Home · Register · Search · View Winners · Software · Hosting · Software · Join Upload & Sell

Moderated by: Fred Miranda
Username   Password

  New fredmiranda.com Mobile Site
  New Feature: SMS Notification alert
  New Feature: Buy & Sell Watchlist
  

FM Forums | Alternative Gear & Lenses | Join Upload & Sell

1      
2
       3       end
  

Archive 2012 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (...
  
 
m-a-x
Offline
• •
Upload & Sell: Off
p.2 #1 · p.2 #1 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


I had all versions (that I know of) and the ring came off each time.
Once the entire rear group unscrewed, but from there one can then unscrew the last retainer ring.
Still, the result counts!
Looking forward to see your pictures.



Dec 27, 2012 at 09:29 AM
timballic
Online
• • •
Upload & Sell: Off
p.2 #2 · p.2 #2 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).




I think it's the same. You can see from the slight brass scratch (top left) that I need to shave a little bit more from one side of the ring. I painted everything shiny, matte black

I'll see if I still have Jim's notes to me.



Dec 27, 2012 at 09:35 AM
timballic
Online
• • •
Upload & Sell: Off
p.2 #3 · p.2 #3 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


These are Jim's notes to me.

"I remove the rear element housing ring and grind down the top half of the ring. This will give mirror clearance on some cameras.
I mark the 12 o'clock position on the rear element housing ring, and unscrew the ring CCW. It can be stubborn (mine wasn't), you need a spanner wrench. Leave the lens face down on a table and cover the rear element while you work on the ring. I made a jig that holds the ring while I use wet/dry sandpaper on a flat surface. I reduce the ridge on the top side only. That would be from 9 to 3 o'clock. Then screw it back on the lens."



Dec 27, 2012 at 10:06 AM
sebboh
Online
• • • • • •
Upload & Sell: Off
p.2 #4 · p.2 #4 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


wfrank wrote:
Well we must have different versions of the lens then. That ring does not come off easy, the full rear element group follows and thats why I kept it in place.


you, simply need to unscrew the rear group and/or hold it tight while you unscrew the retaining ring.

edit: maybe somebody can post the how to on the lens modification thread?



Dec 27, 2012 at 03:09 PM
ZoneV
Offline
• • •
Upload & Sell: Off
p.2 #5 · p.2 #5 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


helimat wrote:
I actually just removed the rear retainer, leaving the rear element in place and safely removed the material well away from any glass.


When I modified my Rokkor 58mm f/1.2 to Canon EOS 5D classic I took the retainer ring from the lens apart, to file it down. A Dremel seems for me much to fast for this delicate work.

I filed down the retaining ring to ~0.4mm thickness (for my two 5D classic) on the border that hold the lens:






Dec 27, 2012 at 03:38 PM
helimat
Offline
• • • •
Upload & Sell: On
p.2 #6 · p.2 #6 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


sebboh wrote:
+1

why do so many people keep trying to operate on their lenses with the glass right there?


It freaks me out too!

wfrank wrote:
Well we must have different versions of the lens then. That ring does not come off easy, the full rear element group follows and thats why I kept it in place.


Actually, I have done it both on the metal and rubber-gripped versions. A tool like this would work great, however the first time I made a tool out out a small piece of what I believe was .050" sheet aluminum. Leave the lens sitting face down and the rear element will stay in pace, the retainer will come off by itself for sure. Then I simply stuck a piece of adhesive-backed sandpaper on a bench and sanded it down. It took 10-15 minutes total at most.



Dec 28, 2012 at 01:19 AM
sebboh
Online
• • • • • •
Upload & Sell: Off
p.2 #7 · p.2 #7 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


Mescalamba wrote:
Well, Im sure that since you will sell it for half a price, someone will appear..

Just not me cause neither of my cams can take this beauty.


it's pretty easy to convert to sony fyi (which you have correct?). i know richard harris (in the UK) from this forum could do it for you if you really wanted.



Dec 28, 2012 at 03:57 PM
wfrank
Offline
• • • •
Upload & Sell: Off
p.2 #8 · p.2 #8 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


Thanks johnahill.

zhangyue wrote:
Wfrank, Nice illustration. Very good timing, As I have some R lens need to trim or trim the mirror.

I am suprised you didn't cover the rear element doing this. Is the long extension standard part of Dremel? What kind of sand paper I have to use for metal?


Thanks. Check image #3, it's probably the most common sand paper roll that goes with these kind of tools. I dont know about the extension thing but it came as standard to mine. I would not hesitate to do this again now when I know what tool to use. It was on of the useless pink colored stone things visible in the same image that hit the mirror..

helimat wrote:
It freaks me out too!


If I had the skill of m-a-x above - creator of the famous Frankenzeiss :-) - I would probably have taken more things apart. But there are possibly more people here that like me dont regularly take delicate things like lenses apart swinging lens groups around and so on. For them, or if I did this a 2nd time, this methods work just fine. The scratch came about when one of the foul tools was mounted, had to press too hard with one of the pinkish stone things - before finding out it was useless for the work. My dremel copy allows for RPM change and I had to raise it to get the right feel - with the sandpaper roll mounted it's very soft and controllable.



Dec 28, 2012 at 07:22 PM
sebboh
Online
• • • • • •
Upload & Sell: Off
p.2 #9 · p.2 #9 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


wfrank wrote:
If I had the skill of m-a-x above - creator of the famous Frankenzeiss :-) - I would probably have taken more things apart. But there are possibly more people here that like me dont regularly take delicate things like lenses apart swinging lens groups around and so on. For them, or if I did this a 2nd time, this methods work just fine.


I just think that for the less mechanically inclined it is much easier and safer (for the person and the lens) to remove the lens group and then the retaining ring. there is nothing delicate about the rear optical block of the rokkor. I'm not fond of these demonstrations of how to trim the retaining ring while attached because I've seen a lot of ruined rokkors from such attempts by people who aren't careful. there is a finite number of these lenses and they'll never be made again.



Dec 28, 2012 at 07:54 PM
wfrank
Offline
• • • •
Upload & Sell: Off
p.2 #10 · p.2 #10 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


Ok I wont promote this method more than I've already done but I am sure you are aware of that there are plenty of examples when people take lenses apart and cant put them back together again because some small spring or bearing ball or similar wont fit without special tooling from the factory. That reduces the finite stock as well.






Dec 28, 2012 at 08:23 PM
 

Search in Used Dept. 



zhangyue
Offline
• • • •
Upload & Sell: On
p.2 #11 · p.2 #11 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


wfrank wrote:
Thanks johnahill.

Thanks. Check image #3, it's probably the most common sand paper roll that goes with these kind of tools. I dont know about the extension thing but it came as standard to mine. I would not hesitate to do this again now when I know what tool to use. It was on of the useless pink colored stone things visible in the same image that hit the mirror..

If I had the skill of m-a-x above - creator of the famous Frankenzeiss :-) - I would probably have taken more things apart. But there are possibly more people here that
...Show more


Thanks for the info, Wilhelm.

I just did the same thing with my newly acquired 35lux R. The lens in merely good condition with previous owner tried file down a little bit of rear retaining ring. But it is just scratch the ring other than any real job done.

I get it at fair decent price. Since previous owner has tried file down the rear ring, I feel less guilty to finished the job by myself. Otherwise, if it is mint copy without any modification, I won't dare to do it given its value.

I file it down by myself use a file. It quite a bit of job that I have to file down about 3mm to be able to clear my D700 mirror. I did the same thing as illustrated by Leitax, similar to your setup. The copper is soft and I prefer use hand file to have better control. I cover the lens element and put cotton to prevent dust into the lens with paper towel and lots of blue tape to wrap the lens. Basically, turn the lens to infinity and use tape to wrap around ring to prevent accident moving.

I also didn't dis-assembly the lens since I have almost zero knowledge about lens construction. So, I understand your concern here. I kind of prefer to hold the lens instead of rear element group. I feel it is hard to get stable operation without proper tool.

It took me 30min total, most of time is preparing. Though I have to do it again, as first time it is only clear up to 10M.

With the experience I have now, I am not afraid to do it on Rokkor if I can get it in future. Less than 1mm, that is a piece of cake




Dec 28, 2012 at 08:33 PM
Mescalamba
Offline
• • • •
Upload & Sell: Off
p.2 #12 · p.2 #12 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


sebboh wrote:
it's pretty easy to convert to sony fyi (which you have correct?). i know richard harris (in the UK) from this forum could do it for you if you really wanted.


Konica Minolta actually, but ofc still Sony mount. Will serve as backup only in hopefully very close future. My newer camera is Nikon F mount, hence no Rokkor for it.



Dec 28, 2012 at 08:47 PM
sebboh
Online
• • • • • •
Upload & Sell: Off
p.2 #13 · p.2 #13 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


wfrank wrote:
Ok I wont promote this method more than I've already done but I am sure you are aware of that there are plenty of examples when people take lenses apart and cant put them back together again because some small spring or bearing ball or similar wont fit without special tooling from the factory. That reduces the finite stock as well.


yes, but ball bearings, springs, and screws easily are replaceable (and ridiculously cheap) while glass is not. also, this particular rokkor has an extremely simple mechanical design, especially if it's already converted to eos mount.

i'm out of town right now, but when i get home i can post a video or picture montage of what it takes to remove the retaining ring from a MC mount rokkor as well as from an eos mount rokkor.



Dec 28, 2012 at 08:54 PM
wfrank
Offline
• • • •
Upload & Sell: Off
p.2 #14 · p.2 #14 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


That would be a good idea. You never know, even I might change my mind if I do this a 2nd time if it looks easy enough :-)

Ya know bro, that info - or why it would be preferable - is simply not available on the net as of now. I've been looking for a year. And why not post it here, I already have a "(not)" in the title.



Dec 28, 2012 at 09:00 PM
sebboh
Online
• • • • • •
Upload & Sell: Off
p.2 #15 · p.2 #15 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


wfrank wrote:
That would be a good idea. You never know, even I might change my mind if I do this a 2nd time if it looks easy enough :-)

Ya know bro, that info - or why it would be preferable - is simply not available on the net as of now. I've been looking for a year. And why not post it here, I already have a "(not)" in the title.


sounds like a plan, i'll make a video when i get home. it's just 4 mount screws, remove mount, unscrew optical block, then unscrew the retaining ring. wearing dish gloves or surgical gloves makes gripping and unscrewing things with you hands easier.



Dec 28, 2012 at 09:16 PM
m-a-x
Offline
• •
Upload & Sell: Off
p.2 #16 · p.2 #16 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


Wilhelm, thank you for the compliments! I am not a professional craftsman, only a hobbyist.
With the normal Dremel sand paper tool, I once completely destroyed the rear element of a 85/1.2 SSC. I was lucky to get a spare for 40 Euros some moths later.
BTW, I don't like the Dremel grinding stones either.

Regarding the Rokkor conversion documentation - there have been a number of threads and websites how this can be done.
Cogitech has one. In this forum are a number of threads, especially discussing the last metal ring, but perhaps they are archived.
And the opinions differ. Some people claim the ring thickness should not be reduced too much or that the ring should not be removed in order to keep everything "factory-aligned". Others state that a thin rim can easily hold the glass element and that its removal is not critical.
Dim_ka, if I recall correctly, even removed the ring for good, and epoxied the glass back in place.

If you follow the picture-hotlink of ZoneV above, you find an active website in German language. I also
support what he is telling us. 0.4mm are strong enough to hold the glass element. I made the ring even thinner.

One more special note: If the ring is removed, one must take care that the last glass element is not flipped inside out before it is re-assembled! This happened to me once and it took me a while to find out why the pictures where so glowy.



Dec 28, 2012 at 11:48 PM
sebboh
Online
• • • • • •
Upload & Sell: Off
p.2 #17 · p.2 #17 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


m-a-x wrote:
One more special note: If the ring is removed, one must take care that the last glass element is not flipped inside out before it is re-assembled! This happened to me once and it took me a while to find out why the pictures where so glowy.


hah, yeah, if you want to be safe don't take the rear optical assembly apart just remove the retaining ring and leave the optics where they are.



Dec 29, 2012 at 12:08 AM
helimat
Offline
• • • •
Upload & Sell: On
p.2 #18 · p.2 #18 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


wfrank wrote:
If I had the skill of m-a-x above - creator of the famous Frankenzeiss :-) - I would probably have taken more things apart. But there are possibly more people here that like me dont regularly take delicate things like lenses apart swinging lens groups around and so on. For them, or if I did this a 2nd time, this methods work just fine. The scratch came about when one of the foul tools was mounted, had to press too hard with one of the pinkish stone things - before finding out it was useless for the work. My dremel
...Show more

I have said it a few times already... You really don't have to take lens groups apart! The retaining ring is simply a threaded 'nut' that holds the rear element in. Sit the lens face down, lefty loosey, and it is off and every other part of your lens is still assembled!



Dec 29, 2012 at 01:09 AM
Ed Sawyer
Offline
• • • •
Upload & Sell: On
p.2 #19 · p.2 #19 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


I usually take out the rear optical block, as the center where the aperture is invariably needs cleaning anyway. Then mask off everything on the rear group except the ring, and grind down the top half with a bench-mounted belt sander. A little hand sanding for cleanup then blacken with a sharpie and it's done. I've done several this way with no damage.


Dec 29, 2012 at 04:24 AM
sebboh
Online
• • • • • •
Upload & Sell: Off
p.2 #20 · p.2 #20 · How to (not) fix your Rokkor 58/1.2 for infinity on EOS (5D2).


ok, i made a video of how to remove the retaining ring here.

i also made a brief writeup of the process on the flickr page and will post it to the lens repair/modification thread.



Jan 03, 2013 at 11:19 PM
1      
2
       3       end




FM Forums | Alternative Gear & Lenses | Join Upload & Sell

1      
2
       3       end
    
 

You are not logged in. Login or Register

Username   Password    Reset password