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Q. MF Technical - Reflective metering useless?
Asked by Snedley Mc'alister
(K=256) on 7/31/2002
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Going over my trannies I thought of another point which is noteworthy and this is the limitation of reflective readings for outdoor photography or nearly anything for that matter. When I first got my L-358 I thought that I would hardly bother with Incident readings and go with reflective readings. Now that I have seen the results of reflective readings against my own hand/18% readings I can't see any use for the reflective operation at all.
Case in point... In my previous photographs I discussed shooting from dark shadowy tree line using branches and whatnot to serve as a frame for my main focus which was open sunlit harbour, boats and sky. I took my hand readings as per compensations for polarizer et al and shot my shot. The light for the shadowy tree's was all wrong for what I wanted on the day because the morning sun had already moved overhead and partly behind the section of harbour I was shooting out into. This was not important, what was important was being able to get the correct exposure for the sunlit scene and to pick up some stray dappled highlights on the tree's when I went back at the right time.
Ok, so I shot my hand reading and then took a reflective reading from the camera position as a comparison and got a totally overexposed image by as far as 2-3 stops over. The reason the reflective reading is useless is because the meter is so sensitive that it gets fooled by the local shady/ambient light from the tree line where I am shooting and takes that into account as the average and doesn't understand that I want the harbour in open light exposed for with the shady area kept as is, picking up stray, dappled sunlit branches.
The end result is the reflected reading exposes the shadows and even manages to blow out those areas, as well as the open sunlit harbour. This is reflected readings I can't use. The best thing I can use the reflected light reading for is close up objects like shrubbery and flowers, my hand or a grey card but thats about it really. It seems to me that a reflective light meter takes everything into account but takes the stronger elements of a scene into account over the weaker elements, which may be distant and the part of the scene you want perfectly exposed, and thus gives you neither a good result or a useful result. This is why I suppose Bob Shell and others claim to barely bother with reflected readings at all!
I think using a spot meter is the only reflective method that is useful and thats about it really. I find the reflected TTL meter on my Contax absurdly incorrect on many occassions also, but for situations at close quarters. I shall be focussing more and more on my incident and hand readings with perhaps a 1 degree or 5 degree spot to work with for tricky distant landscapes from now on.
Syd
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David Goldfarb
(K=7611) - Comment Date 7/31/2002
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Specifically, I think you're talking about averaged reflective readings.
Yeah, I think they're a pretty blunt tool as well, no more accurate typically than going on intuition. People who use systems like center weighted metering effectively, have to apply compensation for the reflectivity of the subject and the brightness of the background--in other words, using intuition and experience to correct for the kinds of mistakes that averaging meters make. Nonetheless, if you can make those corrections, it can work. Art Morris, the bird photographer, does this.
I spot meter whenever I can, and place the values consciously, or I'll use the incident method for subjects and lighting situations that lend themselves to that.
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Snedley Mc'alister
(K=256) - Comment Date 7/31/2002
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David,
I thought I was being specific, reflective metering (average) as opposed to spot metering was my focus so, yes, I am talking about average reflected readings and as far as average goes, the results are less than average. It may be well for someone who has had years with a reflective meter, in camera or hand held, which over time they have learned to compensate for by intuition and get pretty good results with, but what I am talking about in the main here is that this kind of system is really quite useless and obsolete due to the nature of the way a reflective meter gathers it's info on the average scene. Not so the case with spot metering.
The Reflective metering of TTL cameras and even hand held meters is prone to give you all the wrong information, you might get used to it, blow allot of film and then learn how to compensate for it, but this is a messy process at best. There are better ways to achieve predictable results whereby you can obtain more exact data from the overall scene and control those values, average reflective metering isn't one of them.
Syd
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David Goldfarb
(K=7611) - Comment Date 8/1/2002
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I didn't mean to imply that your question was unclear, so much as I wanted to make sure my answer was clear. Average metering, center-weighted average metering, partial metering, 5-degree, 10-degree, and spot metering are all reflective metering.
As I say, I agree that one needs to learn a few things to use average metering effectively (and I don't particularly like it myself), but to be fair to partisans of averaging metering schemes, that's really true of any type of metering system.
If one didn't know a little about the Zone system, for instance, spot metering would produce lousy results, as beginners often discover.
Similarly, if one doesn't think about the reflectance of the subject and brightness of the background, an averaging meter won't do too well either. To continue the example from above, Art Morris publishes a great guide for bird photographers who wish to use center-weighted average metering without the years of experience he has. I still prefer to spot meter and place the values, but lots of people use the averaging system successfully.
Incident metering seems simple, but even then, it is important to account for the contrast range of the film and the reflectance of the subject, to know when to use a flat diffuser and when to use a dome, and how to orient the diffuser with respect to the light and the lens for different kinds of readings.
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Snedley Mc'alister
(K=256) - Comment Date 8/1/2002
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David,
I take your point. To be even more specific, I am talking from the perspective of an all mechanical Mamiya user who uses a hand held meter and not a TTL or electronic prism finder system to get my results.
I agree that knowledge of basic Zone and various other techniques are dependant upon some level of relative understanding in order that they be useful and user freindly. Again it is understood that there are many ways to skin a cat. I can only speak from my own perspective and discuss what seems efficable to me and superfluous on the other hand.
I don't use any center weighted view finder system and frankly since I have moved up to MF from 35mm it has slowed me right down and I think very deeply now about composition, exposure, reflectance, tones, specular light and all manner of things which has enriched my photographic perception and the way I go about working. I am glad of this change and have seen it reflect (no pun) back into my 35mm work which was very MF/LF in the way I saw things anyway.
Even now when I pick up my 35mm Contax I ignore the metering system, which I never had any fun with anyway, and I engage my brain using any number of techniques from hand held metering, hand, incident, reflective close up averaging, etc, etc. Allot of auto metering systems can encourage the user by insidious means to forget to engage brain. Images can be captured with relative ease but all the values are presupposed by some semi-sentient intelligence which dictates a given result.
My point is that reflective metering in the "average" sense, whether it be TTL or Hand Held in and of itself is to me useless, and allot of pro's would concur. There may be some that have success, as in the case of the chap you mention - whose site I saw a while ago and knew he regularly pushed Velvia to 100 - but even so I would prefer the few techniques I have learned which do not involve general *average* reflective metering, to using it, because I have found these other systems more reliable and subserviant to *MY* inherent creative intentions. In other words I have greater creative control given the use of these systems.
I don't claim however that spot metering, whether it be spot 1, 5, et al, to be in the same class as TTL average weighted and average reflective metering at all, I hope this is apparent and therefore self evident as it sums up my bottom line... don't bother with any other kind. But then, thats just me talking.
Syd
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Michael John Banks
(K=2092) - Comment Date 12/22/2002
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Reflected readings are best used to determine the subject luminance range. A spot meter is OK if one does not want to walk about the landscape taking readings--but in the studio where this is not a problem, the reflected reading from the subject is useful--but not for determining exposure. Some believe that an "average" of the reflective readings from important details is a good compromise. I am not one of them.
The grey card is the best way to use a reflected light meter. Point it so that the card is normal to a line from the camera lens to the card. Then take a reflected reading from the card. This is your INITIAL exposure reading. 95% of the time this will get you an adequately rendered monochrome neg. It will get you a useable colour neg about 80-90% of the time.
If you are using slide film, then you bracket one stop either side of this reading in half-stop increments. If bracketing seems a bit expensive, you can refine the initial reading by assessing the VITAL part of the picture to see if it is above or below what would record as the monochrome equivalent of a neutral mid-grey.
Suppose we are dealing with a model with a very pale skin. This will record at least two stops over a mid-grey, but if we reduce the exposure by two stops we will record her skin as a mid grey. We do not want to do this, but we still wish to ensure that the film is able to record her skin's highlight detail. So, we may REDUCE the exposure by one stop. If we are shooting trannies, reduce the exposure by one stop and bracket half a stop above and one stop below in half-stop increments.
Exposure meters are a tool. They do not solve problems, they create them! These problems must be dealt with, as an educated guess is seldom good enough for exacting work.
The thing to remember is that reflective meters provide a reading based on a monochrome film developed in standard developer to a certain standard gamma which will record a mid grey as a mid grey on a print made on standard paper developed to the maker's instructions.
YOU have to make the adjustments. Of course it is necessary to test the meter-film-camera combinations at all shutter speeds and f-stops. I do this by shooting an incremental density scale from white to black. Audio-visual stores may be able to provide you with one. You must get a straight print properly developed of the scale, exposed using a reflected reading taken from a grey card normal to the lens axis.
If the true neutral grey on the chart or scale is in exactly the same place on the print of the density scale, then your meter/camera/film/developer/enlarger exposure/print developer combination is either spot on or has compensating errors!
This is why I would get my equipment calibrated before beginning serious photography. Like a pilot flying in cloud--one has to rely on one's instruments. I like to know that they have all been tested A1 before I waste any money on film, materials,chemistry, model fees or fuel to remote places.
If we are shooting colour-neg film we can over-expose a tad, but never under-expose. If we are shooting trannies, we can under-expose a tad but never over expose.
Look at the scene and determine the areas that you MUST GET correctly exposed. Are they above or below what would print as a mid grey tone?
Adjust your initial grey card reading--and lotsa luck!
Mike.
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