and is capable of high resolution. Although it is slow, the 649F

plate is a popular choice for white light holography. In addition,

most phase holograms using bleached halides or dichromated gels use

the 649F plates due to its thick emulsion.

 Once the various plates have been exposed to a calibrated light

source, they are developed using a standardized developing technique.

In this case, development consists of 5 minutes in Kodak D-19 at

approximately 74F with one-minute agitation intervals. The plate is

then placed in Kodak Stop Bath for one minute and Kodak Rapid Fix for

4 minutes. After a 30 minute wash, the plate is dipped in Kodak Photo

Flo and hung up to air dry. After processing, the intensity

transmission of each exposure step is measured. This measurement is

performed with a densitometer. A commercial densitometer is readily

available and easy to use. Unfortunately, the densitometer gives

results in terms of optical density which must be converted to

transmittance by t=10-D/2.

 The commercial densitometer, as with the sensitometer, is designed

for use with photographic products which operate over a broad spectrum

of colors. Thus the white light in the densitometer may give results

inconsistent with the red laser light used for holographic

experiments. To determine whether this was the case or not, an

experiment to measure the transmission of the film was devised. The

irradiance of the collimated laser beam is measured. The beam is then

passed through each step of the developed plate and the exiting beam

irradiance measured. The power transmission is the ratio of the

transmitted irradiance to the incident irradiance. The amplitude

transmission is the square root of the power transmission. Using the