Primer on Compensating Filters for Black and White Film

[Andre Noble]

To all ye knowledgeable Black and White experts: After four years of fighting w ith my landscape negatives in the darkroom, trying for once to get the sky to re nder something other than Ilford MG-IV pearl white, I've recently converted my e nlarger to a diffusion type, and also learned the subtleties of N-1 and N-2 deve lopment. then, I jumped for joy when I finally got an Ansel Adams type sky, wit h help from the latter modification (and unfortunately, also with 10 minutes of backwrenching burning in), only to be deflated by watching a white marble build ing adjacent to the sky in the scene also turn grey from all the additional expo sure time. (if I'm not too critical, the picture still looks nice, but next time out, I want to do better.)

Can anyone relate to this problem? Help!! It's time to discuss filters for B&W film. I'm ashamed to say that I have not used any to date. I would like to fin ally be able to print a cityscape, landscape, or portrait(w/sky) worth giving as a gift, or hanging on the wall without reservation.

So, I'm about to invest in a dark yellow (15), a yellow green (xo), and a red 25 filter, and possibly a polarizer of circular or linear type?. Likely B+W or Hoy a. Any comments will help.

Large format is awesome, and so is the knowledge I have been getting from this s ite. Thanks again for your help. Andre

[pat krentz]

If you have already established a PIE (perosnal exposure index) for you film and equipment, I would suggest that you take the filters you mentioned and make a couple of exposures with them to see what happens. Make exposures with each one, one allowing for filter factor and another with NO filter factor and then develope normal and print to see what the difference is, you can learn alot about filters and how they do with your own equipment by doing this or you can use other peoples figures and bounce around for a long time before you get what your after. The other thing that is essential for good printing is a Zone VIII print test. Regards, Pat

[Chad Jarvis]

Sounds to me like you needed either more development of your film or higher contrast in your paper.

[ernie gec]

Your use of the filters described will definitely make a difference, but it's also useful to observe that "Ansel Adams skies" are very much part of the world he photographed. High altitude (less moisture in the air ie. haze) and naturally impressive cloud formations due to mountain effects helped him achieve those stunning images.

You can be sure his skies would have been less impressive if his portfolio hailed from, say, Britain, even with his mastery of filter use & development manipulation.

[Carl Weese]

If you want exaggerated "black skies" filters are essential, and as someone already noted, a scene with actual deep blue sky to start with. But if you are simply looking for generally realistic rendering of sky tone, little or no filtration should be needed. If your skies are going white and needing tons of burning, it indicates that your negatives are underexposed and probably overdeveloped. Good exposure and development of the negative will let you print almost any scene with a realistic-looking sky, on normal grade paper with little or no burning

[Robert A. Zeichner]

Yes, filters are essential! The ones you mention seem like a good place to start, only I would add a #8 yellow to the list. I personally tend to shy away from using red filters unless there is no foliage in the scene as these tend to darken leaves to almost black. Instead, I use a Wratten G or 15 deep yellow in combination with a polarizer. This darkens the blue sky nicely without turning everything that's green to black. Yellow filters (8) are generally needed to render on film, what the eye perceives in real life. There is so much UV present (which film is very sensitive to) that without some kind of filter, your skies will always seem a little flat. That said, you must have a blue sky to begin with. If it's overcast or hazy, there's really nothing for the filter to trap and you'll end up with just what you see. The other thing you might try is to use a graduated filter. In some instances you can reduce the relative difference in density of the sky vs. foreground on your negative by placing one of these on your lens. the trick is to use it without making the effect obvious. A rectangular filter holder that lets you slip the grad. up or down might be a good idea. Also, grads come in different transition hardnesses, Which one to use depends on the scene and what focal length of lens you are using.

[Andre Noble]

Good info so far, thank you all. Now this leads to three follow-up questions:

BTW, I may be wrong, but for the particular negative and print in my original post, I'm comfortable with the exposure and development control, as the main body of the image, shot in sunset (foliage, white buildings, shadow detail, etc) printed very reasonably with a #2 filter.

1) On reflection, haze may indeed be a culprit, since I shot at sea level in and around hazy skies S. California and elsewhere. I assume a deep yellow filter will still help here nonetheless? Or should I have used a polarizer? or both at same time?

2) What use are polarizing filters to darken sky values in black and white shooting? Specifically, I've read that using one on my predominant lens (a wide angle 90/f8), for instance may result in a darker, but also possibly uneven sky?

3) Failing this, can someone recommend a good book containing alot of information on this subject of filtering for black and white landscape and outdoor portraiture photography? Thanks again. Andre

[Andre Noble]

Thanks Robert, you beat me to it. Good info.

[Doug Paramore]

Andre: You cannot always control the sky values with development and exposure. You need filters. Panchromatic film is still very blue sensitive, although some of the newer films are a little less so. Ansel Adams book "The Negative" has a good section on filter use, as has about every other book on black and white photography. The three filters you mentioned are quite good. Use a green filter where there is foliage included in the shot. A light yellow or green will give you a natural looking sky with white clouds and medium dark sky. It is easy to overdo things with a red filter unless you are really trying for dramatic skys. I use a yellow-orange filter a lot. A little yellow filtration will also help to cut haze a bit. Make some tests to find the effect you like, and don't overdo the filtration. Incidentally, I use the recommended filter factor with Tri-X and Ilford HP-5, and usually make one at the recommended factor and one one stop over. Watch for lack of shadow detail where the shadows are lit from a blue sky. The filters kill some of the apparent light on the shadow side, so compensate.

Regards,

[chris jordan]

Ansel Adams's "The Negative" has lots of good explanations and comparison photos using different filtrations.

Also, when burning the sky, you might try using a lower contrast filter, such as a "0". (or maybe you've tried this already?)This will help blend the burn and add density in high values more quickly than your base filter, with the added benefit of not darkenning your low values so much. Have fun!

Chris