Cleaning grease off aperture blades in Nikon 50mm 1.4 ais

[Hamish Gill]

I recently picked up this Nikon 50mm 1.4 ais lens for £1! An absolute bargain! Apart from the fact that it was completely unusable!
Its aperture blades were so gummed up with grease that they didn't want to move at all! I suppose it could have just been used for wide open shooting but for the fact it cost me a quid I thought sod it, ill take it apart!

I had a look around online and various info pointed toward doing a good job of fixing this issue by accessing the inside of the lens from the front. Here is a great tutorial on how to do it that way Shooting with a Pentax K10D: Cleaning from fungus: Nikkor 50 f/1.4 ...

He has some fancy tools that I don't have so I wanted a quicker and cheaper (I'd have to buy the tools if I did it that way) way of doing it.

I found some info that said I could access via the back of the lens, but that I would only be able to clean the back sides of the blades ... but key to this, I would only need to undo three screws ... that's my kinda DIY!

This is the back of the lens with the three screws

Took them out, and removed the bit they were holding down

This was what I now had in front of me

I could see straight away that I needed to work out what I was looking at before I went any further.
The round pin that rests against the curved bit of metal is pushed outward by the bit of metal as the aperture control is rotated.
so to take off and reatatch this part I decided it best to hold the pin away from the bit of metal using the stop down lever (the bit that opens and closes the aperture on the back of the lens when you flick it back and forth)

Otherwise basically this bit just slips on and off.

The glass element groups just unscrew.
first one off

Second one could probably do with one of those fancy tools, I just poked my screwdriver in the slot and gently rotated it until she came free.

tada, greasy shutter blades

I cleaned them with some lighter fluid and some cotton wool ear bud things. Only a small amount of lighter fluid and new bud regularly.

In fact, I took these photos afterwards so that is what they look like after a basic cleaning ...
Because it is hard to access the other side of the blades you have to clean, then close the blades, open them and clean again what has been smeared from the other side.
I did actually manage to gently pry up the tip of each blade with the end of the bud and wipe underneath, but no matter how much cleaning I was still left with some residue ... but, after only a small amount of cleaning they moved freely again!
I wasn't after perfection, just normal function so I was pretty happy with the result!

My main tip for reconstruction is to screw the two elements back together, it makes fitting them back much easier and you are much more likely to get them as tight as they were originally!

and here it is, fully functional 50mm 1.4 ais (that cost me £1 )

[video=youtube;uEcu65P1Tss]http://www.youtube.com/watch?v=uEcu65P1Tss&feature=g-upl[/video]

This is obviously not a perfect job, as you can see there is still a greasy blade issue with this lens and it will probably pack up again! I will never use it without checking it is ok first as it getting jammed wide open could ruin a lot of shots ... But, it does work ... and it didnt before ... for me that is a success!

 

[Paul Lange]

Sterling effort Hamish.

 

[Andy Boardman]

What I want to know is where you find these bargains, I mean £1 for that lens ??
You jammy bugger LOL

 

[Dave Green]

Good find and good job

 

[Hamish Gill]

Im not giving up my secrets ...
(I know the guys in the local camera shop quite well and one of them lets me buy their junk cheap )

 

[Austin O'Hara]

Great thread Hamish and excellent photos of the lens interior.
I am slowly accumulating tools for lens repair.

One thing however, when I activated the Pentax link the warning from Google appeared.
----------------------------------------------------
Warning: Something's Not Right Here!
k10dpentax.blogspot.co.uk contains content from Blog Directory • Blogarama, a site known to distribute malware. Your computer might catch a virus if you visit this site.
Google has found malicious software may be installed onto your computer if you proceed. If you've visited this site in the past or you trust this site, it's possible that it has just recently been compromised by a hacker. You should not proceed, and perhaps try again tomorrow or go somewhere else.
We have already notified Blog Directory • Blogarama that we found malware on the site. For more about the problems found on Blog Directory • Blogarama, visit the Google Safe Browsing diagnostic page.
---------------------

I use a Mac and do not have any anti virus installed.
Has anyone else seen this warning?

Will see how Kaspersky at work responds.

 

[Peter Blake]

so in the words of the great Haynes manual, 'refitting is simply a reversal of the removal procedure'?

I just bought the 50mm F1.4 Ai (scalloped barrel) for 25x what you paid.....jealous as hell!

 

[Ambarish Manepalli]

Just wanted to say thanks so much for this article. Totally helped me take apart my Nikon 50mm f1.4 and clean up the aperture blades. I was just about to go get those fancy tools and then I came upon this. It's quite easy to do...

Advice though, don't do what I did. Once you have to unscrew the rear element, do not put a microfiber cloth over the rear element to give yourself more leverage to torque. Your palm will rest on the rear element and cause some cleaning marks through the cloth....

Just bare hand it AROUND the rear element, it's more work but you'll keep your glass clear.
Thankfully there were just a few tiny marks that have not touched picture quality. In all cases, take care

 

[Pete Askew]

Thanks for the tip Ambarish. And welcome to RPF.

 

[Hamish Gill]

Good shout!