Author Archives: Chavvon

I’m kind of a stickler for sharp images, so when I learned that I could adjust my lenses to optimum focus, I was all over it. When you buy a lens, you can look at sample images, but you’re never sure how exact your copy will actually be. Some manufacturers are more consistent than others, so I just invested in a body with microadjustment (D700). To my knowledge, all Canon bodies 50D and up, and Nikon bodies, D300 and up have this ability (Nikon D300, D700, D3, D3x, and D3S. In canon this feature is available in Canon 50d, Canon 5d mark II and also in 1 DS & 1D mark III) Here are some steps to make sure your lens focus is right on.

AF MICRO-ADJUSTMENT:

This focus adjustment works really well for fast primes and low aperture lenses. I find that it’s works ok on 2.8 lenses, but works great on 1.2 and 1.4 primes! After you have the gist of this test, click on the pics below to enlarge them on your screen. You can download them to your PC/Mac or view them right here on our website to run this test. Either way, be sure you focus on the image on your computer monitor. Be sure the images are at 100% and aren’t compressed to fit your screen. I prefer to use the LIVE View feature on my camera, but you can look through the viewfinder as well. The process uses Moire interference patterns produced by these images when they are in focus so you have a good idea of when they are in really nice focus.

1.) Take your camera and place it on a tripod in front of your computer monitor. I find this works best at about 1.5 times your minimum focus distance. If your lens has a minimum focus distance of 2 ft, place your camera about 3 feet away from the monitor. Be sure your camera is at the same level and your lens is parallel to the computer screen: screen| <<3 feet>> |camera

2.) Once you’re all setup, click on the image above to enlarge it (be sure they’re at 100%!). Place your camera in aperture priority at the lenses minimum aperture and also set the camera to manual focus mode with a single focus point.  Place the single focus point on the center of the pattern and manually focus until the main center pattern is in perfect focus. You should see multiple outward rings disappear into the outer edges. Take your time and see what the pattern looks like when it is out of focus. The center rings should just pop! Now, once the image is in perfect focus, look at the focus distance on your lens and take note of what it’s set at.

3.) Now leaving everything untouched, move your camera to auto focus. Press the auto focus button and see what your camera does. If auto-focus doesn’t move and it stays in the exact same place, your lens and camera are in perfect focus and you don’t need to touch microadjustment!

4.) If your camera/lens does move, you now see a different focus distance, and the image is no longer razor sharp, you have a little work to do. Be thankful for micro-adjustment!

5.) Go to your Nikon set-up menu to access AF fine tune or use Custom Fn. III on your Canon to access AF microadjustment. The camera will remember which lens had which adjustments. If the focus distance moved clockwise, use “-” adjustments and if it moved counter-clockwise dial in “+”. Keep changing the AF adjustment until the focus distance is the same as your manual focus (assuming you can see something when it’s in focus!!). After you are done save the setting for this lens. You have to press the OK button on Nikon and the info button on Canon, otherwise none of your settings will be saved.

If your lens is 2.8 or over, this test won’t be so helpful! No more blurry images!!