questions using spotmeter

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my new (to me) CL has a spot meter for setting exposure. The manual says to use a "medium tone area." I'm used to an averaging type meter, and picking "medium tone areas" seems to be giving me trouble, judging by some of my shots with the camera.

In general, with a film like TriX, I'm thinking I could meter off the darkest area I want detail, then set the shutter/aperture a certain number of stops down from that. The question is, how many stops would that be? Two? Five? What's the range of a film like TriX, and what part of that includes detailed shadows and highlights? Zone system literature implies a ten stop range, with five stops actually holding detail. Is this accurate for most all films?

Obviously, the alternative is to meter off people's faces, for example, and expose for that. The problem is when I want a city skyline at night, where everything is mainly lights or darkness to my eye.

I don't even know how to phrase the next question. Assuming I close down five stops from the darkest area when exposing at box speed, would I want to close down only two or three stops when pushing TriX to say 3200 or more? Would I close down fewer stops as I push it more?

I'm rather embarassed that I have a number of badly under-exposed images from using a meter, when in the past I've had a greater success rate winging it without a meter :) I don't feel too bad as it was the first time I used the camera, I just am looking for a way to learn from the effort.

Thanks to anyone who can help.
 
Shadows: start with -3 stops. In the Adams zone system this would give you zone 2 (detailed shadows).
Try also this trick from the 50's:
Measure your handpalm and +1 stop

Wim
 
Grass is medium gray. It also helps to check against sunny f 16. (in sunlight the exposure is 1/ISO at f 16) for 100ISO 1/100th for instance.
 
New cameras or meters can also throw you off. If you are using B&W you may want to expose as follows to see what "film speed" for that combination gives you what you want. I look for (this is classic and can be read in any number of books or articles) the film speed that gives you a density in zone 1 of 1.0 above film fog. Set you camera/meter at box speed, close the lens down 4 stops (or increase speed 4 notches) to give you a zone 1 (meters give you zone 5 in theory). Then expose on a blank wall our of focus. Expose at using a film speed of 1.5 x box, double box, half box and 1/4 box. Develop (it does not matter what developer much or time since there is little effect on zone 1). Then measure with a densitometer (film labs have them) for fog, and then pick the exposure that gives you 1.0 plus fog. That is your film speed. for that camera. Development time effects the higher values so you will have to experiment with that, but you will get good shadow detail this way.

My XPAN with its internal meter and 40mm lens shows Trix at ISO 75. My Leica M with its meter shows Trix at 150. the film is the same, the camera and meter varies.

That is a start, but the best solution is to read up on the Zone system. It is rational and easy, although there are alternatives that you may come across.

I like metering my hand and opening one stop. That is zone 6. It is a shortcut that often works if caucasian skin is in the photo.
 
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Your palm, which you have with you all the time, is medium tone (plus 1). That is meter off your palm and open up one stop.
 
Flyfisher Tom said:
an easy way to remember it is metering off an "open" palm, you "open" up one stop :)
Click to expand...

Thanks for that! I haven't used this technique because I always forget whether you are supposed to open or close the lens. The other day I was tempted to try it, but also forgot how many stops I was supposed to adjust :bang:

Now I just have to remember 'when metering off one open palm, you open up one stop' ... Some days remembering my name is pushing it :), but I'm hoping it will stick now.

Peter
 
You could also try metering off the lightest and darkest parts of the image and then taking the middle stop between them. Count stops, don't average the f-numbers mathematically. Say you get f/16 on your darkest part and f/2.8 on the lightest, then you have 5 stops and need to go 2+1/2 stops from either end. This guarantees you will "fit" the film to the scene and get maximum detail in highlights and shadows. The downside is that you may not fit certain parts of the scene to their original brightness.
 
The hand trick is a great way of doing ZS, and even figuring out contrast range. Caucasian skin is about a VI or possibly VI.5 :). In daylight...a palm in shadow is about a zone IV. So if you meter your hand in shadow (so put your hand between sun and camera), then you close down one stop and you should have good shadow detail.

allan
 
The hand trick is a nice way to take a quick reading, but it assumes the meter and the camera are in synch with the film speed. The true film speed of that camera/meter combo really needs to be ascertained before the hand method can truly work, unless of course the meter, the camera, and the film are all accidentally speaking to each other nicely. I suppose a short cut is to meter the hand, open it one (in bright light, not shade) and then evaluate the negative to see how it feels. Or do a gray card and not open it a stop. I like using my densitometer method for zone 1 the first time Gives me a sense I know what I have. Then I know the hand trick will work for me.
 
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wolves3012 said:
You could also try metering off the lightest and darkest parts of the image and then taking the middle stop between them. Count stops, don't average the f-numbers mathematically. Say you get f/16 on your darkest part and f/2.8 on the lightest, then you have 5 stops and need to go 2+1/2 stops from either end. This guarantees you will "fit" the film to the scene and get maximum detail in highlights and shadows. The downside is that you may not fit certain parts of the scene to their original brightness.
Click to expand...
I agree! This is what spot meters have been invented for, although doing an incident reading based on the inside of a palm remains possible of course.

Just be aware that you don't necessarily need to use exactly the middle stop. You can skew the exposure toward darker or lighter depending on the result you want to achieve..

Oh, and never read directly from the sun, even when it will end up in the frame. It's not good for the eyes!
 
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