Advice needed w/ old school equipment.

[wrs1145]

I've got a bunch of old lenses and RF lenes over the past year along w/ an old Gossen meter. My question is how to compesate for colored filters w/ that set up?

Thanks,
BIll

 

[p.giannakis]

The exposure factor should be written somewhere on the filter box. Usually they are 2x (one stop) but not always.

If you don't have this info, put it on a metered SLR and check exposure with and without filter. That will tell you how much you need to compensate on you external meter (ie set 200asa instead for 400 if it is a 2x filter, etc...)

 

[steveyork]

I generally add a stop of speed for yellow, two for orange and four for red. I figure there's so much variation in using a mechanical shutter and Sunny 16/hand held meter, the if I'm off a little on my colored filters, it'll be the least of my worries. Ha, ha, just remember to take the filter off when shooting colored film. We've all done that!

 

[former member]

Rule of thumb: Yellow (Y2, Y48) 1-Stop; Orange (o56) 2-Stops; Red (R25, R60) 3-Stops.

 

[wrs1145]

Brian:
So you mean the full stops? Like from 2, 5.6, 8, 11, 16, 22?
Thanks,
Bill

 

[Richard G]

Yes, the full stop. That is open up the aperture a full stop for Yellow. Increase the exposure by 2x by increasing the aperture one stop which doubles the area of the aperture. Increasing the aperture is reducing the f stop number: f4 is twice the size of f5.6, which you can see if you look at the aperture blades of the lens diaphragm.

 

[d_c]

Take a meter reading of a uniformly lit wall through each of the filters and compare these to a reading of the same subject without a filter and that should give you a close enough basis for adjusting the exposure in most situations. The different rendering that the filters give to your pictures is something you'll establish by taking lots of pictures.

 

[Coldkennels]

...just make sure that the wall is lit via daylight. The colour balance of internal lighting varies heavily nowadays but is usually considerably more yellow than daylight, and that'll throw off your readings.

 

[Sanug]

You will find a list for the extension factors from the filter manufacturers. This is in german.

https://www.fotografie-in-schwarz-weiss.de/images/stories/fotografie/Allgemeines/Belichtungsmessung/B_W_Filter_Tipp_Verlaengerungsfaktor_de.pdf