When in dark woodland with very little tonal separation between foliage, what would be the best filter to use to introduce tonal separation with black and white medium format film.
I find it rather disturbing that you claim on your webiste to be a Photographer, Print Maker, and Teachers who also offers Woorkshops and then you come here on APUG asking so many very basic questions.
There's something not quite right here, Ive repoterted it to the Moderators.
Because of the changing lighting and occasional sky with clouds that might peek through the canopy, I keep a light yellow/green filter on my lens when out for a shoot in a forest area
I am very green to black and white film, shooting mainly color film for that past couple of years and digital prior. I have a dumb question to piggy back off of the OP's: Are there good resources on specific filter colors and brightnesses and how they expose a scene? For example, if I do not want to buy filters one at a time, but do not know how much I am missing without them, is there a filter simulator that you'd recommend? The manufacturers' websites have some good information, but is there a really good, "Bob's filter breakdown" type site?
But the main thing to know is that filters lighten their own color relative to the other colors in the scene, and darken its opposite colore, relative to the other colors in the scene.
That's a very good article, Vaughn and thanks for the link but depending on where you are, the no filter shot of a sky may not show up clouds as much as is shown in the article. In the U.K. for instance a red filter may not have as dramatic effect on a sky scene as shown in the article and no filter may not be enough for a "good sky"
For landscape shots in the U.K. I'd be inclined to keep a yellow filter on. At least that's been my experience in the Midlands of England
TMax films also seem to be better balanced for blue skies -- almost like a conventional film with a yellow filter. I lost track of the number of times I had to explain to students why their red filter did not darken their overcast sky and that the red filter does not automatically increase contrast.
Ian, I concur with Green filter, in theory, of panchromatic B&W films, a color which you want lighter, you use that same color filter to lighten it, and to darken, use the opposite color on the wheel, in this case Magenta, to darken green matter. There is always a penalty to pay for the deviation, and each film has it's own sensitivity to wavelengths of light which ultimately has to be proven out in actual field testing.
If you want to pre-visualize how a filter may impact a scene, and you have a smartphone, there are some very good apps that simulate this. I have an iPhone 6S+ and I use an app called 645PRO (shown above) which has many digital simulations of legacy b&w film types like Tri-X and HP5 in it, along with graduated and solid filters of all types including green... I use it sometimes like the way I used to do Polaroid 554/54 before visual - to help me understand it before I make the exposure of an important image. Hope that helps you.