KODAK PROJECTION PRINT SCALE

This calibrated piece of film was meant to make life simpler for the home darkroom enthusiast by supplying a graduated series of neutral density filters to attenuate the light of a projected photographic negative onto a piece of photographic paper.  The neutral densities were selected so that when a 60" exposure is given, the photo paper below each pie slice got the equivalent of that many seconds on the indicator circle.  (Note that when referring to step numbers in the sensitometry spreadsheets, these equivalent seconds are what are called out.)

Looks like something got spilled on the package!

For this incarnation, each pie wedge was measured with an X-Rite Model 331 Densitometer, and also measured by a BPW-34 Silicon Detector connected to a Newport Model 820 Power Meter instead its 1 cm2 detector to measure how much laser light is passing through each wedge to calibrate the exposure dose.  The exposure time was chosen so that approximately 100 µJ/cm2 could be obtained with one of the median wedges, like step 8.   Here is this calibration, using 40" as the exposure time for the film sitting on top of the device:

Step

Exposure

Step

Exposure

 2

23

12

133

3

40

16

208

4

45

24

283

6

83

32

400

8

92

48

600

Here is an example of a family of exposed wedges, developed for a variety of times:

The most-trusted developer

Here is the density data gleaned from the above:

Step

Exposure

Agfa 1'

Agfa 2'

Agfa 4'

Agfa 6'

2

23

0.25

0.38

0.63

0.75

3

40

0.58

0.96

1.45

1.72

4

45

0.79

1.27

1.85

2.07

6

83

1.04

2.26

3.08

3.38

8

92

1.15

2.50

3.28

3.64

12

133

1.40

3.12

4.16

5.05

16

208

1.57

3.60

6.72

6.95

24

283

1.68

3.95

7.07

7.00

32

400

1.79

4.18

7.11

7.03

48

600

1.90

4.28

7.15

6.99

And here is that data in graphical format:

CWC2 d-log E curve

More detailed analysis forthcoming in a link yet to be written.