8mm Forum: Colour Correction

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Topic: Colour Correction

Stewart John Boyle
Expert Film Handler

Posts: 170
From: Glasgow,Scotland
Registered: Oct 2009

posted January 28, 2010 12:02 PM

Hi All,
A random question for all the members follows,
Has anyone ever tried to colour correct a red print by placing coloured filters in front of the lens? Eg blue or green?
Linear thinking i know.. but what where the results?
Thanks
Stewart

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I`ve, seen things you people wouldn`t believe,

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John Skujins
Expert Film Handler

Posts: 220
From: Greensboro, NC, USA
Registered: Mar 2009

posted January 28, 2010 12:31 PM

I haven't tried it but I would assume if the print is all red then any filter would result in a single color also. A blue filter would give you blue + red = purple. A green filter would give you green + red = brown, since green = blue + yellow.

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Michael O'Regan
Film God

Posts: 3085
From: Essex, UK
Registered: Oct 2007

posted January 28, 2010 12:42 PM

No, no, no...never!!
It's like wearing earmuffs so that you won't hear the scratches on your beloved old Beatles record.

Faded is faded - get a better print or buy a DVD.

[Big Grin]

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Martin Jones
Phenomenal Film Handler

Posts: 1269
From: Thetford , Norfolk,England
Registered: May 2008

posted January 28, 2010 12:43 PM

Colour filters are "subtractive". A BLUE filter cannot pass RED light, so if your try to shine red light (i.e. a very red print) through a blue filter the result is BLACK.
You can only "correct" if their are traces of other colours in the print as well and the filters are also "combinations of colours"; you can never "correct" completely
Martin

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Retired TV Service Engineer
Ongoing interest in Telecine....

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Stewart John Boyle
Expert Film Handler

Posts: 170
From: Glasgow,Scotland
Registered: Oct 2009

posted January 28, 2010 12:45 PM

Thanks John,Michael,Martin [Smile]

Question answered,almost immediatley !!
Best Wishes
Stewart

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I`ve, seen things you people wouldn`t believe,

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Winbert Hutahaean
Film God

Posts: 5468
From: Nouméa, New Caledonia
Registered: Jun 2003

posted January 28, 2010 12:53 PM

There is a specific topic regarding this and Doug has tried once.

I would try to locate it. But definitely Doug reported that filter worked well for some films.

cheers,

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Winbert

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Stewart John Boyle
Expert Film Handler

Posts: 170
From: Glasgow,Scotland
Registered: Oct 2009

posted January 28, 2010 12:57 PM

Good Morning Canada [Smile]

Thanks Winbert, it would be very interesting reading.
Doug, if you can post your results quicker i would be very thankfull.
Stewart

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I`ve, seen things you people wouldn`t believe,

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Winbert Hutahaean
Film God

Posts: 5468
From: Nouméa, New Caledonia
Registered: Jun 2003

posted January 28, 2010 01:00 PM

Hi Stewart. Is afternoon over here [Wink]

.

Here is the link

Doug is suggesting Wittner which is of course expensive. Anyone can suggest a hand-made cheapo ones? [Big Grin]

cheers,

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Winbert

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Stewart John Boyle
Expert Film Handler

Posts: 170
From: Glasgow,Scotland
Registered: Oct 2009

posted January 28, 2010 01:03 PM

Winbert
Reading it now my friend
Stewart

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I`ve, seen things you people wouldn`t believe,

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Osi Osgood
Film God

Posts: 10204
From: Mountian Home, ID.
Registered: Jul 2005

posted January 28, 2010 01:17 PM

I mentioned this a little whiloe back.

I had went the way of a light blue/cyan filter, and while it does help the color (on a reddish print that still has some decent color, mind you), it cuts down on the available light.

Then I thought of an experiment.

I went to our local art store, (40 miles away, I happened to be ther for something else) and I bought a large light cyan blue poster board, going on the theory that you could get thye same color correction for the print with less loss of brightness. It worked quite well.

Admittedly, colored poster board is hard to come by and a little expensive. Note, I'm talking of the thick foam poster board that also has the shiny surface, which also cuts down on the light loss, being quite reflective of light.

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"All these moments will be lost in time, just like ... tears, in the rain. "

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Martin Jones
Phenomenal Film Handler

Posts: 1269
From: Thetford , Norfolk,England
Registered: May 2008

posted January 28, 2010 01:24 PM

Projecting onto a "coloured" board is "additive" and will add the colours of the board to the light reaching it, but only if some additional white light falls on the board to "generate" the board colour.

Martin

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Retired TV Service Engineer
Ongoing interest in Telecine....

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Stewart John Boyle
Expert Film Handler

Posts: 170
From: Glasgow,Scotland
Registered: Oct 2009

posted January 28, 2010 01:34 PM

I think the problem of Colour degridation will probably never be fixed completely, but perhaps with a number of trial and error experiments,some acceptable results could be produced.
Yours to ponder over
Stewart

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I`ve, seen things you people wouldn`t believe,

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