35 lux pre-asph front focus

[astro8]

Hi again,

I recently bought a 35 summilux pre-asph and had it sent from the seller straight to Youxin for cla along with a 50 rigid cron and a 90 elmarit.

Once I received them from Youxin, I tested them out on my R-D1. The cron and elmarit are smooth and focus seems spot on but the lux is very stiff in focus. What's worse is that it is front focusing way in front. If I focus at minumum distance, approx 1000mm, the focus is at around 850mm, but very sharp.

I contacted Youxin and told him the problem. he replied that it may always have been this way but the seller didn't notice it on film. The seller told me the lens was smooth, sharp and focussed spot on on the M2 he used, which I also bought.

Youxin said it sounds like it needs collimating and to contact DAG so I have sent an email and awaiting a reply.

I've since read a few stories around the web that the 35 lux has to be collimated or it can be appear very soft and front focus.

Does anyone have any experience with this or any advice?

I'm in Australia, is it best to send to DAG? I hear Malcolm Taylor in the UK does great work, is there someone closer anyone can recommend?

Thanks

 

[edftwin]

Did you try it on your M2? Get an inexpensive roll of film and test it out.

Some old lenses work accurately on film Leica M but not on digital, but i'm not sure for your case, worth giving it a try IMO.

The stiff focusing ring can be resolved by spraying a little bit of lubricant oil on the focusing module at the rear mount. I did it on all my old lenses which had stiff focusing issue and everything turned out smooth.

 

[astro8]

Thanks for the replies, looks like this lens will be off on another world trip...if only we all could be so lucky.

 

[menos]

Did you try it on your M2? Get an inexpensive roll of film and test it out.

Some old lenses work accurately on film Leica M but not on digital, but i'm not sure for your case, worth giving it a try IMO.

The stiff focusing ring can be resolved by spraying a little bit of lubricant oil on the focusing module at the rear mount. I did it on all my old lenses which had stiff focusing issue and everything turned out smooth.

DON'T do that!

Oil has nothing to do on that lens!
the pre ASPH Summilux is not an easy lens, to get adjusted, to focus very lightly as of it's internal construction, comprising of total two helicoids and another two surfaces, running against each other.

The correct choice of lubricant (NOT OIL) and a correct adjustment of the lens is needed.

The optic does indeed inherit a focus shift, which can be optimized for your preference (wide open, close up or at medium distances, or, …).

I would personally prefer a setting, where the lens focusses wide open spot on @ 1.5 m and compensate for a slight front focus @ shorter subject distances by moving your body slightly after focussing.

My Canadian pre ASPH Summilux focusses super smooth after rebuilding the focus module and modifying for use on digital Leicas, but it will never be as light to the touch as it's later ASPH follow up as of the mechanical design differences (there is almost no resistance in the focus tab with my Lux ASPH).

 

[__hh]

Have you considered an Australian technician to avoid costs/delay/international postage?

I got my 35mm pre-asph serviced/CLA'ed at http://www.cameraelectronic.com.au some time back (if I remember correctly) - drop them an email at repairs@cameraelectronic.com.au

They also offered a full dis-assembly/rebuild service to the lens at that time, but I did not take up the offer.

Good luck.

 

[astro8]

Thanks for the advice menos and thanks for the links hunghang...I'll send them an email.

This thing is way too stiff. Stiff enough that the pressure to move the focus tab moves the camera as I'm trying to hold it to my eye.

It's front focusing way, way in front...if I focus at something 5 feet away it's very sharp at 3 feet.

I'll let you know how I get on...

 

[Erik van Straten]

.

This thing is way too stiff. Stiff enough that the pressure to move the focus tab moves the camera as I'm trying to hold it to my eye.

It's front focusing way, way in front...if I focus at something 5 feet away it's very sharp at 3 feet.

Is it a chrome or a black lens? The chrome ones are usually more stiff to focus than the black ones.

The front focusing suggests that the lens has been put wrongly together. The focussing helical is put back wrongly after it was dismantled, I guess.
Send it to a good repairman.

Erik.

 

[Lflex]

It's front focusing way, way in front...if I focus at something 5 feet away it's very sharp at 3 feet.

Natural focus shift is characterized by the fact that you can focus correctly at one aperture, and the plane of focus changes when changing aperture. Typically the lens would be adjusted wide open and would exibit the problem until around 5.6~8 where DOF would make up for the problem.
It sounds like you lens is way too much off for the error to be attributed to the natural focus shift of the Lux35, but you may want to specify to the repair person at which aperture you wish the lens to be adjusted.

(for more about the pros cons and considerations you can search this forum for threads about the 50mm Sonnar ZM)

 

[Lflex]

OT Lux35 pre asp focus shift

OT Lux35 pre asp focus shift

OT, this subject made me think why you don't hear people complain all the time about Lux35 pre-asp focus shift, but focus shift is mentioned over and over again in every thread when the subject is the Nokton 35/1.4? After all, the Nokton attempts to emulate the Lux35 and thus shares the inherent weaknesses of this particular compact design.
I recall reading a psychologist mention that the more you pay for something, the less likely you are to complain about flaws because the more mentally set you are that your decision must be right. That would explain why the Lux 35 pre-asp is a legendary lens, The 50mm Sonnar ZM may have a slightly annoying focus shift but it is hardly worth mentioning as it is compensated by loads of wonderful character and the Nokton is merely a piece of cheap junk 😉

 

[Phil_F_NM]

Is it sharp at infinity?
It sounds like the optical module is threaded one whole rotation out from the helicoid. That is just under 1mm and might equate to a focus mis-calibration yielding the front focus you get at the closest range.
If it focuses to infinity currently and is sharp then you probably have something wrong.
While I'm not encouraging you to take your Summilux optical module out of the helicoid to see if there is a superfluous shim in there, doing so won't be any worse than where you are now. The optical module may also need to be screwed in a full rotation more. The threads are aluminum on brass and can get very tight. If this is the case, it's an easy fix with a grippy rubber pad and something like an old bicycle inner tube. Be careful though and if you're uncomfortable messing with the lens it would be best to send it out.
The stiffness of the helicoid comes from the lube having too much shear force. It's supposed to be a very light grease. Oils will usually cause it to feel much stiffer than it should.

My early V2 Lux (with infinity stop) front focuses less than 1cm at close focus wide open.

Phil Forrest

 

[menos]

Is it a chrome or a black lens? The chrome ones are usually more stiff to focus than the black ones.

The front focusing suggests that the lens has been put wrongly together. The focussing helical is put back wrongly after it was dismantled, I guess.
Send it to a good repairman.

Erik.

Erik, putting this lens back together wrongly just by one thread in a wrong position results in totally off focus, like a few meters off. It would nowhere near seem to focus correctly.

Difficulties and potential faults in assembling this particular lens lay elsewhere. The pre ASPH Lux is very sensitive to the correct grease, or it will feel sticky, rough or even impossible, to move.

It is very sensitive in setting it's set screws (and locking them with the correct amount and correct material with the correct strength).
I would rate the pre ASPH Lux a lens, beginners, who are not confident, not to open and work on themselves.

 

[astro8]

Thanks for the replies...

Erik, it's a black lens, very early type2.

Lflex, I'm going to follow menos' advice and tell the repairer I want it to focus spot on wide open at 1.5m.

Phil, something is loose as I can rotate the front of the lens back and forth when it is mounted on the camera. I unscrewed the optical module from the focusing mount, everything looks in order but obviously it is not.

Menos, I'd love to pull this thing apart!...but, yes, I've read this 'lux is very finicky to set right. I'm awaiting a reply from a repairer here in oz but I'm probably better just sending to DAG to set it right and start using it on the newly aquired M2 that it came with and my R-D1.

 

[menos]

1.5m would be my preferred "most working distance" with the 35mm, but your preference might vary.

If you have another 35mm, just shot a while and find out, where you end up most shooting at, and if it is shot wide open at that distance.

Some people would constantly use the minimum focus of a 35mm lens (mine is ~ 0.9m) - for them, optimum setting might be, to have it focus correct at minimum focus and off in the medium range wide open.

Having the front group rotating sounds not normal ;-)
Have it shipped to a reputable specialist and set up properly - you will love this lens - I love mine after having it fixed - this is SOOOOOOO tiny ;-)

 

[RichC]

I have a Summilux pre-aspherical 35 mm that misfocused...

Most Leica lenses I've bought that have been from the 1970s and earlier have misfocused on my Epson R-D1 and (later) Leica M8 - and I know the cameras were fine.

My theory is that the problem results from age/use, and looser tolerances for film compared with digital. Lenses may well have misfocused for decades but may have gone unnoticed since film users rarely see their photographs large, as do digital users.

When buying an old lens I alway assume it needs servicing. Even if the focus is fine, there are usually other problems like dried-out lubricant and loose controls.

Malcolm Taylor services my lenses in the UK, and has agreed with my thoughts. He tends to ensure lenses focus accurately close up, leaving any variances in focusing arising from the optical design of the lens to occur at longer distances where it is unnoticed because of the wider depth of field.

My 1969 Summilux 35 mm lens focus was way out when I bought it. After Malcolm Taylor serviced the lens, the focus is spot on at all distances. Also, the control rings came back "just right" - not too tight, not too loose.

 

[astro8]

After trying to get someone over here to respond to my emails the lens is now with Don at DAG.

In his own words..."Greg, this Summilux 35 lens is all messed up"...."it's a mess"..."this lens needs to be taken all apart, completely overhauled & then re-assembled correctly"

So much for the 'cla' it received.

I suppose you get what you pay for...

 

[astro8]

Don's finished a complete overhaul of the lens and it'll soon be on it's way back to Sydney. That was fast!

I'll let you know how it feels and what it focuses like once it gets here.

The info may help others now and in the future.

 

[t.s.k.]

Wow, 2 weeks from DAG?
Is this his turnaround now?

Congrats on a getting a great lens to work again. Enjoy.

 

[astro8]

Wow, 2 weeks from DAG?
Is this his turnaround now?

Congrats on a getting a great lens to work again. Enjoy.

No, he's only had it a week!

He told me that most people don't include a 'cover letter' with their item stating what they want done and when they need it returned, so I s'pose it just sits there...

 

[astro8]

Finally received the 35 lux back from DAG after 2 weeks in the postal system.

Smooth as silk, spot on focus and clear as crystal.

Now to send Don my M2 for another cla and rangefinder fix as one minute I was looking through it focusing and the next thing I knew the patch disappeared! I haven't even shot a frame with it.

I've just paid Youxin to replace the mask with 'MP upgrade' and to cla it.

Not happy.

 

[menos]

I think, you should contact Youxin Ye first, as the failure might or might not be connected to the work done.
This much seems fair, I guess.

You seem to have a bit of bad luck though.