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Square or circular?

Moravian Instruments C3-61000 PRO Filters Vignetting
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Riccardo Civati avatar
Riccardo Civati avatar
Hi all

Is true that Moravian C3-61000 Pro needs Square 50x50 filters because with circular filters there Is vignetting?

Riccardo
andrea tasselli avatar
andrea tasselli avatar
It depends on configuration, camera + optical system ahead of camera.
Riccardo Civati avatar
Riccardo Civati avatar
TEC 140 ED with flattener 1x f/7.
andrea tasselli avatar
andrea tasselli avatar
Internal or external FW?
andrea tasselli avatar
andrea tasselli avatar
Either way, 50mm unmounted, round. You might get away with 2" mounted with the internal FW, by a very slim margin though. I wouldn't bank on it, however.
Dark Matters Astrophotography avatar
Dark Matters Astrophotography avatar
With your TEC140 you should be able to use 50mm round filters. If you were to upgrade to a different OTA in the future or to a larger sensor the square filters would be required. If you think that may be a possibility it could make sense to go to the 50mm square filters now.
Well Written Concise
Daniel Carter avatar
Daniel Carter avatar
Riccardo Civati:
Hi all

Is true that Moravian C3-61000 Pro needs Square 50x50 filters because with circular filters there Is vignetting?

Riccardo

I'm using the C3-61000 camera on a 12.5" iDK at f/6.8 and I have the 50mm round filters. They work fine with no vignetting. Like Bill mentioned, if you plan on going with a bigger sensor in the future, the 50x50mm filters would make sense.
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Bob Lockwood avatar
Bob Lockwood avatar
I use 50x50mm on my C3-61000 because I already had them. If the price difference is not an issue, I'd just go with the 50x50mm.
Riccardo Civati avatar
Riccardo Civati avatar
Daniel Carter:
Riccardo Civati:
Hi all

Is true that Moravian C3-61000 Pro needs Square 50x50 filters because with circular filters there Is vignetting?

Riccardo

I'm using the C3-61000 camera on a 12.5" iDK at f/6.8 and I have the 50mm round filters. They work fine with no vignetting. Like Bill mentioned, if you plan on going with a bigger sensor in the future, the 50x50mm filters would make sense.

***Hi Daniel
can you send me your master flat frames stretchd ( all filters)?***
riccardo
Daniel Carter avatar
Daniel Carter avatar
Riccardo Civati:
Daniel Carter:
Riccardo Civati:
Hi all

Is true that Moravian C3-61000 Pro needs Square 50x50 filters because with circular filters there Is vignetting?

Riccardo

I'm using the C3-61000 camera on a 12.5" iDK at f/6.8 and I have the 50mm round filters. They work fine with no vignetting. Like Bill mentioned, if you plan on going with a bigger sensor in the future, the 50x50mm filters would make sense.

***Hi Daniel
can you send me your master flat frames stretchd ( all filters)?***
riccardo

I'll get them to you via private messaging later today or tomorrow morning.
Well Written
Valentine Treshchun avatar
Valentine Treshchun avatar

Hi everyone! I wonder if anyone is using 50×50 square filters with Tak FSQ106 or similar scope with this camera, and is ready to share their flats? I’m using the 2” mounted Baader filters, and while I don’t see any issues with calibrated images, I’d love to compare other’s flats to see if it is worth upgrading to square ones.

My 1xLRGB flat frames bin 2×2 (for the sake of size) if anyone wants to take a look: gdrive link

Image train: fsq106edx4, native focuser & CAA, some m90-m68 adapter rings, MI OAG, MI 7×2” FW, MI C3 61k. Flats taken with PLL Giotto 150mm flat panel cover.

Thanks in advance.

Helpful Engaging
Bob Lockwood avatar
Bob Lockwood avatar
This is a lum 2x2 flat using the C3-61000 Pro and 50x50 filters on an FSQ 106 with the 645 reducer, 381mm fl. No tilt has been applied.
2" mounted filters are too small for this chip, 

Riccardo Civati avatar
Riccardo Civati avatar

With moravian c3-26000 and external filters wheel, Is It ok with 36 mm unmounted filters with apo f/7?

Is there vignetting?

Valentine Treshchun avatar
Valentine Treshchun avatar

@Bob Lockwood thank you for sharing your plat! It looks quite similar to mine, but I’m running native FL of 530mm on mine. Attaching L (screenshot of stretched flat) 📷 L_flat.jpg
L_flat.jpgOf course 2 years after purchasing the camera, I open the MI article on FWs: https://www.gxccd.com/art?id=759&cat=22&lang=409 and they do say that 2” will vignette, 50.4mm will be better, 50×50 are best. 50.4 unmounted offer 3mm extra clear filter aperture:

📷 image.pngimage.pngNow I’m considering whether to upgrade to 50×50 or at least 50.4 unmounted.

Slightly hesitant to moving to 50×50 as this requires a new FW (7×2” and 7×50mm square FWs are different in size), and resell demand for MI external non-standalone FWs is probably 0.

Still looking forward to seeing some example flats from FSQ106 & 50.4 unmounted filters to see if the upgrade is worth it.

@Riccardo Civati according to the above, 36 unmounted should work fine with C3-26k & EFW.