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How is film stock made?


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#1 Julie Lew

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Posted 04 October 2014 - 02:15 PM

I'm in the midst of studying film stock. I'm reading about film emulsion and the chemicals needed to develop film, but I'm dying to see how exactly film is made. I understand film needs darkness (making it hard to document its process), but is there something I can see or read to learn more?

 

My two main questions right now are:

* What is done to film to make it faster/slower

* And how do you make film stock a certain balance, like tungsten or daylight?

 

 


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#2 Charlie Peich

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Posted 04 October 2014 - 02:38 PM

Julie,

 

You should read this book: Making Kodak Film, The Illustrated Story of State-of-the Art Photographic Film Manufacturing

 

http://www.amazon.co...king kodak film

 

It's somewhat hard to find, and pricey.

 

Search this forum, the book may have been discussed here.

 

Also, look at what Ferrania is doing. There may be some info there:

http://www.filmferra...t/#home-section

 

Good Luck!

Charlie


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#3 Adrian Sierkowski

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Posted 04 October 2014 - 03:06 PM

The Kodak book is very good. It's short, sweet, and I enjoy having it around.

I also believe someone made a DIY coating machine a few years ago and documented it on here-- try the search function.


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#4 David Mullen ASC

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Posted 04 October 2014 - 05:50 PM

You make a stock faster by putting bigger grains in it, the larger the surface area of a grain exposed to light, the better collector of photons it is. There is also some chemical things that can be done to increase sensitivity. You make a daylight balanced stock by making the blue layer less sensitive, since there is an abundance of blue wavelengths in daylight, and you make it tungsten balanced by making the blue layer more sensitive.
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#5 Julie Lew

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Posted 04 October 2014 - 09:10 PM

Thank you for the awesome replies, guys! I can't find the Kodak book at any of the libraries by me, and I can't afford a fifty buck book at the moment. I'll go snooping around local book shops.

 

The thread about the diy tank processing was interesting. Is it common for DPs to do that?


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#6 Charlie Peich

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Posted 04 October 2014 - 10:23 PM

Julie,

Have you looked at Kodak's site? Here's a link that expands a bit on David's comment about the grain's larger surface area for speed. This link talks about Kodak's T-Grain Technology....

 

http://www.kodak.com...s/vision2.shtml

 

There is a member of the forum that wrote a very good book about film and post production. He discusses film emulsion and processing.

 

"Film Technology in post production" by Dominic Case. He might give you other references. 


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#7 Simon Wyss

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Posted 05 October 2014 - 03:16 AM

There’s a cool video for you:

 


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#8 Bill DiPietra

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Posted 05 October 2014 - 11:14 AM

There’s a cool video for you:

 

 

That is a GREAT video, Simon.  Thanks for sharing!


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#9 Julie Lew

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Posted 09 October 2014 - 01:14 PM

Thank you so much for the resources! That video is fascinating.


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#10 cole t parzenn

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Posted 10 October 2014 - 05:43 PM

You make a stock faster by putting bigger grains in it, the larger the surface area of a grain exposed to light, the better collector of photons it is. There is also some chemical things that can be done to increase sensitivity. You make a daylight balanced stock by making the blue layer less sensitive, since there is an abundance of blue wavelengths in daylight, and you make it tungsten balanced by making the blue layer more sensitive.

 

What voodoo gives Velvia 100 the same (or higher?) resolution as Velvia 50? Is the relationship between resolution and speed (in stops) generally linear?


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#11 David Mullen ASC

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Posted 10 October 2014 - 09:18 PM

There isn't a 1:1 correlation. Kodak Vision 200T is sharper than 50D for example.
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#12 Karl Lee

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Posted 26 October 2014 - 07:52 PM

There isn't a 1:1 correlation. Kodak Vision 200T is sharper than 50D for example.

 

I'm by no means questioning your statement, David, but I'm curious...what's the logic/science behind 200T being considered sharper than 50D?  Conventional wisdom is that slower films yield finer grain, but then grain structure and sharpness aren't necessarily the same thing.

 

That said, would 200T be considered the sharpest of all Kodak color negative camera films currently in production, also trumping 250D & 500T?


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#13 David Mullen ASC

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Posted 26 October 2014 - 08:01 PM

I don't know why 200T is sharper than 50D, it just is -- but barely.  But even a Kodak rep will confirm this.  It may have something to do with edge acutance around the grains after development and the fact that 200T has a fast and slow layer for each color, I don't know.  It may even not be true anymore, this was back before Vision-3 50D came out.

 

A totally separate issue is that grainier stocks can look sharper even when not, because the grain gives our eye a visual clue as to whether the image in focus or not, it creates a type of detail that looks sharp.


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#14 Chris Burke

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Posted 26 October 2014 - 08:15 PM

I agree with david. I have been shooting some 50D lately in Super 8 and have found that well exposed 200T or even a little underexposed looks sharper than the 50d. 50D also falls apart quicker when underexposed, where the 200T is cleaner. Not knocking 50D, it has an almost creamy feel to it, which is quite nice.


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