When Not To Use An Incident Meter? [Archive]

wgerrard

09-11-2010, 19:33

UPS delivered my Sekonic L-398A and I'm trying to get smart about how to use it effectively. Questions and "what if" scenarios spring to mind. Here are a couple:

1. What situations aren't prime time for incident meters? When shouldn't they be used?

2. What if... the light on a scene comes from a single source but, for one reason or another, the actual light in the scene is broken up into areas of bright light, shade, and shadow. E.g., a street shot of two parallel alleys entering a street, shot straight on from the street, with the sun to my right. The alley on the right is brightly illuminated. A building between the alleys casts a shadow over the alley on the left. Is an exposure based on the incident meter going to give me an image that shows the bright light and the shadow, or will something else happen?

charjohncarter

09-11-2010, 20:43

There are lots of tutorials on incident readings on the Internet, but this simple explanation on page 22 and 23 has helped me:

http://www.cameramanuals.org/rolleiflex/rolleiflex_t.pdf

Richard G

09-11-2010, 21:30

Photographing someone sitting in the shade at the cafe in that alley on the left might be accomplished by taking an incident reading in the shade on your side of the main street, but if the upper sunlit windows of that alley partially reflect onto the newspaper she is reading, there'll be no substitute for a spot reflective reading. Same as at concerts, unless the lighting guy has let you take some incident readings before the gig. A bronze door with subtle relief pattern, in shade, might also take an extra stop of exposure, especially on colour negative film, and a reflected reading might actually help there too......

Roger Hicks

09-12-2010, 01:24

Incident keys exposure to the highlights, making sure they don't blow to a featureless white with transparecies and digi. http://www.rogerandfrances.com/subscription/ps%20expo%20slide.html

Reflected (spot) keys exposure to the shadows. It's really difficult to blow highlights in negatives. http://www.rogerandfrances.com/subscription/ps%20expo%20neg.html

Cheers,

R.

Richard G

09-12-2010, 02:52

Having seen these links of Roger's earlier in the afternoon in another thread I was going to cut and paste them here. A great site.

wgerrard

09-12-2010, 03:04

starless

09-12-2010, 04:01

2. What if... the light on a scene comes from a single source but, for one reason or another, the actual light in the scene is broken up into areas of bright light, shade, and shadow. E.g., a street shot of two parallel alleys entering a street, shot straight on from the street, with the sun to my right. The alley on the right is brightly illuminated. A building between the alleys casts a shadow over the alley on the left. Is an exposure based on the incident meter going to give me an image that shows the bright light and the shadow, or will something else happen?

If you measure the light in the brightly illuminated area - then the parts of the image with this lighting will be properly exposed. If you measure in the shade, then the darker areas of the scene will be properly exposed.

You have to decide how you want your image to look and which part of the scene is more important.

oftheherd

09-12-2010, 04:07

Like any other tool, you will need to experiment to see how things work to give you what you like in a negative. But RogerandFrances's site will give you as good a start as you can get.

Pherdinand

09-12-2010, 04:14

1. What situations aren't prime time for incident meters? When shouldn't they be used?

I can name a few situations... astrophotography and safari comes to my mind

Bob Michaels

09-12-2010, 05:17

Can we just conclude that no meter, incident or reflected, will always provide correct exposure information without some human brain power involved? While both types of meters will provide information about the intensity of the light, the final exposure determination or confirmation of an auto reading has to come from the photographer. That personal determination needs to consider the tone of the subject, the recording medium (negative film, positive film, or digital sensor), and the relationship of the subject to the light. .

I sense that too many are seeking that holy grail where they can use zero brain skills but always rely on a device to determine exposure for them. It happens frequently but will never happen all the time.

Maybe that is why photographers who are experienced at using no meter at all consistently get better exposures than many photographers with meters.

sonofdanang

09-12-2010, 05:25

Can we just conclude that no meter, incident or reflected, will always provide correct exposure information ....and the relationship of the subject to the light. .

I sense that too many are seeking that holy grail .... photographers who are experienced at using no meter at all consistently get better exposures than many photographers with meters.

Hear! Hear! Or, in lieu of a device, a "grail policy".

I'm with Bob. Film (or whatever capture media) is the cheapest part of this. If you feel the exposure is complex, bracket the hell out of it. Take a lot of notes if you must, but I know a guy - very successful, very well known - who told me that after reviewing his exposure notes over twenty years of work and trying to correlate various approaches to types of scenes, he couldn't get past generalizations. Shooting chromes with fast moving light he found that the way to get what he wanted was to yes, meter, think hard, and then "bracket the hell out of it".
Shame to miss the shot out of pride!

wgerrard

09-12-2010, 05:51

Certainly not looking for a "Holy Grail", guys. Just a little advice on using what is, for me, a new tool. If I expected the tool to do all the thinking for me, I wouldn't have had a reason to post the questions.

I understand the basic technique of using an incident meter. I'm looking for advice about recognizing situations in which its proper use isn't obvious or intuitive.

sonofdanang

09-12-2010, 06:04

Ah. Apologies. I better work on my reading skills!
I think then the only thing to do is play with it in correlation with making images. See what works for you. Roger's site has really very good info and after that it is how you synthesize that into your own process.

sreed2006

09-12-2010, 06:52

This is a very strange coincidence; I acquired a Sekonic L-398 yesterday evening, and have precisely the same questions (but some more questions, too).

Knowing what I know right now, answering your question #2, I would pick a spot from which to take the picture of the alleyways; cross the street and stand in front of the building between the alleyways; aim the lumisphere at the exact camera position from which the picture will be taken; take a reading with the meter; set the camera shutter/aperture; go back across the street (praying that a cloud doesn't come along); and take the picture.

Now, that may not be the correct way to do it - that is just what I understand needs to be done.

The sun is up today, and what I am doing is using a digital camera in manual mode for shutter speed and aperture. The camera shows a histogram (it's a 5D), and I am just experimenting away. In the few pictures I've taken so far, I haven't always nailed the correct exposure setting. Some of the shots are underexposed, even when I double checked the reading on the L-398. So, it will be a learning experience. At least with the instant feedback of the 5D, I expect to have most of it figured out today.

The L-398 cannot be used as a reflective light meter, other than as a tool to measure relative light differences being reflected from the subject(s). Use that feature to determine if the contrast ratio is within tolerance. So, in the case of the two alleys, use the lumigrid up close to a wall in the brightly lit alley, memorize that, then use the lumigrid up close in the darker alley, and see if the contrast difference exceeds the capability of the film/sensor. From my understanding of the manual, though, you cannot use the reading from the lumigrid to make the exposure settings on the camera. That's not what it is for.

wgerrard

09-12-2010, 09:05

Hi, Sreed. Question #2 was my attempt at conjuring something that appears difficult to meter. (You could recreate it in a studio with two models on either side of a high dividing panel with the light coming from the side.

The premise of an incident meter seems pretty failsafe: Measure the light falling on the subject from along the camera-subject axis, preferably very close to the subject. So, if one half of the subject is bright and the other half is dark, I'd think getting a read would be simple and that the resulting photo should show the bright and shaded areas appropriately. After all, the meter doesn't know that the scene is bright on one side and dark on the other. It's looking the other way.

If my assumption is incorrect, I'm curious to know why so I have a better understanding of the thing. Hence, the question.

sreed2006

09-12-2010, 09:36

I think you have the idea pretty well.

Do you have the manual? On page 19, where there is a picture of a lighthouse in the background with a ledge or cliff in the foreground, it gives instructions for taking two different readings and then averaging the two.

By the way, back from experiments:
1. If you use the High slide with 100 ISO film, and set the shutter to 1/500, then you can take f/stop readings directly from the meter scale.
2. If you let the High slide fall out into the grass, and walk around a lot, it is really hard to find again.
3. You cannot use the incident meter on a bright day without the High slide (the needle pegs out).
4. Using the lumigrid disk in place of the lumisphere and High slide, you can use the meter as a reflected meter, with 100 ISO film and the shutter set at 1/500. This is per the table on page 16 of the manual. Take several readings and average them and the results are acceptable, if not perfect.

wgerrard

09-12-2010, 09:50

Do you have the manual? On page 19, where there is a picture of a lighthouse...

Yep. Pulled that one down from Sekonic's site. Mine was delivered with 18 pages of "Operating instructions" and no lighthouse.

2. If you let the High slide fall out into the grass, and walk around a lot, it is really hard to find again.

I actually called the vendor who shipped mine to say I thought the high slide was missing. The guy on the phone said to pull the little loop sticking out of the top. Shazam! :)

3. You cannot use the incident meter on a bright day without the High slide (the needle pegs out).

I was out this morning. Here in the southeast, it's still f/22 and 1/500 sun.

Roger Hicks

09-12-2010, 10:14

Thanks for the pointers, John and Roger. It'll be a refresher at the latter's site.

I'm very likely overthinking this, as usual.

[EDIT: Wanted to mention I've also found the relevant portions of "Perfect Exposure" by Roger and Frances to be very useful. That's a good book to read and keep. BTW, Roger, an Amazon seller is listing a "new" copy of the hardcover edition at $107.00]

Dear Bill,

Hell's Teeth! Thanks for that. I'll try to persuade one of my publishers to reprint. Or better still, to do a second edition....

(And, of course, thanks for the kind words).

Cheers,

R.

tlitody

09-12-2010, 20:00

1. the meter won't give you the correct reading when its not in the light for which you want a reading.

2. if you are in the same light as the bright alley then it will give the correct reading for the bright alley(i.e. you are in direct sunlight). If you are in the same light as the shadow alley it will give you the correct reading for the shadow alley. (i.e. you are in shade too).
But since you are having both bright and shadow alleys in shot then you want the shadow alley to lokk like its in shadow so I'd suggest going for metering reading in direct sunlight and that way the bright alley will be correct and the shadow will be in shadow.

VinceC

09-12-2010, 20:31

Is there a "correct" exposure? How you expose a scene like that described above determines how the final image will look. You could shoot just for the highlights, or even beyond the highlghts to treat the highlights as midtones and depict their texture while throwing the shadow into utter darkness, like a graphic. There are situations where you might shoot just for the shadows -- to draw attention to something in them -- while the rest of the scene is in over-exposed high key. Or you could strive for some several balances between the two. And, of course, the decision to pop a daylight fill flash is a factor in most lighting situations. All of these will produce correctly exposed photographs, depending on what you want to say and show in the photo.

Remember that the light of the scene is one of your variables, albeit one in which you have less control compared to exposure, focus and camera position (though your camera position depends on, or should depend on, the character of the light).

A lot of times you're trying to make the best of bad light -- because the timing of what you're photographic requires you to take a picture then and there. Other times, you see interesting light, and its character is what makes the photograph succeed. Don't forget that a lot of photographers doing pictoral work will see a specific scene and then wait -- sometimes for a very very long time -- for the light to be "right."

Regardless of what you think of Ansel Adams, his photographs are worth studying for the way he timed their taking. Often his most famous captured fleeting balances of dramatic natural light in otherwise ordinary scenes. That's why he came up with the Zone System to better understand the relationships of light and exposure on film.

Nokton48

09-12-2010, 20:59

I don't bracket, I give myself "a choice of negatives" if the subject is repeatable, and worthy of multiple exposures. This technique is obviously not applicable if I am trying th catch a decisive moment.

wgerrard

09-13-2010, 04:00

1. the meter won't give you the correct reading when its not in the light for which you want a reading.

Yes, but in my scenario I am shooting from a position perpendicular to the two alleys. I.e., I'm in the street the alleys run into, looking down their lengths, centered in front of the building. I want the photo to reflect what I see: the well-lit alley on the right and the shaded alley on the left.

So, what I'm trying to understand is whether or not an incident reading from, say, in front of the building looking back to my camera position, is appropriate for that kind of shot.

Richard G

09-13-2010, 04:19

You were right before: you are definitely over thinking this. With over 2000 posts in RFF I bet if you make 4 shots in that place, if you can find it, you will answer your question. Except, as indicated above in many posts, there is no answer to your question as you re-pose it just now. You have to decide, whether with an incident reading or a reflected reading, what you want in the finished shot: blocked shadow (left alley) or blown highlights (right alley). The meter reading can't make that decision. You must have been watching too much tennis this week.

wgerrard

09-13-2010, 04:29

You were right before: you are definitely over thinking this.

Of course. It's my curse.

You have to decide, whether with an incident reading or a reflected reading, what you want in the finished shot: blocked shadow (left alley) or blown highlights (right alley).

I'd go for the blocked shadows. :)

You must have been watching too much tennis this week.

Tennis? There was tennis? I've actually been shooting more than usually, then processing, the joy that is scanning, and all that.

tlitody

09-13-2010, 04:55

Yes, but in my scenario I am shooting from a position perpendicular to the two alleys. I.e., I'm in the street the alleys run into, looking down their lengths, centered in front of the building. I want the photo to reflect what I see: the well-lit alley on the right and the shaded alley on the left.

So, what I'm trying to understand is whether or not an incident reading from, say, in front of the building looking back to my camera position, is appropriate for that kind of shot.

An incident meter measures the light falling on the scene and not the light being reflected from the scene. If your position across the street is in bright sunlight, then if you point your meter at the sun it will get the same reading as if you were in the brightly lit alley and pointed it at the sun. Therefore to get the correct reading for the brighly lit (in direct sunlight) alley, you can stay where you are and point the meter at the sun. The alley in shadow will fall where it falls relative to your reading which will be darker, i.e. expsoed as for a shadow. Maybe blocked maybe not. It depends on deep the shadow is.

You must make decisions about which lighting source you want to read. If you were standing in full shadow you couldn't take a reading from the sun. It would have to be from the main light source which would be the sky and would therefore make the dark alley look brighter than it does from across the street where the meter would be in bright sunlight.

wgerrard

09-13-2010, 05:14

If your position across the street is in bright sunlight...

In this scenario, the sun is to my right and the building and the ends of the alleys are in front of me.

With an incident meter, am I not concerned primarily with the light as it illuminates the subject? If my subject was the side of the building facing the bright alley on the right, i.e., if I was shooting the side of the building with the sun behind me, then it would make sense to take a reading toward the sun.

However, my subject is at right angles to the sun. So, I'm thinking that if I take an incident reading midway between those two alleys, in front of the building between them, then I can derive an exposure that stands a reasonable chance of producing an image that reflects what I see, i.e., a building between two alleys with the sun shining strongly on the alley on the right.

That's the purpose of the hemispheric dome, isn't it? To read light from every direction as "seen" by the subject.

alexnotalex

09-13-2010, 05:23

tlitody

09-13-2010, 05:43

with an incident meter you measure the light source. The subject will fall where ever it falls relative to that. A white surface will be white a black surface will be black. This assumes they are in the same light. Anything which is not in the same light will be lighter or darker depending on its own light source.
Incident meters are good only when you can put them next to the main subject or when you are confident that the meter is in the same light as the main subject. Otherwise you must guesstimate.
Just pick the part of the subject you want exposed most accurately and put the meter in that light.
When you are distant from your main subject and lighting between you and subject may be different, then a spot meter is the way to go unless you want to walk over to where the subject is (which may not be practical). But a spot meter requires more careful calibratiion of film development so you know where things will fall when metered.
With an incident meter things just fall where they fall which will be correct(ish) if meter is in the same light as main subject.
So once again put meter in same light as main subject. Best policy is to experiment which will teach you much more. A street scene as you describe should be pretty easy to find on a sunny day. Try it out metering in the sun and then metering in the shadows and see what happens.

alexnotalex

09-13-2010, 05:53

I'm confusing myself thinking about this. I think the last post makes most sense, for me.

Put the meter in the place you want best exposed, this may be the sunny part, or the shady part.

Take the reading and set your exposure, it should be "correct" for the place you just measured.

But you still might not like the result!

my best regards,
Alex

somewhere I read that "mostly nothing will be brighter than the light that falls on it" and that's what the incident light meter measures.

(i.e. not how much light it reflects, so the black cat in a coal mine exposure comp rule doesn't apply.)

I guess you shouldn't use it if you can't put the meter anywhere like in the light that's falling on your *desired* subject.

tlitody

09-13-2010, 05:55

wgerrard

09-13-2010, 06:12

One thing I have never understood is the often given advice to stand at the main subject and point the incident meter at the camera. You may be standing in bright sunlight but behind the camera there could be black wall. Why you would want the black wall to influence the result when the subject is in bright sunlight never made any sense to me. Personally I would always point meter at main light source.

Because you are interested in the illumination of the scene from the camera's perspective? The reason for the plastic hemisphere on an incident meter is to read light coming from all directions other than behind the subject. In that sense, you don't actually "point" it at any single source of light. You align it along a line drawn from the camera to the subject. In you case, the black wall isn't an issue. The meter will simply read the amount of light falling on your subject.

tlitody

09-13-2010, 06:25

Because you are interested in the illumination of the scene from the camera's perspective? The reason for the plastic hemisphere on an incident meter is to read light coming from all directions other than behind the subject. In that sense, you don't actually "point" it at any single source of light. You align it along a line drawn from the camera to the subject. In you case, the black wall isn't an issue. The meter will simply read the amount of light falling on your subject.

But you are not metering the light from the cameras' perspective. That is the role of a reflected light meter such as those in camera meters or a spot meter.
No it won't meter the light falling on the subject because 50% of the hemisphere will be pointing at the ground and black wall.:)

charjohncarter

09-13-2010, 06:39

Here are two examples, the first reflective reading of the subject, second incident reading holding the incident meter at the subjects face (and pointing it at the camera).

http://farm5.static.flickr.com/4134/4753395278_bd64a654c6.jpg

http://farm5.static.flickr.com/4141/4752754137_4574882e80.jpg

Maybe the question should be 'when not to use a reflective meter'?

tlitody

09-13-2010, 07:16

but that proves bothing. The white picket fence is in the central portion of the image so will affect reflected metering unless you are using spot or area metering of the face only. Spot meter which is a reflected meter could meter just the face.
But incident meter works just as well providing it is pointing at light source suitable for the subject lighting. In this case because the subject is in shade you wouldn't want the incident meter pointing at the sun. Pointing it at the camera may be just about right as you are getting shade from above and shade from below and some of what is behind the camera which we don't know but it won't be direct sun.

Sparrow

09-13-2010, 07:30

wgerrard

09-13-2010, 08:08

No it won't meter the light falling on the subject because 50% of the hemisphere will be pointing at the ground and black wall.:)

I was imprecise. The plastic cover is not a sphere, at least on my meter, which would read light coming from behind the subject. It's a hemisphere, half a sphere, so it can't read light coming from behind. It's OK if it reads light coming from the ground and from the sides and from above because the light illuminating the subject comes from all those places, too.

alexnotalex

09-13-2010, 08:27

Thanks for an interesting example. The exposure of the second photo is the one which sings to me... it's all about her, not the house and the fence.

Here are two examples, the first reflective reading of the subject, second incident reading holding the incident meter at the subjects face (and pointing it at the camera).

http://farm5.static.flickr.com/4134/4753395278_bd64a654c6.jpg

http://farm5.static.flickr.com/4141/4752754137_4574882e80.jpg

Maybe the question should be 'when not to use a reflective meter'?

charjohncarter

09-13-2010, 17:22

If you ever get a photo-shoot with Naomi Campbell and Cindy Crawford you'er going to get very confused with the metering ;)

The whole point of an incident reading is that it is independent of the subject, it's ambient not specific to the subjects relative brightness

Exactly, in the late sixties I was in the Army and had a close friend that was black (zone III-IV); so hard to get a good exposure with all the other whites (zone VI) or even yellows (zone V). That is when I got my first incident meter. I'll wait for the PC remarks.

Gumby

09-13-2010, 17:49

I'll wait for the PC remarks.

No PC remarks from me. I think using a strobe would have made the sitaution even more difficult. That is the "PC" you were talking about, right?

p.s. That is a perfect example of a good time to use incident metering!

charjohncarter

09-13-2010, 19:53

No PC remarks from me. I think using a strobe would have made the sitaution even more difficult. That is the "PC" you were talking about, right?

p.s. That is a perfect example of a good time to use incident metering!

Probably right, strobes would not be well used in a mixed photo. I found it better to just incident read and then develop for as many zones/tones as I could.

Richard G

09-14-2010, 08:39

In this scenario, the sun is to my right and the building and the ends of the alleys are in front of me.

With an incident meter, am I not concerned primarily with the light as it illuminates the subject? If my subject was the side of the building facing the bright alley on the right, i.e., if I was shooting the side of the building with the sun behind me, then it would make sense to take a reading toward the sun.

However, my subject is at right angles to the sun. So, I'm thinking that if I take an incident reading midway between those two alleys, in front of the building between them, then I can derive an exposure that stands a reasonable chance of producing an image that reflects what I see, i.e., a building between two alleys with the sun shining strongly on the alley on the right.

That's the purpose of the hemispheric dome, isn't it? To read light from every direction as "seen" by the subject.

I begin to get your precise question. Below is an image that has the sun from the left (I'm in the southern hemisphere...) The exposure should have been f 16 but I had long planned to photograph this building just after midday and thought I wanted an extra stop or more to bring out the brickwork. I overdid it. In your scenario my incident meter's cone would have had direct sun on half of it, but I don't know how much that would reduce the reading from the full sun reading. Probably half a stop I suspect. I'll test that. The other aspect of this is the arse forwards notion of pointing the meter back to the camera. I never liked the idea of that. I remember seeing the picture of how to do it in my first Gossen manual, for the SIxtar (Super Pilot.) My newer Gossen has a swivel head and I can look at the subject and the read out of the meter, taking an incident reading. Much more satisfying.

http://farm5.static.flickr.com/4145/4990535804_83a66ce849.jpg (http://www.flickr.com/photos/richardgm2/4990535804/)
F1000012 (http://www.flickr.com/photos/richardgm2/4990535804/) by Richard GM2 (http://www.flickr.com/people/richardgm2/), on Flickr

wgerrard

09-14-2010, 10:20

I begin to get your precise question. Below is an image that has the sun from the left...

Thanks, Richard. I don't think you overdid it in that photo.

If alleys, or streets, ran down both the left and right sides of that building, you'd have my scenario. The alley on the left would be well lit by the sun. The alley on the right would be in the shade. So, I come along with my wide angle and want a straight on photo just like yours, except I want both alleys in the frame. I think that if I took a reading from the front center of that building, with the meter pointing back to my camera position, I'd get the shot I want: A well lit alley on the left, an alley in shadows on the right and a reasonably well exposed building in the middle.

If I took a reading pointing at the sun from the left alley, the shot would be underexposed. If I took a reading pointing away from the sun in the right alley, the shot would be overexposed.

It might be interesting to take and combine 3 readings: One from the center of the building and one from each alley, each with the meter facing out toward the street.