eric gustavo petersen | cinematographer { i.a.t.s.e. | local 600 }

photographic testing | part two – printer lights & emulsion testing

Tests vary from cinematographer to cinematographer and from production to production. Here again, you’re trying to learn how your decisions will affect the images of the production you’re about to start. What I’m imparting here is the way I conduct tests based on how I was taught by Richard Crudo, ASC – with some changes. Remember, like most things in life, you’ll have to find your own way. So use this as a guide and when you understand the principles, modify, improve, and make it your own.

What we’re ultimately aiming for is a matter of control over the images – from the negative to the dailies to the final release print. That aim is achieved by arriving at a set of printer lights – predetermined by the cinematographer and based on the lab chosen – and used over the run of the show (baring any changes that might come about over the run of the show). Establishing these printer lights will have the added benefit of making your answer and release printing much easier since you’ll only have to fine-tune the image.

Another goal is to arrive at the correct E.I. for the film stock chosen and for the process you’ll be subjecting the film through during processing. You’ll also be testing the exposure latitude of the film stock. While establishing a set of printer lights to use for the run of the show, it’s not a bad idea to also find a set of lights that would work for the various situations that the show will encounter, i.e. day interior, night exterior, etc.

Before starting these tests, make sure you’ve done all necessary lens and camera tests.

The Test – Finding you printer lights

Set the light (for example, a 2K junior for Tungsten stocks or a 575HMI for Daylight stocks) at 20° off lens axis lighting the scene to an f5.6. Have the shadow fall on black card – this will give you a very black reference area. Also, don’t use any fill light or diffusion on your light.

Get a stand-in (or stand-ins) with a representative skin tone and neutral clothes to stand in front (about a foot or so) of a black and white 4x8 show cards. Shooting at an aspect ratio of 1.85:1, a 40mm lens (from your lens test, use only one lens for the following tests) with the camera set back about 8 feet from the stand-in should fill the frame nicely. Be careful to protect against spill hitting the lens.

For these tests, remember, always use the same T-stop – vary the light, not the lens. For this example, we’ll be using a T2.8. It’s not a bad idea to tape you T-stop ring to prevent it from accidentally changing over the course of the test. Your best bet is to change to shutter angel, but you can use ND filters, or cut the light with scrims, nets, and ND gels on the light. Don’t use a dimmer on the light – that will change the light’s color temperature. How the film handles shadow detail is revealed in the underexposure part of the test, and is general the more important part to take note of. If you plan on using filters, place the appropriate grade in before the test.

Testing Notes:

Your Name	[ _____ ]	Processing (normal or forced)	[ _____ ]
Production Title	[ _____ ]	Foot-candles	[ _____ ]
The Date	[ _____ ]	Lamp & color temperature	[ _____ ]
Emulsion (type & number)	[ _____ ]	Exposure (normal (N), over (O), under (U))	[ _____ ]
Exposure Index (E.I.)	[ _____ ]	Lab (especially, if more than one)	[ _____ ]
Lens stop	[ _____ ]

The camera reports should indicated the following information for the laboratory:

· DEVELOP __________

(normal, pushed, pulled, or special process like bleach by-pass, cross-process, flashing, etc)

· PRINT THIS NEGATIVE TWO TIMES:

First Pass: Print on best light for gray card / normal exposure only.

Second Pass: Correct each take back to normal at 1/2-stop increments.

(This might be on an 8-point per camera stop scale or 6-point per camera stop scale depending on the lab you’re using.)

· Make it clear that: Normal exposure should all print at the same light in all cases!

· Do not join these rolls together or to any other roll.

Gray Card

Shoot 20’ of gray card to start off the test. Fill the frame with a gray card making sure that you evenly light and accurately measure the card.

Over/Under

Shoot about 20’ of film per exposure. If you plan on only going 2-stops over/under, light for a T5.6.

	Shutter angle / filter	Shooting T-Stop	Light for
NORMAL	180°	T2.8	T2.8
+1/2	135 / ND3	2.8	T8
+1	180 / ND3	2.8	T8
+1 1/2	135	2.8	T8
+2	180	2.8	T8
NORMAL	180°	T2.8	T2.8
-1/2	135	2.8	2.8
-1	180 / ND3	2.8	2.8
-1 1/2	135 / ND3	2.8	2.8
-2	180 / ND6	2.8	2.8
-2 1/2	135 / ND9	2.8	2.8
-3	180 / ND9	2.8	2.8
NORMAL	180°	T2.8	T2.8

When reviewing the projected film, take a look at the laboratory’s printer-light notation. You should find out what are the lab’s “normal” printing lights. We’ll assume “normal” is 25-25-25. The first roll will play at the 25-25-25 and any changes in exposure will be a direct result of the changes to the light. Pay attention to color shifts due to exposure since this is an indicator of how the stock hold up to extremes.

Roll two will have the same series of exposures, but this time they’ll be corrected back to normal by the Hazletine timer. What you’ll get should look something like this:

(For this example, 8-points equals 1 stop of density change.)

Gray Card	25-25-25
NORMAL	25-25-25
+1/2	29-29-29
+1	33-33-33
+1 1/2	37-37-37
+2	41-41-41
NORMAL	25-25-25
-1/2	21-21-21
-1	17-17-17
-1 1/2	13-13-13
-2	09-09-09
NORMAL	25-25-25

Pay particular attention on what’s happening to the black and white show cards. There you’ll notice grain, color shifts and variations in detail as well as information about detail. Another area to pay attention to is the forehead where affects on skin tone will be noticeable.

To determine the Exposure Index (E.I.), review the corrected pass for flesh tones, grain structure, and shadow detail. After choosing the one you consider the best looking, refer to the lab’s printer light’s notation. Those numbers will be the number’s you use for that exposure. It’s a good idea to shoot an additional test with those numbers and with the same setup to confirm these new numbers.

What now? Well, once you’ve got the exposure index and printer lights you like for the stock and lab you’re using, make sure that the camera reports going to the lab during production indicate that the dailies be printed using your numbers instead of the timer’s judgment call on how the footage should look. This will help you and the lab determine if exposure troubles arise.

Additional testing - Hair, Makeup and Scenic

If time is limited, take the emulsions you plan on using and do at least one interior test with costumes and set colors, trying to vary the lighting in the approximate condition you expect to encounter on your project. Try to do some exteriors with stand-ins in appropriate costumes. If the costumes aren’t available or finished, the wardrobe department might have material available that can be place about the test set. Another option is to request from production a large studio or open space where to sets can be roughed in. Include set pieces the production designer proposes on using. Art department might also want to include squares of wood painted with various colors and types of paint to see how it will render on film. Get a dolly to track from a close-up on the actor, pulling out to a wide shot of one set then track to the other set, then finally, track in to a close up. Hold a little on each close-up and wide shot to give enough time for analysis during projection. And if still more time is available, do the above two with some filters and a wider variety of film stocks. Repeat the above test after reviewing the initial results with the Director, Production Designer, Costume Designer, and Make-up Artist. And finally, introduce the lab processes into the equation.

Lab Continuity Tests

While rare, these simple tests can be used as a measure of how accurately and consistently the lab is handling the film that you send them. One is to expose a full can of film (1000’ for 35mm and 400’ for 16mm) in much the same way as described in the above test – i.e. black and white show cards, a stand-in, and gray card. Unload the magazine and divide the exposed film into lengths of approximately 100’ and place them into separate film cans. Label and store these test rolls. At various and regular times during production, the test rolls are set to the lab for processing. When all test rolls return from the lab, have the editor cut 20’ sections from each test roll and splice them together in the order they were sent to the lab. What you’ll find are changes in density, color shifts, grain and contrast.

For additional information on these tests, consult the ASC Manual, 8th edition (ASC Press),

Image Control (Focal Press) by Gerald Hirschfeld, A.S.C.,

or Camera Assistant (Focal Press) by Douglas C. Hart.

I would like to thank Richard Crudo, ASC and Oliver Stapleton, BSC for their instruction.

For examples of Hair and Make-up test information, visit the ASC website.

© 2003 - This material is the sole property of Eric G. Petesen

This material may not be changed, reproduced or citied without the expressed written consent of Eric G. Petersen.