GH5 How to get the best low light, high quality from a GH5

The GH5 lowlight capability really needs to be compared to what another comparable image IQ wise is usable at...for a given ISO...in my case that would be the GH5 at 3200, but if I'm losing light and have to make the shot, I could use 6400...the noise can be dealt with, and the color is there for my taste....useless to have a camera that can shoot in the dark with an unusable image, except as a gimmick...in practical terms, if you can't get it at 3200ISO on an F1.4, add some lights.
 
Shirozina said:
Most of the artefacts ( particularly banding) are a product of high compression and not bit depth. 8bit 4.2.2 from the A7s HDMI in prores is very robust and won't break apart unless it's seriously abused.
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Banding is a consequence of insufficient bit depth.
 
Tom Roper said:
Banding is a consequence of insufficient bit depth.
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It's also a consequence of high compression found in many internal camera codecs esp those originally designed as final delivery codecs and not capture codecs.You can easily test this yourself by taking an 8 bit tiff with a softly graduated tone like a sky and then saving it in progressively smaller jpeg data sizes ( all 8bit) and seeing the banding get worse.
 
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cyvideo said:
I seem to remember that the maximum input aperture for a Metabones Speed Booster is f/1.26. That would indicate that there is no 'speed' advantage in using lenses with apertures larger than f/1.2.
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A 50mm f/1.2 lens attach to a 0.71x SpeedBooster will causes the lens to perform as a 35.5mm f/0.95, but often the camera erroneously displays the aperture as only being f/1.2. Unsure if the error is the SpeedBooster’s, or the body’s, but the actual aperture remains f/0.95.

Any focal reducer, including Metabones’ SpeedBooster(s), introduce their own optical issues, & suggest the OP throughly test before purchasing. Same goes for the m4/3 Voigtlander(s), which get a bit ‘dreamy’ when used wide-open.
 
Bern Caughey said:
A 50mm f/1.2 lens attach to a 0.71x SpeedBooster will causes the lens to perform as a 35.5mm f/0.95, but often the camera erroneously displays the aperture as only being f/1.2. Unsure if the error is the SpeedBooster’s, or the body’s, but the actual aperture remains f/0.95.
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It's by design, not an error. f-numbers less than 1.0 can screw with cameras which haven't been designed to read such low numbers, so Metabones sets pre-SB f-stop for lenses f1.4 and faster, and sends the post-SB f-stop for lenses with f1.5 and up. The actual light transmitted is always 1 stop (or 1.3 stops for the XL) faster.

HTH

Paul :)
 
Re: low light and light.Anyone here had experience with Northern Lights? What camera do you think would be the best for filming it?
I have access to GH5, Canon C300m2, Sony A7r2.
Would Sony a7s2 be better due to low light or would the banding be severe?
 
Tom Roper said:
Banding is a consequence of insufficient bit depth.
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Banding is a consequence of insufficient density of code values as distributed into some part of the output color space. That's a function of the camera's color space, the digital encoding scheme, the bit depth, and how you post-process the video. Bit depth alone won't tell you if there will be banding. And you'll only see banding if the image has the kinds of gradients that make it apparent.
 
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Vino said:
Re: low light and light.Anyone here had experience with Northern Lights? What camera do you think would be the best for filming it?
I have access to GH5, Canon C300m2, Sony A7r2.
Would Sony a7s2 be better due to low light or would the banding be severe?
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I'd take an A7s, an external recorder and some fast lenses.
 
My eyes says that using GH5 10bit HLG gives less noise and better low light quality than other profiles. I have not used it much. What do others think?
 
Vesku said:
My eyes says that using GH5 10bit HLG gives less noise and better low light quality than other profiles. I have not used it much. What do others think?
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Slightly better noise than V-LOG (but the GH5 is pretty noisy / unsuitable for low light work). It's my go-to profie now as it can contain the whole DR of the sensor and maximises the entire data range of the codec (unlike V-LOG). I see no reason to use V-LOG anymore.
 
Thanks for the reply Shirozina, although I was hoping for a different answer...:-). If I want to go wide / anamorphic - gh5 or fake/ crop anamorph on C300m2?
 
Shirozina said:
Slightly better noise than V-LOG (but the GH5 is pretty noisy / unsuitable for low light work). It's my go-to profie now as it can contain the whole DR of the sensor and maximises the entire data range of the codec (unlike V-LOG). I see no reason to use V-LOG anymore.
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Good to see you've come around :) HLG is the best thing to happen to the GH5 since its release!

Cheers,

Paul :)
 
I did a screen test for my next feature last weekend. The scene takes place in a dark basement. The final intent is a very, very dark image with strong directional, almost rim lighting.

My experience told me that no matter the final intent, I should bring up the light levels and expose for a grey card at 40%. (Crush it later in post.)

I didn't listen to my experience. I was rushed, I was trying to direct talent that had barely rehearsed and had not worked together, I was worrying about audio, etc., etc., etc. I let my other camera operator talk me into exposing for "the look" in camera. (3 GH4's.) That involved recording at ISO 200 with ND filters.

Man, I wish I hadn't done that. There are cameras for which you can do this. No member of the GH line is one of them.

No matter your ISO or profile, GH3/4/5 sensors are noisy in the shadows. When you record noise, you're not recording detail. I made my life in post so much harder. Good thing it was a test.

So, my addition to this thread is:

- Shoot with a profile that captures as much DR as possible. (VLOG-L or HGL.)
- Expose by the book (grey card lit with subject lighting, exposed to 40 IRE)...or...
- ...Expose to the right (ETTR)
- Do what you can optically to get more light (open aperture, speed booster, etc.)
- Don't be afraid to increase your shutter angle within reason. For normal action, no one will notice if it is open a little more than 180º. (People WILL notice if you close it LOWER than 180º.)
- If you've done what you can optically and it's still not exposed properly, increasing your ISO (1600 on the GH4, 3200 on the GH5) yields less noise than underexposing.
 
Yep. Always get as much light onto the sensor as you can, for cleaner shadows in post. It's a simple matter to bring down shadows and increase contrast once you have the footage in your computer. It's a pain in the backside to have to de-noise, lift crushed shadows and try to recover the information if you don't ETTR these cameras.

Cheers,

Paul :)
 
I shooted a quite dark and badly lightened Christmas happening with GH5 HLG. When I watch those clips the tonality and noise are more pleasing than I have ever seen with GH5. 10bit HLG is the best option for GH5 low light. How to watch or grade it is another question.
 
Vesku said:
I shooted a quite dark and badly lightened Christmas happening with GH5 HLG. When I watch those clips the tonality and noise are more pleasing than I have ever seen with GH5. 10bit HLG is the best option for GH5 low light. How to watch or grade it is another question.
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This perception is simply because the HLG curve stores shadows within a traditional gamma curve. Put simply, the darks are dark. VLOG-L raises the shadows, revealing the noise. Adjust the shadows back to natural a display range, and the noise won't be evident...or at least not more evident than in any other profile.

HLG isn't "better" than a LOG profile. It's just different. I think a lot of people find HLG easier to work with because half of the image is "normal", but it isn't cleaner than VLOG-L, doesn't retain more DR, etc.
 
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