[ShutterPro]

Hi,
I recently got a Pentax-M 28mm f3.5 over the internet. It is in a marvelous optical condition, completely mint. However, there is dust inside the lens. The front seems fine, but the rear element is pretty heavily dusted.
I have taken apart a lens before and it wasn't Pentax. Do you have any recommendations for me? Do you know about a service manual, a video or a step by step guide? Or is there some kind of assembly workflow same for all Pentax-M lenses?
Thank you for all of your replies,
Jan

[pschlute]

Hi,
I recently got a Pentax-M 28mm f3.5 over the internet. It is in a marvelous optical condition, completely mint. However, there is dust inside the lens. The front seems fine, but the rear element is pretty heavily dusted.
I have taken apart a lens before and it wasn't Pentax. Do you have any recommendations for me? Do you know about a service manual, a video or a step by step guide? Or is there some kind of assembly workflow same for all Pentax-M lenses?
Thank you for all of your replies,
Jan

The manual lenses are pretty easy to take apart. I would suggest you just remove the rear element and give it a clean. You should be able to do this without having to remove the mount. Have a look here

You Tube

You Tube

You will need a spanning wrench to unscrew the element holder. If you do want to remove other parts get yourself a set of JIS screwdrivers.

[pepperberry farm]

depending upon what the amount of dust looks like, it may not affect your captures at all...

have a photo of it?

[Not a Number]

Check the Lens Disassembly thread:
Pentax Lens Disassembly Database - PentaxForums.com

SMC PENTAX-M 1:2.8 28mm version 1 disassembly.

[ShutterPro]

depending upon what the amount of dust looks like, it may not affect your captures at all...

have a photo of it?

Yes, here it is.