Now that many modern DSLRs have calibration ability, we can see just how off-focus some of our lenses are!
There’s a new tool on the market to help you calibrate your lenses correctly: The LensAlignII from Michael Tapes design. You’d be surprised at the results you’ll get just buy spending a few minutes calibrating your gear.
Here’s how it works:
|How LensAlign™ Works:|
|1. Setup LensAlign and the camera to be tested
Mount the camera/lens combination to be tested on a tripod. LensAlign can be table-top or tripod mounted via its 1/4-20 tripod socket. Set the test camera’s aperture to ƒ8. Looking through the test camera’s viewfinder, adjust the camera’s position so that the center Focus “Star” of LensAlign (labeled B) is approximately aligned with the center autofocus point of the camera.
|2. Sight the camera to LensAlign
The goal of alignment is to adjust the camera’s position until the hole in the Rear Sighting Plate “Bullseye” is centered in the center Focus Star (labeled B), and both are centered in the frame. When this is achieved, the Focus Target of LensAlign and the camera imaging plane will be perfectly parallel, which is required for accurate focus evaluation. (Note that only the center Sighting Dot will appear centered when perfect alignment is achieved).
|3. Capture test images
Mount and adjust the Depth Of Field (DOF) Ruler’s angle to position #3 (or a preferred position). Set the Sight Gate to its DOWN (closed) position. Set the camera to Manual or Aperture Priority exposure mode and open the aperture of the lens to its lowest ƒ stop. Focus and capture test images.
|4. Evaluate test images
Using your photo editing software, evaluate your results as displayed on the DOF Ruler in your test captures. In Photoshop, applying the Emboss filter to test images can enhance the visibility of test results. If the test camera has Auto Focus Micro Adjustment capability, use it to correct auto focus errors that you may observe.