rather than a tandem bar on one. Main problem there is orienting the 2nd scope. That's where the Cassady adjustable saddle setup is the go.

Greg.

[loc46south (Geoffrey)]

Dual imaging is feasible and it does work - but it is a real pain. I tried it to beat the weather - tried imaging mono & colour at the same time. Biggest problem is flexure and with 2 DSLR's I don't think you will overcome it. My setup - http://www.pbase.com/loc46south/image/120564600

It used a ED120 Equinox and a SW100EDPro on a Losmandy double saddle Plate. I used internal guidence for mono Luminance and external guide head for narrowband. The ED100 shot continuous colour and I ended up using an AO8 to get rid of flexure issues between the two scopes.

The biggest problem comes when you want to automate it and use off star auto focusing - fun fun fun . In the end I gave up and bought a M250.

Geof

[h0ughy (David)]

Originally Posted by gregbradley

.............

I may still have a Cassady tandem bar (not sure) if you are interested.

.........................

Greg.

do you still have that bar Greg?