The ultimate front or back focus test target

[scott kirkpatrick]

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To my surprise, there is no "help, my new 50-Lux back-focuses!" thread on page 1 tonight, so I'll start one for Michael Tapes' new LenAlign target. It has some nice innovations to simplify alignment and interpretation. This kind of test is pretty tough to get right, and frustrating when the results are inconsistent, so I think this may be a gadget with some real value.

 

Check it out at RawWorkflow.com - Digital Photography Products and Education - LensAlign? .

 

There are reviews on LL and Imaging Resource, linked from Tapes pages.

 

scott

[ho_co]

Thanks for the heads-up, Scott!

 

I was wondering what RawWorkFlow would come up with after everyone had a set of WhiBal cards.

 

This looks well thought out, and it's certainly timely. (How nice to know dSLR manufacturers not only recognize the problem, but build in the ability to adjust for it!)

[photolandscape]

Thanks for the heads-up, Scott!

 

I was wondering what RawWorkFlow would come up with after everyone had a set of WhiBal cards.

 

This looks well thought out, and it's certainly timely. (How nice to know dSLR manufacturers not only recognize the problem, but build in the ability to adjust for it!)

 

Would it work for a rangefinder like the M8?

[lars_bergquist]

The Old Man has decided that focus testing down to the millimetric level is detrimental to your mental health. Sorry, I don't know how to put fat black borders around that announcement.

 

Not only is the rangefinder really not up to the task---you are not, either. Second, how relevant is it? There is only one relevant test---practical use. Do you consistently miss pictures because of a small focus shift (and, is it the fault of the lens, and not produced by your fallible human self?)

 

One of the most discussed lenses is the 35mm Summilux ASPH. I note that Sean Reid, in a discussion of focus shift, states that he has used this lens with full satisfaction for years without having one single picture ruined by focus shift. I'll second that. I bought my specimen back in the previous millennium, and my experience is the same. I note that pro photogs insist on using autofocus cameras, even through it can be proved that they can place the plane of max sharpness exactly where you wanted it, only by sheer fluke. You get it somewhere in the vicinity, and these gentlemen are satisfied.

 

The old man from the Age of Scale Focusing

[scott kirkpatrick]

Would it work for a rangefinder like the M8?

 

Of course, but to feed back what you learn takes a trip to a service center and some $$, or some rather risky work on your camera with a small Allen wrench. Folks like Lars, above, who don't want to get involved in all that quite sensibly do this for the information alone or let the plane of focus fall where it more or less should be (as do I). Pros with really serious tech support budgets (think Time-Life or National Geographic) send whole suites of lenses and bodies off to DAG to get them calibrated to work together precisely. Really obsessed amateurs take out the Allen wrench and make very tiny adjustments at two points on the linkage that drives the rangefinder mechanism -- but that only adjusts the camera, and if there are multiple lenses it may tighten tolerances for only one of them. So we amateurs tune for the Noctilus or 90-lux, and then we can get head shots with the eyelashes sharp and that dreamy bokeh on the glasses and earlobes.

 

This gadget is really intended for the latest generation of DSLRs which allow you to key in an autofocus correction for each lens you normally use.

 

scott

[scott kirkpatrick]

The Old Man has decided that focus testing down to the millimetric level is detrimental to your mental health. ...

[also detrimental to your health could be]... the 35mm Summilux ASPH. I note that Sean Reid, in a discussion of focus shift, states that he has used this lens with full satisfaction for years without having one single picture ruined by focus shift.

 

Focus shift (in which the plane of focus isn't sharply defined and shifts as you stop down) isn't as common an issue as having lenses and cameras which individually meet manufacturing tolerances but together exceed them.

 

I've done this sort of testing with a strong vertical line marked on a pad of ruled paper, and arrows to mark where I am supposed to be focusing. At first I thought I might be seeing focus errors of order 10 cm (definitely more than a nose) but repeated trials, careful tripod setup, and some practice reduced my errors to the point where only 2-4 cm could be blamed on the camera, and this seems to be consistent across several lenses.So when my turn comes for an upgrade next month in Solms I can send precise instructions on this point, hold my breath, and see what comes back.

 

scott

 

PS of course the cost of the TapesTarget is about $100, and the cost of a pad of paper is... but he saves you some of the time spent in reducing personal error contributions.

[Rick]

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The Old Man has decided that focus testing down to the millimetric level is detrimental to your mental health. Sorry, I don't know how to put fat black borders around that announcement.

 

First, Old Man... this is getting old. You don't have an absolute on this just because you claim you have been around since ... what ever. Who cares? The point is that anyone can lay out a meter stick and do the same thing that this piece of crap can do. Don't buy it unless you are a fetishist! That is the point.

 

Further, it is important to know what your lenses are doing because lenses can get out of focus and it becomes apparent when the focusing mechanism is not tied through the lens. It doesn't have anything to do with wether you have decided it is detrimental to your mental health.

 

So, it is important to call Leica on it and it is important to know if your lenses are back focused... like the 35/1.4 @ 2.8. Nothing to do with mental health...

[lars_bergquist]

I do not claim authority because I was born in 1936. I claim the right to voice my opinion, in this case because I am more interested in pictures than in tests.

 

The egregious old man from the Age Before the Deluge (1939--45)

[farnz]

... First, Old Man... this is getting old. You don't have an absolute on this just because you claim you have been around since ... what ever. Who cares? ...

I care.

 

What I don't care for is your disrespectful tone to a member who has provided expert help and assistance to many on this forum for a long time. Certainly, voice your opinion but please don't be disrespectful.

 

Pete.

[jaapv]

The Old Man has decided that focus testing down to the millimetric level is detrimental to your mental health. Sorry, I don't know how to put fat black borders around that announcement.

 

First, Old Man... this is getting old. You don't have an absolute on this just because you claim you have been around since ... what ever. Who cares? The point is that anyone can lay out a meter stick and do the same thing that this piece of crap can do. Don't buy it unless you are a fetishist! That is the point.

 

Further, it is important to know what your lenses are doing because lenses can get out of focus and it becomes apparent when the focusing mechanism is not tied through the lens. It doesn't have anything to do with wether you have decided it is detrimental to your mental health.

 

So, it is important to call Leica on it and it is important to know if your lenses are back focused... like the 35/1.4 @ 2.8. Nothing to do with mental health...

 

I disagree not only with your tone, but also with your opinion. Testing is unproductive when carried out for the sake of testing alone. It only makes sense if you images lead you to think that something is wrong with your equipment or if it enables you to adjust/improve your equipment and through that your images. And Lars is fully entitled to make that point in a tongue-in-cheek manner.

[ho_co]

Auni, you blew it. Don't be disrespectful to anyone, particularly if that person is expressing his opinion reasonably.

 

Auni, you've completely lost my respect. Read how the focus target is constructed and used before you call it a piece of crap that can be replaced by a meter stick.

 

 

 

Scott, I don't think the full-size unit would work with the rangefinder because the finder/lens parallax would not work with the LensAlign's mechanism for trying to get the target and camera plane-parallel.

 

I don't know about the LensAlign Lite, since it doesn't have the two-level target and I'm not sure how the mirror would work.

 

 

IMHO, zone focusing is good enough for a lot of the kind of work that the Leica is best at. As Lars implied, in close-tolerance situations such as using a wide-open Noctilux, just breathing creates enough movement to move the focused-on object out of the focus plane.

 

And the fact that dSLRs aren't up to focusing as well as a lot of people used to think is illustrated by the fact that their manufacturers are beginning to build into them the mechanism to correct for consistent deviations.

[scott kirkpatrick]

....

Scott, I don't think the full-size unit would work with the rangefinder because the finder/lens parallax would not work with the LensAlign's mechanism for trying to get the target and camera plane-parallel.

 

I don't know about the LensAlign Lite, since it doesn't have the two-level target and I'm not sure how the mirror would work.

.....

And the fact that dSLRs aren't up to focusing as well as a lot of people used to think is illustrated by the fact that their manufacturers are beginning to build into them the mechanism to correct for consistent deviations.

 

Howard, I hadn't thought about parallax issues, but if the system gets the image plane parallel to the focussing target in the LensAlign, parallax (horizontal displacement) shouldn't matter. The Lite (the only unit that interests me) uses a mirror behind an aiming point of some sort, and it sounds like a better solution anyway, besides being more shippable.

 

DSLR autofocus is a real matter of taste. With my E3, I've concluded that using the center AF point only and reframing after a half-press is fast and reliable. Sean Reid made a comment somewhere that he does that with his Canon 5D. Yet another working photographer that I respect goes to great length to use a single AF point in precisely the position needed for the final framing, and has learned how to move the active point around in the matrix of AF positions without taking his eye away form the viewfinder of his K20D.

 

With a little care, I can focus and hold the M8 to the tolerances of wide open lenses and a subject's eyes, so I find this information valuable, despite the hoots and thigh-slaps of the detractors.

 

scott

[Rick]

ho_co... "Auni, you blew it. Don't be disrespectful to anyone, particularly if that person is expressing his opinion reasonably."

 

"Auni, you've completely lost my respect. Read how the focus target is constructed and used before you call it a piece of crap that can be replaced by a meter stick."

 

 

Sorry if you read it as disrespectful. I was supporting Scott who was frustrated because he had a lens that was back focussing. Lars told him that back focus testing was a mental health issue. I found Lars' tone condescending. A member was trying to find answers. I simply wanted to point out that testing certainly does have its place. Maybe I misread Lars' post and it was tongue in cheek. Sorry Lars.

 

Your comment about losing your respect for me and accusing me of not reading "how the focus target is used" ... isn't that disrespectful?

 

I believe testing is fine when you are having a problem and especially for the sake of pure exploration of optics and personal education. I have sat for hours at an optical bench purely for the sake of education and not even a picture was taken. Ok, maybe a polaroid was required for the lab notebook. I hope Scott figures this out. I think it must be very frustrating.

 

And, I still think the target is a piece of crap... not to be found on an optical bench. Just my opinion, that's all.

 

 

Edit: After rereading my original post, the tone was not exactly what I intended.

[farnz]

... Sorry if you read it as disrespectful. ... Maybe I misread Lars' post and it was tongue in cheek. Sorry Lars. ...

Edit: After rereading my original post, the tone was not exactly what I intended.

Auni,

 

Thank you for posting an apology and I accept that you were not intentionally showing disrespect.

 

Back on topic ...

 

Pete.

[gfspencer]

Check it out at RawWorkflow.com - Digital Photography Products and Education - LensAlign? . scott

Even though I thought it was a little pricey, I ordered one yesterday . . . . mainly for the auto focus on my Canon 50D. I'll let you know how it works on the M8.

[ho_co]

We'll all be interested. Looks as if RawWorkflow has gone to a lot of effort to design a product that isn't just a ruler with some lines drawn on it. I'll be curious how it works with both Canon and Leica.

 

Keep us posted, GF!

[ho_co]

Auni--

Thanks for the apology to the forum.

 

ho_co... "Auni, you've completely lost my respect. Read how the focus target is constructed and used before you call it a piece of crap that can be replaced by a meter stick."

...

Your comment about losing your respect for me and accusing me of not reading "how the focus target is used" ... isn't that disrespectful?

Hmm. Is saying that I've lost respect disrespectful? I think they are quite different.

 

Or if you're calling me disrespectful for saying you haven't seen how the LensAlign is used, read the offending post:

... The point is that anyone can lay out a meter stick and do the same thing that this piece of crap can do. ...

Just for starters, how does a "laid-out meter stick" accomplish proper camera-target alignment?

 

... And, I still think the target is a piece of crap... not to be found on an optical bench. ...

Mabe that's our difference. IMHO, this isn't a tool for an optical bench and it isn't priced like one. It's designed to give a lowly camera user a better means for checking focus than the home-made Nikon target we all know and love, or ruled sheets of paper on the wall or rulers laid on the floor.

 

I see a couple facets of improper focusing that this target isn't designed to address, but that fact can't be addressed by dismissing it as a "piece of crap."

 

I can't say "piece of crap" because I haven't seen the device. You might call the WhiBal card a "piece of crap" as well if you just see pictures of it. But I haven't been tempted to say that after using it.

 

 

Now if you'll pardon me, I don't see a need to continue the discussion. This whole subsegment of the thread has been a wasted digression in my opinion. You're entitled to your opinion. I respect your apology. The only reason I've posted this is that you placed these comments in the same note that contained the apology, implying that they should stand separate from the apology. That is, if you had thought better of these remarks, you'd have deleted them from the apology.

[thompsonkirk]

"Would it work for a rangefinder like the M8?"

 

Getting back to the issue: it's not about focus anxiety as a mental health problem, however intriguing that might be to psychologists (DSM-IV, sec. xxx?); it's about what the gizmo is designed to do.

 

The answer is you could diagnose focus error but couldn't correct it. LensAlign works for any camera at a diagnostic level, but 'mates' only with a few DSLRs to make corrections.

 

If you read the review on the Luminous-Landscape site, Michael Reichmann explains that it works best with the half-dozen new DSLRs that have a capacity for microfocus adjustments built into their firmware, so that you can program corrections for each of your lenses into the system. The camera then recognizes the lens & adds a microfocus adjustment.

 

If you used it with an older DSLR, you'd be half-way there: you could tell you had a problem, but wouldn't be able fix it yourself. If you used it with a rangefuinder, you'd have to be sure first that the rangefinder wasn't at fault.

 

Personally, I'll just continue to stick a pin in a sheet of newspaper & shoot crosswise, whenever I have an attack of focus anxiety. That's $138 cheaper than either LensAlign or an hour with a psychologist/psychiatrist.

 

Kirk

[ho_co]

Kirk--

I love your term "focus anxiety."

 

To carry the diagnosis a step further, some AF bodies are now being built with a psychiatric function, viz to treat that ailment!

 

Psychiatrists take note--you can be replaced by certain photographic apparatus!

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Hallo,

Look here: Leica M

[jaapv]

Auni,

 

Thank you for posting an apology and I accept that you were not intentionally showing disrespect.

 

Back on topic ...

 

Pete.

 

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