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Lens Align Pro Focus Calibration System and Long Ruler KitUse Lens Align Pro to help you get the optimum focus accuracy from your camera and lenses
Most people who take photographs using a Digital Single Lens Reflex (DSLR) camera buy a camera body, a lens or two, and shoot away, happy with their results. However, some people are not so happy. If you've been around the various camera forums on the Internet you've read countless postings over the years by less than happy owners of Brand X or Brand Y camera's stating that it was consistently focusing in front of, or behind, where it should be.
This next part might upset some of you who have spent thousands of dollars on your camera gear but no matter how hard we try to achieve perfection nothing in this world is perfect. The best we can strive for is to get as close as possible to that ideal. Manufacturing being what it is, has to allow some small variances from the ideal as being close enough. These variances are usually kept within factory specifications or those outlined by larger organizations the manufacturer abides by.
Okay, so how does this effect your picture taking? Taking into consideration this variable accuracy you have two items that can effect how accurate your camera is actually focusing, the lens and the camera body. Now all would be fine if both were within 0% of the ideal measurements but that's seldom the case. For example, your lens may be at the upper end of acceptable tolerances and so might your camera, say both are +-X% from perfect. If your lens consistently focused closer by this fraction and your camera consistently focused further away by the same amount then most likely your focus will still be right on target. However, if your lens focuses consistently a fraction closer and your camera also focuses closer than it should, then the two errors add to each other to make the focus of your camera less than ideal, if not downright soft.
When the latter happens and the errors total outside the acceptable range then you should take the camera body, along with the lens, and have both tested by the manufacturer's service center. If you're not dropping it off in person then talk to someone in the service department or include a letter describing the problem when you ship it to them. Communication is important since the service center might test the body and lens separately and find both are within normal tolerances. Remember, its the combination of the two that might be the problem.
If you normally shoot at apertures like f8, f11, etc. any errors in focus might be covered by the normal depth-of-field of the lens. If you shoot wide open most of the time then any shift in focus could mean the difference between a razor sharp image and one that's consistently out of focus.
I have to give kudos to the camera manufacturers who decided to do something about their customer's complaints. They've introduced a new feature to several of their models, being able to fine tune your Auto Focus. Certain models from Canon, Nikon, Pentax and Sony now offer this feature. Basically this feature lets the user make tiny adjustments to the camera's standard focus, moving it nearer or farther by a certain amount. Canon, Nikon and Sony say you can adjust 20 steps, plus or minus. Looking at the Pentax manual for the K20D, the best I can judge is they use 10 steps, plus or minus. Just what sort of value each 'step' is is a mystery.
All four companies give dire warnings that you should know what you're doing before you start making adjustments using this control or you'll really make a mess of things. So just as with doing your own sensor cleaning - be extremely careful with this feature!
Michael Tapes to the rescue
Enter Lens Align, brainchild of Michael Tapes, the same man who brought us the WhiBal Certified Neutral Gray Card, and the handy (and free) Instant JPEG from RAW utility.
Looking like some sort of cross between a hypnotist's aid and a shoe sizing device the Lens Align was at first available in two configurations, the standard Lens Align for $79.95 and Lens Align Pro at $179.00 Recently added is a third version, the Lens Align Pro Plus for $249.00 which adds a longer ruler, larger target, and data recorder (Enumerator). The reason for these new items was that the original target/ruler was too small for use under certain circumstances, like testing some long telephoto lenses and some wide angle lenses. Even wide open your depth of field at longer distances could be larger than the original target. With some of the very wide angle lenses out there the original target may be too small to work with so the longer ruler and bigger target help there as well.
Basically the advantages of either Pro system over the Lite is sturdier construction, easier to use sight alignment (Lite version uses a mirror), and compatibility with the Long Ruler Kit.
The advantage of the Lite unit is smaller size and weight, and the device can be broken down if you plan to carry it with you.
Otherwise both systems are equally accurate.
Users who've already bought the Lens Align Pro can purchase the Long Ruler Kit for $70 which has both the long ruler and larger target turning it into a Lens Align Pro Plus. Sorry Lens Align Lite users, you're out of luck.
Shooters whose equipment gets a heavy day-to-day workout should opt for the Lens Align Pro Plus and calibrate their gear frequently. If you shoot sports for a living, are a photojournalist, a commercial photographer with picky clients, or just want to see your work at its best you'll want to look into any of the Lens Align trio.
I'm going to split this section into two. One for setting up the Lens Align Pro and the second for adding the Long Ruler Kit.
Lens Align Pro
Its pretty basic to set up, unpack everything, peel off the adhesive backing paper on the Sight Gate Magnet and place it over the outlined area on the back of the dark slide/Sight Gate. Place the Sight Gate, red lettering facing the front of the unit, on the backside of the front focusing plane. Take the metal ruler and place it over the magnetic pins on the right side of the Lens Align so that the notches in the ruler fit over the magnets. The back end of the ruler is held in place by magnets inside the rear focus plane. The ruler can be positioned in any of several positions from nearly flat to a steep angle. Its adjustable to allow you to fine tune the focus. The more upright position the position the more numbers will be in focus but might be harder for the new user to determine exact focus. Lowering the back of the ruler emphasizes the initial focus offset area but can be harder to read. My advice is to start with the ruler positioned near the middle at #3 or #4.
Either attach the Lens Align to a tripod or light-stand with 1/4-20 thread on top or with an adapter to step it down to a 1/4-20 thread. Position your tripod/lightstand far enough away from the wall or furniture so you can get behind the unit to use the easier line-of-sight alignment method.
To align by sight: The design of the Lens Align Pro make achieving perfect alignment of the target with your camera a breeze. I first positioned my camera and Lens Align at approximately the same height using the center column on my tripod for fine positioning. Then I set my zoom lens to the longest focal length and placed the center focus sensor of the camera on the Lens Align Pro's center hole. Next I moved around behind the Lens Align and removed the ruler (to avoid poking myself in the eye or knocking the ruler off). I made sure the gate was up and the holes on the front panel were fully exposed, then I carefully sighted through the center hole on the back of the Lens Align Pro, through the center hole on the front panel, and made fine adjustments till I had it pointed down my lens barrel. This should get you close enough to move back to your camera for fine adjustments. Most of the time no further adjustment was needed.
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