View Full Version : How color film actually looks

Photo Engineer
02-28-2007, 05:25 PM
Here are photo micrographs of actual color films.

One compares film to a human hair, and the other shows film before and after processing.

In the before and after process photos, you can see the silver grains in one and not in the other, and you can also see the change in the layers.

Again, I am indebted to my friend, Dr. Bruce Kahn for permission to use these photos.

You can see from the size of the hair in comparison to the thickness of the film layers why I have likened photo engineering to designing a biological system, as we are working on the scale of cellular structures or smaller, when we build and examine film.


02-28-2007, 08:19 PM
Thanks PE,

Those are a 10 on my neatstuffometer.

02-28-2007, 09:47 PM
So the yellow layer...before processing it looks quite diffreren than the magenta or cyan...yes?

richard ide
02-28-2007, 09:54 PM
I was told many years ago (I think by my Kodak rep.)That your colour films are coated wet on wet with as many as 20 layers. Does that seem right? technically, what an amazing challenge to produce. I worked for a diazo coater many years ago so have a slight clue.

Michel Hardy-Vallée
02-28-2007, 11:57 PM
Does the "before processing" means "after silver development, but before color developer," given the visible grains?

Steve Smith
03-01-2007, 12:38 AM
Those are a 10 on my neatstuffometer.

That would be a coolness factor of 1000 milliFonzies!


03-01-2007, 03:02 AM
This is fascinating stuff!
I've looked at film under my microscope, and the grain structure is fascinating.
I'll have to try a bit on edge, and see if I can see the layers.
Any idea what mag these are at?

Anyone got a spare microtome? ;)

Photo Engineer
03-01-2007, 11:04 AM
In answer to the questions above, the yellow layer is usually the coarsest grained, fastest of all emulsions, and yes, Kodak coats up to 20 or so layers at one time in a single pass. I believe that my max was 14 or so.

You have to remember that this is also at very high speed, probably 3x faster than most of the industry standards, and orders of magnitude faster than many 3rd tier companies.


03-01-2007, 11:09 AM
I'm not sure what the correct metric is....feet per second? How fast can those lines run?

Photo Engineer
03-01-2007, 11:55 AM
Sorry, I would rather not discuss actual figures on the speed.


03-01-2007, 11:56 AM
I understand.

03-01-2007, 12:12 PM
Thanks, PE. Please keep posting this kind of stuff. :)