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View Full Version : GH2 GH2 + Vari ND filter Users - Input Wanted



Bassman2003
11-26-2011, 05:32 AM
Hello,

I have been trying some variable ND filters with my GH2 and have found a strange issue when filming outdoors. When there is sky in the frame I see horrible banding. This happens at all angles related to the sun and is not really present when shooting stills. I can't really see the effect anywhere but when sky is present.

So I wanted to ask: Have you seen this? Or could you test with your filters to see if this happens?

I want to go with the variable because it is so flexible, but it looks like a topographical map wherever there is sky.

Thanks for your help!

L1N3ARX
11-26-2011, 01:06 PM
I use a cheap $9 ND Fader that works great until you go right up to the nd400 value, where you start to see banding and that odd purple color cast that you have as well. What ND value are you seeing banding at, all ? Have you directly compared sky footage with the ND Filter on / off? The faders, even the pricier ones seem to fall apart at the higher stops...

Bassman2003
11-26-2011, 03:14 PM
Thanks for your reply. This effect seemed to be there throughout the range of the filter. I am trying to decide which way to go, variable or single filter. I purchased two GH2s to give me a SDOF alternative while shooting outdoors, but shooting outdoors is quite unpredictable. I guess I could go with a 7 or 8 stop filter and adjust ISO & shutter small amounts for exposure. The variable is so easy but the banding is not good.

aljudy
11-26-2011, 07:31 PM
I would like to see two photos side by side from the same position, one with and one without the ND filter you are using. I can't judge if there is a problem with your ND filter or not by looking at one photo only.

Bassman2003
11-26-2011, 07:47 PM
Just to clraify, this is not a photo but a frame grab from my NLE. Trust me, the banding is there the entire time and moves position as I rotate the ND. In still photos the effect is not very visible. I have already gone through this with the company... I am just wanting to see if anybody else has seen this while shooting outside with the sky in the frame.

Thanks

mr bill
11-27-2011, 02:08 AM
You either spend a lot on a vari ND (tiffen, singh-ray, heliopan) or buy ND4 and ND8 filters. Neither will add to the banding already present in the codec

Bassman2003
11-27-2011, 05:50 AM
Mr. Bill, is your reply based upon personal experience? The vari ND filter I am using is one of the expensive choices. If you have one that works outside pointed at the sky in video mode (f 2.8) I would be happy to know which one so I can get it.

Thanks

LoganMackay
11-27-2011, 07:00 AM
so which brand do you have?

Bassman2003
11-27-2011, 07:59 AM
I would rather hear about personal experiences from users than go negative and start a discussion on the brand. Thanks

LoganMackay
11-27-2011, 08:34 AM
The brand you are using is likely the cause of your problem. It is of no help to anyone to leave out a crucial detail like that.

Bassman2003
11-27-2011, 09:55 AM
With respect, I am not posting to diagnose the problem. I am posting to ask if any users have vari ND filters that do not show banding outside with sky in the frame using video mode. Thanks

mr bill
11-27-2011, 01:15 PM
I'm shooting with a GH13 and a GH17 using a tiffen variND and so far haven't run into any banding problems - maybe I've just been lucky (lpowell's 75Mbps peak performance patch). I've had the well-documented problems using the lightcraft workshop ones (both mk1 and mk2) with wide-angle and telephoto lenses.

HTH

Bassman2003
11-27-2011, 02:09 PM
Thanks Mr. Bill. If you have a chance, could you shoot some video of the daytime sky at a wide aperature and rotate the vari ND? Is this free of any banding?

mr bill
11-27-2011, 03:33 PM
They've locked me up again in an edit suite, but I'll see what can be done.

Bassman2003
11-27-2011, 07:16 PM
Appreciate your input.

Bassman2003
11-30-2011, 05:58 AM
Anybody else use variND filters with the GH2?

skyak
12-03-2011, 10:17 PM
I've been using the heliopan variND with the 25mm f1.4.

mr bill
12-04-2011, 03:07 AM
On a very very grey day, I see no banding with the tiffen variND

Bassman2003
12-04-2011, 08:23 AM
Thanks for your test. I wonder if the GH2 sensor is the reason? I am looking at some Cokin "P" series filters for solid filters with some flexibility.

Skylak, could I ask if you see banding if sky is in your frame? If you have a second, could you do a little test?

Thanks

MalfunctioningHuman
12-04-2011, 11:25 AM
I really don't think it's your specific ND. What you are seeing is the result of the ND filter doing its work properly. Basically, by using the ND filter you are increasing dynamic range in the sky (more gradations in the sky.) At specific times of the day, depending on the position of the sun, and in absence of clouds, this will cause banding due to the 8 bit color reproduction of the GH2. It's a well known issue.

Bassman2003
12-04-2011, 12:18 PM
I see banding with the GH2, I agree, it is a weakness of the camera. But if I go out and film with the variND on and see huge banding in the sky, then take the filter off and the banding goes away, it has to be related to the filter. What do you think?

mr bill
12-04-2011, 01:31 PM
Seems reasonable

Lucas Adamson
12-04-2011, 05:00 PM
I see banding with the GH2, I agree, it is a weakness of the camera. But if I go out and film with the variND on and see huge banding in the sky, then take the filter off and the banding goes away, it has to be related to the filter. What do you think?

Except, there are variables there at play. If you shoot without a vari-ND, you have to compensate for the brightness somehow, which means either aperture or ISO or shutter speed. Any of these can affect the results. The only true way to get a solid "blame" for the filter, is to do a direct comparison with another equivalent filter. I realise that's expensive/ awkward to organise. Is there a good vari-ND comparison online? I've been looking, in vain....

Bassman2003
12-04-2011, 07:28 PM
I also own a cheaper variND that shows the same behavior. I thought by stepping up to the $200 version the problem might go away. I was about to buy some screw in 7 stop filters when I read about the magenta color cast in the first B&H review. Seems like there are thorns on either side of the road.