Clean the aperture blades of a Nikkor 50mm f1.4 LTM

[aizan]

The recent discussion of whether oily aperture blades have any downsides got me thinking it would be nice to clean them anyway.

Has anyone does this before? Do I disassemble the front or the back? Will I need a pointed spanner wrench (I only have the ones with flat tips)?

 

[jonmanjiro]

With the Nikkor 5cm F1.4, you can access the blades from the front. The lens pictured below is an S-mount Nikkor-S 5cm F1.4 but all RF Nikkors are constructed similarly. The entire front optical group easily screws off to give direct access to the aperture blades. To actually remove the blades, you need to do a bit more disassembly. First you separate the optical block from the focus helical by removing the retaining ring around the rear element on the back of the lens and pulling the optical block to the front. I use a pinset with filed down tips for that. From there, my memory is a bit rusty but you need to remove a guide screw which governs the amount of rotation of the aperture mechanism. This screw screws into the side of the aperture blade retainer piece. Then from the front of the lens, you remove the circlip that holds the aperture blade retainer piece in place, then remove the retainer piece, and then the aperture blades. RF Nikkors are very logically designed and very easy to work on, so take notes as you go and you should be fine.

 

[aizan]

Thanks, Jon! I'll give a crack at it ASAP.