hilltime
Well-known
I have a Carl Zeiss 180/F2.8 Sonnar Zebra version which I've recently dug out to use on my latest acquisition, Pentacon Super. I recently obtained a M42 mount adapter for this lens and have removed the Exakta adapter which has been on it for 15+ years. Looking at it closely there appears to be some haze inside on an internal element and I'm wondering what the best way is to open this up, from the front element or getting into the rear?
If anyone has ever had one of these lenses apart, I'd appreciate any feedback as to the best way to proceed. I've opened a number lenses before to clean and have had good success most of the time, with an occasional disappointment. I know this lens had a bit of fog when I first acquired it, but it now seems a bit worse, even though stored in an A/C environment all this time. This was from my days of getting as many different focal length lenses for Exakta I could find 10-20 years ago as they were pretty cheap at that time. Have had a number of surprises as to how much some of them have gained in value in the marketplace because of classic lens use on digital.
Any experience would be appreciated..
Gary Hill
If anyone has ever had one of these lenses apart, I'd appreciate any feedback as to the best way to proceed. I've opened a number lenses before to clean and have had good success most of the time, with an occasional disappointment. I know this lens had a bit of fog when I first acquired it, but it now seems a bit worse, even though stored in an A/C environment all this time. This was from my days of getting as many different focal length lenses for Exakta I could find 10-20 years ago as they were pretty cheap at that time. Have had a number of surprises as to how much some of them have gained in value in the marketplace because of classic lens use on digital.
Any experience would be appreciated..
Gary Hill
Whether to proceed from front or rear depends on where the haze is exactly. Some of the optical groups will extract from the front, others from the rear. Potentially, you may have to extract optics from both.
The CZJ lenses of the era typically keep the focusing unit as a discrete module from which the optics may be detached without Eg upsetting the focus calibration. But there are exceptions. If removing retaining rings from the rear, take care not to upset the relationship between the focusing ring threads and the helicals, as, potentially, a lot of trial and error assembly and disassembly may be needed to restore this, if it's lost. The pieces will assemble in any number of thread combinations, but, only one of them will give you accurate focus.
Cheers,
Brett
hilltime
Well-known
That's Brett. Your comments are always well received. Sounds a bit more complicated than I had hoped for.
Thanks. Well, it might get involved, or not. Providing the helicals remain firmly secured to the focusing ring, removing the retaining rings for any optics, in itself, will not produce any drama. I've worked on a number of different CZJ lenses: both 58mm and 75mm Biotars; Tessars; Flektogons; Biometars; Pancolors; and probably a few more. But sadly, as yet not the 180mm Sonnar. I say "sadly", because I'd love one, myself.
Most of those as I alluded will dismantle in such a way that the optics can be separated from the focus module without having to split the helicals to get to them. But I learned the hard way when servicing my reasonably uncommon early 80mm Biometar in Praktina breech mount that sometimes the focus module connects with the optics in ways you don't anticipate. Yes, I got it all back together and working well, but it was a long night...
Also depending on the lens involved in some cases there may not be enough clearance for a spanner around the inside rear of a lens without first extending the helicals so far that they split. This gets you in the deep end immediately if you haven't been noting the precise positional relationship between the focus ring and helicals at the point they split. Obviously the helicals won't thread apart when the lens is fully assembled. But if you have already had to partially dismantle the lens by Eg removing its rear securing ring—if it has one—once the helicals screw past their keyway to the lens barrel, if they rotate with the focus ring, instead of being driven up and down the barrel by it, you're in all sorts of strife.
I would not be discouraged, if you are able to keep the focusing unit entirely complete and reach the optics you can get to, you may have a good result. If needed, post up some pics as you go along and I'll take a look.
Cheers
Brett
hilltime
Well-known
I will hopefully get some time this weekend to have a look. Again, thank you for your expertise. I also have an 80/2.8 Biometar for Praktina, but it is clean and doesn't need help. On the other hand, I did sent a Carl Zeiss 75/1.5 Biotar for Praktina out for a CLA, as I didn't want to mess this one up. Was very pleased with the result from Radu Lesaru in NY.
Regards,
Regards,
Nokton48
Veteran
Actually you might want to try this site. Used to be uber helpful, now sort of a ghost town. But your issues are nothing new. Good patient help is here
https://forums.delphiforums.com/kievreport
https://forums.delphiforums.com/kievreport