Cleaning aperture on Pentacon MC 2.8/135mm

[emukang1]

teach you step by step cleaning aperture on pentacon lens

I used pentacon 2.8/135 m42 electronic version. The following will explain step by step how to clean the aperture blades.


1. First we look at today's protagonist, pentacon 2.8/135 m42 electronic




2. Pentacon 2.8/135 head is the easiest to clean aperture, it's more easier than 50mm and 28mm lens. The whole journey takes 3 screws removed. But you need the following tools.


3. First, unscrew the front lens group, this work does not require any screws removed, the first lens group can be directly screwed down. Hold the hood and the zoom ring is between the site, counter-clockwise twist on the line


4. Unscrew the front lens group, you can see the inside of the aperture ring


5. Gently loose aperture ring above three screws and toggle aperture ring, you can shrink the aperture blades. As shown, the aperture blades covered with oil


6. Remove the aperture ring on the three screws, then the aperture ring and aperture blades can be taken out.


7. After remove the aperture ring and aperture blades, you can see 3 yellow metal nut, at this moment we do not need to touch them


8. Gently clamp the aperture blades one by one removed from the aperture ring to (this action must be light, aperture blades are very thin, big force will bend the aperture blades, very difficult to recover)




9. Put the aperture blades into a container, and put water and detergent (washing powder or hand sanitizer), and shaking the container, washed off the leaves glued to the aperture of the oil (do not rub with bare hands, it is easy to bend the aperture blades)


10. Aperture ring should also be washed, and then put the aperture on a soft paper, wait the water dry.


11. Now put the aperture blades back to the aperture ring.


12. You can now put the aperture ring and aperture blades mounted back. Because between the aperture ring and aperture blades out of oil, the aperture ring and aperture blades are easy to fall off, so you have to install inside backwards. Is the aperture ring on top of a cylinder (I use glue stick), then loaded into the lens upside down. This action should be slow.


13. Now adjust the position of the aperture ring


14. put 3 screws back, first gently, do not tighten. Then adjust the aperture ring position, to ensure that when the aperture at 2.8, the aperture fully open. When the aperture at 22, the aperture fully contraction. This step may be adjusted several times to ensure the position of the aperture blades. Finally tighten the three screws


15. Screw on the front lens barrel. Well, you're done, the aperture can not completely solve the problem of shrinkage.


related links
Servicing a Pentacon 50/1.8
http://gabriel.mp3-tech.org/blog/index.php?entry=entry080827-180800

Cleaning aperture on Pentacon MC 1.8/50mm
http://forum.mflenses.com/cleaning-aperture-on-pentacon-mc-1-8-50mm-t33418.html

Camera.Maintenance.and.Repair.Book1，2.pdf
http://www.filestube.com/a6630c97319ae93903e9,g/Camera-Maintenance-and-Repair-Book1.html

www.praktica-users.com
http://www.praktica-users.com/

Disassembly Guide for Pentacon 135mm f2.8 (Preset) Lens
http://frozenfate.blogspot.com/2010/08/disassembly-guide-for-pentacon-135mm.html
http://frozenfate.blogspot.com/2010/08/disassembly-guide-for-pentacon-135mm_10.html

How to Strip and Clean a 29mm Pentacon M42 Lens
http://www.wikihow.com/Strip-and-Clean-a-29mm-Pentacon-M42-Lens

[Gonzoo]

Instead of using water and washing detergent for cleaning, I recommend lighter fluid or similiar to avoid corroded blades.