Juan Valdenebro
Truth is beauty
A spot meter (reflected light) and a piece of gray card make the best option, but the difference with a well done incident reading is smaller than an f-stop (usually on direct sun), so if you're really underexposing, check the way you do it or the meter with another one you know is OK and has spot metering...
Cheers,
Juan
Cheers,
Juan
Bob Michaels
nobody special
That works well when you return home with sheet film holders and notes how to develop each one.
I return home usually with a ziploc bag full of exposed rolls of film knowing that some images were made in hard direct sun, some made inside in very flat lighting, and often some that I had to underexpose a stop or more when there was no other option. So I must expose everything knowing that it will be all developed the same.
Rob-F
Likes Leicas
The first thing when using incident light measurement is to make sure that the light falling on the meter is the same as that falling on the subject; not in shadow when the subject is in a brighter area, or vice versa. When possible, I walk to the subject and point the meter at the camera. I make sure the meter is not being aimed up toward the sky.
I've been known to also take a reflected reading. I usually use my Gossen meter that has a sliding dome, so I can take both kinds of readings quickly without wasting time. If there's much difference between the two readings, the reason has to be understood and taken into account before I press the shutter. It will usually be that the subject is much lighter or darker than the hypothetical average reading for which the meter is calibrated.
If I can't get the same lighting condition on the meter as is on the subject, I don't take an incident reading.
I've been known to also take a reflected reading. I usually use my Gossen meter that has a sliding dome, so I can take both kinds of readings quickly without wasting time. If there's much difference between the two readings, the reason has to be understood and taken into account before I press the shutter. It will usually be that the subject is much lighter or darker than the hypothetical average reading for which the meter is calibrated.
If I can't get the same lighting condition on the meter as is on the subject, I don't take an incident reading.
Scrambler
Well-known
Using the meter as Rob F reports, (and as I previously mentioned) - you are using a foot-powered spot meter to take the shadow readings. If the subject is further than you want to walk this doesn't work as well 
so then a true spot meter has more function.
I don't have the experience that many on this thread have to judge exposure without a hint from a meter. A handheld meter, patience, and measuring reflectively in dark and light areas rather than getting "average" metering works better for me. Put the readings onto a calculator like the Westons have (the Master 5 would be my preference but I have a Euro-Master with additional ISO ratings and 1/2 (rather than 1/3) stop increments.
so then a true spot meter has more function. I don't have the experience that many on this thread have to judge exposure without a hint from a meter. A handheld meter, patience, and measuring reflectively in dark and light areas rather than getting "average" metering works better for me. Put the readings onto a calculator like the Westons have (the Master 5 would be my preference but I have a Euro-Master with additional ISO ratings and 1/2 (rather than 1/3) stop increments.
Roger Hicks
Veteran
No. mfogiel explained it perfectly. The less you care about shadow detail, the more you can afford to cut exposure.
Cheers,
R.
Roger Hicks
Veteran
Exactly.
Somewhere -- I can't find the reference -- I recall reading that Ansel Adams reckoned his exposures increased by at least a stop, on average, when he got a spot meter.
Of course you can use a spot meter with equal success without going down the Zone System path, though the naming of Zones remains an invaluable trick.
Cheers,
R.
Roger Hicks
Veteran
Dear Juan,
Definitely not. Spot meter + grey card is merely a much more complicated, expensive, hard to use version of incident light metering. You are still using an "artificial highlight" (the old name for incident light metering) but you've merely made it about 2-1/2 stops darker.
The only way to be sure of enough light in the darkest areas in which you want texture and detail is, unsurprisingly, to meter the darkest areas in which you want texture and detail. Otherwise, you have to "fudge" based on experience.
A lot of people with fancy theories on exposure get away with it only because (a) neg/pos photography is extremely tolerant and (b) they give more exposure than they actually need, based on all sorts of nonsense such as the belief that films are not "really" as fast as their ISO speeds -- which in most cases merely shows that they don't understand what ISO speeds mean. See http://www.rogerandfrances.com/subscription/ps iso speeds.html
Cheers,
R.
Sparrow
Veteran
... that's why I said 'one need only adjust from that to the subjects illumination' as it depends where the subject is ... any method which slavishly follows a meter or method without thinking about it is bound to fail sometimes
Ranchu
Veteran
In most cases it merely shows that people like their results better when they use a different ASA than what is on the box.
I don't think you should imply people don't understand things, Roger. If you take an incident reading of the sky, and slide the dome back and take a reflective reading of a grey card facing the sky, you'll get the same reading with a sekonic L-308. That's not an "artificial highlight" and doesn't involve any 2 1/2 stops.
Roger Hicks
Veteran
Dear Stewart,
And how do you reliably make that adjustment...?
See also my other two recent posts.
Cheers,
R.
Roger Hicks
Veteran
Changing EI is fine. I do it myself, normally overexposing by 1/3 to 1/2 stop. But ISO speeds are almost invariably accurate under the specified test conditions, and to deny that is a flat misunderstanding of what ISO speeds mean.
And, sorry, it IS keyed to an artificial highlight: see my post above, to Juan.
EDIT: A grey card is an artificial mid tone -- which is defined with reference to a highlight and is therefore keyed to it. It is NOT keyed to the shadows.
Cheers,
R.
Sparrow
Veteran
Ansel
Well-known
Then the solution is plainly obvious surely: adjust your ASA until you are getting correct exposure. If you consistently underexpose, set your ASA to half the current speed and try again. And repeat Until it is right.
A light meter is never wrong, but by the same token it is just a dumb tool. It is up to you to interpret the results you get and adjust accordingly. Tri-X is know to have quite a long toe area.
For the record, I rate Tri-X at 200 ASA, but where I live we have lots of sunlight. The reason I prefer an incident meter is that I only have to meter a scence once (normally on entering it) and then I can just concentrate on shooting. With a reflective meter I would have really had a problem metering the following scene:
Untitled by - Antonio Russell -, on Flickr
wakarimasen
Well-known
Which explains why my B&W efforts with incident metering were something of a disappointment
Spanik
Well-known
If with "consistently" you mean a full 100% then there is something wrong in the chain. And I would argue that it isn't even your metering. I'd start by comparing your meter with a "know good meter". Can be another incident one or a reflective and a grey card. If they both agree, look further up the chain.
Try another camera or lens or film, never change 2 things at the same time and take notes. Try getting some slide film as it already bypasses a lot of variables in development and printing. Could be the shutter of your camera is failing, the lens has got a bump and the diaphragm isn't ok, control of the diaphragm by the body isn't ok, iso setting of the body is not ok, lots of things.
Actually no, slavishly metering the right way will give you consistent results, always. I always use slides and incident metering and it never fails even when the handheld incident meter and the internal meter disagree by several stops it is the incident that gives the usable results.
If it goes wrong it is me that did something wrong. Mostly because I tought I was smarter than the meter, set the wrong iso (if using different films/ camera's/backs at the same time), forgot I had a filter on the lens or didn't stood in the same light and was too lazy to walk up to the subject.
On some occasions spot metering is the only way to go like stained glass or when it is plain impossible to get at your subject to meter and you know that you're not in the same light.
Likewise full sun isn't always and averywhere the same. Autumn full sun isn't spring or summer full sun and that will depend on the time of day.
charjohncarter
Veteran
Then the solution is plainly obvious surely: adjust your ASA until you are getting correct exposure. If you consistently underexpose, set your ASA to half the current speed and try again. And repeat Until it is right.
A light meter is never wrong, but by the same token it is just a dumb tool. It is up to you to interpret the results you get and adjust accordingly. Tri-X is know to have quite a long toe area.
For the record, I rate Tri-X at 200 ASA, but where I live we have lots of sunlight. The reason I prefer an incident meter is that I only have to meter a scence once (normally on entering it) and then I can just concentrate on shooting. With a reflective meter I would have really had a problem metering the following scene:
I'll agree with that, I have a pool at home and reflective is out. I use my 35mms by the pool and they are always fooled. Incident and set is the best way.
Here is a dumb photo, but incident reading:
Juan Valdenebro
Truth is beauty
Hi Roger,
I fully and respectfully disagree...
If a scene is correctly metered and exposed for medium values printing as what they are, who cares about what's the amount of texture in the darkest grays?
After using the zone system for years, I learnt I never need to place zones far from what they are in real life...
Apart, spot metering is not, as you say, a version of incident light metering, but the purest reflected light metering... Direct sun can sometimes cause wrong incident metering, you can test it easily, but spot metering on a well placed gray card is extremely precise...
Complicated? Expensive? Hard to use? No way... Anyone can learn how to do it in 20 seconds.
Cheers,
Juan
Roger Hicks
Veteran
Dear Juan,
Consider the shape of a d/log E curve, and the fact that both the slope and to a lesser extent the shape of the curve can be changed. Then consider the simple truth that if a print has a brightness range of 2.1 -- seven stops -- you're doing very well indeed. In other words you're compressing the brightness range of the real world immensely: a sunny scene can easily top 10 stops. And you're not compressing it linearly. In other words you can, depending on your intention and your skill, record more or less of the shadows in any print. That's before you start dodging and burning...
Now consider that the old name for incident metering was the "artificial highlight" system, because that's exactly what it is: the meter reading is based on the brightest highlight you can record without "blowing", i.e. the meter reading is keyed to the highlights. ISO speeds for negative film are based on the minimum exposure required to give texture on the film, i.e. they are keyed to the shadows.
A grey card is about 2.5 stops darker than the "artificial highlight". That's how it's defined: 18% reflectance, whereas a pure white is about 90%. A moment's thought reveals that a grey card is therefore keyed to the highlights, and that any shadow much darker than about 3-4 stops down from the grey card will have no detail. Often, shadows are a good deal darker than 3-4 stops down. Unless you read these shadows directly, you cannot guarantee adequate exposure.
In other words, you could read a sheet of white paper; or a sheet of grey paper; or the inside of an incident light receptor; and they should all give you the same reading, after you've adjusted for the reflectivity of the paper or the translucency of the incident light receptor (different index marks on the meter for spot, auto-compensated by the density of the incident light receptor). But none of those readings will give you detail in shadows much more than about 3-4 stops down from your artificial mid tone. It doesn't matter whether you read the incident light off the white paper, grey paper or incident light receptor: it's all incident light, and it's all keyed to the highlights.
If you don't want shadow detail, fine. But if you don't, why piddle around with taking a reading with an (expensive, inconvenient) spot meter and an even more inconvenient grey card instead of an incident light reading?
Of course "Direct sun can sometimes cause wrong incident metering" but so can incompetent positioning of a grey card. My argument is that it's just as easy to learn to use an incident light meter competently, and a lot easier to actually use it. And you will get exactly the same reading both ways.
If you prefer to use a spot meter and a grey card, well, that's fine: it works for you. But it's still logically and practically exactly the same as incident light metering.
Cheers,
R.
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x-ray
Veteran
For most of you the sunny 16 rule applies but not where I live. I live in a valley where the mountains trap moisture, dust and particulate matter until a strong weather system sweeps it out. Generally the rule for average bright sun is the sunny 11-1/2 rule. We lose about a half stop of light on an average day. Rarely do we have true full sunny 16 light.
I'm a pilot and when flying out of the valley it's quite apparent. There's a very visible layer of smog up to roughly 8,000 ft. It works just like a 1/2 stop ND filter.
I'm a pilot and when flying out of the valley it's quite apparent. There's a very visible layer of smog up to roughly 8,000 ft. It works just like a 1/2 stop ND filter.
Sparrow
Veteran
... all a meter does is measure the light and that isn't necessarily the same as the correct exposure. A meter can give one a baseline to work from but its up to the photographer to think through the correct exposure.
For photographic purposes full sunlight is the same year round and in any location I've ever visited, so I would not use a meter when the sun was out ... I'd just decide how much I needed to adjust from f16 1/film-speed to get the negative I wanted