Quick reflection density question

[Michael R 1974]

Hi - what is the reflection density of middle grey/zone V. I guess let's assume 18% grey for middle grey for now.

Thanks

[Bill Burk]

Around 0.75

[Michael R 1974]

Just to be clear - you're talking about reflection (paper) density, not transmission (negative) density, right?

Thanks

[Bill Burk]

Yes, the math is the same I think...

Just to confirm though, I fired up the densitometer and measured the 18% gray card in an old photoguide.

It read exactly 0.75

[Chan Tran]

Hi - what is the reflection density of middle grey/zone V. I guess let's assume 18% grey for middle grey for now.

Thanks

If it's 18% reflectance then the density is .75

[Michael R 1974]

Thanks for the help, guys.

Michael

[Helen B]

For reference the formula is

Reflection Density = log10(incident/reflected)

so for 18% it is log10(100/18)

Best,
Helen