dual imaging setup, camera combination choice?

[Gonzo]

If one would like to setup a "light" wide field dual imaging rig, using two identical telescopes and identical camera sensor specs (in terms of physical size), which camera combination would you be better off with?

mono+mono

OSC+mono

OSC+OSC

[Tomatobro]

This Dual setup has an ATIK Horizon 2 with an IDAS NBZ filter on one side and a ZWO ASI1600 mono with filters on the other. Lenses are Samyang 135mm F2

It works reasonably well but given the budget I would change the cameras for Rising Cam OSC both with the IDAS NBZ filters

The ATIK and ZWO cameras have the same sensor but for the OSC version in the Atik

[Adam J]

17 minutes ago, Gonzo said:

If one would like to setup a "light" wide field dual imaging rig, using two identical telescopes and identical camera sensor specs (in terms of physical size), which camera combination would you be better off with?

mono+mono

OSC+mono

OSC+OSC

Mono + Mono in general. 

Allows you to collect duel band data HOO in a single evening. 

For LRGB you can use one for L and the other for RGB. 

Its just more flexible. 

The only time I might go for Duel OSC or Mono + OSC is if I did not intend to do any narrow band imaging and wanted to save some money on filters. 

Adam 

[Elp]

Depends on what you want to achieve, are you looking for OSC data or want the flexibility but sometimes more work/user intervention involved in using mono? With bits and pieces left around I put together a DSLR+mono astro cam setup so technically I can have a finished project done in one night, the dslr will collect RGB and the mono I can supplement with luminence or ha data.

[Gonzo]

I'm contemplating getting two Askar FMA-135 mounted side by side and a pair of Player-One cameras, the Saturn version.

Reasoning behind is that we're getting less and less imaging time (crap weather) so I want to maximise every sessions, I do prefer wide field images hence my choice in the FMA-135 and it's an inexpensive scope (230 is too big and I have a RedCat 51 with a 533mc pro, I would have considered the 180 for it).

To simplify my new setup I'm going with an un-cooled camera (we talked about it in this thread) I do not image in summer, only in the cold months of the year. I won't be using a filter wheel but a filter drawer, again for simplicity.

The filter drawers can be remotely changed by making a simple phone call if needed... (Control room in the UK, Obs in Germany).

I was thinking of the mono with a HA filter and the OSC as it is (with a simple UV/IR filter).

[Gonzo]

27 minutes ago, Tomatobro said:

This Dual setup has an ATIK Horizon 2 with an IDAS NBZ filter on one side and a ZWO ASI1600 mono with filters on the other. Lenses are Samyang 135mm F2

It works reasonably well but given the budget I would change the cameras for Rising Cam OSC both with the IDAS NBZ filters

The ATIK and ZWO cameras have the same sensor but for the OSC version in the Atik

That's a cool setup there you got. 👍

[ollypenrice]

I've always used mono+mono but, these days, I'd be very tempted by OSC unfiltered + OSC with dual or tri-band filter. If you're fighting severe LP then mono+mono will always win but, if not filtered and unfiltered OSC would be very productive, I think, especially at fast F ratios.

Olly

[Tomatobro]

1 hour ago, Gonzo said:

That's a cool setup there you got.

Thanks. Although I allowed for the rotation of each camera/lens for image alignment what surprised me was (despite my careful engineering) just how much left/right and up/down movement was required to get the star fields to align so keep this in mind when putting the rig together. At least once its done its done so its not a maintenance issue.

Edited July 4, 2022 by Tomatobro
spelling

[Gonzo]

I'm not suffering from light pollution where the observatory is, it's a bortle 3/4 location. As for the "OSC with dual or tri-band filter" this is where I'm a bit confused with filters on an OSC camera, aren't you reducing the effectiveness of your OSC sensor?

Edited July 4, 2022 by Gonzo

[Elp]

No, you're filtering out the unwanted light

[Elp]

4 hours ago, Tomatobro said:

just how much left/right and up/down movement was required to get the star fields to align

Your rig looks sturdy. I did it like this so it's just a 180 degree flip, how it is atm I do need to ensure the dslr is aligned square to the bracket as it's only fixed via the single screw, astro cam doesn't have this issue as it has two fixing points:

 

[Tomatobro]

The dual rig is operated remotely and has two small stepper motors one each for the Samyang lens. I only had one black version Hitec stepper motor controller available so there is a comm port switched relay bank to switch the Hitec focuser output from one stepper motor to the other.

With the comm port switched one way the ZWO can be focused and then switching the comm port the other way the Atik can be focused.

The rubber focus grip ring on the lens has a 2mm pitch which looks as if the lens designers had in mind a toothed belt driven focuser.⭐

[ollypenrice]

15 hours ago, Gonzo said:

I'm not suffering from light pollution where the observatory is, it's a bortle 3/4 location. As for the "OSC with dual or tri-band filter" this is where I'm a bit confused with filters on an OSC camera, aren't you reducing the effectiveness of your OSC sensor?

Any filter blocks light. That's all they ever do. What the dual band filters provide, like equivalent mono filters, is the isolation of the Ha and OIII structures. I'd be aiming to make a 'host' image in RGB from the unfiltered camera and before applying the more aggressively-stretched filtered data in a lighten-only mode. This is how I work with LRGB + Ha/OIII. Where it wasn't appropriate, say on dusty targets, you could run the second camera unfiltered.

Equally, OSC and mono for NB would work but I'd be wary of expecting L on one side and OSC on the other to be productive. I tried it with CCD cameras a good while ago and found that the OSC signal would not support the addition of much luminance. It was not as strong as RGB from a mono in the same time.

I found it harder than expected to align two scopes and ended up sourcing the discontinued Cassady T-GAD alignment device (at prodigious expense even second hand!) This would allow you to set the two fields of view up with an overlap in order to shoot two panels of a mosaic simultaneously if you so wished.

Olly