Nikon F6 and metering using yellow green Hoya XO flter

So, I've been using a yellow green filter with a filter factor of 4, so two stops additional exposure.
Reading the spec sheet for Kodak Tmax 400, it confirms that a yellow green filter requires two additional stops of exposure.

So, too make things easy I dialed in two stops of exposure compensation and got dense overexposed negatives. Huh ? WTF ? Oh, I'm meterning through the filter, no need to add expsosure compensation you big dummy you.

So then I metered a scene with no filter and then metered the same scene with the filter expecting to see two stops difference but guess what ? I'm only seeing two thirds stop difference using on camera spot metering and only a third of a stop using matrix metering.

What gives ?

Your meter doesn't have the same spectral response as the film. Use the filter factor.

Thanks Matt

MattKing said:

Your meter doesn't have the same spectral response as the film. Use the filter factor.

Click to expand...

This is an issue for every single exposure meter I have ever tested. None, in camera or handheld, meters correctly through colored filters.

My handheld meters, of which I have way too damned many, are the ones I know best, so I'll talk about them. Not only do they give incorrect readings through most colored filters, they only agree with each other (without filters) in daylight. In bright sun or overcast conditions, they all agree with each other. Under artificial light, they often do not due the differences in spectral sensitivity between them.

Under incandescent lights, my Minolta Flash Meter IV, Sekonic L-758DR, and Weston Master V all agree perfectly. Even the two digital meters (the Minolta and the Sekonic) which read to 1/10 stop agree perfectly, not even 1/10 stop difference. The Gossen Ultra Pro and Gossen Luna Pro SBC both read exactly one stop higher (meaning one stop of underexposure) than the Sekonic L-758DR and Minolta Flash Meter IV. The gossens are much more red sensitive than the Sekonic and Minolta. Which give correct exposure? The Sekonic and Minolta both give correct exposure and the Gossens underexpose a stop. I've tested on black and white film and with a digital camera with the same results.

Under LED lights, the cheapie ones sold for household use, not the expensive ones sold to professional photographers, there is also disagreement. Here, the Gossens and the Sekonic agree and the Minolta reads 1/2 stop too high (underexposure of a half a stop).

I remember they disagreed with each other under flourescents too but I don't remember the amounts and I'm too lazy to go to my flourescent-lit basement to test it now.

When measuring through colored filters, reds, oranges, and yellows had the most error. The Flash Meter IV actually indicated NO compensation at all for a Yellow filter that normally needs a stop of compensation!

I have a Zone VI Modified Pentax Spotmeter V, the analogue meter, not the digital one. It does a better job of metering through colored filters than either the spotmeter on the Sekonic or the Flash Meter IV with one of the Minolta spot attachments, but it still underexposed red, orange, and yellow filters. Just not as much as the other meters did. It certainly doesn't give the perfect results that Fred Picker claimed.

Matt & Kris, Thank you! Helps explain why the meter baffles me at times.

Don't use the filter factor as has been recommended above. You already tried that and got grossly overexposed pics!!!
You are overthinking this, meter normally and shoot. Do NOT dial in any filter factors. I use my F6 like this with zero issues. The reason that you are seeing different values with matrix vs spot is because filter or no filter, they will give different values as they are a different metering pattern! Matrix is a fancy name for avg meter pattern, spot is (as the name suggests) a spot meter.
Simple test - shoot another roll with no filter factor dialed in and see for yourself. But remember the matrix pattern will underexpose back lit subjects, filter or no filter. It's why Nikon provides the center weighted and spot options.

Spot metering through a b&w filter will always be influenced by the hue of what you are spot metering. With your yellow-green filter, a significant difference in spot meter reading between, for example, a blue object vs. a red object can be expected, even if metering off the same two objects without filter shows same value for both objects.

bascom49 said:

So, I've been using a yellow green filter with a filter factor of 4, so two stops additional exposure.
Reading the spec sheet for Kodak Tmax 400, it confirms that a yellow green filter requires two additional stops of exposure.

So, too make things easy I dialed in two stops of exposure compensation and got dense overexposed negatives. Huh ? WTF ? Oh, I'm meterning through the filter, no need to add expsosure compensation you big dummy you.

So then I metered a scene with no filter and then metered the same scene with the filter expecting to see two stops difference but guess what ? I'm only seeing two thirds stop difference using on camera spot metering and only a third of a stop using matrix metering.

What gives ?

Click to expand...

the film's spectral sensitivity doesn't always match the meter's spectral sensitivity.I meter without filter and add two stops before exposing.

RalphLambrecht said:

... I meter without filter and add two stops before exposing.

Click to expand...

+1 - That's the way !

bascom49 said:

I'm only seeing two thirds stop difference using on camera spot metering and only a third of a stop using matrix metering. What gives?

Click to expand...

Apparently the matrix metering doesn't "like" filters with a filter factor other than one (1). Nikon recommends using center-weighted metering.