Should I Expose in 1/3 or 1/2 Stops?

This simple setting may be slowing you down.

Precision is a good thing because it usually improves results. But it is also possible to be too precise. When precision doesn’t give you any benefit and costs you something, that is too precise.

Your cameras are costing you speed with the way it adjusts exposure with the shutter speed, aperture, and the EV (Exposure Value) Compensation dial.

That is why I have my camera set to use exposure steps of 1/2 stop instead of 1/3 stop (0.5 EV exposure steps instead of 0.3 EV). Setting up my camera this way lets me work faster, because I can make large changes in exposure more quickly. It only takes me two turns of the control dial to add or remove a stop of exposure. Or, I can add two stops of exposure with four turns instead of six.  That might not sound like a big difference, but in practice, I find it is.

It also helps that I can interpret the settings faster. I memorized all the full-stop shutter speeds and aperture settings long ago, but I confess I have never memorized the 1/3 stop setting, and knowing if 1/320 of a second is 1/3 stop more or 2/3 stop less than 1/250 is a skill that eludes me.

But with half stops, I can easily interpret the settings because the settings in between the standard f-stops are obvious. For example, if my camera reads ƒ3.5, that setting is obviously the 1/2 stop setting between ƒ2.8 and ƒ4 .

It is just as easy with shutter speeds. The whole stop settings of 1/8 second and 1/15 second are burned into my brain, so it is obvious that 1/10 second falls in between them.

This lets me compute exposures in my head more quickly so I can work faster.

You may be thinking, “I’m giving up something by not using 1/3 stops.” No, you are not. The difference between 1/3 stop and 1/2 stop is only 0.17 EV, which we can comfortably call 1/6 stop. So all you can gain by using 1/3 stop settings is 1/6 more stop accuracy.

Testing and observation tells me that that 1/6 stop is meaningless; you are not going to be able to see the difference. By using 1/3 stop settings, you are not really gaining anything, but you are giving up speed and efficiency when working. If you have taken my exposure workshop, you know that even metering within one stop of ideal exposure is very challenging. Gaining 1/6 stop is not a win.

That’s why I have my camera set to use exposure increments of 1/2 stop, and I think you should too. I’d go as far as recommending that lens manufacturers mark manual aperture rings in 1/2 stop increments as well, and change the EV compensation dial to 1/2 stop.  All that 1/3 stop marking does is make you think you are being more accurate than you are.

I actually think cameras should also offer a choice of using full stops. If the camera can offer settings for 1/3 stop and 1/2 stop, why not offer it for full stops as well? In sports, wildlife, and other action settings, this could be valuable.

But don’t take my word for it; put it to the test and see how it works for you. That’s what I did, and I found by setting my exposure increments to 1/2 stop, I am able to work more quickly and with greater confidence. It helps me get more photos, and I’m not losing a thing.