Replacing rear group of elements on Sonnar 150 C

[fotoroberto]

I have an Sonnar with slightly etched (not too serious) rear lens.
Now, I have an opportunity to get an non working Sonnar with fine rear lens group. Should I get it and replace the ones on my lens ?
I am afraid that the lenses are corrected for each individual Sonnar at factory, and that it won't be good to just replace them inside.
Any facts about it...?

Thanks in advance

 

[Daniel Unkefer]

Ask David Odess who is the repair expert I use. I bought a black T* 150mm F4, turns out the rear mount was impact damaged beyond repair. David replaced the entire rear mount, new parts were not available, but the overall price was very reasonable.

The 150mm F4 is a killer workhorse lens. One of my favorites.

 

[polypal]

Roberto,


Zeiss lenses do allow simple exchange of elements like a rear lens or lensgroup.
If the price is right buy the "donor" lens and replace or have the rear elemt replaced.

I just ordered some rear lenses from Carl Zeiss.
Exchanging damaged elements can be done in a couple of minutes.
It pays to check the lens with new or other used lens element with a collimator.
That instrument also allows a correct adjustment of the lens for infinity.


Paul

 

[fotoroberto]

Good to know, although, Hasselblad repairman in my town is telling me that it is not possible or advisable, because they are made and corrected per unit.
I suspected it is not entirely the truth, but you'll never know...

 

[polypal]

Ask your repairman if he believes Carl Zeiss are selecting lens elements during production for each lens they produce.
Of course that is not the way they operate with an exception for lenses that need to meet ultra high standards like MK versions of the 100 MM Planar.
All critical parts of these MK lenses are matched to improve the results of an already excellent lens.

Maybe a good idea to look for another repairman?

 

[fotoroberto]

I see your point, it is my opinion exactly; no way that they select their lenses individually in serial production...

Unfortunately, he is the only one qualified for the job here in Zagreb, Croatia, and he has spare parts for Hassies... but anyway, I'm waiting to see how will he do the job on my 500cm, and cleaning/repairing that Sonnar.

Good to know that I can put that rear element group on my lens...

Thanks

 

[polypal]

Besidesthe fact that a lens with a spotless rear element may give better images it certainly gives the user a good feeling that he succeeded to have the problem corrected.
Using a lens that was upgraded with a new part gives a lot of fun.