Which Adapters have Accurate FFDs and don’t Wobble?

I want to adapt a Nikon lens to an L Mount camera.  The lens has floating elements, so it is key that the mount registers the lens at the proper FFD, as opposed to going shorter to make sure it hits infinity.  Novoflex, for example, seems to intentionally go short to do this.

Metabones and Kipon make the F to L adapter, but I am interested to see if people have see if people have any insights into companies that consistently make accurate adapters.

Hello!

1/ not hitting finity, or

2/ going beyond infinity?

In all my years adapting (amongst others) Nikon F to pretty much every system out there, with numerous adapters, I have never come accross a make that offered the exact same tolerances for one and the same adapter.

That said, I have - fortunately - never had a problem hitting infinity with either of them. Going beyond is not an issue for my shooting anyways.

I do not think you will get away without trial and error of adapters if your goal is to get as close to accurate infinity as possible

Best,

Alex

Doppler9000 wrote:

I want to adapt a Nikon lens to an L Mount camera. The lens has floating elements, so it is key that the mount registers the lens at the proper FFD, as opposed to going shorter to make sure it hits infinity. Novoflex, for example, seems to intentionally go short to do this.

Metabones and Kipon make the F to L adapter, but I am interested to see if people have see if people have any insights into companies that consistently make accurate adapters.

I would suggest Rayqual adapters. However they do not seem to make adapters for L mount. I would try to buy an adapter that is deliberately made short, and shim them with tin foil or paper to get the desired thickness, using a precise measuring device.

EDIT: maybe they do make adapters for L mount. Link

Aoi Usagi wrote:

Doppler9000 wrote:

I want to adapt a Nikon lens to an L Mount camera. The lens has floating elements, so it is key that the mount registers the lens at the proper FFD, as opposed to going shorter to make sure it hits infinity. Novoflex, for example, seems to intentionally go short to do this.

Metabones and Kipon make the F to L adapter, but I am interested to see if people have see if people have any insights into companies that consistently make accurate adapters.

I would suggest Rayqual adapters. However they do not seem to make adapters for L mount. I would try to buy an adapter that is deliberately made short, and shim them with tin foil or paper to get the desired thickness, using a precise measuring device.

EDIT: maybe they do make adapters for L mount. Link

Thank you for this - I will look into this one.

Aoi Usagi wrote:

Doppler9000 wrote:

I want to adapt a Nikon lens to an L Mount camera. The lens has floating elements, so it is key that the mount registers the lens at the proper FFD, as opposed to going shorter to make sure it hits infinity. Novoflex, for example, seems to intentionally go short to do this.

Metabones and Kipon make the F to L adapter, but I am interested to see if people have see if people have any insights into companies that consistently make accurate adapters.

I would suggest Rayqual adapters. However they do not seem to make adapters for L mount. I would try to buy an adapter that is deliberately made short, and shim them with tin foil or paper to get the desired thickness, using a precise measuring device.

EDIT: maybe they do make adapters for L mount. Link

+1 for Rayqual adapters. They are the best of all I have used (which includes most names you have heard of).

Most of them do so this could be a long dry recommendation process.

Tom Caldwell wrote:

Most of them do so this could be a long dry recommendation process.

There are two strong recommendations for Rayqual.

I don't think they manufacture, but they do source and specify - I've been rather impressed with dumb adapters from K&F concept.

ProfHankD wrote:

Doppler9000 wrote:

I want to adapt a Nikon lens to an L Mount camera. The lens has floating elements, so it is key that the mount registers the lens at the proper FFD, as opposed to going shorter to make sure it hits infinity.

Logical, but, for lenses designed to be used with film, the aberrations introduced by the presence of a sensor cover glass are usually more than the aberrations caused by slightly wrong register for a floating-element lens. I.e., it's close enough.

Nothing's perfect and you'll be a lot happier if you accept that, but if you insist....

Novoflex, for example, seems to intentionally go short to do this.

Metabones and Kipon make the F to L adapter, but I am interested to see if people have see if people have any insights into companies that consistently make accurate adapters.

EVERY MECHANICAL DEVICE IS BUILT TO A TOLERANCE RANGE -- nothing is precise. I would argue it is good engineering design to err on the short side of the tolerance range and likely every competent adapter manufacturer is thus at least a hair short. Otherwise, they wouldn't hit infinity on cameras with the body flange on the long side of it's tolerance range. Tolerance ranges for body flanges are usually tight enough so that DoF will effectively hide the error, but not always. Incidentally, body flange accuracy was generally worse on DSLRs/SLRs because the PDAF sensor or manual focus screen was not quite in the same plane as the sensor or film (that's what PDAF microadjustments are about)... and film emulsions were relatively thick and roll film never lies very flat, making the film plane itself an imprecise thing. It's largely the thinner and flatter nature of sensors that makes these little errors more visible than they were with film.

The catch is, it's actually pretty easy to add shims to many adapters to make them arbitrarily accurate for your particular camera body and lens combo. Some adapters are explicitly user adjustable, but shimming others usually isn't really any harder. Where this level of perfection matters (mostly in some very technical computational photography situations), I've generally used Scotch tape for thin shims and aluminum duct tape for thick shims. Obviously, adapters that are too thick need to be shortened, and that's much harder than adding shims....

One more note: be sure you shim at the working temperature. Lens barrels expand and contract significantly with temperature changes. A large change in rear focus with temperature something people generally expect of long lenses, such as 500mm mirror lenses, and that's why many long lenses are explicitly designed to allow focus somewhat beyond infinity. However, short focal length lenses are much more sensitive to tiny changes, and the lens I own that has the greatest effective focus shift with temperature is actually my Laowa 10-18mm (in native FE mount). For example, I was recently shooting that lens in ambient temps ranging from about 75F down to 25F, and infinity can move to nearly the 3m mark over that temp range.

Thank you, Professor. I will try to pick a good median temperature. Perhaps seasonal shimming? ; )

I came to the same conclusion regarding overall tolerances, after reading some articles by Roger Cicala.

The bottom line for me is that a well-made, precision adapter is a good starting point, but manufacturing (in)tolerances on camera bodies and lenses mean that, as Aoi Usagi said, shimming is probably going to be required if you want the correct FFD.

Excellent Point about the asymmetric nature of shimming, versus trimming.

Shimming most adapters is fairly easy.

The most difficult part is deciding which material and thickness to use.

Here is an old thead which discusses that:

https://www.dpreview.com/forums/post/62748507

Basically, you can use fairly stiff tape, metal foil or, very functional, metal feeler gauge.

Typical thicknesses are about 0.1-0.3mm. You can try measuring, but it isn't easy. Trial and error works well...

Who gave helpful, practical input.

Looks like Rayqual and shims will be the way to go.  The Rayqual adapters seem to be better baffled than most or all of the others, which is a nice bonus.

Only have one Novoflex:  C/Y to Z and it happens to be spot on in terms of hard infinity stop preservation over about 15 C/Y Zeiss and Yashica lenses - surprising, I thought that tolerances on the lenses themselves might have been more noticeable especially since you can interpolate the "best" focus point much more easily on an MILC than on a a SLR.

Also have used many others mainly K&F and Beschoi ( possibly another marketing name for K&F ) for Sony FE.  I did waste too much time trying to 'mic the depths but don't have accurate enough metrology kit / conditions to do that although the Novoflex was within measurement tol. of the design whereas the K&F were a bit short ( Beschoi ) more so.  All lenses focussed past infinity on these to varying degrees.

Subsequently I used these with various FE to Z adapters on a Z6:  this added more shortness since even the Kipon FE to Z was measurably shorter.

Floating elements ( and zooms ):  interesting oft repeated requirement for accurate registration distances.  Have tried 2.8 WA ( Nikon 24 and 28 ais CRC ) on various adapters and native i.e. DSLR, FTZ to Z6, aforesaid K&F dumb FX to FE to Z on Z6.  I haven't seen any adverse effects. Not tried much faster glass.

Bit like with macros which all have complicated focussing schemes.  The mantra ( every time a new one comes out like the Z 105 MC ) is that you can't use tubes because it throws the design reg distance so far out ie 10's mm for 10's um. I just use tubes or TC's with impunity.

I am probably wrong -  not seeing what I should see BTW