EV comp for yellow filter

Discussion in 'Medium Format Cameras and Accessories' started by revdocjim, Mar 9, 2012.

  1. revdocjim

    revdocjim Member

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    Today I finally found a hood for my Mamiya Six (folder) and am very pleased! The hood is a Hansa 36 and it came with a yellow filter that is marked "Hansa Y-2". So my question is how much light loss do I compensate for if using this filter. I've never used colored filters on a fully manual camera so I'm pretty clueless.

    All advice appreciated! :smile:
     
  2. David Allen

    David Allen Member

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    The effect of filters varies with the time of day / weather due to differing levels of the colours that make up 'white' light. Therefore, all filter factors are given as a guide only.

    The best way to make accurate compensation for the effect of a filter is to meter the scene without the filter and then meter the scene with the filter. The resulting difference is then the filter factor you need to apply for that particular filter at that time of the particular day you are using the filter.

    By the way, calculating the filter factor in this way when metering a shadow area that you wish to retain detail in can, at high altitudes particularly, help a great deal when using either a minus Blue filter or a very deep Red filter because of the unusually high levels of blue light present in the shadows and the related effect of the filter. When I used to do landscapes, i experienced situations where the correct filter factor was more than one stop in variance to the stated 'official' filter factor

    Hope this helps,

    David
    www.dsallen.de
     
  3. revdocjim

    revdocjim Member

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    Thanks David. When you say "The best way to make accurate compensation for the effect of a filter is to meter the scene without the filter and then meter the scene with the filter." do you mean somehow attaching the filter to my light meter? I could probably do that if taking a reflective reading but when measuring incident light that seems tough.
     
  4. andrew.roos

    andrew.roos Member

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    The filter factor of a Y-2 (medium yellow) filter is 2, meaning that for a "normal" subject in daylight you should double the exposure over what you would use without the filter - i.e. +1 EV exposure compensation. Obviously this depends on the subject and lighting - if your highlights are yellow then the filter won't affect them much so no (or very little) exposure compensation should be used.

    One use of a medium yellow filter in B&W photography is to improve the definition of white clouds against a blue sky by reducing the apparent brightness of the sky, which otherwise can end up with a similar tone in the print to the clouds. For example, http://www.flickr.com/photos/andrewroos/6951910467/in/photostream.
     
    Last edited by a moderator: Mar 9, 2012
  5. Too old to care

    Too old to care Subscriber

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    I don't know why, but I get under exposed photos if I meter through filters on my Leica M6. It is a little more accurate with the yellow filter, but with a red filter I am almost 2 f-stops off. However, metering through the same filters with my Gossen Luna Pro the filter factors seem to work fine. I think some light meters are more sensitive to one color than another, that is you cannot always trust them. Because of this I have taken sample shots at different settings to find out what the correct exposure is, then compensate with my ISO setting so I get correct shots. With the Leica I set the ISO setting about 30% less than true ISO for the yellow filter, and about 60% less for the red.
     
  6. Jeff Kubach

    Jeff Kubach Member

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    Usually 1 stop for yellow.

    Jeff
     
  7. Ian C

    Ian C Member

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  8. Vaughn

    Vaughn Subscriber

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    Add a stop whenever you have it on the camera. Then look at your negs. If they seem a little thin, then add more light, if over-exposed, add less. But B&W films have such lattitude that just adding one stop will get you where you want to be.

    That said, you will see a greater effect with TMax films than with most others films, as they seem to have a more even response to cyan/blue than most films. I think TMax films without a yellow filter act like other films with a yellow filter. So I usually do not use one with Tmax -- unless I need to bring down the sky values a little relative to the foreground. Otherwise I like more natural-looking light skies as over-dramatic skies can be a bit over-used and be a bit of a cliche if one is not careful.

    Vaughn
     
  9. Rob Skeoch

    Rob Skeoch Advertiser Advertiser

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    When using a field camera I give one stop for the filter and enjoy the results.
    When using an in-camera meter I usually put the filter on and meter through it, which seems to give me underexposed results more times than not. As mentioned it's worse with the orange and red filters. I'm starting to think the meter is more red sensitive and the filter factor isn't taken into effect. Of course a few tests would help.

    -rob
     
  10. benjiboy

    benjiboy Subscriber

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    Rule of thumb - + 1stop
     
  11. Dan Grisez

    Dan Grisez Member

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    Agree with above. I go 1 stop for yellow, 2 stops for orange. Hasn't failed me yet!
     
  12. revdocjim

    revdocjim Member

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    OK... thanks for the great advice and instruction. For starters I will adjust 1 stop and see how it turns out. Right now everything is cloudy and raining so I'm just shooting without the filter.
     
  13. Vaughn

    Vaughn Subscriber

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    Good! Our students will occasionally try to darken the sky with a filter on our typical dreary foggy days...then wonder why it didn't! LOL!
     
  14. E. von Hoegh

    E. von Hoegh Member

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    I've been told recently, by a "photographer", that you cannot use color filters on B&W.
     
  15. David Allen

    David Allen Member

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    Regarding my original response I forgot to mention that I only use selenium cell meters. I never use built in meters due to the varying sensitivity of the electronic cells.

    David
    www.dsallen.de
     
  16. E. von Hoegh

    E. von Hoegh Member

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    That's a good plan, for more reasons than varying spectral sensitivty, to use one meter for all cameras.
     
  17. R.Gould

    R.Gould Member

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    With a hand held meter, which I need to use all the time as none of the cameras I use has a built in meter, and using iso 400 as an example, I would set the meter at 200 for yellow, 100 for orange and 50 for red. keeps things nice and simple and works for me, and has done so for around 40 years.
    Richard