Zeiss 35/2 front focus repair

[brbo]

Thanks for your opinion, Roland. I disagree, though. Looking at the first shot, do you really find intended plane of focus within DOF?

I have Bessa R3A. 1:1 viewfinder magnification makes it really easy to focus. I really really doubt that I somehow can consistently correctly focus 40/1.4 and consistently miss focus on 35/2 (this is not some Sonnar after all). The longest lens I've shot (very briefly, though) on this body is 50/2 Zeiss Planar with no problems. I know that previous owner of this R3A loved his 35/1.2 and 35/1.4 on this body among other lenses.

I did shoot Nokton @f2 in the above samples.

And, no, Nokton @f1.4 does not shift to front:

Shots with paper test chart were taken handheld with high enough SS (500 I think), I braced tripod (but not mounted the camera on it as I wanted to shoot in portrait orientation to help with focusing on horizontal focus line) for stabilization. The others were taken (multiple times, I'm only showing one as there is practically zero variance in focusing) at exactly 45deg and body mounted on tripod.


Can you link to or give more precise instructions on how to tighten 'span ring'? How hard a procedure is this for a person that never played with lens mechanics before?

Thank you!

 

[brbo]

But, on second thought. Roland might be right. Lens just might be within spec. Roland certainly thinks so.

Does any other reader of this thread think that I can put it for sale with clear conscience? How would you describe the lens? Focusing/sharpness wide open perfect? Within specs?

 

[thegman]

I don't know about whether this lens is OK or not, however I've had a great experience with Zeiss Germany, they fixed my ZI for no cost, even though I fully admitted the salt water damage was of my own making. They were great for me, and not terribly slow either. The fact they did not charge me was just the icing on the cake. I have nothing but good things to say about Zeiss service.

 

[ferider]

I'm not saying the lens is perfect, just that the error is within your measurement error, brbo, and that if your Nokton, your Bessa or your Biogon are off (and it can be either of the three), it's within normal variations that you can expect from CV (manufacturer of all three items). You can only get closer to perfect via minuscule adjustment, and have to measure the result very carefully. You also have to decide what you want, for example, do you want your Nokton to be perfect at f1.4 or at f2 ? How does infinity look, etc. Fine-tuning a system to that degree (if you need it) is a lot of work.

If you look at your tests like this:

To my eyes:

1) the Nokton does shift (from 23 to 24cm?) (mine would do the same, BTW).
2) the Biogon looks pretty good within the error of this test.

As a parenthesis, adjusting a system to be perfect in the center of a DOF window might not even be desired. A 1/3rd / 2/3rd optimization might be more useful in practice.

Don't have a Biogon here, if you can take a picture of the rear of the lens, I can show you where the span ring is.

Best,

Roland.

 

[Nigel Meaby]

I think it's a bit drastic to consider selling it due to this. I can understand how you may now have a bad feeling about the lens but whether it is in spec or out, if it's checked over by a competent technician it can be adjusted if needed, and will serve you well for many years. If it has a problem it's a minor one. Maybe as Thegman says, get in touch with Zeiss first and see what they suggest. They are well aware that some of their lenses suffer from wobble problems. I mentioned having talked with Malcolm Taylor about Zeiss lenses and he had identified the problem when working on some lenses and had advised Zeiss on a solution to the design fault.
So you may get the repair for free but even if it does costs you to get it repaired, you should then have years of use from a very good quality optic, comparable to the Summicron Asph, at a fraction of the price.

 

[rlouzan]

Interesting, I thought that the V2.00 focus test chart was intended for SLR/DSLR use only.

 

[sanmich]

Another thing to think about:
You are assuming that your camera is ok based on one lens.
I'm not saying it's wrong, but there are variations and the only way to be almost sure the lens is at cause is to have a bunch of lenses saying the same thing and one "disagreeing".

More important:
How many times did you repeat the experiment while refocusing?
Did you repeat it by focusing from one side alone or from both direction?

Our eyes are not perfect. Your focusing technique itself has its own limited precision.

all that being said, I agree with Roland:
Tightening back whatever is loose will probably set you back in specs.

 

[Landshark]

IMO, at 700 Euro/$1,000.00+ The argument that the lens became defective in shipping is hard to swallow. I know things can and will loosen in shipping but to say the lens was damaged? Please.
Were I the seller, any of the three solutions the OP made would be acceptable AND I would allow the buyer to make the choice of which solution.
I believe the seller should make it right.
That's me though.

 

[jenhao]

Brbo,

I think you were absolutely correct to simply "move on" and focus on how to fix your lens. Sorry this thread brought up old issues regarding the seller and who is to blame. So.....what to do now?

Mark

 

[horosu]

I have had a great experience with Zeiss customer service: focus on my newly acquired C-Sonnar was a little stiff. The lens was under warranty so I sent it in. Not only did they adjust focus, they also adjusted the lens for perfect focus at f1.5 and sent it back via UPS free of charge 7 days later.

I was very impressed and would gladly recommend them.

 

[brbo]

> 1) the Nokton does shift (from 23 to 24cm?) (mine would do the same, BTW).

It does not. 24 is sharpest at both apertures.

> Interesting, I thought that the V2.00 focus test chart was intended for SLR/DSLR use only.

How would a rangefinder target look like? It's childs play to focus this target with a rangefinder. Even more so in portrait orientation as I did.

> More important:
> How many times did you repeat the experiment while refocusing?
> Did you repeat it by focusing from one side alone or from both direction?

Yes. I did that. And I'm not just saying that now. Seller can confirm that I described my focus testing technique and provided corresponding shots to him. I did from infinity, from MFD and standard 'back&forth'. I would consider myself able to perform a front/back focusing test. I wouldn't dare judging sharpness of a lens as millions of on-line photographers so vehemently do, but I would dare judging focusing accuracy. In DSL world front focus like this in a plastic 35/1.8 150 EUR lens would be branded as nothing less than horrible.

> I don't know about whether this lens is OK or not, however I've had a great experience with Zeiss Germany, they fixed my ZI for no cost, even though I fully admitted the salt water damage was of my own making. They were great for me, and not terribly slow either. The fact they did not charge me was just the icing on the cake. I have nothing but good things to say about Zeiss service.

That is really great to hear. I think I'll just send it to Zeiss and if it comes back and still out of sync with my rangefinder I don't think I'll have a problem selling it for a fair price with an official Zeiss Germany certificate.

Thank you all. I'm glad that everyone thinks this really is an easy problem to fix.

 

[pmu]

Brbo,

I think you were absolutely correct to simply move on and focus on how to fix your lens. Sorry this thread brought up old issues regarding the seller and who is to blame. So.....what to do now?

Mark

My curiosity made me to come back and I just wanted to add something that I forgot to mention in my original post:

You people do not know all the facts how our deal went. There happened something unusual in the procedure of doing business and it caught we with a big surprise to hear back from him. I appreciate that the buyer was not going to mention who he bought the item from. I am also not going to tell any details about anything... I feel genuinely sorry that this mess happened. If I seem to be the bad guy, I guess I have to deal with it.

Brbo, like I told you, the repair who I consulted told that this kind of adjusting is just a standard procedure to pretty much every camera service... His rate: "...few tens of euros, max.60€".

Now, I will stop following this thread. I hope you will get it fixed cheaply.

 

[brbo]

> You people do not know all the facts how our deal went. There happened something unusual in the procedure of doing business and it caught we with a big surprise to hear back from him.

I said 'water under bridge', errr... But I still feel like I'm, again, forced to present my side of story. The seller is talking about 11 days that took me to communicate my final observation (front focus) about the condition of the lens. I did tell him about the wobble and focusing ring play the next day I got the lens. And I said that I'm fine with that if lens is optically ok and that I'll let him know about that. Now, I can't have film developed and scanned in one hour. My local lab usually does it in 3-4 days. So, first roll (only had 2 cheap Superia 200 rolls at that time) came back really soft. Ordered Kodak Ektar online (I didn't want upsetting the seller after only seeing only one roll of cheap film with random snaps), waited for it to arrive (shot the second roll of Superia in the mean time - shooting improvised "GhettoLensAlign target" I posted here), then shot Ektar (some 'real' pictures and paper focusing taget). Again, waited to have my film developed and scanned. Notified the seller the same day I got the scans. 11 days. Seller then went on about how he personally would do it in 4 hours and that if I had notified him within 1-2 days he would happily take the lens back.

I guess I really was just unlucky with all this unfortunate sequence of events, wasn't I. 🙂

 

[rlouzan]

Your lens just needs to be tightened! Just send the repair bill to the carrier.

My usual procedure is to check lens accuracy with a 8x Magnifier + focusing screen on a test chart. No offence, your system is a bit like using a TLR paramender (been there, done that).


> Interesting, I thought that the V2.00 focus test chart was intended for SLR/DSLR use only.

How would a rangefinder target look like? It's childs play to focus this target with a rangefinder. Even more so in portrait orientation as I did.

 

[brbo]

> Your lens just needs to be tightened! Just send the repair bill to the carrier.

Roland showed me the spanner ring and it's tight. Very tight.

> My usual procedure is to check lens accuracy with a 8x Magnifier + focusing screen on a test chart. No offence, your system is a bit like using a TLR paramender (been there done that).

Now I'm interested. So, parallax correction only works for framing and not focusing? The rangefinder position on R3A and the position I held the body (shutter button down) would actually push the plane of focus to the back not to the front, wouldn't it. How would parallax explain front focus (of about 20cm) at 3m distance?

If the focused spot was not marked in the picture, where would you place the focus plane in this shot (would you say it's within DOF):

pic


I get by without paramender on my Mamiya C220, but never knew that rangefinder photographers compensate for parallax with fast lenses even on parallax corrected rangefinders. Huh, you live, you learn...

 

[rlouzan]

The chart is printed on A4 paper. You are shooting a mosquito with a shotgun🙄. Get a bit closer to the target ,and you you might end in another state. Now do you get the joke?
😀

> Your lens just needs to be tightened! Just send the repair bill to the carrier.

Roland showed me the spanner ring and it's tight. Very tight.

> My usual procedure is to check lens accuracy with a 8x Magnifier + focusing screen on a test chart. No offence, your system is a bit like using a TLR paramender (been there done that).

Now I'm interested. So, parallax correction only works for framing and not focusing? The rangefinder position on R3A and the position I held the body (shutter button down) would actually push the plane of focus to the back not to the front, wouldn't it. How would parallax explain front focus (of about 20cm) at 3m distance?

I get by without paramender on my Mamiya C220, but never knew that rangefinder photographers compensate for parallax with fast lenses even on parallax corrected rangefinders. Huh, you live, you learn...

 

[brbo]

> The chart is printed on A4 paper. You are shooting a mosquito with a shotgun. Get a bit closer to the target ,and you you might end in another state. Now do you get the joke?

No. Nothing should be photographed from 1m distance? I really don't know what you are trying to tell me. 🙁

 

[bobby_novatron]

Sorry to hear this has happened -- to all parties involved. As mentioned ealier, one of the things that all of us here like to believe is the issue of trust between RFF members. I have bought several items on eBay and felt disappointed, but I have never bought anything on RFF and felt like I got a bad deal -- quite the opposite.

brbo -- good luck with your lens repair / adjustment. The Zeiss 35/2 is a fantastic lens. I'm sure that once yours is working the way you want it to, you will be 100% happy with it.

 

[rlouzan]

Hi,

Look, I don't think the seller acted in bad faith.
Zeiss/VC lenses are optically outstanding but not as good as Leica mechanically. I bet the lens became defective in shipping ,and the carrier should be responsible for the repair bill.

As for the chart ,it's not easy to take a picture of a sheet of A4 paper at 1m with a RF - just that.

Hope it works out for you.

Regards,
Robert

 

[Ranchu]

> The chart is printed on A4 paper. You are shooting a mosquito with a shotgun. Get a bit closer to the target ,and you you might end in another state. Now do you get the joke?

No. Nothing should be photographed from 1m distance? I really don't know what you are trying to tell me. 🙁

I don't get it either.