Exponometry Excercise 1

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Code Completion Credits Range Language Instruction Semester
304EEX1 credit 1 2 hours (45 min) of instruction per week, 4 to 9 hours of self-study English summer

Subject guarantor


Name of lecturer(s)

Miroslav GÁBOR, Josef PECÁK


The students learn determination of corrected sensitivity of the film negative materials. They will get acquainted with the issue of the digital image exponometry.

Part 1: Exponometry of the assigned types of scenes

Program of the exercise:

A/ Sensitometric test and its evaluation

B/ Students (in pairs) photograph the following scenes:

1/ A grey chart with a reflectance factor of 0.18 in exposure lighting

2/ Medium Close-up of Person with the chart in city exteriors (a grey street) - under the condition of the overcast sky, diffuse lighting

a/ standard

b/ +1 FSTOP

c/ +2 FSTOP

d/ -1 FSTOP

e/ -2 FSTOP

f/ -3 FSTOP

g/ -4 FSTOP

3/ Same as the scene 2 with the side sun light (a-f)

4/ Same as the scene 3 - back light (a-f)

5/ Person with the chart against a dark passage - overcast sky (a-f)

6/ Same as the scene 5 with the side sun light (a-f)

7/ Medium Close-up of Person with the chart against the window (a-f)

Have 3 prints processed: a/ standard print

b/ +12 printer points

c/ -12 printer points

The students make a record of the brightness structure of the scene (grey chart for maximum and minimum brightness, skin, background.).

The analysis and evaluation will take place together with the tutor at the seminar.

Stock: 2 cassettes of film stock for two students - ECN II colour negative

Part 2: Brightness analysis of primary reality in relation to film stock

Program of the exercise:

The student will photograph the premises of the Slavia café - towards the embankment. There will be a person sitting at the table in the forground, and luminance will be measured on the person's face - both Key Light and Fill Light. The illumination will be measured using a Spotmeter on a grey chart with a reflectance factor of 0.18. This shot will be the first and will be used to determine the filtering and the print points to be used for all other shots. The subsequent shots will be underexposed in steps by 1 FSTOP down to the min. relative reflectance (0.18; 0.09; 0.04; 0.02; 0.01) and overexposed in steps by 1 FSTOP up to the max. relative reflectance of 0,72 (0.18; 0.36; 0.72) - resulting in a sequence of 6 FSTOPs ranging from lowest underexposure to highest overexposure.

Then the student will do the same with a scene in the opposite direction - towards the interior of the café - so that the windows are not visible.

The student will thoroughly measure and record the various luminance values for the individual planes of the image taken - the sky, the Petřín hill, the bridge, the café's pillars, the gloss of the figure's clothes, the table top, the shadow areas etc.

Stock: 1 cassette film stock for two students - ECN II colour negative

The analysis and evaluation will take place together with the tutor at the seminar.

Learning outcomes

Practical introduction to basis of film exponometry.

The students verify the relation between the primary reality and its reproduction on film stock (the negative-positive process) and learn to practically use the spot exponometry method to determine the limit values of brightness of the shot scene, reproducible on release print and observable during projection (the definition of the „limit white“ and „limit black“). They will also learn the possibilities for correcting incorrectly exposed negative stock during the printing process and the contrast (and/or saturation and colour) degradation of image when using the extremes of the film stock's sensitometric curve.

Prerequisites and other requirements



American Cinematographer Manual

Evaluation methods and criteria

Attendance at the lecture, activity during discussions



Further information

No schedule has been prepared for this course

The subject is a part of the following study plans