Guest Post by Ara Roselani – Follow Ara on Twitter
If you focus on an eye and are getting a sharp nose instead, chances are you could use the services of the LensAlign® PRO Focus Calibration System. I have indignantly examined a red focus box around something that isn’t as in-focus as another part of my subject. In an effort to correct this issue, I invited two other photographers with similar complaints to join me for an equipment test.
The Lens Align Pro is a three-sided box with focus targets and a ruler/guide with stop marks. Using it is easiest with two tripods, one for the box and one for your camera (you can also set it on a table). It is important to realize that the system does not align your lenses, but tells you how much to adjust your camera to compensate forward or backward for each lens. Before buying the system, you should make sure your camera allows for “Auto Focus Micro Adjustment”. You can only use it with auto-focus lenses, and if you have multiple cameras, each will need to be programmed separately with the adjustments you calculate.
I used the online videos and step-by-step instruction pages to set the system up, all linked from the company website. About three feet away from the tripod holding the target box and ruler, I set my Nikon D700 with Nikon 24-70 f/2.8 lens on another very stable tripod (flimsy tripods can make the alignment inaccurate if they move around). As recommended in the instructions, I turned on live view, set my aperture as wide as possible at 2.8 (showing the narrowest depth of field), and turned on auto-focus with the AF point on the center target of the box.
The hardest part of the alignment process is moving your camera in 1/8-inch nudges until it shows a red circle from the back of the box perfectly centered in the middle target’s hole. Live view makes this much easier, especially if you zoom in significantly. Once centered, you can push a magnetic flap down behind the targets so focus is on the front of the target, not inside on the red bit (the instructions recommend this, but I didn’t find it a problem so I stopped bothering with the flap). I popped my focusing ring all the way out of focus, re-focused by half-depressing the shutter, and took three shots. I used a 2-second time delay to avoid camera-shake–a remote release works too.
If you have multiple lenses to align, it is easiest to repeat this process with each of them before reviewing the images. You can keep track of lenses by taking a picture of the next lens you’re about to align before you switch, or by using the metadata when you download the pictures.
Once finished, I opened the images in Adobe Bridge (any review software will do). I chose the best of the three images I took and brought it up in Photoshop. The ruler on the right tells you how much the lens forward- or back-focuses, as the “0″ line is on the same plane as the target on the box. Apply an Emboss filter in Photoshop and zoom in on the ruler for super-easy reading.
Here where I highlighted, I can easily tell that I need to adjust my “AF Micro Adjustment” backwards for the forward-focusing. I ended up with about -5 points. The Nikon AF Micro Adjustment seems to correlate well with the smallest line of numbers, though it isn’t precise.
If you have multiple lenses, review the images, switch the lenses and adjust as you go. The camera will save data for each. Once you’re done, check your images again to make sure everything is now aligned by repeating the nudging/alignment process. I know. That was my least favorite part. Fortunately, everything aligned for me after two tries.
After my D700, we tried the Canon 5D mark II with the Canon 85mm f/1.8, 50mm f/1.2 and 24mm f/1.4. All the lenses needed to be adjusted anywhere from 3 to 20 points but focused perfectly after alignment. The 24mm f/1.4 had already been shipped back to Canon once for a back-focusing problem, which was still very apparent:
We also tested using a Pentax K20D with several lenses, all with fantastic results. Every lens needed adjustment.
The ruler can be tilted at different angles for wide and telephoto lenses to make it easier to adjust. There are other tiny adjustments documented on the website, but I found the main functionality excellent with the defaults.
The Lens Align Pro is a quick, portable and accurate method with easily-measurable results. It’s well-built and seems made to last, and takes the rulers/charts/headaches out of manually aligning a lens.
EDITOR’S NOTE: WE held off on a review of this product because the manufacturer was supposed to be re-writing the documentation. This re-write may or may not have happened but we received no notice of it. The original documentation is a bit confusing and without watching the videos on the company’s web site, we believe most people will have trouble properly using this product. So be forewarned. Watch the videos before trying to align your lenses.
This post sponsored by the Digital SLR Store