Exposure with yellow filter?

[David Craig]

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Please can someone advise if I need to adjust the exposure using my M6 loaded with Tri-X pushed to 800 ASA with a B+W 022 (2x) yellow filter.

 

Thanks, David

 

 

[MSB]

The 2x filter factor indicates that you need one stop more light than without the filter, but if you use the light meter on your M6 it will calculate the light after it has passed through your lens and filter and so it will – generally – give an accurate reading and you won't have to take the filter factor in account. However some light meters can get fooled by the filter (especially heavy colored filters like deep red and IR-filters) so some people prefer to meter the light without filter and then manually adjust the exposure ackording to the filter factor.

 

For more information I found this little PDF article from Schneider Kreuznach:

http://www.schneiderkreuznach.com/fileadmin/user_upload/bu_photo_imaging/fotofilter/Produktfinder/Tipps_und_Tricks/B_W_Filter_Tip_Exposure_Compensation.pdf

Edited October 30, 2015 by Markus B

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[David Craig]

Thanks, that's really helpful. I suppose my question is really is this - is the M6 meter likely to be 'fooled' by my B+W 022 yellow filter?

[assaf110]

No.

[MSB]

Unfortunately I don't have an answer for that since I haven't used filters with my M6, but since you know the filter factor you can always use a bit of ”trial and error”. Take one reading without filter and one with filter on a couple of subjects and if the two readings differ according to the filter factor I would say the meter should be good for generally use. But then I'am more pragmatic than scientific in my approach to this matters. I'm sure someone else will come up with a more comprehensive answer.

[too old to care]

I have the same camera and filter.  A couple of years ago I used a gray card outside, first in the sun, and later under a tree to determine if the light meter would correct for the filter. It did not read the full f-stop, more like a half stop. I usually set the ISO to half the rated value to over expose one f-stop anyway, so it did not matter much.  

[Suede]

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I'm not too sure as I generally don't use filters, but I'm inclined to think that it depends on whether the camera is a plain old M6 or the M6-TTL.

I'd be happy to know for my own sake if I'm thinking along the right line about this.

Cheers,

Pritam

[wattsy]

I'm inclined to think that it depends on whether the camera is a plain old M6 or the M6-TTL.

 

No, both cameras are use the same basic metering system (which is TTL), the TTL designation of the latter camera only relates to metering flash exposures. 

[wattsy]

Incidentally, I tend to agree with the poster above who suggests that the exposure difference isn't always a full stop. I think it actually depends upon the film characteristics and the scene in question (the colours that the filter is acting upon) but in my experience, for an average scene, somewhere between a half and a stop is usually right for an 022 yellow filter. Of course, most neg film will have sufficient latitude that it is not something to get too excited about.

[Sailronin]

The meter will read correctly, it is reading light transmitted through the lens. 

[pico]

Please can someone advise if I need to adjust the exposure using my M6 loaded with Tri-X pushed to 800 ASA with a B+W 022 (2x) yellow filter.

 

First, pushing film is a separate matter (why are you doing that?), but to answer, 2X means one stop additional exposure, however keep in mind that color filters work with the color of the scene. If the sky is overcast, then a yellow filter will not do anything significant.

[fotohuis]

It indeed also depends on the film charcateristics so with a film with extended Red you can correct less then one F-stop. In general a TTL measurement with the Leica M6/M7 or MP will be correct. Small deviations you can correct with the +/- LW dial.

[too old to care]

To add to my first post.  On my first post I mentioned that I used a gray card, one that reflected 18% of the light.  This is the "standard starting" point for for film processing, because if the colors of the average outdoor scene are scrambled, you will get a gray that reflects 18% of the light.  Light meters are designed around this, so is the equipment in photo labs.   This is not to say all scenes once scrambled reflect 18% of the light, or all are gray, only the starting point.   

 

As Pico said, yellow filters have little effect on scenes with mostly yellow present, or those colors with yellow in them such as orange, because they are designed to pass yellow.  If the scene is a cloudy day in the fall, the filter will pass most of the light, the meter will meter it correctly, and you will get the typical photo, the filter will have little effect.  

 

If on the other hand the colors are overly blue, such as taking a photo on a bright, cloud free day, the filter will block the blue rendering the sky dark IF you use the one f-stop rule, while the other objects are exposed correctly.  

 

However, if you rely on the light meter, the filter may block so much blue light that the meter may over exposed the other colors, and turn the sky into the muddy 18% gray, instead of the dark sky you expect.   

 

That is what I experience.  Using the filter, I have sometimes been disappointed.  I no longer rely on my meter, but instead use the one f-stop rule, or if I am lazy, I cut the exposure by an extra half-stop or more just to make sure.  

 

Wayne 

Edited November 4, 2015 by too old to care

[pixie]

The meter will read correctly, it is reading light transmitted through the lens.

No.

I agree with Markus B.

It will not, esp. with strong colored filters, red, blue and true infra-red.

I need to add exposure when I read thru the lens metering.

Same for any camera, LeicaM6TTL or a Nikon F3,Photomic.

Error in excess of 2 stops.

Yellow less so, esp. light yellow, green yellow.