Scarlet Dragon Gio Scope Exposure Test (LLO OLPF)

[Akin A]

Video #2 added 2/27/15 (new version of this video):

http://youtu.be/YCyYJnKkdjk
This is a lighting fill ratio test, using the Gio Scope tool on the RED Scarlet Dragon, with the Low Light Optimized OLPF.
I kept the key light at stop 10, which I find is best for my skin tone.


Resolution: 5K WS (2.37:1) 5120x2160
- downscaled to a 1080p timeline.
Lens: Sigma Art 50mm F/1.4
OLPF: LLO
Shutter: 1/48s
REDCODE: 7:1
ISO: 800
Color Space: DRAGONcolor2
Gamma Curve: REDgamma4
Color Temp: 5500K
Tint: -20


NLE: Davinci Resolve
- Export: DNxHD 1080p 220/185/175 10-bit
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Video #1 added 2/8/15:

http://youtu.be/OmZZjAjJAPQ

This is an exposure test, using the Gio Scope tool on the RED Scarlet Dragon, with the Low Light Optimized OLPF.

I wanted to see effects on image quality when overexposing (without clipping) and underexposing skin, and then fixing the exposure in post.
(I removed the audio, but my lips are slating the key and fill values, according to the Gio Scope)

Resolution: 5K WS (2.37:1) 5120x2160
- downscaled to a 1080p timeline. The zoomed area is a 5K crop.
Lens: Sigma Art 50mm F/1.4
Shutter: 1/48s
REDCODE: 7:1
Color Space: DRAGONcolor2
Gamma Curve: REDgamma4
Color Temp: 5500K
Tint: -17

NLE: Davinci Resolve
- Export: DNxHD 1080p 220/185/175 10-bit

Notes:
- The key stop listed only represents the brightest light splash on my cheek, not the whole key side of my face. Most of the key side of my face (forehead, nose, jaw, chin) was actually one stop lower, as you can see in the Gio Scope image. Having most of the key side of my face at stop 10 (shown with the brightest light splash at stop 11) looks the most accurate. If I was to redo this test, I would make the whole key side evenly lit, with no bright light splashes on my cheek.
- I used the Gio Scope to estimate the aperture value on my Nikon G mount version of the Sigma Art 50/1.4. My Nikon G to Canon mount adapter doesn't have a scale on the aperture ring. I started wide open at F/1.4 and closed down the iris until the Gio Scope read one stop lower, at the same lighting setup.
- I used RED's FLUT adjustment tool to adjust the exposure in post. FLUT value of 1.0 = 1 stop of light.
- For key stop 8, fill stop 6, I moved my lights back instead of closing the aperture, since the lens was already at the minimum aperture, F/16.
- The downscaling from 5K to 1080p, plus the compression of the export (DNxHD 220/185/175 10-bit), plus YouTube's compression, hides a lot of the noise that is visible in the .R3Ds

 

[Patrick Tresch]

Don't you find redgamma 4 to be too dark (contrasty) as a starting point. I do usually prefer redgamma3.

Thanks for your test.

Pat

 

[Akin A]

Don't you find redgamma 4 to be too dark (contrasty) as a starting point. I do usually prefer redgamma3.

Thanks for your test.

Pat

Yeah RG4 is darker, but I chose something that we'd be familiar with, based on the tests we share on this forum. I'd use RLF as a starting point if I was actually grading though.

 

[Eli Jarra]

thanks for sharing this!

 

[Akin A]

New video added 2/27/15 (new version):
Gio Scope Fill Ratio Test

http://youtu.be/YCyYJnKkdjk