please help me learn exposure

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gabrioladude

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I mainly shoot digital but have a real desire to learn how to use my Contax IIa properly.

I am finding that I consistently underexpose my shots. Finally got so frustrated that I did a test with my two cameras to make sure I wasn't having a shutter problem (which I don't)

I have checked the obvious:

-the light meter works (usually use a Gossen digi-six but also have an older Luna Pro) and I know how to use it
- in uniform light (interior shots for instance) no problem
-have used my Canon Rebel Xsi and set it to the same ISO and aperture and find the camera usually in exterior locations meters at a slower speed than I would have used based on my meter reading

so the issue/problem seems to be with uneven lighting outside I can't seem to get the hang of it. And don't want to continually carry a DSLR just to make sure I am getting my exposure right :bang:

what techniques do the experienced shooters on this board use?

thx for the advice
 
From your 3rd observation, that your Canon consistently gives you a slower shutter speed for a given aperture, it sounds as if your handheld meter(s) are simply disagreeing w/what you (& your Rebel) consider "proper" exposure. This is not unusual as many older meters were calibrated for slide film & therefore have a bias towards underexposure (to prevent highlights from being blown out). Digital behaves somewhat like slide film, but doesn't always blow out highlights quite as readily as E6 (depends on the light in my experience). If the meters are consistently different from your Rebel & your exposure preferences, then you can recalibrate them to agree w/the Rebel.

2nd, if you're not familiar w/taking incident readings, you may not realize how important the angle of the reading is, i.e., you really have to make sure that the dome is pointed towards your camera, e.g., the difference between pointing it towards your camera (say straight 90 degrees away from your subject) & towards the sky (say 45 degrees upward from the subject) can be 1 or 2 stops right there.

Also, I'm not sure how much experience you having shooting film in other cameras, but have you considered the possibility of shooting your film @ a slower ISO (e.g., many C41 emulsions can give better results, especially in flat light, when exposed @ a 1/3rd or 1/2-stop over their rated speed)?
 
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gabrioladude said:
-the light meter works (usually use a Gossen digi-six but also have an older Luna Pro) and I know how to use it
...
so the issue/problem seems to be with uneven lighting outside I can't seem to get the hang of it.
Click to expand...

The problem is simply that you need a spot meter. The meter you have is fine for low contrast situations, as you report.
 
It would be useful to see some of the shots that were underexposed.

From your post, I see that the problem occurs in situations with a wide dynamic range; for instance, with your subject is in the shadow in a bright outdoor setting.

In that case, either you could try to expose for the shadows (incident) or take a reflected reading and manually compensate by a stop or two, as needed.
 
Try to find some quite evenly lit and grey surface outside or / and always make sure to point your meter down (point it to a point ~ 5 meters away from you to the ground). The Digisix has an angle of around 30 degrees and it is very easy to measure to much sky when holding the meter horizontal.
 
If you are consistently underexposing by X amount, then just compensate by consistently opening up more and/or using a slower shutter speed.

When using your incident meter, understand that it measures the light falling on the meter and that is going to be 18% gray calibrated. You still need to adjust based upon your subject.
 
If you measure a scene and keep holding the button down while moving the digisix around, you will see positive and negative values appear: these tell you the dark/light areas of the subject and by which amount (light values, exposure values) they differ (contrast measure). Read the meter manual!
You can also use incidence reading; read the manual as well on how to. or search these pages for exposure, light meter, the tutorial sections etc etc. And visit your library for books on this subject, please. [AND: Please do not follow Ellliot's advice above of adjusting incidence readings for subject matter. Don't, because they are right on all the time. (Once you know how to take them properly, that is ... the problem.)]

That contrast measurement can help you decide on an average exposure.

Now each film desires a different exposure, never mind its ISO rating. Once you have finished a roll of one kind of film with the factory ISO rating set on your light meter, you can look at the film and in case the images are light, thin: you have underexposed. If dark, thick: you have overexposed. Guesstimate the number of stops off and compensate by rating the film at a different, more appropriate ISO rating than the (dumb) manufacturer has suggested to use ...

I have the same meter and use the ISO 200 setting for Kodak 400 VC for example. So what, as the film and pics come out perfect that way 99 % of the time.

Now change your film and the game begins anew.... Good luck and read up on "stuff". Books are so smart ...
 
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Perhaps, but then you have to lug around a spot meter, which can be almost as big as a camera (though they do look cool). Also, he has to learn where to aim the spot meter.

bmattock said:
Seems like taking a simple spot meter reading would be a lot easier than waving the Digisix around and guessing. Just me, I suppose.
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furcafe said:
Perhaps, but then you have to lug around a spot meter, which can be almost as big as a camera (though they do look cool). Also, he has to learn where to aim the spot meter.
Click to expand...

These seem like surmountable problems to me. I haven't really had the problem of my spot meter 'weighing me down' to tell the truth. Seems to fit in my shirt pocket. Maybe I just have big shirts.
 
kshapero said:
Sometimes I have also these problems, where to start on getting an exposure meter. Which kind, etc.? Really ignorant about this.
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Two basic types of meter - incident and reflective. A spot meter is a subset of the reflective meter. So are flash meters.

Incident meters are used by putting the meter where the subject is and pointing it towards the light source. This measures the light falling on the subject.

Reflective meters measure the light falling on the meter after it bounces off the subject. The type of meter in your camera is a reflective meter.

All meters are designed to give an accurate light reading for middle tone gray. That means that if you select the reading the meter gives you, then an object in your photo that is middle tone gray should be properly exposed.

The problem is that reflective meters measure more than just the subject you had in mind. In a scene that has a lot of dark areas, but you wanted to expose the lighter areas correctly, you might get a reading that would, if taken, expose the darker areas as if they were middle tone gray. That would mean your lighter tones might be blown out and lose detail.

How do you know what your meter is measuring? Reflective meters have all sorts of patterns, and it helps to know. Your in-camera meters often have more than one method of measuring the scene, and this can change the way the scene is metered.

You can use an incident meter (it has a white dome over it, usually) if you can physically get to the subject. Hold the meter in the darkest areas of the scene and the lightest areas of the scene and note the difference between the two readings. Then you have some idea what to use depending on what the darkest area of the subject you wish to hold detail is (and some for the lightest area).

You can also use a spot meter. This lets you stand at a distance from the subject and take a very precise measurement from more than one place in the scene. Some meters then perform the math for you, or you can do it yourself.

Ansel Adams and those who follow his zone system require the use of a spot meter. I am also a fan of spot metering. If you want to be precise, there really isn't another good way of doing it.

Bracketing or guessing at exposure offsets might work - or they might not. With a spot meter, you know for a fact.
 
Spyderman said:
+ if measuring reflected light, try to measure off of something approximately middle gray on the ground - grass, or asphalt on the sidewalk.
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Works great if you're taking a photo of something equally lit as the ground, grass, or asphalt. If it's in the shadows, or just shade, or lit differently due to reflections, etc...
 
I like the Gossen digital meters that have contrast scales. They allow incident and reflective metering, and are very fast to use. While not a full substitute for a spot meter, the contrast range very quickly gives you the dynamic range of the scene and allows to use a method very similar to the zone system, quickly.
 
uhligfd said:
[AND: Please do not follow Ellliot's advice above of adjusting incidence readings for subject matter. Don't, because they are right on all the time.
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I disagree.

Incident meters are calibrated around 18% gray. They give proper exposures for 18% gray. If your subject is much lighter or much darker, you do need to adjust.

EDIT: Kodak agrees with me. See http://www.kodak.com/cluster/global/en/consumer/products/techInfo/af9/index.shtml#54503

"The exposure determined by an incident-light meter should be the same as reading a gray card with a reflected-light meter. Fortunately, many scenes have average reflectance with an even mix of light and dark areas, so the exposure indicated is good for many picture-taking situations. However, if the main subject is very light or very dark, and you want to record detail in this area, you must modify the meter's exposure recommendations as follows:

For light subjects, decrease exposure by 1/2 to 1 stop from the meter reading.
For dark subjects, increase exposure by 1/2 to 1 stop from the meter reading.
You will notice that these adjustments are just the opposite from those required for a reflected-light meter. An incident meter does not work well when photographing light sources because it cannot meter light directly. In such situations you will be better off using a reflected-light meter or an exposure table.

If the scene is unevenly illuminated and you want the best overall exposure, make incident-light readings in the brightest and darkest areas that are important to your picture. Aim the meter in the direction of the camera position for each reading. Set the exposure by splitting the difference between the two extremes."
 
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david.elliott said:
I disagree.

Incident meters are calibrated around 18% gray. They give proper exposures for 18% gray. If your subject is much lighter or much darker, you do need to adjust.
Click to expand...

Not all meters are adjusted to 18%. Some manufacturers use 12% and some use 14%. I agree that you have to adjust if your subject is much darker or lighter - assuming you want to expose your subject medium gray.

EDIT: Kodak agrees with me. See http://www.kodak.com/cluster/global/en/consumer/products/techInfo/af9/index.shtml#54503

"The exposure determined by an incident-light meter should be the same as reading a gray card with a reflected-light meter. Fortunately, many scenes have average reflectance with an even mix of light and dark areas, so the exposure indicated is good for many picture-taking situations. However, if the main subject is very light or very dark, and you want to record detail in this area, you must modify the meter's exposure recommendations as follows:

For light subjects, decrease exposure by 1/2 to 1 stop from the meter reading.
For dark subjects, increase exposure by 1/2 to 1 stop from the meter reading.
You will notice that these adjustments are just the opposite from those required for a reflected-light meter. An incident meter does not work well when photographing light sources because it cannot meter light directly. In such situations you will be better off using a reflected-light meter or an exposure table.

If the scene is unevenly illuminated and you want the best overall exposure, make incident-light readings in the brightest and darkest areas that are important to your picture. Aim the meter in the direction of the camera position for each reading. Set the exposure by splitting the difference between the two extremes."
Click to expand...

Reasonable info from Kodak, but it just allows you to make an exposure that will ensure your subject is neither over nor under-exposed. If your intent it otherwise, then it won't help. A spot meter would be ideal if you have specific intent regarding exposure that is not simply 'well exposed'.
 
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