Improvised Gray Card?

I use anything white or black too. Just dial +2 or -2, respectively. I've found that most shades of red are -1, yellows are +1. Caucasion faces are about +.5. I leave it set to zero for 1/2 stop of underexposure.

Why not simply take a gray card reading then compare it toother possibilities. Since the palm of your hand is alwaysavailable and presumably unchanging, simply read it andcorrect accordingly. If your hand gives a reading of, say, onestop brighter than a card, simply subtract one stop! The true function of a spot meter is to record the various elements of a scene's brightness range, and then to extrapolate a proper final exposure to best record that scene, in my view. Most films are limited to about a 130:1 brightenss range, but nature can provide scenes of 1000:1, hence the Zone Systemin B&W. ANY exposure is bound to be something of a compromise.

Have a look here. (http://www.photonaturalist.com/chromozone/index.asp)

Why are you so interested in complicating your photography? Most causasian faces are are close enought to one stop over what your meter thinks is neutral gray (which of course can only be determined after you have adjusted your meter of course to take into account the mechanical and optical characteristics of your camera and lenses, the processing of the film, determined the "true" sensitivity of the film stock you are using and how your film will be printed) that you can simply dial that in. <P> Or are you just more interested in overcomplicating the whole photo taking process? Sop being so fearful! Do some simple tests and figure out what is going on! How simple? Go outside with a friend, your camera and a roll ofthe film you use most. Set the manufacturer's film speed. Switch toi spot metering, Take a portrait of your friend so that their head fills about 60-75% ofthe frame. Make six exposures: on at the suggest reading, one at 1/2 stop over, one at 1 stop over, one at 1&1/2 stop over, one at 2 stops over, one at 1/2 stop under. Shoot the rest of the roll on a variety of other subjects: bracket if you like. Get the film processed normally, and see what seting works best for the face portraits. You'll have no more need for a gray card.

Why are you so interested in over complicating your photography? Most causasian faces are are close enought to one stop over what your meter thinks is neutral gray (which of course can only be determined after you have adjusted your meter of course to take into account the mechanical and optical characteristics of your camera and lenses, the processing of the film, determined the "true" sensitivity of the film stock you are using and how your film will be printed) that you can simply dial that in. <P> Stop being so fearful! Do some simple tests and figure out what is going on! How simple? Go outside with a friend, your camera and a roll ofthe film you use most. Set the manufacturer's film speed. Switch to spot metering, Take a portrait of your friend so that their head fills about 60-75% ofthe frame. Make six exposures: on at the suggest reading, one at 1/2 stop over, one at 1 stop over, one at 1&1/2 stop over, one at 2 stops over, one at 1/2 stop under. Shoot the rest of the roll on a variety of other subjects: bracket if you like. Get the film processed normally, and see what seting works best for the face portraits. You'll have no more need for a gray card.

I was taught in photography school (RTI) that the palm of the human hand is roughly 1 stop brighter in reflectance than an 18% gray card. And it doesn't matter what race you are! So, unless your hands are covered, or extremely dirty, you can take a reflective reading off the palm of your hand and open up one stop from the reading given. This assumes, of course, that your hand is under the identical lighting conditions as your subject matter. However, this does not take into effect the brightness range of your subject. Does that help you?

Victor Lioce

Grass lit by a high sun and the blue of a sky away from the horizon are both useful analogues to a mid tone. Victor is right however, getting a mid-tone does not necessarily give you the right exposures for highlights and shadows, and you should meter also the brightest and darkest areas in which you wish to record detail and ensure that these fall within a couple of stops of your selected reading. If they don't then you may want to reassess your mid-tone or take some step (recomposition, use of a ND grad) to control the extent of brightness within your composition.

I learned something pretty similar to what Victor said while I was in photo school as well. In studying the zone system, we learned that caucasion skin tones look best at a zone VI, or one stop brighter then Zone V (which is what a grey card is) This makes it easy to get a quick exposure reading with a spot meter. Just read of the back of your hand, or if your shooting a person the highlight side of the face and open up one stop from what the meter reading says.

Unlike what Victor said though, I do think it will change based upon the shade of your skin. We learned that when shooting portraits, placing the highlight side of the face in Zone VI almost always looks the best regardless of race, but that doesn't mean it will give the same exposure value. If you take a reading off of someone with very dark skin and someone with very fare skin, the readings will be different. It just turns out that if they are going to be in the photograph, they will usually look there best at a Zone VI.

I hope I'm not totally confusing you, its a little hard to explain without taking up tons of room. To make it simple, do what another poster said and meter a grey card and then the back of your hand. Find out what the difference is and then you'll have something to meter off of no matter where you go (unless you get into some freak accident and loose both of your hands I guess) Chances are it will be very close to a 1 stop differnce, which makes it easy to remember and easy to set.

Green grass in the sun, north blue sky, palm of the hand-open one stop; all have worked for me.