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LensAlign Gets Long Ruler Kit


The Imaging Resource Digital Photography Newsletter

Review Date: May 2009

Since the debut of the LensAlign, Michael Tapes has been refining a Long Ruler option tuned for longer focal length lenses at distances 25 feet and beyond. After months of work, the Long Ruler for the LensAlign Pro has made its debut. "It was actually quite a challenge, but I am really thrilled with the way it turned out," Tapes said.

The LensAlign designed by Michael Tapes provides a reliable tool for measuring and correcting back and front focusing problems in autofocus lenses. Both the Pro and Lite versions include a 9.5-inch ruler to measure focus. And that scale works well with most lenses up to 25 feet away. The addition of the Long Ruler Kit (which includes the new Large Focus Target) and the new Enumerator, also making its debut, complete the package.

Enumerator. Set the Autofocus Adjustment and Distance scales for the current camera setup.

The Enumerator, which will ship with new LensAlign Pros, consists of two panels that attach to the front of the LensAlign. The top panel can be set to the camera's current Autofocus Adjustment and the bottom to the Distance. Small magnet markers are used to indicate the camera settings. So each shot you take with the LensAlign Pro captures both the distance and Autofocus Adjustment setting of the camera.

"With the addition of the LongRuler Kit and the Enumerator, we now offer the complete solution to measuring the focus performance for all your camera bodies and lenses, including wide-angles and long teles," Tapes said.

LONG RULER | Back to Contents

In brief, the Long Ruler is a lightweight vinyl ruler three inches wide by 47 inches long (hence the name). It is shipped in two parts with a protective clear plastic over the vinyl lettering. The vinyl is stiffened by a thin carbon fiber rod that extends a few inches past the end of each side. Each of those fiber fingers slip under their respective mating piece so when you lay it flat, they are joined together.

To lock the connection, you attach the original 9.5-inch scale to the underside of the Long Ruler. A set of small round magnets holds the original ruler to the vinyl Long Ruler, locking the two pieces together and providing a mount to the LensAlign Pro itself. The Long Ruler does not work on the LensAlign Lite.

The base ruler supplies the hinge and angle adjustment magnets that position the Long Ruler in the LensAlign Pro.

Very Little Sag. The carbon fiber rod keeps the Long Ruler pretty stiff.

Viewed from the side, the carbon fiber rod appears to hold the Long Ruler fairly level. A peek down the barrel, so to speak, reveals that not all sag is eliminated but Tapes said he believes, "the performance of the system will not be degraded since the sag is out at the ends, and would only affect the transition point of a 3+ foot DOF."

Alignment. The trick is to make sure zero on the ruler aligns with the front of the LensAlign Pro.

SET UP | Back to Contents

The two halves of the Long Ruler are shipped with protective plastic on the scale that is easy to remove. Each half is identified on the back. Top Half will sit above the LensAlign Pro and Bottom Half below it.

Sliding the two carbon fiber fingers under the mating half of the ruler is also easy to do. The easiest way we found to do it was to hold the two halves in a V shape, tap the two fiber fingers together and slide the halves together, closing the gap while keeping the fingers together. When the two middles touch, you can open the V flat.

Assembly. Start by aligning the carbon rod fingers (top) then locking the two ruler halves together. Position the base ruler (shown here face up) over the rods, aligning the pin cutouts to the gap between halves of the Long Ruler. Finally (bottom), make sure the edge of the base ruler is flush to the edge of the Long Ruler.

Turn the Long Ruler upside down to attach the base metal ruler. You'll see eight round magnets on four standoffs and the outline of the base ruler for alignment. We turned the base ruler over so the unprinted side would touch the magnets (and avoid scratching the scale) and matched the outline, disregarding the middle point.

The outline is merely a starting point. For precise positioning, make sure the pin cutout on the base ruler is centered over the butting end of the two ruler halves. That should align the zero position on the scale to the front of the LensAlign Pro -- a critical alignment because any shift will imitate a focusing problem.

Large Focus Target. Included in the Long Ruler Kit is this larger target.

At the same time, make sure the base ruler's long edge extends at least flush to the edge of the Long Ruler so the alignment magnets on the LensAlign Pro can attach themselves.

Because the Long Ruler is 47 inches long, you'll no doubt want to mount the LensAlign Pro on a tripod. That way the tip of the ruler can extend well below the base of the LensAlign Pro.

With the Long Ruler assembled and the LensAlign Pro mounted on a tripod, set the Longer Ruler into the LensAlign Pro just as you would the standard ruler. The hinge notches on the base ruler should slip right onto the pins of the LensAlign Pro and the angle adjustment magnets should hold the Long Ruler in position.

USING THE LONG RULER | Back to Contents

The beauty of the Long Ruler is that it works just like the base ruler, setting the angle to most clearly display depth of field (steep for shallow and flat for deep). The difference is that you can position the LensAlign Pro further away from the camera to reveal back or front focusing on long focal length lenses (300m and above).

In the Lab, Luke Smith shot a set of images at both 24 and 48 feet. The trick to aligning the camera and LensAlign at distances like 48 feet is to back sight through the LensAlign to the camera as described in our LensAlign review. The new Long Focus Target is an easier target for the camera's autofocus system to find. At long distances and using a multipoint autofocus mode, the camera might not lock onto the smaller original target. But at twice the size of the original, the heavy-duty stainless steel Large Focus Target is hard to miss.

The results clearly show the value of the Long Ruler at 48 feet and just f/5.6. At f/2.8 depth of field is shallow enough that the base ruler would work, but as you stop down and depth of field expands, only the Long Ruler can show you what's going on.

And as you increase distance, the Long Ruler also proves necessary. A Canon 300mm lens opened to f/2.8 at 25 feet, for example, showed a depth of field of 3.8 inches. But at 50 feet, it was 15.6 inches and at 75 feet it stretched to 35.4 inches. All within the 47-inch limit of the Long Ruler.

The table below represents crops of the full-size images shot in the lab by Luke Smith using a Canon EOS-1D Mark III with a Canon EF 300mm f/2.8 L IS USM lens. To view the full resolution crop, click on any image.

Full Resolution Crops
24 ft RedDots 24 ft at f/2.8 24 ft at f/2.8 Edges 24 ft at f/4.0
24 ft at f/5.6 24 ft at f/5.6 Edges 48 ft RedDots 48 ft at f/2.8
48 ft at f/2.8 Edges 48 ft at f/4.0 48 ft at f/5.6 48 ft at f/5.6 Edges

In addition to the above table, we have a Flash gallery and slide show of Luke's shots showing smaller images with sufficient detail to reveal the added functionality of the Long Ruler. The animation provided by the slide show option under the View menu (or by clicking the first icon under the main image) helps reveal the focusing issue as the image transitions from the studio shot to the Edges filter shot.

Gallery. Try the slide show.

For more on using the LensAlign itself, refer to our earlier reviews of the LensAlign Pro and LensAlign Lite.

PRICE & AVAILABILITY | Back to Contents

The Long Ruler Kit, with both the Long Ruler and the Large Focus Target, and the Enumerator can be used with any LensAlign Pro system. The Lens Align Kit can also be purchased with a LensAlign Pro as the LensAlign Pro Plus, available May 18. Special upgrade pricing is available to current LensAlign Pro owners.

Until May 18:

  • LensAlign Pro: $139.95
  • LensAlign Long Ruler Kit: $70 (available for pre-order now, shipping May 18
  • LensAlign Lite: $79.95

Effective May 18:

  • LensAlign Pro Plus (LensAlign Pro with Enumerator plus Long Ruler Kit): $250
  • LensAlign Pro (includes Enumerator): $180
  • LensAlign Long Ruler Kit (requires LensAlign Pro): $100
  • LensAlign Lite: $79.95

Tapes said current LensAlign Pro customers can order the Enumerator alone for a $4.95 shipping and handling charge. Current customers who upgrade to the Long Ruler Kit before May 18, will receive the Enumerator at no additional charge.

Orders may be placed directly with

CONCLUSION | Back to Contents

The LensAlign impressed us as "a measuring tool that can cut through the vagaries of focus to help you fine tune the autofocus accuracy of your gear." With the Long Ruler, the fine tuning extends to long focal length lenses at smaller apertures than the original could measure. In no small way, that and the new Enumerator complete the product. And, as with all of the products we've tested from Michael Tapes' drawing board, the uncompromising design and reliable production turn the unique concept into a valued tool.