Does your incident meter also have a normal reflected-light reading? Often, meters will have dual-use: 40deg averaging reflected and incident light, by sliding a light dome. If so, then meter the face in shadow (put your meter closer to the face), meter the window, and if you have more than four stops of difference, then reduce development time+overexpose about a stop or so. Testings should be made if you can, of course.
Using film since before it was hip.
"One of the most singular characters of the hyposulphites, is the property their solutions possess of dissolving muriate of silver and retaining it in considerable quantity in permanent solution" — Sir John Frederick William Herschel, "On the Hyposulphurous Acid and its Compounds." The Edinburgh Philosophical Journal
, Vol. 1 (8 Jan. 1819): 8-29. p. 11
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I stand corrected.
Donald, Does your metering assume the OP wants detail behind the subject? As I understand it, the way you are suggesting to meter this scene would allow for detail behind the subject.
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I am unsure what you mean by "behind the subject". If you mean outside the window, yes the film would exhibit exposure in that portion of the scene since that would carry a luminance that is higher than any other aspect of the scene.
This would be to allow for detail to be exhibited in the backlit subject. It would hold the rim lighting and it would show detail in the unlit aspects of the subject.
With the latitude of the film, typically, it would even show detail in the lit portions outside of the window. This exposure and development would allow us to make a determination at the printing of the negative how we want to interpert the exposure. We could show detail outside the window (if we carried sufficient depth of field) or we could allow it to render without detail...in either case our density range would be appropriate for the backlit subject.
It comes from the range of reflectances of real-world surfaces - from about 3% to about 96%, ie five stops. It predates BTZS. Minor White's beautifully concise Zone System Manual includes the method that would later be better known as the BTZS incident method.
Originally Posted by mark
At what SBR do you start taking a delution of Pyrocat HD in considaration ?
What paper is this all calibrated for?
Just wonder. ILYA
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Originally Posted by ilya1963
I don't consider dilution of Pyrocat as a means of dealing with SBR. I would rather diminish development time and under more extreme conditions I would much prefer other means such as preflashing of film for dealing with these extreme brightness situations.
I have arrived at my development times based on the papers that I use (Polywarmtone and Nuance) but more importantly for the enlarger and light source that I use. In my case I use a modified condenser light source.
Having said all of that, I have developed with different dilutions of Pyrocat...for instance 1-1-150 for minimal agitation and enhanced edge effects. Also 2-2-100 when I needed to arrive at a higher density range. But in none of these instances was dilution predicated on the SBR.
This is one of the situations that I cannot figure out how to get a measurement with an incident meter.
Say, a subject is siting in front of a window where there is a lot of details in the interior that I want to keep, not to mention the face of the subject.
How do I go about getting the measurement with an incident meter? Should I be able to do it without a spot meter?'....................
................My suggestion is to consider measuring your scene, like I do it, with as little math as possible, taking readings in f-stops, with your incident meter set to the same shutter speed as you measure illumination coming from wherever it's coming from as it hits the subject matter/sitter, relative to what your lens sees.
Set your shutter to whatever, aim your incident meter's dome at the lens holding the meter directly in front of the sitter, giving you a reading of the illumination within the room as the lens sees the light hitting the subject.
Turn the meter around and point its dome directly at the illumination coming in from the window and take a reading.
Say the reading inside the room is F4 @ 1/60sec, and the reading pointing the meter out the window is F8 @ 1/60sec, obviously a 2 stop difference.
At some point in considering how you're going to expose this scene, I suggest that you have to mentally switch gears and set the math aside, and consider what's going to 'look right'/going to give you the 'look' you want. If the subject is frontally lit by the illumination coming from inside the room, and is lit by a rim/crescent from the illumination coming from the window, you have some choices in deciding the 'look' you want for this scene.
A subject sitting in front of a window is frontally lit by the illumination coming from inside the room, bias toward the above mentioned F4 @ 1/60sec and the subject's face is going to look less like a shadow, and the illumination coming in from the window is going to look hot.
Expose @ F5.6 or F8 @ 1/60sec and the light hitting the subjects face is going to look more like a shadow relative to the light hitting the sujbect from behind(coming from the window).
The numbers are important, but in order to eliminate mistakes, I simply try to keep the shutter speed the same when measuring at different positions and calculate in F-stops, in the above scenario with a 2 stop difference in your measurements, there's no 'correct' exposure, the best exposure is the one you pick to give you the 'look' you want, or where the shot 'looks right' to.
Having said that, things would get quite a bit more interesting if say measuring the light hitting the sujbect from inside the room, versus the illumination coming through the window, and hitting the sujbect from behind turned out to be a difference of 4-5 stops, picking an exposure between F4 and F16(22), since you want detail on the subjects face without the light coming from the window ending up way too hot or blown out becomes more problematic. Or possibly you might expose at F4 for the illumination inside the room, with light coming in from the window at 4-5 stops hotter creating an interesting effect instead of something garish, it's been done.
If there's a 4-5 stop difference in your scenario, you might want to bias between the two extremes, I'm discussing this assuming the use of neg film and what I've been able to do with a film like Illford HP5, YMMV.
I could play around w/EV numbers, add and subtract, but I prefer a simpler way, particularly when I'm tired/been shooting all day.
Good luck, I hope this helps.
Thanks for the example Donald, and the meaning of "five" Mark and Helen.
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As a simple aside, often when using an incident meter, I will "flag" the dome with my hand to eliminate light coming from one direction or another, to give an accurrate value for the area I am metering, in regard to establishing ratios.
For example, if I had a steep backlight that would illuminate part of the dome when oriented towards camera, I would flag the dome with my hand, or block the backlight with my body, to get a value for the subject without the backlight. When using an incident meter, always be aware of the biggest variable of all, your rather opaque self. Metering towards the camera, with the backlight striking the dome would give an approximate average of the front and backlight, depending in part, on how much of the backlight is striking the dome. (It is, perhaps, the least useful of the three readings), and metering towards the backlight would give the value of the backlight. In all instances the values would be for 18% grey, for the light used in the reading.. remember that light striking a subject from an angle that is close to or equal the opposite angle to the camera, particularly if it is a point source, will give a higher resultant exposure in the illuminated area than light coming from 90 degrees and forward on the camera side. The exposure you choose with this information in hand, can be biased in any direction you choose, and the negative will reflect that. If, for example, you expose for the low reading you can expect detail in the low values, at the expense of the highlights ( the window, in the scenario you describe), but with less penalty than if you were to expose for the high reading, and lose the low end. (It's a bitch to print what's not there)
You can also expect lower contrast exposing for detail in a heavily backlit subject, if the source of the backlight is in or near frame, because the lens elements can not be flagged, and the contribution the exagerated exposure brings to backscatter, in regard to exposing the low and middle, in the face of high contrast, where you are letting the highlights go.. (Insert reference to fabulously coated lens here)and
(Insert reference to Pyro developers here)
All things being equal, it's a fine line between clever and stupid, in this scenario.
Last edited by JBrunner; 11-30-2006 at 10:39 PM. Click to view previous post history.
Shinnya....................do some tests w/this lighting situation, bracket your exposures in half stops, starting w/your meter reading for the illumination hitting your sitter from inside the room, keep bracketing until you reach the meter reading you get from pointing your meter out the window. Take some accurate notes of your exposures for each particular frame.
Take what you've heard here, and whatever input you've gotten, and do some involved testing, doing it yourself, and seeing the result, is ultimately going to be the best teacher.