Adding Filter Factors- B&W

[thetooth]

Have you added in a bellows factor?

FWIW, you are correct in thinking that if you meter through the filter you've already included the filter factor...all things being equal. Reflected reading from a gray card?

just curious what is FWIW ? and no i don't use a grey card i just try and image what part of the scene i want to fall in that space ( 18% grey space )

[GaryT]

just curious what is FWIW ? and no i don't use a grey card i just try and image what part of the scene i want to fall in that space ( 18% grey space )

"For what it's worth"...in other words, I was just agreeing with your assumption that using your meter through a filter would effectively incorporate the filter factor...but wanted to make clear the it was only my opinion and was worth very little!

You've stumped me as to the problem. i would think that by metering through the filter in an area that you want to render at 18% should yeild a negative that would print that way, provided that it's developed properly.

[Scott Kathe]

but did you factor for the sand ? which would throw off the meter by a stop or 2 ( reflected light )

Good point.

Scott

[Peter K]

There are two main characteristics of a film: the exposure index and the color sensitivity. So the filter factor depends strongly on the color sensitivity of a certain film.

The sensitivity of a photometric cell used in an exposure meter differs from that of a film. Normaly this is adjusted with buildt-in filters in the exposure meter to simulate the color sensitivity of an average panchromatic film. So than the color sensitivity differs from this, the filter factor differs also.

But this has nothing to do with the film size. With the same kind of emulsion the filter factor is the same with 35mm- and LF-cameras.

[thetooth]

"For what it's worth"...in other words, I was just agreeing with your assumption that using your meter through a filter would effectively incorporate the filter factor...but wanted to make clear the it was only my opinion and was worth very little!

You've stumped me as to the problem. i would think that by metering through the filter in an area that you want to render at 18% should yeild a negative that would print that way, provided that it's developed properly.

no problem i just couldn't figure out the FWIW . still learning .

take care

tim

[steve simmons]

The other 'factor' no one has mentioned is the reflective value and color of the subject and that of the filter,i.e. that a subject reflecting red light will get more light through a red filter than a subject reflecting blue light. This is why Hutchings recommends metering through the filter and not just applying an arbitrary factor.

Just do it the way Hutchings recommends, he has done all of the studying and testing for you already. View Camera magazine and Using the View Camera have covered this topic extensively, I am surprised there are still questions.


IMHO (In my humble opinion) you should not simply meter for the supposed middle value. This does not tell you about the contrast range of the scene. You could easil;y not have enough density in your zone 3 to get good detail and texture and/or blow out your high values. Or, if the scene is low in contrast, get a very flat negative. I always meter the low value I want on zone 3 and that gives me my exposure, and then the high value where I still want some hint of detail and texture, for me this is zone 8, and this determines my development time.
steve simmons

[gregstidham]

When I purchase a new filter, I use my spot meter and compare a reading with the filter and without to determine the filter factor of the filter. I then mark the factor on the filter case. When working in the the field, I simply apply the filter factor of the filter without regard for the format I am shooting or the type of film (color or BW). I've never had any problems.

[timbo10ca]

The other 'factor' no one has mentioned is the reflective value and color of the subject and that of the filter,i.e. that a subject reflecting red light will get more light through a red filter than a subject reflecting blue light. This is why Hutchings recommends metering through the filter and not just applying an arbitrary factor.

Just do it the way Hutchings recommends, he has done all of the studying and testing for you already. View Camera magazine and Using the View Camera have covered this topic extensively, I am surprised there are still questions.


IMHO (In my humble opinion) you should not simply meter for the supposed middle value. This does not tell you about the contrast range of the scene. You could easil;y not have enough density in your zone 3 to get good detail and texture and/or blow out your high values. Or, if the scene is low in contrast, get a very flat negative. I always meter the low value I want on zone 3 and that gives me my exposure, and then the high value where I still want some hint of detail and texture, for me this is zone 8, and this determines my development time.
steve simmons

This is exactly what I do- I have found in the past that the same filter can have a different ff, depending on the light and subject. What stumps me is that I've tested my LF system the same way I tested my 35mm system. I've never applied the "Hutching's Factor" before, because I never knew about it. I read your book and thought "Hmmmm- I've never had to do this before and I've been O.K."..... so I didn't when I tried it with LF. I discovered I should have applied the extra exposure. I'm stumped on the discrepency. If it ain't broke with 35mm, why fix it. If it is broke with LF, I'll fix it, but that doesn't make me any less confused in my situation.

Tim

[john borrelli]

Just wondering ...are you comparing the results to two different meters, that could make a difference. For example, if you are comparing a 35mm camera's meter to a separate spot meter perhaps there is a difference there. Maybe the 35mm meter was slightly overexposing. Also, when metering with the 35, the 35 took into consideration the lenses focal length which might provide a different meter reading as well. Another possibility might be due to using different film types or different processing. I have used the technique that Steve Simmons describes above and it has worked for me.

[steve simmons]

OK, time for a true confession. I did not do what I suggest in a recent 7x17 shot, I just taped the #12 filter inside the camera on the lens, cut the film speed in half and shot. The results, not very good, are in the March issue. The neg was underexposed and the results are flat and kinda mucky. No amount of work in the darkroom or PS could save me.

I'll follow my own suggestion next time.

steve simmons