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Accessory Review: LensAlign
Michael Tapes has been at it again. The inventor of camera aids like the WhiBal white balance card has devised a clever way to take advantage of the microfocusing feature of some Canon, Nikon and Sony dSLRs. He calls it the LensAlign. We call it pretty sharp. See our review for the whole story...

Comments (12)

...this is a good article but I don't see the advantage of going through all of this vs just using a segmented rule viewed at an angle. Which is very fast to make, easy to do and above-all cheap. It would have been nice if more effort was made to explain why this is *necessary* given whatever considerations there are of covering the center cross-points, it's not hard to make a ruled line that has rules that extend over the cross-point. Also why not look at what happens if the horizontal-only focus points are used? Also it would truly be a good idea to explain why this is mainly an issue for lenses that aren't stopped-down, and at what focal-lengths and F# combinations this is not an issue, that is to say, what degree of front or back focusing will cause a problem with what FL's F# and focus-distance combinations. I'll bet that will save a lot of people from agonizing over this unnecessarily. It is probably a huge issue for macro and portrait shooters but not much of an issue for landscape shooters.

Which again is a good parameter to test when testing DSLRs and I think there's a lot more usefulness in looking at that then in micro-adjusting the lens and camera. I know for a fact that that caused me to sell at least two DSLRs, the 400D is simply awful in this sense and the Sony A700 not much better. For good all-around shooting an accurate AF system is essential and in low-light/low-contrast situations it's extremely hard to beat the Nikon 51p AF system with it's 15 cross-points with a single cross-point system. Compared to that, at least for me, focusing-offsets are minor issues. Sure it's speed vs accuracy but a "fast-focusing" system that is inaccurate in low-light/low-contrast situations is of no use when the light and contrast are not good...

Comment #1

This looks like a great product...but $140? Wow. Maybe $99. Maybe...

Comment #2

Front and back focusing has nothing to do with low light focusing. LensAlign addresses a completely different issue than contrast detection focusing problems in low light. Aperture controls depth of field. The shallowest depth of field is at the lens' widest aperture. That's going to make the focus point most obvious, so that's why we test wide open. As the review explains, at smaller apertures, you aren't likely to notice a front or back focusing issue.

Finally, making a measuring device that can test this problem accurately is not trivial. Setup is indeed quick and easily adaptable to different lenses...

Comment #3

The Lite model, which we did not have to review, is only $80. As the review notes, the only difference between the two models is how you align the LensAlign to your camera. On the Pro model, you use a sighting panel behind the focus panel. On the Lite, you pop a mirror on the front of the focus panel, adjusting the camera position until you can see the lens in the mirror. That's not a big difference to me. But again I haven't used the Lite model.

The ruler tells you what the lens focused on as it tried to get the focus panel target in focus. Both models do that...

Comment #4

Thanks for the review on this nifty product. My camera, a Nikon D60 does not have micro adjustments as far as I know. If I were to find a problem with front or back focusing with the LensAlign, what could I do ? Also the auto focus accuracy seem to be lens dependent in some cases, and as indicated, one can apply micro adjustments for individual lenses. Might autofocus errors also be distance dependent? i.e. Can a camera that auto focuses well at a few feet be significantly off at infinity ?

Comment #5

Cameras that don't offer a microfocus adjustment menu option have to go back to the factory for adjustment (with the lens). Just as they always did <g>. Focusing accuracy is far more critical at near distances than at infinity. It's unlikely you'd notice an issue at infinity even with back or front focusing. The problem is also mitigated when you stop the lens down, increasing depth of field...

Comment #6

Mike,.

 Thanks! Your review is very helpfull especially since no instructions came with the unit,( mine arrived yesterday). Can the Pro unit be used with all size lens say 24mm to 600mm ? Between Chuck Westfall's article and your article, I think I can make the adjustments with some confidence. But not sure about the distance from the camera to the target for each lens, is that critical as long as if the center focus sensor is covered on the target?.

Thanks again.

Jack..

Comment #7

Hi Jack, Glad you received your LA PRO. We have a few instructional videos on our site that should be helpful to you as well. Regarding long lenses, the answer is yes, with a caveat. Depending on both the shooting distance, the focal length of the lens and the aperture, there are cases (long/long/wide) where the DOF display ruler is "swamped" by the actual DOF of the combination of parameters. In this case the full DOF cannot be displayed. and you would use the trending aspect of the parallel black graphics to see whether the lens is F or B focusing.

So proceed with the PRO and if required for your situation (and that is a yes for the 600mm at distance) you might want to pick up the LRK. For photographers with smaller lens kits (70-200 as the longest let's say) who shoot portraits and events, for example, PRO is all they need (or LITE for that matter), but for long lens sports or BIF, I would suggest the LRK. Watch our site, and IR News for details. Hope this helps... Michael Tapes..

Comment #8

Just curious on this adjustment. I just did quick calculation using a D3 with a 50mm 1.4 and the depth of field at 8.2 feet(10x50mm)is.

Form 7.87 feet to 8.56 feet, therefore I come to the conclusion that adjusting focus to center the depth of field would be a mistake. Am I mistaken in my thinking?..

Comment #9

You really want to the sharpest plane of focus to be on the ruler's zero because that's where the camera was focusing. The range of focus is not equivalent to that sharpest plane (just nearly so). Making the adjustment is trial and error, but repeating the test will confirm the results for that lens...

Comment #10

Why, when you say calibration distance should be 50x focal length, do you set the 100mm lens from 'a couple of feet'?.

Also, in my experience, when using the system at the recommended distance the target is so small the calibration marks are almost meaningless. This is the case with my Sony A900 and it is certainly not lacking in resolution!!!..

Comment #11

Ah, you have to read me more carefully, Peter. That isn't what I said. I said, "The rule of thumb, however, is that camera-to-subject distance should be no less than 50 times the focal length of the lens. For a 50mm lens, that would be a little over eight feet. For our lens, we probably should have been 30 feet away. But that would have required remodeling." As to the second point, two things.

Or to shoot the target closer so you can see what's happening. At great distances, the problem is, of course, minimized, so you're really talking about situations in which depth of field is narrow. - It sounds like you're using a very long focal length. Tapes has recently introduced the Long Ruler Kit (http://www.imaging-resource.com/ACCS/LA/LRK.HTM) for long lenses. Hope that helps...

Comment #12

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This question was taken from a support group/message board and re-posted here so others can learn from it.

 

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