The Digital Photo Guy

Assign Different Buttons to AE/AF

by on Oct.07, 2009, under Monday Morning Tips

UPDATED – 10/13

Yesterday, I wrote a Quick Tip about changing your camera’s default setting from Auto Focus/AutoExposure with the shutter release button to the * (asterisk) button on the back of Canon cameras. On Nikons and Pentax, it’s called the AE-L/AF-L Button (Auto Exposure Lock/Auto Focus Lock). Different cameras have different combinations of AE/AF Lock so you’ll have to check your manual and see how you specific camera works. If you’re still confused, leave a question in the Comments (below).

Here’s a real life example of how to use separate AE/AF Lock assignments. In the first photo, I pointed the camera at the medium blue sky behind me (second photo) and half-pressed the shutter release. This set the Auto Exposure to f/16, 1/80 second, ISO 200. Next, holding the shutter release at half-press to “lock” the exposure, I recomposed the frame and pressed the * (asterisk) button on the back of my Canon 10D which has been programmed to activate AF. When I received AF confirmation, I released the shutter. The second photo shows the medium blue sky behind me which I knew would give me the correct exposure.

Rabbitbrush along CA168


King of the Mountain

King of the Mountain

In the first photo, I focused about 20 feet into the patch of rabbitbrush at f/16, 35mm. This gave me a near focus distance of about 8 feet which wasn’t close enough for the closest flowers which were only about 3 feet away. That’s why they’re out of focus but everything else from about 8 feet to infinity is acceptably focused. To get everything in focus from 3 feet to infinity, I should have used f/32 but that particular lens only goes to f/22 at 35mm. Bottom line, I had to make some compromises.

Here’s a photo from earlier in the day as I was leaving Beatty, NV. It felt as if the old grader was looking at a road it had graded “back in the day”. Here, I didn’t have a medium blue sky so I  metered off the brown hills, took a photo, checked my histogram and adjusted EC (exposure compensation) as needed.

Admiring Past Accomplishments

Glory Days

Glory Days
Glory Days

The 2nd cropped image was after Rob Sheppard critiqued it. I told him I took the photo because it felt as if the grader were wistfully looking at roads it used to grade. Rob asked, “If that’s what you want to show, why did you include all that bright sky and clouds which take the eye away from the grader and the roads.” The point is, we all learn.

Finally, last one. Just a few minutes earlier, a small herd of about 10 cows were grazing on the green grass. When I walked up to the barbed wire fence, they all came over to check me out. The others eventually went off to do their cow thing but this one was fascinated by me for some reason. It stared at me until I finally took this picture and left. It would have been more picturesque if the cows had stayed on the green grass and done their cow thing. That way, I could have framed the photo to cut out the brown area in front.

Curious Cow Curious Cow

2 Comments for this entry

  • Susan Wheeler

    Could you add the feature “print acticle” on your articles, it would really help! Thanks for all you do!

    • Lee

      Hi Susan,
      Thanks for reading my blog. I don’t know how to make articles printable but I’ll look into it. Of course, the intent of the blog is to get people to come back for more. It’s a double-edged sword for bloggers who offer free material on the web. Sooner or later, the blog has to pay for itself or it simply dies.

Looking for something?

Use the form below to search the site:

Still not finding what you're looking for? Drop a comment on a post or contact us so we can take care of it!