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  #1  
Old 25th February 2013, 11:49 AM
DaveUral DaveUral is offline
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Default filter factors?

I've just acquired a set of Kood B&W filters (yellow,orange,red and green). There is no packaging with them and no info on the mounts as to the filter factors required. I had a butchers on the web and came up with nothing useful on the Kood site. After a bit more "research" I reckon a good starting point would be: Yellow, factor 2. Orange, 5. Red, 8 and green, 6.

Does that sound OK to anyone or am I way off the track?
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Old 25th February 2013, 11:57 AM
Richard James Richard James is offline
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That looks about right and a good starting point, but you can only really determine the actual factor through experimentation under your normal photographic conditions. Good luck.
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Old 25th February 2013, 12:33 PM
Mike O'Pray Mike O'Pray is offline
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If you have TTL metering on your camera check the reading with and without the filter and see how close this conforms to the filter factor. I suspect that in the case of yellow the difference is unimportant but for green, orange and red it may be different.

I have yet to check this myself but it is said that many TTL camera metering systems underestimate the extra exposure needed for red.

Mike
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Old 25th February 2013, 11:07 PM
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Carl V Carl V is offline
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For what it's worth, I have the coloured filters you mention (B+W filters) and on my Nikons the TTL metering works fine measuring through a medium-yellow filter and the meter does indicate one extra stop of exposure correctly. The same goes for the yellow/green filter I also have.

However with the orange filter, I found I have to give it an extra half a stop on whatever the meter indicates, and with the red filter attached, it's around a stop to one and a half stops. I dare say this can vary from meter to meter but it is better to experiment with your own camera to be absolutely sure.

Just as an added note, the filter factors quoted for the B+W ones are:

Yellow - 2
Orange - 4
Red - 5
Dark Red - 8

The yellow/green filter I have isn't listed any more as it's no longer made, but I'm almost certain it's exactly the same factor as the plain yellow.
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Last edited by Carl V; 25th February 2013 at 11:28 PM. Reason: Added info.
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Old 26th February 2013, 10:18 AM
DaveUral DaveUral is offline
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Thanks for all that team.

As always, very helpful and I'm now more confident about giving the filters a go.
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Old 26th February 2013, 10:31 AM
Alan Clark Alan Clark is offline
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Hello Dave,
I believe the old selenium cell meters give a false reading through filters. I know the cds meter in my OM1 used to. It doesn't any more. It's broke!
I give yellow and yellow/green filters an extra stop. My orange filters get an extra one and a half stops. And the red filter is given an extra 3 stops.

Alan
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Old 1st March 2013, 04:01 PM
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Martin Aislabie Martin Aislabie is offline
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I use B+W Filters and they have the following correction factors printed on the side

Yellow/Green = + 1.5 stops
Green = +1 stop
Medium Yellow = +1 stop
Deep Yellow/Light Orange = + 1.5 stops
Medium Orange = + 2 stops
Medium Red = +2.5 stops
Dark Red = +3 stops

Not sure if this helps you much but you can ignore it at your leisure

Martin
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Old 1st March 2013, 05:41 PM
Richard Gould Richard Gould is offline
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I give Yellow filters 1 stop extra, orange 2 stops and red 3, as I need a hand held exposure meter for all my work I simply set it at,(for 400, which I always use) at 200,100 or 50 Iso for each filter.
Richard
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Old 1st March 2013, 06:51 PM
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Steve Smith Steve Smith is offline
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Quote:
Originally Posted by Richard Gould View Post
I give Yellow filters 1 stop extra, orange 2 stops and red 3, as I need a hand held exposure meter for all my work I simply set it at,(for 400, which I always use) at 200,100 or 50 Iso for each filter.
Exactly what I do.


Steve.
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