MS-optics - Perar - fault?

[Cagger]

I've just obtained a Perar 28mm.
It seems to be in new condition - but - there seems to be some problem with focussing.

When I first put it on and trying to focus on an image a couple of meters away, the infinity focus - according the rangefinder patch was at the 0.8m mark. -. Moving the lever would then move the image in the patch - into focus at about 3 meters and then at close focus near the infinity mark. - So focussing in reverse.

Inside the lens there is an inner body of it which swivels - and I kept on moving that into different positions and refitting the lens - getting different focussing results until I eventually got something which seems to be right - in terms of the focussing marks and the patch - although I haven't taken any pictures to see if it is operating correctly.
I can't understand what is happening and I can't see any pattern to it.

Does anyone have any idea how it all works?
Even now, as you get towards the infinity stop, there is some resistance - and it seems to need a bit of a push to get it to focus. I don't think that one should be pushing or forcing these precision items.

 

[Ranchu]

I've never had one but what you are describing should never happen.

 

[Cagger]

Thanks for the response. There is definitely a fault.

I am certainly going to try and contact him and take some advice about it

The arrow indicates the inner ring which spins around freely. I'm sure that it should only turn as the lens turns.

 

[Cagger]

What I'm not looking forward to is having to return it and then having to convince customs that it really isn't an import and that I don't have to pay taxes on it.

It's a real nuisance.

 

[Jockos]

What I'm not looking forward to is having to return it and then having to convince customs that it really isn't an import and that I don't have to pay taxes on it.

It's a real nuisance.

In my country, I send the dialogue with the repairman as proof, and also have them mark the box: returned from repair. Worked every single time, YMMV.

 

[nongfuspring]

It's not that big a deal, just tick the correct box on the customs slip. The MS optical lenses are handmade individually by one guy, not a factory production line. Occasional human error is a small price to pay for such an unusual lens.

 

[Cagger]

I didn't buy it from him. It came from an eBay seller who described it as mint and fully checked and functioning.

It certainly is in mint condition. Almost new - but it isn't functioning very well - and if it was checked - then it wasn't checked very well.

 

[Cagger]

In fact - the inner ring has just fallen out!!

I'll post pictures and describe later on.

 

[Cagger]

OK - the inner ring dropped out. It turns out that it is screwed into the lens body. So far as I can see, the lens is calibrated is by screwing the inner ring to a point where the patch alignment is true.
However if you don't screw it in so that it tightens at the end, then it remains loose and can drop out. On my copy, if you screw it in to the end then the patch won't align at infinity. The bizarre thing is that it actually needs to screw in further than it is able to: infinity is beyond its maximum.

There seems to be no way of fixing the inner ring if you want to calibrate it at a point before it tightens ...
... except I notice traces of something like dried glue. Can it really be that you screw the ring into to a point where the lens is calibrated and then you fix it there with glue????

There are two tiny holes in the ring - at opposite sides. I don't know what they are. I am sure that they are too small to take a grub screw.

 

[Monochrom]

hi, i had for some time an apoqualia.

it ahppend that from time to time the scale ring got lose and then the marks wouldn´t fit the actual patch.

It produced the lens miss focus, so what i did was to set everything to infinity, check pics and tighten up the screws

Perhaps it´s something like that.

Good luck!

🙂

 

[Cagger]

Thanks. The only problem is that there are no tightening screws on it.

The only thing you can do is to try and tighten it the ring into the body as much as possible.

However, I found this very detailed article - http://www.japancamerahunter.com/2012/08/ms-optical-rd-apoqualia-perar-by-lars-goran-hedstrom/ which includes a comment -

One note; At first focusing won’t go to infinity. It’s due to a heavy greased helicoid thread. It’ll settle very quickly when using the lens.

This certainly is a very new-looking lens - despite the fault in it. Maybe that is the problem.
The focus lever is certainly very soft against the infinity stop.

 

[Pioneer]

The inner ring on my Sonnetar loosened up. I sent mine back via Japan Exposures and had it back in about two weeks with everything fixed up. No charge. Had no trouble whatsoever with customs.

 

[Cagger]

That's good to know.

But why do these inner rings get loose - and what is it that get's it to tighten at the exact correct point so that it is calibrated>

 

[Pioneer]

I'm not sure why mine loosened up, I didn't ask. Mine may have had a completely different cause. I kind of suspected I may have done it myself while fiddling with the coma ring on the backside.

I do know this however. I own the Sonnetar 50/1.1, the Sonnetar 25/1.1 for Q, the ApoQualia 50/3.5 for LTM, the Perar Super Triplet 35/3.5 and the Perar Super Triplet 28/4 and have only had one small problem with the 50/1.1. And that was repaired quickly with no questions asked.

 

[Cagger]

I emailed Dirk at JE a few months ago on another query - and got a very helpful response back.

I emailed him again about 3 weeks ago and got no reply.

I emailed Bellamy about this Perar problem 2 days ago and got a reply yesterday.

I'll see what Bellamy says during the week. I'll call Will van Manen as well. It would be easier if it goes to the Netherlands.

 

[Cagger]

This is my guess as to what has happened.

It may be useful to other owners.

Looking at the back of the lens with a strong magnifying glass, I see that there is quite a lot of grease on the surfaces. This is a nearly new lens so it seems to me that as it is bedding in, excess grease is working its way out of the moving surfaces.
This is worrying because this is grease which could eventually end up on your sensor.
As the inner lens body moves round within the outer body, you can see grease moving - or being displaced through a minute gap between the mating parts. Are there bearings in there? If so, then what I see is grease being rippled as the tiny bearings travel along the ball race track. If there aren't bearings, then it is for some other reason - but the grease between the mating parts is clear.
I wonder if the lens has been over-greased during assembly? It certainly can't be a good thing having grease coming out - and I was able to collect a tiny drop of it on the end of a wooden toothpick.

At the bottom of the female thread in the outer shell there is a rim which mates against a corresponding surface of the inner ring (the bit which has fallen out).
When the inner ring is screwed into the shell, the two surfaces meet - and incredibly (to me) the calibration is only true when the inner ring is fully tightened into the shell so that the two surfaces are fully in contact with each other. If this is right, then there is no calibration adjustment. It is all or nothing - and this means that the parts must be machined to a very high level of accuracy.

What is it which ensures that the inner ring won't loosen? - because with constant focussing, there will be repetitive pressure applied against the inner ring which will eventually cause it to loosen - however tightly it has been screwed in.
I think that answer is that it is secured by a small drop of glue - some rigid LocTite.
In the case of my lens, now that the inner ring has come out, you can see the remnants of the glue on the surface of the rim of the outer shell.

I have tried to scrape it away with a toothpick - and it is too hard. However, I have noticed that the little remnant of glue is slightly proud of the surface.
This means to me that when one tries to screw the inner ring back into the shell, it is prevented by the glue remnant from seating all the home. We are talking tiny fractions here but it is enough to prevent the RF mechanism from focussing at infinity - and that is exactly what is happening here.

I don't know if it is right - but for me it provides a satisfactory explanation.

It may be that the lens was never true.
It may be that the LocTite fixing was tainted by over-greasing.

Anyway, I think that the lens has two problems. It is over greased - and too much LocTite was applied - or else it was not applied correctly.

I'm interested to see that someone else has a lens with an inner ring which comes loose. If you are able to tighten it back so that it focusses correctly then you probably don't have a build up of glue residue. However, the reason it comes loose is because the LocTite bond has failed.

I don't know if using LocTite is good engineering.

 

[Cagger]

This thread has been moved to Leica film cameras. Not sure why because it is also relevant to Leica digital as well. IN fact it is relevant to any camera which will take an M mount.

Still, I have had a very positive message from the seller of the lens offering me a partial refund - so that is very decent.

Bellamy has seen this thread and says that he agrees that there is an issue with this lens and has suggested I send it back to Japan.

Will van Manen of Kamera Service in the Netherlands has also read through this thread and he agrees that there is a problem. He says that he can fix it - and says that in 42 years, he has never found a lens which he couldn't repair.
My previous dealings with him have been excellent so I may send it back to him as it is less complicated keeping it within Europe rather than sending it to Japan - with any associated re-import problems.
I haven't decided yet. I am waiting for the seller to confirm the refund so that I will have funds for the repairs.

 

[back alley]

threads about lenses normally go into the camera mount it belongs to section…this is an m mount lens…m mount started with film cameras and then digital was added later.

 

[Pioneer]

Hope it all works out for you. Both of the Super Triplets are awesome little lenses. Not everyone likes them; as triplets they do tend to be a little soft in the corners when wide open, but I enjoy using them both.

 

[Cagger]

Thanks.

I receive a very sensible partial refund offer from the seller and now the lens has been sent off to Will van Manen http://www.kamera-service.info/index.php/en/ who does good work with quick and reliable turnaround.
I look forward to using the lens in the new year.