DCAudioDIY.com

_________________
Walt

Fantastic! I believe the film you are mentioning is is the original Kodachrome that was started in 1935. It had an ASA rating of 10. Then Kodachrome II came along in the 60s and had an ASA rating of 25. It was a very unique and complicated process as described below because it started life as B&W and the color was added during processing as compared to other color transparency films such as Ektachrome that had the dyes already in the raw film stock.


The first step in the process was the removal of the antihalation backing with an alkaline solution and wash. The film was then developed using a developer containing phenidone and hydroquinone, which formed three superimposed negative images, one for each primary color.[43] After the first developer was washed out, the film underwent re-exposure and redevelopment. Re-exposure fogged the silver halides that were not developed in the first developer. A color developer then developed the fogged image, and its exhaustion products reacted with a color coupler to form a dye in the color complementary to the layer's sensitivity. The red-sensitive layer was re-exposed through the base of the film with red light, then redeveloped forming cyan dye. The blue-sensitive layer was re-exposed through the emulsion side of the film with blue light, then redeveloped forming yellow dye. The green-sensitive layer was redeveloped with a developer that chemically fogged it and formed magenta dye.[43] After color development, the metallic silver was converted to silver halide using a bleach solution. The film was then fixed, making these silver halides soluble and leaving only the final dye image. The final steps were to wash the film to remove residual chemicals which might cause deterioration of the dye image, then to dry, cut, and mount the film in slide frames.[43]

One of the companies I worked for built an electronic flash unit called the Sunlight Master designed for studio work with large format view cameras (8X10 and above) that used very large f-stops (small diaphragm openings) and required a lot of light. It stored energy in oil filled capacitors and worked at 4KV. Maximum energy storage was 40,000 watt-seconds by interconnecting individual 800 or 2,400 watt second capacitor banks compared to around 25 WS for a modern small camera with built in flash. The original power supply used 866A mercury rectifiers to get the high voltage DC and the later Super Master power supply used solid state rectifiers and phase control to handle the much faster charge rates. The transformer had a secondary voltage rating of 1,600 volts and a current rating of 2 amps. I used to service those and can tell you some hairy stories of what happens at those voltage and power levels. Here is a photo of a typical stack of capacitors and the heavy duty rubber cables with "mine connectors" used.

_________________
Walt

I guess you don't want to give a shit because of the toilet paper shortage.

I thought it was an interesting story. Amazing what had to happen back then to get results that pale today with a smartphone. When we were at Cape Canaveral a few years ago the tour guide said that the computing power in any of our phones was greater than NASA had when the Apollo missions were flown. Makes you wonder how people survived back then...

_________________
I have too much stuff - https://www.pleasebuymystuff.com

I’m with Shashi it’s just tv, what a waste

Family movie? I was a bit too young when my parents gathered our family to watch this movie. Scared the bejeezus out of me. Nightmares for weeks. Still can't watch it. This was second only to my other family movie fail when my first grade class did a field trip to see, "A Christmas Carol". The black and white scary as sh*te version. Another movie I can't watch.

_________________
Walt

No Problem. I was just trying to add a little to the history of imaging and the problems photographers and cinematographers had to deal with back then. BTW, my personal opinion is that some of the cinematographers in the days of B&W only did a phenomenal job of using lighting and composition to create moods with only shades of gray.