Review: LensAlign PRO

Calibrating your camera’s autofocus system for best performance with individual lenses

By Ellis Vener

Every now and then a specific autofocus lens and body combination just do not work perfectly. You may not even be aware that one or more of your lens/body combinations do not perform as well as it might if it were properly tuned, or maybe you require above average performance and want assurance that is what you are getting for your money. Several manufacturers now include a function for fine-tuning autofocus performance in their newest top-of-the-line bodies. (As of early August 2009 these include: Canon EOS-50D, 5D Mark II, 1D Mark III, and 1Ds Mark III models; Nikon D300, D300s, D700, D3, and D3X; Olympus E-30 and E-620; Pentax K20D; and Sony A900.) If your camera has that option, we now have a good reliable tool from rawworkflow.com for finding out exactly how out of whack a lens /body combo might be and what AF micro-adjustment setting is needed to maximize performance.

The LensAlign PRO kit consists of three pieces: a target to focus on, a steel Depth of Field Display Ruler, and a settings Enumerator to keep track of your settings in the photo. There are two other versions available as well; a Lite version, which is less fully featured, and the PRO PLUS, which features a larger target and a 47-inch long ruler.

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Image ©Ellis Vener

The main component of the LensAlign PRO kit consists of the focusing target, a smaller target behind that to make sure the sensor and the target are in perfect alignment, and the holder for the ruler. The ruler can be positioned at five different angles from near vertical (useful for close-up photography where tolerances are very tight) to nearly flat (useful for longer distances), but start with the ruler tilted to the middle position. The ruler itself is 9.5 inches long and is marked in different sized numbers.

The enumerator on the front of the target allows you to note the camera-to-target distance expressed in magnitudes of focal length. For general use, 25x the lens focal length as the target-to-camera distance is good, but if you know that you’ll be working at closer distances, do the math and calculate the magnification factor: distance in mm / focal length = magnification. The upper half of the enumerator lets you keep track of AF adjustment settings from -20 to +20. 

With the camera and lens and LensAlign unit mounted on good tripods, setting up and aligning the LensAlign PRO is easy. I used either undiffused electronic flash or bright daylight as a light source. Once attached to the tripod, slide up the “site gate” on the rear of the focusing target and peer through the center hole in the rear panel until you can see the center of your lens. Move back to the camera and carefully adjust the camera’s position on its tripod until you see the red alignment target through the central hole in the focus target. Once aligned, close the site gate and make sure the camera is in Single AF mode and set to use the center AF sensor.

With your lens wide open, shoot your first test frame with the camera set to no AF adjustment. Download the file (or shoot tethered) and then open the file at 100% magnification on your computer. If there is an error in any direction, do more shots starting with your camera's most extreme AF adjustment in one direction and moving back toward zero adjustment, being careful to make the adjustment on the camera and to note it with the Enumerator. Once you have found a camera’s ideal AF adjustment setting for a specific lens, program it into the camera’s database, and from then on your camera will automatically use that setting whenever you use that lens. Repeat with each lens. Plan on about five minutes per lens.

Zooms are understandably a bit more complicated. You should test a zoom lens at both ends of the range and in the middle of the range. If the lens is off to varying degrees at different focal length settings, you can use the resulting samples to document the problems when you communicate with the lens maker’s repair center.

The beauty of the LensAlign PRO is that it is a simple, reliable and repeatable way of verifying that you are getting all of the image quality your cameras and lenses can deliver. To make the testing process more efficient, have an assistant or buddy change the enumerator settings while while you work with the camera.

Given the price of the LensAlign PRO, it might make sense for a few photographers to go in together and buy one as a shared asset, but if your organization has multiple cameras and lenses, multiple photographers, or regularly rents lenses or extra bodies, and you want to be in a position of actually knowing that you are giving your clients the best possible results, owning or at least having access to one makes sense.

LensAlign PRO $179
LensAlign PRO Plus $249
LensAlign LITE $79.95
Long Ruler Kit $99

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Comments (5)

no joke, I want one of these... but really, the price just makes me want to just take a book and set it up level and then take another book and lay it at a 45 degree angle and then set my camera up and take a photo... using a tripod to keep the camera level...

yeah?

reply to Tim

Yeah? No. Maybe. Yes.

If you have just one or two cameras and the only lenses you'll ever buy than what you suggest Tim might work fine but if that isn't the case, and you are obsessive enough to want the reassurance that you are getting the best performance out of your gear possible I think you will want something that is standardized and repeatable.

With the set up you propose it will also be harder to make sure you are are truly aligned with the focus target (target centered and square to the sensor plane). I know because I've done that for film cameras and medium format digital cameras.

Also if you really have a problem with a lens, particularly a zoom lens, then having something that is a standardized measurement tool to make your test photos with it will make communicating with the camera and lens manufacturer(s) much simpler and give you a bench mark to compare the results after they reprogram the lens.

As to price, if you read the review all the way to the end you'll see my suggestion about getting together a pool of photographers to share the expense.

This really is a tool for those who are willing to go to the effort and expense of going those hard last few percentage points to get the most out of their gear. With the cameras that have the micro autofocus adjustment function built in and the LensAlign Pro, anyone can now do what only the very high end pros used to have done by legendary repair shops like Marty Forscher's long closed Professional Camera Repair in New York City.

So if you are obsessive about making sure you are deliver better technical quality images than your competitors, then this tool makes sense. If that doesn't describe you, then it won't.

Josh Perkins:

Ok, I'm with Tim. $180 or $250 is a bit of a joke for this. For $49 I'll buy one to save me the extra 30 minutes of my life that it would take to construct myself.

OK, this looks great, but does that mean that you have to recalibrate each time you use a different lens. If so, it seems like it would be useless. How do you avoid having to change your settings for each lens/body combination?

"OK, this looks great, but does that mean that you have to recalibrate each time you use a different lens?"

Well, yes. You are calibrating the autofocus system -- tuning how individual lenses work with with individual bodies.

"If so, it seems like it would be useless."

Hardly. The point is to make sure you are getting the best performance out of your lenses and cameras that you can. Whether or not that is useful to you is a question you'll have to answer for yourself. But from a marketing point of view, If your photos look even a little "sharper" than your competitors I think that is an advantage. And being able to tell your potential clients that you go through the effort of calibrating your cameras and lenses so that you deliver the best technical quality photos your gear delivers seems like a potential marketing advantage as well.

"How do you avoid having to change your settings for each lens/body combination?"

Most of the recent high end cameras (there's a list at http://www.whibalhost.com/forum/showthread.php?t=8888 ) that allow users to tune auto-focus performance
have a database in the camera you use to record your auto-focus fine tune settings for different lenses. When that lens is mounted the body automatically changes the AF fine tune setting. Some bodies may even be able to differentiate between two similar lenses, for example if you have two 70-200mm f/2.8 lenses you use on a body it would be great if the camera uses the data from the lens to know which lens needs which adjustment setting.

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