I've got one of these in truly awful condition physically. The ring holding the front element is so loose I can pull it away from the front element, it badly needs some grease in the helical and infinity focus needs to be reset. Since it's in such bad shape, I thought I might have a try at getting it back in functional service before paying someone else to do it since I'm handy (and an Engineering student so crazy that way). I've had it partially disassembled already.
So a couple questions:
How the heck to I tighten up the front ring once I have the optical group out of the focusing helical?
Any recommendations for grease? Needs to handle the weather in Canada (-30 to +30C)
What's the best way to adjust infinity focus on these? Or is it just trial and error in reassembling the helical.
1. Get a spanner wrench.
2. Grease is a catch-all. They say to get a synthetic grease because of out-gasing from the petroleum products. Most synthetic greases I've tried are too thick and make movement stiff. The acceptable one is a syntehtic grease that works great, but costs $30 for a very small amount.
3. If you take it all apart, it will be apparent how to adjust the infinity focus.
Infinity focus:
Open up the lens wide open. Tripod, mirror lockup, 2 second delay. Target truly at infinity, like telephone pole, mile or two away. Take shot, import to LR, 100% crop or 1:1 crop.
You may have to unscrew the adjustment screws to get the lens past infinity, then turn back incrementally, until the view does not get any sharper. Then, loosen the screws and turn the focus ring to “infinity” setting and tighten the screws. Done.
Huh? in all the versions I've disassembled, the front group is cemented solid! No way the front-most element could be loose... (?) I've had three of the four version on my bench now. If my memory serves me right, the one missing is the German MM version, made in only a few copies before transferring the manufacturing to Kyocera completely.
If by "front ring" you mean the front cover-ring that sits mounted in the filter-thread (with the Zeiss 50 text on it), then you use something round with lots of friction to unscrew it. Actually, the back surface of the rear lens-cap with some strong double-bond tape is just about perfect in size. Try finding the thick white db tape that carpenters use in stead of glue when fixing floorings...
Beneath this, the front group is press-fitted to the central barrel of the lens. If your front ring is as loose as you say, the front group will have moved forward a bit, ruining your sharpness and making infinty focus impossible. Please post a picture if you can, that would help...
I use a synthetic Molub-Alloy grease that probably is impossible to find if you don't have good connections in a large mechanics service center. I'll ask the "slick guy" that handles the lubrication/oil department for equivalents next time I see him.
The front group seems solid, its the ring that's loose. I'm glad to hear the ring is not holding the group in, I was worried it would fall out.
As to infinity focus, the issue is almost certainly improper assembly, I've had the lens disassembled to the point the optical group was seperate from the mount section and the focusing helical. I'm pretty sure I reassembled it off from proper infinity. I guess I'll just have to reassemble it by trial and error. I do get inifinty by the way, and it seems sharp, its just focusing past infinity as well.
-Adam
theSuede wrote:
Huh? in all the versions I've disassembled, the front group is cemented solid! No way the front-most element could be loose... (?) I've had three of the four version on my bench now. If my memory serves me right, the one missing is the German MM version, made in only a few copies before transferring the manufacturing to Kyocera completely.
If by "front ring" you mean the front cover-ring that sits mounted in the filter-thread (with the Zeiss 50 text on it), then you use something round with lots of friction to unscrew it. Actually, the back surface of the rear lens-cap with some strong double-bond tape is just about perfect in size. Try finding the thick white db tape that carpenters use in stead of glue when fixing floorings...
Beneath this, the front group is press-fitted to the central barrel of the lens. If your front ring is as loose as you say, the front group will have moved forward a bit, ruining your sharpness and making infinty focus impossible. Please post a picture if you can, that would help...
I use a synthetic Molub-Alloy grease that probably is impossible to find if you don't have good connections in a large mechanics service center. I'll ask the "slick guy" that handles the lubrication/oil department for equivalents next time I see him.
