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Author Topic: What colour is photographic film?  (Read 14350 times)

Offline Atomic-S

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What colour is photographic film?
« on: 09/05/2011 04:10:10 »
What is the colour of new photographic film as it comes from the factory?
« Last Edit: 19/06/2011 20:29:05 by chris »


 

Offline Bored chemist

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Re: What colour is photographic film?
« Reply #1 on: 09/05/2011 18:58:00 »
Black and white film is a sort of yellowish grey.
I suspect that the question is rather more complicated for colour film because there are several varieties.
 

Offline Atomic-S

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Re: What colour is photographic film?
« Reply #2 on: 13/05/2011 06:17:23 »
How do you know?
 

Offline Bored chemist

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Re: What colour is photographic film?
« Reply #3 on: 13/05/2011 06:53:59 »
Because I have seen it.
Have you never loaded the film into an ordinary camera?
 

Offline Geezer

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Re: What colour is photographic film?
« Reply #4 on: 13/05/2011 17:47:57 »
What's film?
 

Offline imatfaal

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Re: What colour is photographic film?
« Reply #5 on: 13/05/2011 18:42:22 »
Because I have seen it.
Have you never loaded the film into an ordinary camera?

Yes - but I always used to do it in the dark by touch, or with my hands under a cloth or in a bag to avoid exposing the film.  Am I now being told that I was being a little obsessively over-cautious?  I have recently started using my old 35mm again, there is something that concentrates the mind if you have only 36 shots not the thousands of a digital sd card.
 

Offline Atomic-S

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Re: What colour is photographic film?
« Reply #6 on: 23/05/2011 05:58:41 »
Quote
Because I have seen it.
Have you never loaded the film into an ordinary camera?
If you have seen it, then presumably it was exposed to light, and therefore is not in its original condition.
 

Offline Geezer

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Re: What colour is photographic film?
« Reply #7 on: 23/05/2011 06:29:44 »
Quote
Because I have seen it.
Have you never loaded the film into an ordinary camera?
If you have seen it, then presumably it was exposed to light, and therefore is not in its original condition.

There is no visible difference between a photographic emulsion that has been exposed and one that hasn't. The image only appears on film when it is developed.
 

Offline Bored chemist

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Re: What colour is photographic film?
« Reply #8 on: 23/05/2011 19:07:34 »
If you watch a bit of film it slowly turns dark in sunlight. The change is slow enough that you can get a good look at the stuff before it changes much.
 

Offline Geezer

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Re: What colour is photographic film?
« Reply #9 on: 23/05/2011 20:37:30 »
If you watch a bit of film it slowly turns dark in sunlight. The change is slow enough that you can get a good look at the stuff before it changes much.

Had I known that, I could have saved a lot of money needlessly spent on film processing.
 

Offline Atomic-S

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Re: What colour is photographic film?
« Reply #10 on: 06/06/2011 04:33:18 »
Quote
There is no visible difference between a photographic emulsion that has been exposed and one that hasn't. The image only appears on film when it is developed.
How do you know if you have not seen one that has not been exposed to light?
 

Offline Geezer

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Re: What colour is photographic film?
« Reply #11 on: 06/06/2011 04:44:36 »
Quote
There is no visible difference between a photographic emulsion that has been exposed and one that hasn't. The image only appears on film when it is developed.
How do you know if you have not seen one that has not been exposed to light?

I have, using red light in a darkroom.
 

Offline techmind

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Re: What colour is photographic film?
« Reply #12 on: 12/06/2011 15:52:46 »
The 'colour' negative film that I've used (mostly Kodak) normally appears a light brown/beige colour before it's been processed. If exposed to a lot of light (eg few seconds or tens of seconds in full sunlight) then it does change colour slightly  - but this is many thousands of times the exposure you'd give when making a photograph to develop and process normally.
 

Offline Atomic-S

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Re: What colour is photographic film?
« Reply #13 on: 19/06/2011 02:50:25 »
Quote
from: Atomic-S on 06/06/2011 04:33:18
Quote
Quote
There is no visible difference between a photographic emulsion that has been exposed and one that hasn't. The image only appears on film when it is developed.
How do you know if you have not seen one that has not been exposed to light?


I have, using red light in a darkroom.
Undoubtedly it must have appeared red, then.
« Last Edit: 19/06/2011 02:53:26 by Atomic-S »
 

Offline RD

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Re: What colour is photographic film?
« Reply #14 on: 19/06/2011 04:43:09 »
The opaque colour on the unprocessed film may be to prevent halation, rather than due to the light sensitive emulsion itself.
« Last Edit: 19/06/2011 04:53:38 by RD »
 

Offline Geezer

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Re: What colour is photographic film?
« Reply #15 on: 19/06/2011 05:22:53 »
Quote
from: Atomic-S on 06/06/2011 04:33:18
Quote
Quote
There is no visible difference between a photographic emulsion that has been exposed and one that hasn't. The image only appears on film when it is developed.
How do you know if you have not seen one that has not been exposed to light?


I have, using red light in a darkroom.
Undoubtedly it must have appeared red, then.

Yes - whether exposed or not.
 

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Re: What colour is photographic film?
« Reply #15 on: 19/06/2011 05:22:53 »

 

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