One and a half stop? (I only have thirds)

Discussion in 'Beginner Questions' started by sarah_michelle_larsen, Jun 28, 2009.

  1. Hi !
    Just a quick question from this spotmetering tutorial:
    He writes:
    "For very dark or black subjects like Buffalo I will stop the lens down a stop and a half or so "
    Then my absolut beginner question is, how do I do that, when my camera only shows 1/3 of stops (Or I can choose to only use half stops, but then I get the same problem when i want to stop something down 1 stop and two thirds etc)
    I have a Canon 5d.
    Does anyone have a really really good link to a tutorial about (In camera) spotmetering? The Ansel Adam book is on the way, so in the meantime I might as well prepare with all the basic stuff, when I suspect the Ansel Adam book is very advanced.
  2. -- "stop the lens down a stop and a half or so "
    In thirds, you either go with 1+1/3 stop or with 1+2/3 stop ... each of them is
    1/6 stop away from the desired 1+1/2 stop. ... Since the author wrote "or so",
    there is an indication that you'll be ok, if you're near the desired value.
    On the other side, there is a custom function in the 5D that tells the camera to
    either count in halfes or in thirds. (Just have a look through the custom functions).
    I personally found thirds more convenient.
  3. Thanks Rainer. I will have to learn from experience if I should choose 1/3 or 2/3 then:)
    Yes I know about the halfstop setting in the camera, but then I dont get the thirds possibility.
    Which one would you recommend? I would say the thirds, because it gives me extra an extra possibility.
  4. As said, I personally use thirds ... but I could live with halfes as well.
    It depends a bit on your workflow if this selection is important. If you want the best possible out-of-the-camera result (especially if you shoot jeps), I would certainly use thirds. If you shoot raw and finetune the last half stop in the rawconversion, halfs or thirds are much less important.
  5. SCL


    I doubt you will see much noticeable difference between 1 1/3->1 1/2 or 1 2/3->1 1/2 stops. The best solution is for you to see for yourself. Put your camera on a tripod and find a fixed dark subject where the light isn't changing. Take a shot adjusting for 1 1/3 stop and then at 1 2/3...reset the custom function and take a shot adjusted for 1 1/2 stops. Now line your shots up on your pc in order and I think you will find negligible differences between the 1/3->1/2 ranges. Sometimes too much reading and not enough personal experimentation can create unnecessary anxiety, when the actual differences in results are virtually negligible. Your author was discussing how one would expose a dark subject "directionally", not specifically.
  6. The difference between a 1/3 stop increment or decrement and a 1/2 stop change is trivial in most applications. The point of having the 1/3 stop option is just to give you a bit more control.
  7. Some cameras let you choose under the menu items whether you want to do 1/2 or 1/3 stops exposure compensation...
  8. IMHO. For static subjects, 1/2s make shooting easier and more enjoyable. It keep one's brain from jumping between 1/3s and 2/3s. For moving subjects inside a poorly lite gym (where shutter speed matter), you want 1/3s. In fact, I wish there are 1/4s then.
  9. You can change your aperture increment to 1/2 stops, via Custom Function 6, as outlined on page 152 of your 5D Manual.
    That said, I find the implementation awkward: the over/under bar graph display is kind of odd looking, the pointer changes to a double pointer at each 1/2 stop. You'd get used to it though.
    Addendum: I see now this has already been mentioned, should have read more thoroughly. Anyway, will leave my post as-is for the page reference.
  10. Working in increments of 1/3 stop is just fine. Don't change to increments of 1/2 stop just because a spotmetering tutorial happened to be written using 1/2 stop increments. As Rainer and Stephen said, if you choose the nearest step available, you will only be 1/6 of a stop off. You won't see a difference of only 1/6 stop. Plus, of course, the tutorial that said to use minus-one-and-a-half was only giving a rule of thumb in the first place. Your buffalo may be darker or lighter than theirs.
    The best spotmetering tutorial I know of comes in book form from Bahman Farzad. Similar information can be found elsewhere, but this is such a basic, direct presentation that it will drum it into your head (maybe at the expense of being boring from the repetition).
    link to book at
    link to web site
  11. Thank you very much everyone. Im glad to heat that metering does not have to be 100% accurate. I thought it balanced on a knifes edge:)
    I played around with the build in spotmetering today. It is really timedemanding if a boat sails by:) So I decided to get me an extermal Sekonic flash master.

Share This Page