Trouble measuring light. Light meter?

[Luke]

Surely, if you're got an in camera meter, there's no need for a handheld? Or is there a big difference in 'ambient' and 'Reflective' light meters that im not getting?
If you need to expose for a specific subject, say a backlit face, you go right up to it with the cam, and take a reading, then step back, and use that reading (and of course you adjust accordingly, probly one stop over to put their face in zone 6 for caucasians). How can a hand held do this any better?

 

[Torus34]

[Takes deep breath . . .] OK. Here we go, Luke.

Let's start with the fact that in-camera meters are reflectance meters. They read the light reflected from a subject or scene. [Incidence meters read the light falling on a subject or scene.] Add in that you must move the camera if you wish to read different parts of a subject or scene [This is quite apart from changing a metering pattern in the camera.]

Now think of studio portraiture. The camera is usually on a tripod. On top of that, you might wish to adjust your lighting of the subject in order to change the placement and relative intensity of the shadows on your subject's face. For this, a separate, hand-held incidence meter is close to ideal. Placing the meter close to the subject's face, you can read the intensity of each light in stops [or zones] with ease. If the meter 'freezes' the reading, so much the better.

Now imagine doing the same job with an in-camera reflectance meter. Which way is quicker and, more important, less disturbing to the subject?

Next scenario. Here, you've walked around with your camera and read the shadows and highlights of a scene. As noted above in this thread, the reflectance meter is better at this particular job than the incidence type. You've set up your camera on a tripod and oh so carefully composed your shot. And the light changes!

With a hand-held reflectance meter, you simply go and re-take the readings without disturbing the composition.

To sum up:

1. A hand-held meter means convenience. Period.

2. Reflectance and incidence meters both work but, in some situations, one type is better than the other.

[I love the button which says 'Post Quick Reply'. Actually, I take quite a bit of time thinking through a post such as this one. There's nothing quick about it at all.]

 

[Luke]

okay, sure, yeah practicallity is obvious, but now you've got me thinking bout metering... (sorry )
What use is an incedence meter if it only reads from the light source. surely you'd rarely get an accurate reading if this was truly the case? I mean, the same amount of light can fall on both a white and black chess square, they will both require different exposures for zone 5 middle grey. What am i missing?

 

[Christie Photo]

...the same amount of light can fall on both a white and black chess square, they will both require different exposures for zone 5 middle grey. What am i missing?

You're missing the fact that you want NEITHER the BLACK nor the WHITE to record GRAY.... they should be black and white. So, ideally, when using a reflective meter to determine the proper exposure of a black and white chess board, you should place a gray card in the scene when metering. The meter is telling you how to achieve GRAY, so it's necessary to meter something GRAY. An incident meter will give the same appoximate reading as a gray card reading.

BTW... Both of these meters read ambient light. Ambient light is the existing or available light. Some meters can read STROBE lighting... these are FLASH meters. They can read both ambient and strobe light.

Pete

 

[Digital Matt]

I just want one that I point at the subject or direct source of light, and it can tell me what aperture and shutter speed to use.

Meters don't tell you what aperture and shutter speed to use. They tell you what quantity of light is hitting the scene, and what settings to use to record it at 18% gray. The meter cannot possibly make the artistic decision for you of telling you what settings to use for YOUR shot.

 

[DocFrankenstein]

If your scene's tonal range exceeds that of the film [for digital, read 'sensor'], slavishly following an averaged reading will cause you to lose both ends of the range.

When did I say that incident meter is a replacement for brain cells? It just makes it easier in some situations... and if you use your brain and point the dome in the right direction, the reading is very accurate.

 

[Christie Photo]

Now, boys.... remember.... this forum is the Beginners Place.

A bit of patience and let's go step by step.

 

[Torus34]

Doc: At no point did you say that metering was a replacement for judgment. Nor did I wish to imply that you had. I was concerned, though, that some readers might think that a meter removes the need to make any decisions regarding exposure. We agree that there are situations where this is not so.

And I think I see where the trouble started. I was using 'you' and 'yours' as a simple generic. I did not intend that 'you' = 'Doc.' I'm sure that you were using 'you' in the same sense, right? Sorry for any misunderstanding.

And Luke, just keep thinking and reading. It will all make sense. It took me a while to straighten out zone numbering in b&w prints from zone numbering in negatives in my own head.

 

[gender bombs]

I apologize if I caused some sort of argument in here. All my quesitons have been answered, thank you.

 

[Luke]

You're missing the fact that you want NEITHER the BLACK nor the WHITE to record GRAY.... they should be black and white. So, ideally, when using a reflective meter to determine the proper exposure of a black and white chess board, you should place a gray card in the scene when metering. The meter is telling you how to achieve GRAY, so it's necessary to meter something GRAY. An incident meter will give the same appoximate reading as a gray card reading.

BTW... Both of these meters read ambient light. Ambient light is the existing or available light. Some meters can read STROBE lighting... these are FLASH meters. They can read both ambient and strobe light.

Pete

Okay, i get it, i just wasn't putting two and two together in my head, i didn't realise that if you expose only using the light source, than objects will naturally fall to their own zones, within your negs range of course.
But I'm thinking it's gotta be refelective for me, besides i'm practising shooting sans meter.

 

[Torus34]

Good luck, Luke.

And best wishes to all.