Acceptable focus error?

[skinnfell]

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I have bought a used 90mm TE, which is in very nice condition, but has a ever so slight short focus. Probably an inch or so at the close focus limit.

This is not visible at distances over 2-3 meters and apertures above 4. Perfect focus at longer distances and infinity at all apertures. Mechanically it is very clean and smooth.

The price I paid is roughly in line with what I see on ebay etc for a lens of this vintage and condition.

 

I bought it privately and the seller is quite reluctant to take it back saying this is to be expected on such an old lens, and points to the fact that it does indeed focus very correct at all other distances and apertuures than 1m/2.8.

 

I admit that focusing a 90 can be tricky, and I did indeed buy a brand spanking new 90AA last year that had far more short focus than the 90TE in question.(I returned that one to the store). Also I am losing more shots on behalf of my own focus misses than can be attributed to the lens misfocusing. I am planning on getting a M240 soon, I expect to be able to use LV focusing at critical shots. Also, I do in fact shoot it mostly at f8 because its so much sharper here than 2.8. This aperture camouflages any errors.

 

 

So heres my question:

Is there such a thing as an "acceptable amount of miscalibration" when we are talking about a used 30 year old lens? Am I being too @nal about focusing perfection and asking too much from a venerable vintage?

 

Is it worth while to pick a fight with the seller or just accept this as a way of life with older lenses and work around it?

 

What's your take?

[jankap]

What camera do you use?

I think it could be your rangefinder mechanism.

An M240 is of no use, if you would only use its LV.

Jan

 

You can not rely on the DOF. At 1.5 m your DOF is 6 cm (+3 and -3cm), that is true. But this a calculated sharpness only.

Your lens is at its best in one plane. So if your rangefinder is off, you always loose sharpness in one of the directions.

A 30 year old lens was designed for film. I would not blame it. Many members here use customer service for calibration, search for the term CLA.

[skinnfell]

Jan: M9 and I dont think it is a camera error, my new summicron 50 is spot on.

 

To re-phrase my question: when you buy a older used lens, do you expect it to be perfect or is it common to accept a slight margin of error?

[jankap]

Sorry, see above.

Then, you could think of sending your lens to Leica. 30 years ago people did not know, what a sensor would be. Film was more forgiving, because the light penetrated in it. A sensor delivers a light sensitive plane only.

I would stay with the M9. Things are moving fast still.

Jan

[earleygallery]

I can understand the sellers reluctance to take back a perfectly good lens!

 

If you have bought it s/h and privately then it is effectively 'sold as seen'. When I buy stuff over the net, I do so with the expectation of an element of risk in that the item may not be quite as good as described or may need a CLA. Of course I also bid accordingly (although if said item was clearly faulty or significantly different from the description then I would complain).

 

You can send the lens to be calibrated (many new Leica lenses need this too) or work around the issue - do you think it will be a problem in real life situations?

[skinnfell]

Thanks for the (edited) reply, Jan!

 

This is not an issue that renders the lens unusable, I was just raising the "philosophical" question of how much perfection one can expect when buying old and vintage and intend to use it digitally . I must re-iterate that it does take -wonderful- photos at all apertures above 4 and all distances above ca 3m.

 

A full leica CLA will cost more than half of what I paid for the whole thing, and even the repair place says it is not guaranteed to be 100% because of it being old after all.

[StephenPatterson]

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1. Always take your laptop along when looking at used lenses. Shoot 1m and infinity wide open and see what you get. Having a retina display MBP at 100% will show you what you need to see. I've rejected quite a few older lenses, but also found some gems.

 

2. There will always be a tolerance, as there is no such thing as a perfect rangefinder lens or camera body. However front focusing by "an inch or so" at 1m and f/2.8 is far from acceptable, and unless the price was adjusted or there was some other mitigating factor I would not have bought the lens.

 

3. As for the M240 and LV focusing I much prefer using the rangefinder. LV can be slow and tricky, and without a way to adjust the 5x or 10x zoom box away from the center your focus can often be incorrect by the time you recompose the image.

 

The next step is really up to you. You can shoot at 1m only using apertures smaller than f/4, and have DOF hide the focus error, you can use LV with the M240 and hope your subject stay still long enough for you to eventually get the shot, you can have the lens calibrated or you can attempt to return the lens. There is no engineering or mechanical reason why this lens should not be able to focus accurately wide open at 1m, however it seems this sample has a problem.

 

Good luck.

[jankap]

Not knowing, what you have paid for the lens, I assume a calibration will cost around 400 Euro. I would pay that. Cameras go, good lenses stay.

Imagine, what the upgrade from M9 to M240 will cost you. And then you have to work with 2 worlds (RF and LV), which is very irritating.

 

I am puzzled, why the 90AA did not work for you.

Jan

[skinnfell]

So if I get this right?, so far:

2 votes for "its a vintage lens and some sloppiness is to be expected" and

1 vote for "not acceptable".

 

The seller did indeed offer that i come and try it, but this meant driving over a thousand miles each direction so that was out of the question. I failed to ask for a free return time period, but I did manage to haggle the price down by $100. I ended up paying $1000 inc shipping which seems to be a normal going price for a nice looking lens of this kind. I bought it privately, not through ebay or paypal.

 

Did I get the short end of the stick or should I I keep it and foot a future calibration bill myself?

 

stephen: The seller is quite reluctant to take it back as he claims this is to be expected in an old lens. 2 votes so far says he might be right...

 

jan: The 90AA had front focus of about a foot at 2m. I returned it to the store with no questions asked. Either way it was way too big so I would probably be dissatisfied with it anyways.

 

 

Finally: this is not a heartbreaking deal to me, I am more interested in the general consensus around buying vintage lenses unseen.,

[StephenPatterson]

 

stephen: The seller is quite reluctant to take it back as he claims this is to be expected in an old lens. 2 votes so far says he might be right...

 

 

Being out by one inch at 1m is not a minor focus error. Even on film that would result in the tip of the nose being sharp and the eyes being soft. Yes, there is a tighter tolerance needed for digital sensors, but older lenses are capable of this. Just look at all of the posts concerning shooting vintage lenses on Monochrom and other digital bodies. Lots of very nice results.

 

I had to try three copies of the 90/2.8 Fat Tele Elmarit before finding one that had no calibration issues, but the third one was spot on.

 

I can see the seller's point, but this lens definitely needs a calibration (as long as there are no issues with your camera's rangefinder).

[jankap]

Stephen, is the TE sensitive for focus shift?

The distance transmission to the camera seems to be by a ring in the lens. Not by a stick. A ring is better.

Ebay prices run from 700 to 1000 Euro, seems to fit.

Jan

[skinnfell]

Ebay prices run from 700 to 1000 Euro, seems to fit.

Jan

 

$1000=€725 with today's exchange rates.

[StephenPatterson]

Stephen, is the TE sensitive for focus shift?

The distance transmission to the camera seems to be by a ring in the lens. Not by a stick. A ring is better.

Ebay prices run from 700 to 1000 Euro, seems to fit.

Jan

 

Focus shift was never a problem for me, as it was usually hidden by increased DOF, although these older designs never perform like a modern lens with floating elements.

 

Focus coupling by a stick? I'm not sure I understand your question. Leica has always used a focus helicoid "ring" as you say, that mates inside the camera mount against the rangefinder roller cam.

[jaapv]

Not knowing, what you have paid for the lens, I assume a calibration will cost around 400 Euro. I would pay that. Cameras go, good lenses stay.

Imagine, what the upgrade from M9 to M240 will cost you. And then you have to work with 2 worlds (RF and LV), which is very irritating.

 

I am puzzled, why the 90AA did not work for you.

Jan

400 Euro?? I would expect to pay something like a quarter of that - if I sent it to one of the reputed independents.....

And I rarely use liveview with a 90 mm lens. The M is primarily a rangefindercamera and focusses perfectly OK with a 90 mm lens. Considerably better than the M9 in fact.

[wattsy]

I think I'm with the seller on this. Leica lenses from the pre-digital days were calibrated to a different (arguably less exacting) standard and I think used lenses, unless otherwise agreed, are on a "sold as seen" basis.

[jankap]

Stephen, my Canon 135 has a metal stick, that moves the roller of the camera in or out. Saving weight.

I assume, that the lens is optimized for 5.6 in behave of focus shift. Otherwise I don't know, what could be adjusted in a lens. If this is true, using the rangefinder the plane of sharpness is taken at 5.6 and - of course - independent of the chosen f/stop.

 

Jaap, that sum was a wild guess. My father in law had a Leica CL, that had to be opened and Odin estimated the operation at 400 guilders.

I had the same brown/yellow filters in my eyes, three weeks ago the second (left eye) lens was exchanged. After 60 years of wearing specs, I am seeing better than ever now.

Jan

[Berth]

It sounds to me like you got a very fine lens at a very fair price. If you want perfection then new is the way to go.

[jaapv]

Jan, Leica has this 'stick" as well on the 135. It is just a lever to transfer the movement of the helicoid which is located inside the lens because of the length. There is no difference really to a shorter lens which has the roller running on the helicoid directly.

[earleygallery]

I don't think the lens is faulty, it's just that when used on a digital body a front/back focus issue is noticeable. Lots of new Leica lenses seem to need subsequent recalibration for the same reasons, of course such work is covered under warranty, but yours is an older s/h lens.

 

I agree with Jaap, a lens CLA should be in the region of 100 Euro, not 400!

 

If you're unhappy with the lens and begrudge parting with more money to have it CLA'd then just sell it on, much easier than getting into arguments with the seller, who in fairness hasn't sold a dud, and might wonder if you've damaged it in some way.

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[skinnfell]

Thank you all for a balanced and fruitful discussion!

 

My lens does not need C(leaning) L(ubrication), just A(djustment).

 

Guess I can live with that and shop around for a workshop that can do such trickery for less than the roughly $500 + shipping that my local Leica dealer quoted for me. (I assume that includes a full spa treatment, though).

 

People can PM me if they have tips ( I suppose open post endorsments are against forum policy?)