Film Colour Sensitivity and Colour Filters

[Animalcito]

I was always curious how film colour sensitivity will impact results when using colour filters. I haven't found anything on the internet. Therefore, I tried on my own.

This is not a scientific work. The shots were done on different days, the film gamma is not identical and the film scanner has its own life, too. However it may be interesting for someone.

 

[Sirius Glass]

Yellow filters will bring out clouds better and slightly darken the sky.
Orange filters will bring out clouds even stronger and darken the sky more.
Red filters will bring out clouds much stronger and almost blacken the sky. They also make lips black.

 

[pentaxuser]

Yellow filters will bring out clouds better and slightly darken the sky.
Orange filters will bring out clouds even stronger and darken the sky more.
Red filters will bring out clouds much stronger and almost blacken the sky. They also make lips black.

Won't red filters lighten lips? Isn't it green filters that will darken lips?

I ask this for clarification in case someone reading this decides to buy a red filter thinking it will darken lips. If red filters do darken pink/red lips then I apologise.

pentaxuser

 

[Gerald C Koch]

Learning to understand and use the color wheel will answer all questions like that of the OP. This question has been asked so many times please look up color theory and the color wheel.

https://en.wikipedia.org/wiki/Color_wheel

 

[Animalcito]

Maybe I was not precise enough explaining my motivation. My interest was not in the general behaviour of the filters themselves. Their overall behaviour is well known, e.g. darker sky with yellow etc.

My particular interest was to see if the individual colour sensitivity of the film will alter (pronounce or reduce) such effects.

 

[Andrew O'Neill]

Good job doing the test. I think everyone should do it, at least with the their main film(s). Another helpful test to do is an exposure compensation filter factor test.

 

[Gerald C Koch]

Still not clear as to what you are seeking. Black and white films differ in their response depending on what sensitizing dyes the manufacturer uses for a particular emulsion. These curves are often published in the technical information section for a particular film. The relative area under each section of the curve (corresponding to each of the primary colors) are what your color swatches) represent for unfiltered light..

 

[Doremus Scudder]

I think the test is interesting. Seeing how the same colors are rendered as different shades on different films with and without filters is an eye opener. Knowing that, for example, that using a yellow filter on Foma 400 has almost the same effect as using a red one could come in handy. It's a good visualization tool (especially if you can't visualize from the response curves).

What's missing here is a measure of contrast using different filters. It's been my experience that some films change contrast rather drastically when using extreme filters. TXP for example gains almost a +1 (in Zone System parlance) when using a red #25 filter.

It's a good idea to test the films one uses with the filters one has for both grey-scale rendition and contrast.

Doremus

 

[DREW WILEY]

If you want a wonderful specific explanation of theory, along with a full catalog of traditional color filter numbers, get ahold of an old Kodak
Wratten Filter Guide. You can find these in used bookstores or using a used book web search.