Yellow Filter to counter shadowsgreenspun.com : LUSENET : Large format photography : One Thread
Somewhere I picked up that using a yellow filter would help a little in shadow details. Because of the 'blue' light? I thought all this time yellow darkened 'blue'. Remember sky/clouds contrast. Does anybody know about this yellow filter/shadow thingie? Is there any truth to it?
-- David Godwin (firstname.lastname@example.org), June 15, 2001
Yellow filters lower blue values, as you mention. Shadow light contains a significant proportion of blue reflected light and so will definitely result in lowered negative densities where a yellow filter is used. The extreme of this is achieved through the stronger red filters, where shadow values are often completely "dumped." If you want to preserve shadow values avoid the yellows oranges & reds.
It is somewhat possible to increase shadow placement & reduce development to couter-act this tendency when using these filers, but the question then is why use them in the first place?
-- Ernie Gec (email@example.com), June 15, 2001.
Sounds like I had it backwards. I was thinking the Yellow filter would aid in maitaining shadow details. This would have been useful in contrasty lighting situations. However, the Yellow Filter will actually lower the negative density and increase the contrast between light and shadow. This makes more sense since I was already taught that a Yellow filter would increase contrast between blue sky and clouds. All that said, the crux of the matter is that the Yellow filter will deepen shadows. Am I thinking straight yet?
-- David Godwin (firstname.lastname@example.org), June 15, 2001.
Filters are great for increasing local contrast/separation in areas of a given color range (sky, foliage, red rock faces). It takes some time experimenting to learn how film reacts to different color filtrations (I'm still learning!) A good resource is Adam's book, the negative. It offers some good comparison photos. I like light yellow for many landscape/foliage shots because it doesn't give an artificial, over-dramatized look.
I've found the loss in shadow detail can be compensated for by METERING through the filter to determine my shadow zone placement. Just take the filter off the lens and hold it in front of your meter. I've had better results this way than applying filter factors (and its more intuitive for my somewhat taxed brain). Hope this helps.
-- Chris (email@example.com), June 15, 2001.
David, when compensating for filters it is best to begin with the recommended filter factors written by the manufacturer and then adjust from there. Metering through the filters helps out some but the meter doesn't see the same way that your film does and may give you an incorrect reading. If you are having troubles with your shadow detail, consider increasing your exposure and reducing your development. With some practice, you'll be able to predict how your filters are affecting your shadows.
-- Dave Anton (firstname.lastname@example.org), June 15, 2001.
Take the time to run a test exposure or three with the filters and the specific film you want to use. Change film & you may change more than you expect. Tmax 100 has an extended red sensitivity that might make your filter factors for shade way off when you look at the processed negatives. If you test it first you know how much to open up to compensate.
-- Dan Smith (email@example.com), June 15, 2001.
To get more shadow detail, try a blue (47, 47B) or blue-green (44A) filter. I use these as often as I do yellow. Shadows do open up, but you may need to increase development time a bit, to avoid a mushy look.
-- William Marderness (firstname.lastname@example.org), June 16, 2001.
I think a polarising filter gives a lot more control over contrast than any coloured filter. You can cut the reflected light off foliage and other semi-reflective surfaces with it, and this really brings the overall contrast down. The effect is deceptive to the eye, because colour saturation is increased, and you really need to experiment with a roll or two of 35mm to see how B&W negatives respond.
-- Pete Andrews (email@example.com), June 18, 2001.