ZWO Filter Wheel with 183GT?

First question; why?

Guessing you want to leave 1 slot open in the GT, to have more filters in a second filterwheel? to give the full range of 7? (if you're at least going for the big 7. SHO&LRGB)- Because I don't think shooting through 2 filters would help at all.. so.. can't see that being useful.? But I have no experience with that.


back focus wise at least, I guess it fits?... I see that the GT has 26.5mm.
A ZWO Filter wheel would add 20mm. 46.5 in total, meaning you have about 9.5mm left to cover (55mm+1mm that "usually" is needed when filters are used) - not enough space for an OAG though, so you'll never be able to upgrade to that..

You could however run into issues,

the main one being vignetting. 
For obvious reasons, you want the filter as close to the sensor as possible. I doubt that a 5 slot - 1.25" filterwheel would work when placed that far away from the sensor. 
This could perhaps be mitigated by going for large filters like  36mm or 2" filters for example. But.. this does ramp up the cost... a lot... to the point where it might almost be easier to sell the GT and buy a "normal" MM camera + 7 slot filterwheel.

Weight
Certainly not the biggest problem, but you are adding quite a bit of weight to the system.
Putting a bigger strain on your focussing system. More chances that things start slipping, tilting, or issues with auto focussing. As you're adding a 7 slot filterwheel (400+ grams), just to ad 2 filters to your system.

Control
I doubt that the available astrophotography software are meant to be used with 2 filter wheels in one rig. So even if you connect it all up, I'm not sure you're able to control both at the same time.- especially not with the ASIAIR software. Which seems to be the one you're using? - that certainly won't run 2 wheels in 1 rig.

TLDR:
I don't know why you would want to do that. It creates problems that can simply be avoided. And seems to be an expensive work-around just to ad an additional 2 filters to your system. When a normal DSO camera + 7 slot filter fixes the issue. Or 5 minutes with a screwdriver.

First question; why?

Guessing you want to leave 1 slot open in the GT, to have more filters in a second filterwheel? to give the full range of 7? (if you're at least going for the big 7. SHO&LRGB)- Because I don't think shooting through 2 filters would help at all.. so.. can't see that being useful.? But I have no experience with that.


back focus wise at least, I guess it fits?... I see that the GT has 26.5mm.
A ZWO Filter wheel would add 20mm. 46.5 in total, meaning you have about 9.5mm left to cover (55mm+1mm that "usually" is needed when filters are used) - not enough space for an OAG though, so you'll never be able to upgrade to that..

You could however run into issues,

the main one being vignetting. 
For obvious reasons, you want the filter as close to the sensor as possible. I doubt that a 5 slot - 1.25" filterwheel would work when placed that far away from the sensor. 
This could perhaps be mitigated by going for large filters like  36mm or 2" filters for example. But.. this does ramp up the cost... a lot... to the point where it might almost be easier to sell the GT and buy a "normal" MM camera + 7 slot filterwheel.

Weight
Certainly not the biggest problem, but you are adding quite a bit of weight to the system.
Putting a bigger strain on your focussing system. More chances that things start slipping, tilting, or issues with auto focussing. As you're adding a 7 slot filterwheel (400+ grams), just to ad 2 filters to your system.

Control
I doubt that the available astrophotography software are meant to be used with 2 filter wheels in one rig. So even if you connect it all up, I'm not sure you're able to control both at the same time.- especially not with the ASIAIR software. Which seems to be the one you're using? - that certainly won't run 2 wheels in 1 rig.

TLDR:
I don't know why you would want to do that. It creates problems that can simply be avoided. And seems to be an expensive work-around just to ad an additional 2 filters to your system. When a normal DSO camera + 7 slot filter fixes the issue. Or 5 minutes with a screwdriver.

Well… I already have the 183gt and SHO filters but learned that I need LRGB as well for what I want to do. I wouldn’t use both filters simultaneously… likely just open the GT and put all the filters in the second wheel.

That said, the reason I’m wondering about this is to mitigate swapping filters out because wouldn’t I then have to reshoot calibration subs with each change or am I overthinking it and can simply handle it with a screwdriver easily without too much worry?

I have a 183gt. Just use the screwdriver and switch the filters in it when needed. Yeah, its a pain, but the whole point of the 183 is to be self contained and easy to use. Hook it up, use the included adapters and your backfocus is good to go. Too many other things to troubleshoot/stress over/fix in this hobby. Rules out at least one thing by doing this

Workflow efficiency is probably your best pain reliever - try to get a series of targets in RGB during new moon and SHO during full(ish) moon. This way you basically only do it twice a month. I'd go crazy switching them every night otherwise. My wife also hates the sound of me screwing in/out filters and focal reducers so I try to keep a happy marriage by minimizing these changes too

First question; why?

Guessing you want to leave 1 slot open in the GT, to have more filters in a second filterwheel? to give the full range of 7? (if you're at least going for the big 7. SHO&LRGB)- Because I don't think shooting through 2 filters would help at all.. so.. can't see that being useful.? But I have no experience with that.


back focus wise at least, I guess it fits?... I see that the GT has 26.5mm.
A ZWO Filter wheel would add 20mm. 46.5 in total, meaning you have about 9.5mm left to cover (55mm+1mm that "usually" is needed when filters are used) - not enough space for an OAG though, so you'll never be able to upgrade to that..

You could however run into issues,

the main one being vignetting. 
For obvious reasons, you want the filter as close to the sensor as possible. I doubt that a 5 slot - 1.25" filterwheel would work when placed that far away from the sensor. 
This could perhaps be mitigated by going for large filters like  36mm or 2" filters for example. But.. this does ramp up the cost... a lot... to the point where it might almost be easier to sell the GT and buy a "normal" MM camera + 7 slot filterwheel.

Weight
Certainly not the biggest problem, but you are adding quite a bit of weight to the system.
Putting a bigger strain on your focussing system. More chances that things start slipping, tilting, or issues with auto focussing. As you're adding a 7 slot filterwheel (400+ grams), just to ad 2 filters to your system.

Control
I doubt that the available astrophotography software are meant to be used with 2 filter wheels in one rig. So even if you connect it all up, I'm not sure you're able to control both at the same time.- especially not with the ASIAIR software. Which seems to be the one you're using? - that certainly won't run 2 wheels in 1 rig.

TLDR:
I don't know why you would want to do that. It creates problems that can simply be avoided. And seems to be an expensive work-around just to ad an additional 2 filters to your system. When a normal DSO camera + 7 slot filter fixes the issue. Or 5 minutes with a screwdriver.

Well… I already have the 183gt and SHO filters but learned that I need LRGB as well for what I want to do. I wouldn’t use both filters simultaneously… likely just open the GT and put all the filters in the second wheel.

That said, the reason I’m wondering about this is to mitigate swapping filters out because wouldn’t I then have to reshoot calibration subs with each change or am I overthinking it and can simply handle it with a screwdriver easily without too much worry?

I have a 183gt. Just use the screwdriver and switch the filters in it when needed. Yeah, its a pain, but the whole point of the 183 is to be self contained and easy to use. Hook it up, use the included adapters and your backfocus is good to go. Too many other things to troubleshoot/stress over/fix in this hobby. Rules out at least one thing by doing this

Workflow efficiency is probably your best pain reliever - try to get a series of targets in RGB during new moon and SHO during full(ish) moon. This way you basically only do it twice a month. I'd go crazy switching them every night otherwise. My wife also hates the sound of me screwing in/out filters and focal reducers so I try to keep a happy marriage by minimizing these changes too

Do you reshoot calibration subs (flats…) every time you swap out?

Yeah, I just reshoot flats after every session (and subsequently after every swap out). I've sometimes been able to reuse, but as soon as I skip taking them... I find I have to go back out and shoot them after all. Not sure what software you use, but in NINA,  I just use the flat wizard, select all the filters and let it run. I'm usually too sleep deprived to play a guessing game on them

Not saying you have to do that, but the act of opening that case and swapping exposes them to air and I use a dust blower every time since there's always some little spec that gets on there as part of that process that I might miss.