GH5 GH5S Noise?

J

JChang

Active member
Hey DVXusers.

Working with the GH5s and noticed in the 120fps shots there was some excessive horizontal noise? could be wrong on what it actually is though. Any thoughts on what this was?

Settings I believe was the following.

NTSC
Mov 8bit FHD 24p
250 Shutter
800 / 1600 ISO?
120FPS

This was outside. Higher ISO cause i accidentally threw on the wrong ND filter so just pumped up the iso to compensate as it was a live event.

Thanks yall!
 

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8-bit, lower light than should be due to your ND, so a high ISO to pump data that's not there, stretched thin on the internal codec.

High ISO is good but the more it has to pull from darker shadows VS brightening up midtones the rougher it gets. The more ISO and low light you stretch thin on 100mbps the worse the quality is going to get.
 
Google 'Blackmagic Horizontal Lines'...looks identical. Camera may need a black balance if possible.
 
Hi - I'm noticing this in high contrast scenes that low light areas have this horizontal streaking, Fixed patter noise on the GH5S. Even in 400 ISO. Particularly evident in V-LOG (in 10 or 8 bit ALL I or Long Got), but also noticeable in HLG which seems to have very strong noise reduction going on. If this is a camera issue - I'd like it fixed! It cleans up ok in Neat Video but I don't want to have to do that to every shot with a bit of contrast in it. Noise In the blacks I don't mind, but these video-y horizontal streaks I don't like.
 
I've been doing a few more tests today comparing various codecs and colour profiles. I'm noticing one key thing. GH5S is noisy in the shadows at any ISO. (with this striped horizontal feel) Even, dare I say it noisy-er in the shadows than the GH5 at lower ISOs. Now, obviously when you start ramping UP ISOs GH5S is a clear winner in terms of how clean it is OVERALL, but in terms of noise in the shadows it is pretty noticeable. What's going on?
 
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I always shoot 60P and do not see this on either my GH5 or the GH5S. Just did another quick test of the GH5S, UHD60P, ISO 6400, shutter 1/60, Panasonic 12-60mm wide open at f2.8 in my dark closet and at this level it was as if I had put the light on so not something I would use at this level in any production as it would be brighter than reality !!!
 
It will do it Ron. Put the GH5s on ISO 320 HLG, remove the shade from a table lamp and position the lamp 1-2 feet in front of a white wall in a dark room with no other lights, in darkness. Make sure you do not clip the light source. Expose for the glowing lamp for 90-100 IRE but do not let it clip. You’ll see the pattern happen on the white wall which will be at a very low IRE, approx at 10 bit code value 32, around 2% IRE, because you exposed for the bright lamp. It is an extreme test. I have the GH5 as well, haven’t noticed it with that model but have not put it to the same test so I have no comment on it.

The noise is transparent, mostly invisible and is obscured in front of a black background at low ISO but for this test you have a white background under strong illumination but exposed so low it is just below the noise ceiling making the noise visible.
 
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I don’t think so, but I have not exhausted the possibilities. But to be clear, it’s not the high iso noise one might expect from filming with the lens cap on at high iso, rather it’s high DR stress, light or white color panel under good illumination but exposed very dark.
 
Well I tried with both the GH5 and the GH5S and cannot see the issue. Used HLG UHD 30P 150Mbps, 10bit 4:2:2, lens was my 12-60 f2.8 -f4 wide open, iso 3200. lamp was at 70% zebra so white wall was clear but underexposed, also did one with lamp at 90%. In Resolve used lift to make the image really washed out and I cannot see anything. Will try again but if I have to go to this much trouble to induce the problem I am not going to see this in the way I normally shoot !!!
 
Ok - so I did another shoot today, using V-Log in very high contrast scenes and various amounts of slow mo and noticed that - its much cleaner in the shadows since I turned 'extended ISO' OFF! Give it a try chaps and see what you think!
 
My tests were done with ext ISO OFF as I had learned that from early on before I got my first GH5 so have not used that since.
 
I was about to make a new thread about this but scrolled down and saw yours. It really seemse like the GH5s is noisier than the original GH5. Even at 400 ISO. I can post some samples later.
 
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