Hi!
I want to buy a C3-26000 PRO CMOS, but I already have the ZWO filter wheel and OAG-L. Is it possible to bolt the ZWO EFW to the camera? If not, which adapter do you recommend?
Cs
Moravian C3 camera
Short answer, NO, just sell all the ZWO and buy the Moravian C3, there CFW and OAG, there not that expensive, and if you get everything at the same time, you're ready to go, no assembly required. If you are in the US, use Tolga Astro, there great to work with.
If you can attached it through a male T-Thread or M48x0.75 male adapter then yes.
I have two of those and would suggest the built in filter wheel. There is no reason to get the external filter wheel unless you want more than 7 filters. It is much more compact.
I would also suggest the enhanced cooling unless you live in a place where it never gets above 90 F. It does not cost that much extra.
FYI, I would NOT use their OAG. It totally sucks. I have one from my first C3 and it is sitting unused. If you get the one with the built in filter wheel, you can use a ZWO OAG-L with only minor modifications (slight enlargement of the mounting holes on the OAG). This assumes you have the back focus available but even with the ZWO OAG, it is a tiny bit shorter than the same ZWO system.
📷 OAG-Mor.jpg
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Well, I do agree with Bill 100% on their OAG, that's why I make my own. As for the built in filter wheel, your limited to (5) 2" or the OP will need to buy 36mm filters if he doesn't already have them. I also have both C3 61000 Pro and the C3 26000 Pro.
Thank you everyone! I have 2 inches filters, SHO and LRGB, so I need an external filter wheel.
Bob Lockwood · Jan 9, 2026, 04:31 PM
Well, I do agree with Bill 100% on their OAG, that's why I make my own.
Not sure if the ZWO OAG will fit the external filter wheel, you would have to ask Moravian if the hole spacing is the same. It might be since I would guess they would both use the same Moravian OAG.
It was by sheer accident that I discovered that the tapped hole spacing on the front of the C3 built in filter wheel was exactly the same as the mounting holes on the ZWO OAG-L. The only difference is that the tapped hole size on the C3 are slightly larger than the bolts for the OAG but there is still plenty of metal on the OAG to slightly enlarge the holes to fit the larger bolts needed by the C3 built in filter wheel.
To be honest, if I did not have full frame, I would rather have the built in filter wheel even if it meant new filters.
I would also guess that the eternal FW will add to your back focus but I am not sure if that is the case or if that is even an issue for you.
To get to the same backfocus with the ZWO OAG and C3 as it would be with a full ZWO system, you need to add a 3mm spacer (applies to built-in FW only).
📷 OAG.png
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Not that it helps or matters, this is one that has a 6.12mm back-focus that is made for the C3 or G3 and the Astrodon MMOAG.
Thank you Bill and Bob. For how long have you been imaging with Moravian? I know that they are well regarded, but what is your opinion?
CS
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I've had mine for about 2 years now, at the time FLI had not come out with their versions yet, so I went with Moravian. It was my only second option, otherwise I would still be using my FLI CCD's.
Nicolas Molina · Jan 9, 2026, 05:48 PM
Thank you Bill and Bob. For how long have you been imaging with Moravian? I know that they are well regarded, but what is your opinion?
CS
I have had one unit for only a few months and it has not been used much due to weather.
OTOH, the other unit I have had for almost 4 years and it has been used a huge amount since is is at the remote site. The only thing it has required is a change of desiccant and one session of filter cleaning and blowing dust and insects out of the heat sink. It has been flawless otherwise.
FYI, Tolga tells me that he maintains a stock of parts such as main boards so some (but not all) repairs can potentially be done in the US
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Thanks Bob and Bill, again. I have to buy it directly from Moravian. I’m in Chile; there is no official distributor here. It will be used in a remote observatory in Atacama, 800 km from where I live.
I think I will buy both C3 and Moravian external filter wheel. I have to check if I can use my ZWO OAG-L. Bill, what issues did you find with Moravian OAG?
Bill, I know FLI makes great cameras, but do you think Moravian isn’t at the same level? Or do you prefer it because you’re used to it?
Nicolas Molina:
Bill, I know FLI makes great cameras, but do you think Moravian isn’t at the same level? Or do you prefer it because you’re used to it?
Nicolas Molina · Jan 9, 2026, 07:14 PM
what issues did you find with Moravian OAG?
Bill, I know FLI makes great cameras, but do you think Moravian isn’t at the same level? Or do you prefer it because you’re used to it?
I agree with Bob. Although I have not owned an FLI camera for well over 20 years, my impression of them is that they are overpriced, albeit good quality. The biggest issue with Moravian is not really Moravian but the present damn tariffs.
The issue with the OAG is that is is very basic with poor FOV and poor adjustability.
I would also NOT recommend the Moravian OAG. I ordered it with my C3-61000 pro and have never used it. Getting to focus is a very painful experience. Unlike their cameras, the build is also flimsy. If you have the backfocus, get an Optec Sagitta. Moravian sells adapters that allow you to mate the Sagitta with the Moravian EFW easily.
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I fully agree. The original OAG is terrible and focusing is very basic and inaccurate, but I’ve also bought the new type MarkIII OAG they developed. It has a better and more accurate way to focus, but the available focus distance is really very short (4 mm), so gives problems too if you’re not already in focus with the guide cam.
However following the guidelines with the OAG guide sensor backfocus distance at 22.5 mm (in my case with C3-26000EC PRO, external filterwheel type M (10 × 36 mm filters unmounted) and C3-OAG offers perfect results.
The C3-OAG is delivered with a 10mm CS-1.25” adapter, which fits my Lodestar PRO guidecam, so the total backfocus will be 22.5 mm.
See :
https://www.gxccd.com/art?id=766&cat=1&lang=409
and page 50 of the C3 Manual :
https://www.gxccd.com/download/C3%20Manual.pdf
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Good morning
I just received the Moravian C3-61000 with an external filter wheel and OAG.
I tried it this morning with SGP and encountered a small "problem."
When I disconnect the filter wheel (via SGP) and reconnect it (via SGP), it always tells me it's on the luminance filter, even though it might actually be on the green filter.
However, if I tell it to go to the green filter, the wheel stays still, as it should.
Basically, it's as if it's just an initial reading problem, as if it's not updating in SGP.
Do you have any suggestions?
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I had similar problems but found the solution after reading the camera manual :
All new setups with external filter wheels, which are fully controlled by the camera, require an initialization the setup with the GxNumFilters tool, to inform the camera about the external filter wheel properties which will be written into the camera software before it will work correctly.
(It’s explained in the camera manual too)
You can find this tool here as well as the newest camera firmware :
https://www.gxccd.com/cat?id=150&lang=409
Tool for setting of number of filter positions in Cx and Gx camera filter wheels v3.0
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I have also read that there Is an heating module in the C3-61000 that Is set to 100%. Is It the correct value?
Hi,
In the context of the Moravian Instruments C3-61000 or C3-26000 series astronomical cameras, the "heating module" refers to integrated front glass heating elements designed to prevent fogging or dew formation on the camera's optical window.
Function and Control
The heating system is a critical component for long-exposure astrophotography, where cold sensor temperatures (managed by a separate cooling system) can cause moisture to condense on the external glass.
Anti-Dew Protection: The heating elements are positioned at the front of the camera to warm the glass just enough to keep it above the dew point.
Manual Regulation: Unlike the sensor cooling system, which is automatically regulated to a precise temperature (e.g., ±0.1 °C), the front glass heating elements are typically regulated manually between 0% and 100% and are not controlled automatically by the camera's internal logic.
I’m using a 50% heating level and always use a sensor temperature of -10C.
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Perfect explanation, very help full!