Combination for Dual rig

[Clarkey]

I am in the process of setting up a widefield dual imaging rig to take advantages of the rare clear skies we have in sunny Cumbria. The question I would like to ask is what is the best combination of scope / camera? I currently have 3 scopes of similar FL - a SW ED80 (510mm with FF), a StellaMira  90mm triplet (540mm with FF) and an F4 6" reflector (600mm). These will be combined with a ASI1600mm pro and a Canon 600D (although this will hopefully be upgraded in the summer to an IMX571 based OSC - 'accountant' permitting). My initial thought is to pair the 90mm triplet with the ASI1600 for luminance data and use the Canon 600D with the F4 reflector for the colour. The slight increase in sensor size will in part offset the longer focal length. Is this the best option or should I use a different combination? Also, with the new more sensitive camera would this still be the better combination?

Any thoughts would be greatly appreciated.

[catburglar]

I’m not an expert imager, but I think I’d put the 1600 on the reflector… this way you maximise both the resolution of your luminance dataset and the ‘speed’ that you collect the signal.

You can capture the colour data at lower resolution and tolerate a lower SNR in your colour data and this will (I think) have less impact on your final image…

Although you will lose a bit of FoV (approx 1.8x1.2 degrees with this approach versus 2.0x1.8 if you put the ASI on the frac). 

[Clarkey]

4 hours ago, catburglar said:

I’m not an expert imager, but I think I’d put the 1600 on the reflector… this way you maximise both the resolution of your luminance dataset and the ‘speed’ that you collect the signal.

You can capture the colour data at lower resolution and tolerate a lower SNR in your colour data and this will (I think) have less impact on your final image…

Although you will lose a bit of FoV (approx 1.8x1.2 degrees with this approach versus 2.0x1.8 if you put the ASI on the frac). 

Having debated in my head for a while I have decided on a different approach. For a couple of reason I have decided not to use the newt. Firstly trying to blend and remove stars with and without diffraction spikes is likely to be a pain. Secondly, when I get the new camera I can use the DSLR on the Newtonian which hopefully will remove some of the reflection issues I have had.

For now I will get the luminance data from the 90mm triplet and the colour from the ed80  with an L-3 filter. It won't be quite so fast but will hopefully still give good results.