GENorkus Loc: Washington Twp, Michigan

Back in the analog days I used a simple light meter here and there mainly to save film. Once again, I've started looking at light meters and now have a question. (Actually I thought about this years ago.)

If you weren't in a hurry, why couldn't a modern camera be used to get a light reading by holding the camera directly in front of the subject/model and pointing it to where the camera will be taking the image from? I doubt a flash could be used but ambient seems like it could be.

Yes, I know the camera attempts to get an 18% gray but regular light meters go for a similar look.

This is just something I was wondering about.

IDguy Loc: Idaho

Cameras have and use a sophisticated light meter. You can measure reflected light from a single point or averages of many points.

Put the camera in M exposure mode and you will see the meter.

The grey only comes into play when you have the camera use the meter to set exposure.

Curmudgeon Loc: SE Arizona

A simple answer to your question--It can. Just be sure the ISO matches your film speed.

tradio Loc: Oxford, Ohio

Don't forget about using your hand as a "gray card".

arathorn357 Loc: Sydney, Australia

Also did this back in the day - and then I saw that there were digital light meters out there, but at a solid price for quality.

Your phone also has a sophisticated light meter built in and a simple app like Pocket Light Meter for iOS (there will be an equivalent for Android but I don't know it) gives a very useful starting point on your phone for what the correct exposure of a scene might be.

Love when you find the things of your youth have not died, just changed a bit ...

BebuLamar

If you mean using a digital camera as light meter for a film camera? You can definitely do that. Just don't use Nikon Matrix mode for negative film, it works well for slide though.

rook2c4 Loc: Philadelphia, PA USA

It seems to me what you are talking about is turning the reflected light meter of your camera into an incident light meter. For that, it will work best with one of these:
http://jimdoty.com/learn/exp101/exp_expodisc/exp_expodisc.html
I suppose you could make one yourself, but the characteristics of the filter would need to be just right to be useful.

Longshadow Loc: Audubon, PA, United States

I don't understand this one.
Will it read different when you use it to set the exposure?

BebuLamar

If you want to use your camera as an incident meter you need a diffusing disk or dome then calibrate it.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

One of the amazing things about digital is being able to shoot raw and expose to the right. If you can set your exposure just shy of blowing out the highlights, your signal to noise will be high, which results in cleaner images. I use the spot meter function in my cameras, and pick the brightest area in my scene in which I would like to retain detail, and add 1.5 to 2 stops more exposure than the meter's recommendation. This works in 100% of the situations, and is as reliable as the 18% card or incident meter for scenes of average contrast, and better for low contrast and extreme contrast. Of course using this method for low contrast will result in bright images before post processing, and high contrast images will look dark, but post processing will make great images in either case.

Using a gray card or incident meter works great when you can move to the subject's location, but it work work at all when you are in a blind under tree cover shooting birds under a blue sky, a concert or stage performance where the performers have spot and flood lights on them and you are in the audience, or any situation where it is inconvenient to access the subjects location. This is where a spot meter measuring reflected light shines!. The skill required to correctly read and interpret the reading is something that comes with experience.

FWIW, meters are calibrated to 12% not 18%

http://bobd.tv/files/Mid-gray.pdf

IDguy Loc: Idaho

No.

It will read differently when you choose different metering modes, e.g. spot vs. matrix.

But you do not see the meter when using one of the autoexposure modes...except maybe M with auto ISO.

Unless you use exposure compensation. What you see then depends on the camera.

Doc Barry Loc: Huntsville, Alabama USA

The Expodisc does exactly that and working quite well I have found. I have also been successful using it at the shooting position by having the hood on the lens (keeps the extraneous light out reasonably well).

Wallen Loc: Middle Earth

The camera can. It needs to be in the spot metering mode so it can meter exactly where you want it to meter from and that the metering should be locked after it is taken. Then recompose and take your image.

CO

No, You can't use your camera as if it's an incident light meter. Your camera's metering is "fooled" by the reflected light from different objects in the scene - some bright, some dark. Also the different metering modes - matrix, center weighted, spot will have an effect. That's the great thing about an incident light meter. It's not affected by different tones in the scene. It measures purely the light level.

Longshadow Loc: Audubon, PA, United States

That's metering on reflected light, not incident light.
(Spot, average, matrix, etc. are different incident light readings.)