Voigtlander MFT adapter problems

[bmock]

I've had the following results testing V MFT VM and F adapters:

VM: variety of leica, V, and Nikkor lens. All focus correctly to infinity on the LCD using manual support (FW 1.1), BUT all are in focus for infinity objects, on the LCD with the lens focus index before the the lens focus scale infinity mark. With lenses set on max aperture and the infinity mark against the focus index the infinity objects are out of focus on the LCD.

To me the reason is the adapter is too thick?

F: works correctly to infinity for all Nikkors tried but will not allow a Leitax adapted Leica lens to be inserted.

This could be either the V-F or leitax adapters are slight out in diameter clearance?

Before returning the adapters to the supplier I would be interested to hear if anyone else has had similar experiences.

 

[squirrel$$$bandit]

These adapters all focus a little past infinity to compromise for differences in tolerance...it's a feature, not a bug, that insures you'll get to infinity for all your lenses. I use the lower end of the distance scale for street, but use the screen for infinity focus.

 

[splitimageview]

To infinity and beyond.

Yes, it's actually a slight compromise. Adapted lenses focusing past infinity means that close focus won't be quite as close. But it's a minor quibble, won't really make any practical difference.

 

[splitimageview]

One example where micro 4/3 may not be the best choice, with either native or adapted lenses.

 

[JoeV]

One example where micro 4/3 may not be the best choice, with either native or adapted lenses.

I would argue that this is an example where using Leica M-mount lenses may not be the best choice. You may recall, before there was a u4/3 standard or cameras, people for years had been getting their M-mount lenses tweaked to match the rangefinder cam in their camera body. And they would buy and sell said lenses, and people would subsequently have these compatibility issues between various lenses and bodies. If you read in the digital M forums, people are still having these issues on M8/9 series bodies with legacy M-mount lenses.

This is an example of why the mechanically coupled rangefinder mechanism is an outdated design, replete with problems that arise when metal parts wear from use, altering the focus tolerances between lens and body.

So I think it's fair to state that there have been these focus issues on M-series lenses long before u4/3 cameras came along, and that blaming the camera format, or the adapters, may be premature. In the case of the adapters, there are quality differences between various brands, but they all are forced to engineer a solution that takes into account the poor tolerances found between many samples of M-mount lenses.

~Joe

 

[squirrel$$$bandit]

I disagree--I think this is a non-problem. When you start shooting, you magnify and then focus on a distant point. Now you're at infinity and can shoot with impunity without adjusting focus. Worst-case scenario is you take note of where on the focus scale infinity really is, and you memorize it, and you're good for the rest of the day. Closer scale focusing is rarely off by much, and if you're doing it at small apertures, your focus will be fine.

Adapted lenses work very well for all but the most fussy photographers, or those with specialized needs. The OP may be one of the latter, but I still think m4/3 can work just fine for him.

 

[jlw]

You are of course correct for typical use, except for two reasons, a) scale focusing selecting hyperfocal distances becomes messy and b) I use my cameras for aerial photography, auto-focusing not being of much use, where being able to set the correct infinity on a manual lens is needed in a lot of circumstances.

The aerial-photography issue is a very legitimate point. If your lenses all focus slightly "past infinity" on the adapter, it means the adapter is too thin (not too thick.) Conceivably you could correct it by putting a shim ring over the mounting face of the adapter... although bear in mind that, based on measurements I've made of various adapters, yours is probably "off" by no more than 0.01 - 0.02mm. That would make the shim ring too thin and delicate for field use. It might be easier to prep for aerial-photography sessions by carefully focusing each lens to true infinity and taping the focus ring in that position.

I wouldn't think the hyperfocal-distance setting would be as much of an issue. Hyperfocal distance itself is only an approximate concept to begin with, and the focusing scales on still-camera lenses are calculated based on an "average" focal-length value and can't be expected to be 100% precise. I'd guess the results you get will be plenty close enough; the lens' deviation from infinity gets swallowed up in all the other cumulative "noise" in the system.


As others have said, manufacturers deliberately make adapters slightly "thin" to account for differing mechanical tolerances and standards from lens to lens. One of the first readily-available M adapters for µ4/3 was a Chinese-made one sold on eBay -- and those of us who bought the first batch found that many of these adapters had been made slightly too thick and wouldn't allow lenses to focus to infinity!

Taking apart one of these and measuring it, I concluded that the adapter had been designed to be exactly the "right" thickness. But manufacturing operations added enough extra thickness to throw off the result. For example, just the thickness added by chrome-plating the front flange could be enough to skew the result, if this buildup had not been accounted for in machining the brass piece. These two operations might well have been done by two different subcontractors, each of whom might have assumed that the other had applied the needed compensation.

Obviously, for most uses (although not, I admit, aerial photography) it's better to avoid this situation by erring a bit on the side of "too thin," which at least allows infinity to be reached, than risking winding up "too thick"!

 

[Dwig]

... That would make the shim ring too thin and delicate for field use.

Putting the shim between the flange, either the rear or front, and the body of the adapter would result in a more rugged arrangement.

It might be easier to prep for aerial-photography sessions by carefully focusing each lens to true infinity and taping the focus ring in that position...

The other approach would be to carefully focus the lens to infinity and then mark a new focusing index on the lens barrel. If done carefully, this would be functional for both the infinity-only aerial situation and for general scale focusing, though most scale focusing situations are done by guess and the adapter's error would be smaller than the error in the guess.

 

[bmock]

Thanks for all comments. On balance I will either have the VM adapter replaced or adjusted to my needs.

Also, FWIW, I will only use the gf1 for single handed (use the other to hold on!!!) in aircraft or oblique scene shots (along with D300, M6 or 500 C/M as appropriate); main frame photos are taken with either Wild RC10 or Leica RCD105

best regards, Bill