DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   BlackMagic Cinema Camera (https://www.dvinfo.net/forum/blackmagic-cinema-camera/)
-   -   BMPCC 3D LUT appear overexposed (https://www.dvinfo.net/forum/blackmagic-cinema-camera/527373-bmpcc-3d-lut-appear-overexposed.html)

Frank Grygier March 21st, 2015 08:39 AM

BMPCC 3D LUT appear overexposed
 
When I apply a LUT or use FilmConvert in Premiere CC the footage appears way over exposed. I get similar results when using Raw or Prores. Any thoughts.

Gary Huff March 23rd, 2015 07:42 AM

Re: BMPCC 3D LUT appear overexposed
 
How are you exposing your image?

Chris Medico March 23rd, 2015 07:58 AM

Re: BMPCC 3D LUT appear overexposed
 
It could be that you have exposed your image above the design.

I also would like to know what tools you are using to measure exposure and what values you are exposing to.

Frank Grygier March 23rd, 2015 11:42 AM

Re: BMPCC 3D LUT appear overexposed
 
I generally use the histagram on the Pocket Cinema Camera and 100 zebras for the highlights.Is it critical to expose to the right for the best results wen using a LUT. Any thought on VisionColor ImpulZ? - 35mm Film Emulation LUTs

Thanks

Chris Medico March 23rd, 2015 12:32 PM

Re: BMPCC 3D LUT appear overexposed
 
Can you post some images that show where you are exposing things?

Do you have a grey card? That is an essential tool to shooting LOG or RAW.

Chris Medico March 23rd, 2015 12:56 PM

Re: BMPCC 3D LUT appear overexposed
 
I just checked out some examples on their website and they are setting skin tones between 40% and 60%.

Where are your skin tones falling on your exposure?

Chris Medico March 23rd, 2015 01:01 PM

Re: BMPCC 3D LUT appear overexposed
 
1 Attachment(s)
Here is what I measure.

Frank Grygier March 24th, 2015 01:23 PM

Re: BMPCC 3D LUT appear overexposed
 
Thanks for your guidance. I will get a screen shot for you this evening.

Frank Grygier March 24th, 2015 01:24 PM

Re: BMPCC 3D LUT appear overexposed
 
So skin tones are about middle grey?

Gary Huff March 24th, 2015 05:53 PM

Re: BMPCC 3D LUT appear overexposed
 
Quote:

Originally Posted by Frank Grygier (Post 1880718)
So skin tones are about middle grey?

No, they should be around 60IRE.

Frank Grygier March 24th, 2015 09:11 PM

Re: BMPCC 3D LUT appear overexposed
 
Got it.
Thanks for putting me on the right track.

Gary Huff March 24th, 2015 09:12 PM

Re: BMPCC 3D LUT appear overexposed
 
Actually, I should clarify that 60IRE is for Rec.709. So once you de-log the footage, it should ideally be in that range.

Chris Medico March 25th, 2015 03:30 AM

Re: BMPCC 3D LUT appear overexposed
 
The thing to do is to buy a grey card and do some exposure tests. That will allow you to know exactly what you should expose to for the best results with your LUT of choice.

As an example when I shoot S-LOG the design for that curve is for mid grey to be at 38IRE. If I stay close to that my LUT works well. LOG isn't RAW so that exposure won't work for you.

With a $20 grey card and a few hours playing around with your camera you'll be able to get it dialed in just right and have a great method for nailing your exposure on set. Remember to keep the card square to the lens. Don't tilt it up or down. Straight at the lens.

Frank Grygier March 25th, 2015 08:38 AM

Re: BMPCC 3D LUT appear overexposed
 
I do have a grey card but have neglected to use it. I have been relying on zebras and histogram.I will do some testing and get back to you all with the results. I can see now that I am overexposing the footage.

Thanks to you all. It is great to have this forum.

Alex Humphrey June 16th, 2017 02:34 PM

Re: BMPCC 3D LUT appear overexposed
 
I'm on a different camera currently, but I'm finding the same answer for 709 Log as well as raw cameras is an incident light meter. Middle grey 35-40 IRE seems to be the most common middle ground on most cameras, 709, Log, and raw.. so maybe try it out or meter a grey card to read around 35%-38%. My Lumu ($59 at amazon) light meter ball that plugs into my iPod touch and $29 Cine Meter II app work well, though a real light meter that doesn't have a iPod touch running an app would be better, but more expensive.


All times are GMT -6. The time now is 11:06 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network