Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
10-26-2019, 08:44 AM   #1
Site Supporter
Site Supporter
Nick Rowland's Avatar

Join Date: Oct 2019
Location: Eastbourne, Sussex, UK
Posts: 28
Carl Zeiss Jena Tessar 50/2.8 Zebra Problem

Hi all,

Does anybody have detailed experience of repairing a Carl Zeiss Jena Tessar 50/2.8 Zebra M42 please? This came to me with sticking aperture blades and a loose focus ring. The lens was very oily/greasy from someone else's botched previous attempt and the blades were flooded. I have sorted that but can't stop the focus ring loosening. If you look at the image the focus ring is secured by a notched spanning wrench ring (the outer notched ring). When I tighten the ring and then turn the focus it loosens again and repeated movement of the focus ring just undoes the the ring. I am reluctant to use more than a smear of oil on the mating surface for obvious reasons.

It is almost like there is a thin slip ring missing or the notched ring needs to have thread lock to stop it moving. This type of lens is new to me and I haven't stripped one before. I have looked at a schematic which suggests there isn't a part missing but I can't work out how to stop the ring unscrewing :-( .

Anyone know the answer please?

Thanks Nick

Attached Images
View Picture EXIF
X-E2  Photo 
10-26-2019, 02:02 PM   #2
PJ1
Site Supporter
Site Supporter
PJ1's Avatar

Join Date: Jul 2012
Location: Mosquito Creek, Australia
Photos: Gallery | Albums
Posts: 3,769
I have two of those and both could do with a helicoid lube job (one day). Anyway, I googled "disassemble and clean tessar 50mm f2.8"and got more than I needed. One site looked like it might have the answer. In it he refers to a locking ring being sealed with a small dot of varnish. So maybe locktite is the way to go:

Carl Zeiss Jena 50mm f/2.8 strip down and clean ? Simon Hawketts' Photo Blog

Let us know how you go.
10-27-2019, 12:16 AM   #3
Site Supporter
Site Supporter
Nick Rowland's Avatar

Join Date: Oct 2019
Location: Eastbourne, Sussex, UK
Posts: 28
Original Poster
Thanks PJ, I had read that article buy completely missed that comment, probably because it was referring to a different ring and I didn't make the connection. Yes, if one ring was secured by a dab of varnish, others might have been too. I'll try 4 dabs of varnish (it's a big ring) and see what happens.

Cheers
Nick
10-27-2019, 08:18 AM   #4
Loyal Site Supporter
Loyal Site Supporter




Join Date: May 2016
Location: East Coast
Posts: 2,350
Not uncommon to find a dab of I believe shellac to lock threads from original assembly when taking apart old lenses. Some clear nail polish will work just fine. If you use Loctite, make sure to use the weakest formula - don't use the red.

10-27-2019, 08:41 AM   #5
Site Supporter
Site Supporter
Nick Rowland's Avatar

Join Date: Oct 2019
Location: Eastbourne, Sussex, UK
Posts: 28
Original Poster
I've looked through a loupe at other threads and I can see signs that it has been used before. I'll do the same I think, I tend to use clear nail varnish and it has worked before.
10-31-2019, 07:45 PM   #6
Loyal Site Supporter
Loyal Site Supporter




Join Date: May 2016
Location: East Coast
Posts: 2,350
QuoteOriginally posted by Nick Rowland Quote
I tend to use clear nail varnish and it has worked before.
Nice and easy and readily available.

11-20-2019, 08:05 AM   #7
Site Supporter
Site Supporter
Nick Rowland's Avatar

Join Date: Oct 2019
Location: Eastbourne, Sussex, UK
Posts: 28
Original Poster
Just a follow up, it was all sorted with a couple of small blobs of nail varnish and working fine. Only small issue was setting the infinity focus point but that doesn't take long.
11-21-2019, 08:02 PM   #8
Site Supporter
Site Supporter




Join Date: Nov 2015
Photos: Albums
Posts: 1,782
So do we get to see it all back together?

-Eric

11-22-2019, 02:42 PM   #9
Site Supporter
Site Supporter
Nick Rowland's Avatar

Join Date: Oct 2019
Location: Eastbourne, Sussex, UK
Posts: 28
Original Poster
QuoteOriginally posted by TwoUptons Quote
So do we get to see it all back together?

-Eric
Here you go, a poor phone pic but shows the finished article. Have another to do now.
Attached Images
 

Last edited by Nick Rowland; 11-22-2019 at 02:48 PM.
11-22-2019, 04:33 PM   #10
Site Supporter
Site Supporter




Join Date: Nov 2015
Photos: Albums
Posts: 1,782
QuoteOriginally posted by Nick Rowland Quote
Here you go, a poor phone pic but shows the finished article. Have another to do now.
Itís a cool look. I like it. Thanks.

-Eric
11-23-2019, 02:16 AM   #11
Site Supporter
Site Supporter
Nick Rowland's Avatar

Join Date: Oct 2019
Location: Eastbourne, Sussex, UK
Posts: 28
Original Poster
It performs quite well and was a popular lens in its day. The problem with most of them now, is the helical grease has gone hard and the focus stiffens right up. Folk then squirt thin oil in to free up the focus and the oil sooner or later ends up on the aperture blades.
11-30-2019, 08:25 PM - 1 Like   #12
Loyal Site Supporter
Loyal Site Supporter




Join Date: May 2016
Location: East Coast
Posts: 2,350
Looks nice. Always satisfying to have them back together and working.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
blades, carl zeiss jena, focus, jena, lens, pentax service, repair, service, tessar, tessar 50/2.8 lens, tessar 50/2.8 zebra, warranty, zebra, zeiss, zeiss jena tessar
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Fixing (keeping?) Carl Zeiss Jena Tessar 50 f2.8 w/ frozen focus ring mgvh Troubleshooting and Beginner Help 5 06-11-2017 02:09 AM
For Sale - Sold: Carl Zeiss JENA DDR Tessar 50/2.8 (M42) [Reduced & Free Shipping] ripper2860 Sold Items 2 07-27-2015 07:55 AM
carl zeiss jena tessar 50mm f2.8 problem kh108 Troubleshooting and Beginner Help 8 01-03-2012 04:07 AM
For Sale - Sold: Carl Zeiss Jena Flektogon 20mm/4 and Tessar 50/2.8 Zebra style lenses farfisa Sold Items 3 10-09-2009 11:51 AM
For Sale - Sold: Carl Zeiss Jena Tessar 50mm/2.8 M42 Zebra style farfisa Sold Items 1 07-08-2009 05:15 AM



All times are GMT -7. The time now is 08:43 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top