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Are you using a Dark Filter in your setup?

Equipment Filter Wheel 3D Printing
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Are you using a dark filter?
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Johannes Maximilian Möslein avatar
Johannes Maximilian Möslein avatar
I printed a dark filter for my filter wheel, and started using it for bias frames and dark frames. I find it really convenient, because I don’t have to disassemble the rig to take those frames, just put the lens cap on, set the filter wheel, and start.

I haven’t tested it for darks longer than 10 seconds yet, we’ll see if there are light leaks affecting longer frames.

Now I’m just curious how many of you are using one.
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Scott MacKenzie avatar
Scott MacKenzie avatar
I picked one up on Agena, put it in a ZWO filter wheel, and shot perfect Darks for 30, 60, 180, and 300 seconds.
Reg Pratt avatar
Reg Pratt avatar
Nope. When I image at home I just cover the rig with the Telegizmos and switch the the sii filter. At the observatory it's dark enough that the scope doesn't need to be covered at all just sii and go.
Shun-Chia yang avatar
Shun-Chia yang avatar
I have a dark filter in my filter wheel because I am using a non-cooled camera, and I also want my setup to be fully automatic.
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Oscar avatar
Oscar avatar
It would save a lot of time if used in an EFW.

I might do this later.
Peter Graf avatar
Peter Graf avatar
I am also using a dark filter in my filter wheel. But when shooting darks during daylight I additionally have to cover the whole rig as I somehow experienced little light leaks. And to really have no light leaks, I just unscrew the camera and put the plastic cap on. smile

On the other hand, it is sometimes said that dark frames are no longer absolutely necessary with the latest CMOS sensors.
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Scott Lockwood avatar
Scott Lockwood avatar
No dark filter. My camera has a shutter.
Fritz avatar
Fritz avatar
Peter Graf:
I am also using a dark filter in my filter wheel. But when shooting darks during daylight I additionally have to cover the whole rig as I somehow experienced little light leaks. And to really have no light leaks, I just unscrew the camera and put the plastic cap on. 

On the other hand, it is sometimes said that dark frames are no longer absolutely necessary with the latest CMOS sensors.

The plastic cap might not be enough for longer darks as IR will pass it.
Huib Wouters avatar
Huib Wouters avatar
I find that with the (metal) lense cap on, I can take darks in daylight or at night, doesn't make any difference. No need to cover the scope.

In my old setup, I had some light leaks around the camera connection (Sony A7), but some laps of black tape solved the issue.
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Peter Graf avatar
Peter Graf avatar
Fritz:
The plastic cap might not be enough for longer darks as IR will pass it.

Thanks. Good point, as many cameras just have a clear glass filter in front of the sensor.
Wouldn't that also be a problem with a 3D-printed dark filter?
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Fritz avatar
Fritz avatar
Peter Graf:
Fritz:
The plastic cap might not be enough for longer darks as IR will pass it.

Thanks. Good point, as many cameras just have a clear glass filter in front of the sensor.
Wouldn't that also be a problem with a 3D-printed dark filter?

Well, can't answer that as I have not the slightest idea about 3D printing. I use a metal cap which works fine for me
Keith Mombourquette avatar
Keith Mombourquette avatar
I use one on my OSC rig, but not mono because all 7 positions are filled with filters.  On my 5 position wheel with my OSC camera I put a dark filter in position 1 as extra protection from dust.
Brent Newton avatar
Brent Newton avatar
Never bothered. Telescope has a cap (motorized Flats panel now, but same effect) and when I retake any Darks I typically wait for a cloudy night to do so anyway, so its Dark enough in the storage garage that it doesn't matter
Monty Chandler avatar
Monty Chandler avatar
What would you use it for?   I read the comments about darks, but those are an annual thing taken during the day in the garage or somewhere similar.   Maybe for dark_flats?  Of course I still need the t-shirt for the flats.
Peter Wacker avatar
Peter Wacker avatar
Yes I use one in my setup. Is it really of any value? To be honest; I doubt it. 
For the darks itself it isn't really any help, as the "filter" won't give total darkness to the camerasensor. Consequently one still has to put the lid on the telescope.