Cleaning SMC Pentax M 50mm f1.4 - Step by Step Documentations

I am going to share something but no gunpla this time. I have Pentax manual camera with interesting lens attached to it. It is Pentax SMC M 50mm f1.4 (or goto Amazon link). The condition is not good as it buried in the library for over 30 years. It is dusty and worst, a sign of fungi inside. In a quick research it is well known that many manual focus lens can still usable with adapter ring to get it attached into modern DSLR body. I am using Canon body and the PK mount (goto Amazon link) adapter needed to get this Pentax lens attached to it.

As a gunpla builder, ehem, it is challenging to try dissembling the lens and that's exactly what I just done. The lens is quite simple actually in term of construction, and if you used to done small parts in gunpla, this looks quite easy. The most challenging part is how to correctly clean up the dissembled lens (there are 7 lens inside) , remove the dust and fungi. As I am only amateur in lens cleaning, DO NOT take this step by step documentations as 100% correct.

Dismantling Pentax manual focus lens by gunpla lover

The tools I am using :
- screwdriver with correct size
- wet tissue for cleaning the body, lens cleaning cloak  for the lens
- lens air blower 
- something circular to used as cover opening tool, see step 2

This is my step by step documentation on the process for cleaning , dissembling the SMC Pentax-M 50mm 1:1.4 manual focus lens:

step 1, you'll need to open the cover in front of the lens

step 2, you'll need to find something in your household, something circular tube that match the diameter of the lens. I found a baby tube cover which exactly match the diameter. Put in double side tape.

step 3: used it to open the lens cover

step 4: it will easily un-screwed and the cover is now open

step 5: you'll see three screws, use the correct screwdriver to unscrew it

step 6: unscrew and bring out the first ring

step 7: unscrew the next three screws inside, you'll need smaller screwdriver

step 8: you can now unscrew the first lens holder ring , unscrewed it by hand

step 9: on that first lens holder, there is three lens, you can dissembling it easily

step 10: enjoy the lens construction and see how nice the technology from thirty years ago.

step 11: carefully clean all the lens we just dissembling, using necessary cleaning tools (air blower, clean cloak etc.)

step 12: now we go to the mount side. unscrew it.

step 13: take off the metal mount

step 14: a thin ring to be taken out as well.

step 15: unscrew the first lens by hand

step 16: the next lens need to be open by using a screw driver push to the given gap in the ring, do it opposite clock-wise (see the next picture)

step 17: this is how to open the next lens, this photo is taken not in order to the last photo (I do it after resembling the lens), I'm just showing how to do it

step 18: btw, you'll need some oil to deal with rusty part. I use baby oil because it has no color. DISCLAIMER: this is not the professional advise, do it precautionary 

step 19: the other important thing to consider is how the aperture blade going. Make sure it is still in function and smooth.

step 20: enjoying the lens in this section. then carefully clean all of the lens. do not left a dust or whatever. 

step 21: the SMC Pentax-M 1;1.4 50mm manual focus lens, after cleaned and resembled

the whole process actually already video documented in this Youtube Video.

AND THE PHOTO RESULT TAKEN WITH ASAHI PENTAX-M SMC 50mm 1.4 MANUAL FOCUS LENS 

X - Maoh taken with Pentax SMC 50mm at f 1.4

super bokeh in the background

X-Maoh taken with Pentax SMC 50mm at f 5.6

I found f 5.6 is very much enough to create excellent bokeh background

and then the sharpness is amazing