Jump to content


Photo

short end test numbers


  • Please log in to reply
4 replies to this topic

#1 C.J. Scheppers

C.J. Scheppers
  • Basic Members
  • PipPip
  • 27 posts
  • Cinematographer

Posted 21 November 2007 - 11:57 PM

Hi, what are fairly good and bad test numbers for short ends? For example, 12-63-102?

I know blue is the third number and goes bad (higher number) quicker than the first two.

Thanks.
  • 0

#2 C.J. Scheppers

C.J. Scheppers
  • Basic Members
  • PipPip
  • 27 posts
  • Cinematographer

Posted 13 December 2007 - 05:49 PM

(bump)
  • 0

#3 Jonathan Bowerbank

Jonathan Bowerbank
  • Basic Members
  • PipPipPipPip
  • 2815 posts
  • 1st Assistant Camera
  • San Francisco, CA

Posted 13 December 2007 - 11:49 PM

Hi, what are fairly good and bad test numbers for short ends? For example, 12-63-102?


I don't even think 102 is possible. I think most timers only go as high as 50, but there may be exceptions out there.

In a supervised timing you set your own lights according to what you're going for, so there really isn't a good or bad in this instance.

But if you're just wanting to know what your lights are, going off of a timed print referring to a greycard shot at the beginning of the roll, then your numbers shouldn't stray too far from the base 25-25-25, give or take a few points here and there.

And of course, overexposing and underexposing your negative will increase or decrease your numbers in accordance with what system your lab uses. At Monaco here in SF, every stop is in increments of 3.
  • 0

#4 Jonathan Bowerbank

Jonathan Bowerbank
  • Basic Members
  • PipPipPipPip
  • 2815 posts
  • 1st Assistant Camera
  • San Francisco, CA

Posted 14 December 2007 - 03:53 AM

I apologize if I misunderstood, I just reread your original post, and may have written a lot about something unrelated, ha ha

Are you asking about a clip test that you had done? If so, I'm sure the lab tech could tell you immediately what those numbers mean in regards to your short end :)
  • 0

#5 K Borowski

K Borowski
  • Basic Members
  • PipPipPipPip
  • 3905 posts
  • Camera Operator
  • I.A.T.S.E. Local # 600 Eastern Region

Posted 14 December 2007 - 10:00 AM

I apologize if I misunderstood, I just reread your original post, and may have written a lot about something unrelated, ha ha

Are you asking about a clip test that you had done? If so, I'm sure the lab tech could tell you immediately what those numbers mean in regards to your short end :)


Even if you did misunderstand, I agree that 102 is almost off the charts.

As both test numbers and printer lights are RGB values, they are related, though I seem to recall the maximal 50 printer light being a different scale than a fog number, in that the printer light number increases more slowly than a comparable increase in fog.

You can also measure these values logarithically in addition to arithmetic measurement, so it does get very confusing.

General rule of thumb: THe higher the number the worse the film is. You can compensate with negative film somewhat by giving the film overexposure. For instance, you cann shoot old 500T stock at EI160-200 to compensate for high fog levels. Greater exposure effectively compresses image information in the upper level of the curve and therefore "boosts" the information above the base fog levels.

Dominic Case would have a better explanation than this. Labs, houses, film manufacturers, and short ends sellers all seem to have their own opinions as to what levels of fog are "acceptable", but really only the user can decide.

One final thing, after a certain point, fog will cause color crossover in the shadows (even with overexposure) that is impossible to correct using optical printing and a PITA to correct even digitallly.
  • 0


Gamma Ray Digital Inc

Metropolis Post

Glidecam

Opal

Visual Products

Aerial Filmworks

The Slider

Willys Widgets

Tai Audio

Broadcast Solutions Inc

rebotnix Technologies

Paralinx LLC

Media Blackout - Custom Cables and AKS

CineLab

Ritter Battery

Technodolly

Wooden Camera

CineTape

Abel Cine

FJS International, LLC

Rig Wheels Passport

Ritter Battery

Wooden Camera

Technodolly

Metropolis Post

Visual Products

Abel Cine

Rig Wheels Passport

Gamma Ray Digital Inc

Paralinx LLC

Broadcast Solutions Inc

rebotnix Technologies

Willys Widgets

Glidecam

CineLab

Media Blackout - Custom Cables and AKS

Opal

Tai Audio

Aerial Filmworks

CineTape

The Slider

FJS International, LLC