How To Always Keep A Gray Card At Hand

How To Always Keep A Gray Card At Hand


This tip is so easy I am sure some of you out there will kick yourself when you finish reading. Like you, I still learn things and this tip was passed to me a year ago…after 20 years of shooting without it. Photography is a journey, not a destination. Don’t’ sweat when you learn something, just be happy you’re smarter because of it.

A gray card is a card that is 18% gray. Why this is important is because your camera assumes the world is, on average, 18% gray. And it’s right, part of the time. This is the main reason scenes are not exposed as you would like when using P or A or S mode; because your camera is programmed to assume the scene in front of it is 18% gray and it wasn’t 18% gray. To demonstrate this on your own, set your camera to P mode (gasp!) and take a picture of a white piece of paper. Now set your exposure compensation to +1 or +2 and take the same shot. Which one looks more like the white piece of paper?

The overexposed one. Because the piece of paper is not gray, but your camera tried to make it that way.

Enter the gray card! To use a gray card, hold it up in the light that is the same as the light hitting your subject, point your camera at it (preferably using spot metering mode for best results) and you now have a ‘perfect’ setting. This 18% gray card is what your camera assumes the world is; placing such a card in front of your camera now makes it able to meter the light with better accuracy. Perfect exposures. Or at least a great place to start.

Just like eating enough fiber or getting enough sleep, you know using a gray card is good for you(r photography) but you don’t do it all the time. I don’t do it all the time either. Why? My number one reason is the card is not always with me. A dedicated shoot I am being paid for? Of course it is there. But taking my daughter to school and seeing something worth shooting on the way? It’s not with me 100% of the time (also because I test many camera bags and it doesn’t always get packed into the right bag). Plus, who has time to pull out the card when the lighting is just right and the card is in your bag in the car? I’m as good at making excuses as the next guy.

Now what if I told you you could have a gray card with you all the time?

That’s right, as long as you have two hands, your gray card can always be with you.

The technique is simple and the idea is that the color and tone of the palm of your hand doesn’t change much. Certainly not as much as that back of your hand which has more pigment and sees more sun. Why not use that?

To use your hand as a gray card you will first need a gray card. They are cheap and you can order them online or find them at a local photo shop. In a nice even light, using spot metering and manual exposure mode, point your camera at the gray card. Set your ISO so it is not on Auto and maybe to 800, the number isn’t too important. Now adjust aperture and shutter speed until the camera metering is at zero, meaning it is not over or underexposed according to the camera. Next place your hand (I suggest your left hand) where the card was, with your fingers together. Ensure the center metering spot is completely covered by your hand.

What does the camera’s meter read now? Mine says the settings I had for the gray card are 2/3rds of a stop too dark for my hand. It thinks these settings will make my hand too dark, but not so, because we set the camera’s settings using the gray card, which is accurate and matches the camera’s metering expectations. This means whenever I point the spot metering at my hand, and my hand is in the light hitting my subject, I just have to adjust my settings until my camera thinks the exposure is 2/3rds of a stop too dark and I am set!

Try it!

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Peter West Carey leads photo tours and workshops in Nepal, Bhutan, Seattle, Portland, Los Angeles and beyond. He is also the creator of Photography Basics - A 43 Day Adventure & 40 Photography Experiments, web-based tutorials taking curious photographers on a fun ride through the basics of learning photography.

Some Older Comments

  • shootabike September 6, 2012 05:39 pm


    I'm afraid that the surface has to be completely non-reflective...

    Being mainly synthetic, it's probably hard for a bag panel to match that.


  • Siggo June 12, 2012 01:20 am

    It seems so obvious, but as far as I know it's not done...Why don't camera bag makers use 18% grey material for at least one panel and promote it as a feature? Am I missing something?

  • Jan June 11, 2012 06:56 am

    My lens cleaning cloth acts as a grey card.

  • Sola Otori June 8, 2012 04:05 pm

    very cool thanks for the tip, does this gray card trick work for shooting video on your DSLR or do you have to use a white card or material for WB ? thanks

  • AlexS June 7, 2012 03:18 pm

    Great tip....but I have a question that I'm hoping those more knowledgeable than me can answer:

    Isn't there supposed to be some consideration given to the reflectivity of the gray card vs the reflectivity of your skin? I'm sure in most situations it would give a consistent reading of 2/3 stop difference between the 2 but not ALL situations, if the reflectivity of the material is different? Am I correct here or totally mistaken?

  • Thinkeye June 7, 2012 09:59 am

    Thanks for the good tip. I'll try it, but I'll keep an eye on the color of the light. My palm is not grey and it will certainly respond differently for different light temperature. However, I don't expect it to be more than half stop, so it will be probably OK for the starting point for exposure compensation.

    What I also sometimes do is casting a shadow on the subject (with my hand :-). Just put hand as close as possible and move it slowly away.
    Is the shadow sharp or soft?
    Is it deep, or shallow?
    How does it change with the growing distance?
    Is there a color difference between shadow and full light?

    A couple of hand movements, and the shadow tells you whole story about your ambient light.

  • Heather June 7, 2012 03:14 am

    Thanks for the tip. I am off to find my camera and figure out my 'hand' setting.

  • Tanguero Chino June 7, 2012 02:42 am

    This is a great tip for adjusting exposure. However, the palm does not replace the grey card for its other use - adjusting white balance, This is less of a problem with higher end cameras nowadays, as they get the WB close to corrrect over 95% of the time, and I shoot raw. However, it was very helpful with my previous camera when the lighting got tricky. Ironically, it is easier to set manual WB with a grey card on my point and shoot than my DSLR.

  • Eric Leslie June 7, 2012 02:17 am

    That is one heck of a great tip. Love the title as well haha