My biggest problem shooting in forests has nothing to do with spectural response of the film but with the extreme contrasts. Dark shaded areas with patches of bright sunlight bursting through - magic stuff.
I have begun to experiment with overexposed XP2 in my 6x12 back - the images from my trip to Weott were really good - even sold a panoramic last weekend at a local show. The other benefit of XP2 is has really good reciprocity characteristics - handy when you can get into multiple second exposures.
By the way - I will be heading up to Weott & the Matole Road for the second part of my field trip - love that area
Mike
That's why when I printed silver gelatins, I always photographed on overcast days (that's the advantage of living here...step out side, check the weather, and if it feels right head into the redwoods!) Now that I carbon print, I look for that sun coming through the redwoods as the process eats up that contrast for lunch!
I prefer the redwoods 40 miles north to the redwoods 40 miles to the south (Weott). Mostly because there is no poison oak to the north! but the redwoods on the flood plains along the Eel River are beautiful.
When will you be heading up this way?
Dan, A blue-desensitizer for film is availible -- it is called a yellow filter.
That's why when I printed silver gelatins, I always photographed on overcast days (that's the advantage of living here...step out side, check the weather, and if it feels right head into the redwoods!) Now that I carbon print, I look for that sun coming through the redwoods as the process eats up that contrast for lunch!
I prefer the redwoods 40 miles north to the redwoods 40 miles to the south (Weott). Mostly because there is no poison oak to the north! but the redwoods on the flood plains along the Eel River are beautiful.
When will you be heading up this way?
Dan, A blue-desensitizer for film is availible -- it is called a yellow filter.
Vaughn
Probably the last weekend of October. In the summer I usually stay at tge Hidden Springs Campground - but this time it will have to be the Burlington.
I will probably be leaving Walnut Creek early Friday morning and should arrive around 1:00 PM in the afternoon. Will stay through lunch time Sunday before heading back.
You are right about the poison oak - its all over the place as well as the mosquitoes. I was eaten alive the last afternoon I was there. I was OK setting up the 4x5 and tripod and had made about three shots when they decided I was a free meal - but that goes with the territory.
Consider the chance you are thinking this out waaaay
too much. ....... Just go shoot "the forest floor" and see
what you get. Best, C
I've scrubbed 1ea, Uv, Y8, Hoya Orange and Y/G and
a color film blue. Also I've dusted off my ETRSi and
loaded it with Acros 120. As soon as the dentist
and bad weather are out of the way I'll head
for the woods. Dan
I've scrubbed 1ea, Uv, Y8, Hoya Orange and Y/G and
a color film blue. Also I've dusted off my ETRSi and
loaded it with Acros 120. As soon as the dentist
and bad weather are out of the way I'll head
for the woods. Dan
You might as well toss in a polarizer filter, also. I read that tip on some forum somewhere for use with color...esp slide film. The leaves reflect the light from above, which tends to be bluer than the surrounding light -- so by reducing the reflections from the leaves, one gets rid of the blue cast they can have. Of course, adding a couple stops or more to one's exposure under a forest canopy is not always a desirable thing!
Dear Dan, True. You said 'balanced for tungsten' (post 1)
which is equally meaningless -Cheers, Roger
Balanced as with color films are balanced for indoor
or outdoor use; ie taken to mean tungsten or daylight.
Unless I've forgotten the terminology?
Apart from all that I'm now struggling to understand
why precisely filter factors are necessary. Any clues?
I think it may have to do with an averaging of negative
densities across the spectrum. Filtering out some portion
of the spectrum does not affect film sensitivity yet most
filters require an increase in exposure. Dan
Filters filter out light. White light is a combination of all wave lengths of visible light -- remove some of that light by using a filter and you have less light hitting the film. Some objects reflect a limited spectrum of light (if that is the correct way to say it). Thus an object that reflects primarily red light, would be darker when photographed thru a blue filter -- it would be "underexposed" relative to the rest of the scene. But the rest of the scene also is reflecting light that includes red (such as white objects, orange, brown, etc.) giving the film less exposure over-all.
I suppose even that red object is reflecting some blue light, tho only a small amount -- thus we have different shades and intensities of "red".
In theory, a scene of nothing but blue objects photographed thru a blue filter, would not need any filter factor applied. But scenes are typically full spectrum.
You are correct, film sensitivity is not changed by filters -- the filters reduce the amount of light reaching the film. Film is more sensitive to blue light -- use a red filter and you have eliminated a major portion of the light the film is most sensitive to -- thus one of the reasons that the filter factor for red filters tend to be highter than blue filters (along with the large amount of blue light that makes up a daytime landscape.)
I use a yellow filter to photograph the Fall colors in the redwoods (only yellow really -- not the East coast variety of colors). The yellow filter reduces the exposure of the blues (and also greens, purples and whites). Rather than have most of the scene underexposed and the yellows unaffected, I increase the exposure to bring the blues, greens and purples back to their proper exposure and the yellows are "over-exposed" and create wonderful hightlights.
Balanced as with color films are balanced for indoor
or outdoor use; ie taken to mean tungsten or daylight.
Unless I've forgotten the terminology?Dan
Not forgotten, you but applying the terminology out of context. Color film is made out of layers of emulsions, each with their own sensitivity to different colors -- balencing the responce of these layers requires careful balencing of the color temperature that the film is exposed to...in order to reproduce the colors we see.
B&W films being a single emulsion layer does not have this concern. However, because B&W film differs in its sensitivity to different areas of the light spectrum, there is some effect. Thus, a yellow filter is often used with pan film to render skies closer to what our eyes see.
Copy film (ortho -- not pan) is relatively highly sensitive to blue...so in copy work, different ASA's are given to copy film depending on the light source. Tunsten light has less blue light in it -- so the ASA is lower than when used in daylight. So copy film is not "balenced" for tunsten, it is just not as sensitive to it because tunsten light has less blue light..but our light meters don't know that.
Vaughn has answered both questions perfectly, with the slight addendum that some B+W films are in fact bipack (double layer) emulsions and some may even be tripack, though I think (I'm not sure) that if there are 3 or more emulsions then normally some of them are blended instead of being coated separately.
Dan, take a look at the sensitivity curves for Ilford FP4+.
It has reduced blue sensitivity compared to most other films.
A "blue de-sensitizer" is easy: Yellow dye. I don't know if
that's what Ilford uses, but I like the colour response of
FP4+ better than other films I've tried for most
outdoors work.
The FP4+ curve is quite different with it's steady rise to
a peak in the very red. Ilford's curve is plotted at 2850K.
It is the least 'balanced' of any of several curves I've just
reviewed including Acros 100. May be it is faster in use
than some other 100 to 125 films; skip the use of the
light yellow filter.
Ilford's SFX is interesting with it's extended red sensitivity
but still a fully panchromatic film. Have not considered it
due to it being not so fine a grain film. Likely will add a
few rolls to my next order. Dan
as well as the mosquitoes. I was eaten alive the last afternoon I was there. I was OK setting up the 4x5 and tripod and had made about three shots when they decided I was a free meal - but that goes with the territory.
Linear Mode
