Disassembly and Cleaning the Eiki 50mm f1.2 lens:


Since I had a spare lens I thought I would attempt to take it apart and clean it. It did not appear to have fungus in it, so I did it more in the interest of general cleaning, and more so just learning. You will no doubt see how similar the process is to Tom's recent post on the Elmo f/1.1 lens.

The process is actually quite simple and only one special tool is needed. The special tool is an adjustable "Camera Lens Opener" to remove lens rings. The one I have is made by japanhobbytool.com. There are a couple of different styles of these tools. The one I used has knurled locking nuts to allow precise adjustment. This tool has pins that fit into the small grooves on the lens ring. The spread or distance between the pins can be adjusted to fit the lens ring you are trying to remove. This distance differs between the front and rear of the Eiki objective---obviously--as the diameters differ. It is then used as a wrench of sorts to loosen the lens ring. The lens ring is a thin threaded metal ring which holds a glass lens element in place. It can then be safely removed without scratching the glass lens using this tool.

This particular lens comes apart from both the front of the objective and the rear. Once it is disassembled from the front and the back, there is another center lens element that remains inside the barrel that does not come out, but this element can be cleaned from both the front end and the rear once the other pieces are removed.

You can disassemble the front half of the lens, and clean all the elements--including one side of the center element that remains in the tube--and then you can reassemble this front half. Then you can adjust the size of the "Camera Lens Opener" tool to fit the rear of the lens and disassemble the rear and get at the other side of the center element that remains in the tube.


Tools needed:
a. Camera Lens Opener
b. Q-Tips
c. Lens Cleaning Wipes and
d. Lint-Free Cleaning Cloth
e. Nail Polish Remover/100% Acetone - for loosening lens ring (if needed--I did not have to use this)
f. Soft towel to protect lens elements
g. Artist's tape - I used this to mark the outer facing side of the lens to make sure I did not flip a piece over incorrectly during cleaning
h. Head lamp - if needed, for extra light
i. Magnifying lens - if needed, to clearly see the lens ring slots
j. Nitrile or cotton gloves to help keep finger prints off the glass elements


Here is what I did to take apart and clean the Eiki lens for my 16mm projector.

--For the front of the lens, put on some nitrile gloves and place the soft thick towel on your work table...
1. Manually unscrew the knurled outer ring

2. Adjust the "Camera Lens Opener" to the precise size to fit the pins into the slots of the lens ring.

3. Fit the lens opener pins into the slots and with one hand holding the barrel of the lens twist the tool counter clockwise to loosen the lens ring. Once the lens ring is loosened, you can probably use your finger to continue to unscrew the lens ring until it is completely removed.



4. With the lens ring removed, you can tip the lens so that the first lens element comes out of the barrel and safely onto the towel.
5. Place a piece of artist's tape on the outward face of the first lens element. This will be removed prior to cleaning the lens element, and only served as my reminder so I did not inadvertently make a mistake.
6. To remove the next lens element, hold the lens with the rear end up, and the front end safely over the soft towel. Give the butt end a bit of a rap with the heel of your hand and this should cause the next lens element to pop out safely onto the towel.
7. Place a piece of artist's tape on the outward face of the second lens element. This will be removed prior to cleaning the lens element, and only served as my reminder so I did not inadvertently make a mistake.

8. Now, using your preferred method for lens cleaning, clean the accessible side of the center lens element which is still inside the barrel. Inspect and re-clean as needed. The most difficult part of the whole process is keeping dust/lint off the pieces. I found that I had to repeat the cleaning and inspection to ensure the glass was clean of lint as I reassembled things.
9. Clean the lens elements which you have removed and carefully re-insert both of the glass elements in reverse order--making sure the proper side is facing to the front of the objective.
10. Thread lens ring on using your hand. This lens ring can hang up when it is only halfway threaded back in. If this occurs, it means it is caught up on the edge of one of the lens elements. What i did was gently jiggle the lens slightly which then aligned things so I could continue threading the lens ring all the way in. Once the lens ring is flush to the top of the barrel, I used the camera lens opener to complete the tightening. Reinstall knurled outer ring.
11. Take a look thru the objective from the front and see what you think. If you are satisfied with the outcome you can move on to the disassemble of the rear half.
12.Adjust the "Camera Lens Opener" to the precise size to fit the pins into the slots of the lens ring from the rear (or smaller end).

13. Fit the lens opener pins into the slots and with one hand holding the barrel of the lens twist the tool counter clockwise to loosen the lens ring. Once the lens ring is loosened, you can probably use your gloved finger to continue to unscrew the lens ring until it is completely removed.


14. Remove both of the rear elements using the same technique as for the front side.




15. Clean the other side of the center element.
16. Clean the removed lens elements and carefully reassemble.
17. Repeat step #10 above for the rear lens ring.
18. Examine the lens from both sides and ensure you are comfortable with the results.
19. That's it! I believe the steps detailed here are complete. I did the disassembly twice to be sure. Please note, I am no expert or optician, so I can only share what worked for me. I welcome any and all suggestions about how to do this differently/or better. Of course, I cannot guarantee things will work out for you as they did for me, so please reach your own decision on attempting this. Also, I understand that anamorphic lenses require precise re-alignment, however this was simply a standard issue lens. Everything looked good on the screen to me using the newly cleaned up lens....

That's a very valuable post Greg; I had never heard of that lens tool before. I'm sure a lot of other people haven't, as I've seen posts in SLR forums of people asking how they can disassemble a lens.

The same hear. I didn't know such a tool existed :-) I have a scope lens with a slight fungus issue. Things get slightly blurry. But not so sure I am brave enough to open that :-) Very nice post!

What a great post and so well put together with the images showing exactly what to do. Thank you for this one Greg.
I like that lens tool as well, the tool i have is fine but one has to be careful in case it slips.