If you're brave enough take the whole lens apart and give the helicoid the new grease it deserves after all those years of working and exposure to dirt and heat😅 I used Molycote EP lubricant on my own lens, which contains molybdenum. Use only a little and your lens will turn nicely tight, and this grease has very little chance of running to the diaphragm blades again! If you only clean the diaphragm you may have to do it more often because the grease has been degraded and keeps leaking out!

Thank you very much. After watching this video I conducted my first m42 lens repair. I cleaned the stuck aperture blades and removed the fungus from a 55mm f/1.7 chinon lens. Please continue to post videos like this. Bravo..

Your video comes on the day I started researching that topic, yay!

Exact lens I was trying to fix, and it worked perfectly! Also gave me the chance to clean some spots off inside the elements. Thanks so much!

Excellent timing!!! I am trying out my Minolta collection on my new BMPC 4k today. I still remember your Vid on the 45mm f2. weird lens... It's going to be first with a speed boost. Thank You.

@MathieuStern

3 ай бұрын

Enjoy!

this is common issue with "auto" lenses, most famous with this problem is Carl Zeiss Sonnar 135mm f3.5. I have two of them repaired this way (i've used isopropyl) and they still working after 18 months

Thanks for this vid. I got a dirt cheap Leica 135mm lens but it has a stuck focusing ring which I wanted to fix but couldn’t figure out how. Do you have any tutorials on that you can make?

Fantastic tutorial. I managed to knock the ball bearing for the aperture ring somewhere on the floor, so now the aperture ring is smooth like a focus adjustment instead of clicky but oh well.

Some pretty old lenses have a tunnel filled with grease to hold the aperture control, which can be seen as the aperture ring is stuck. Sometimes this grease just dries up, and it can be revived by mildly putting some temperature on the lens - but be careful, i mean something like 50°C max...

That lens is notorious for having stuck apertures. I ordered one from ebay and it came stuck despite the seller saying it was mint. I then went online and heard many stories of others having the same issue haha.

Just got that lens recenly in my pursuit of finding a "nifty fifty" with great bokeh for my GFX. Think this will be a winner. I love my Contax Planar 50/1.4 but it's a touch too wide on a GFX. Tried a Canon 50/1.2LTM and absolutely love how compact the setup is, but the lens has huge vignette on GFX and the same issue with the angle of view happens. Was a bit antsy to try a classic 6 element design after working with 7 element lenses for some years, but I think the Rokkor will be a winner!

This particular Minolta model is a bitch to work on if you end up disassembling the diaphragm and cleaning the blades separately. The reassembly requires a careful readjustment of the iris. If you don't do it right, the aperture will not correspond to the actual F value in the aperture ring. I had to open and readjust mine a few times before nailing it.

You don't re-lubricate the blades with anything after cleaning it with the lighter fluid?

What causes this oily aperture in the first place? I have Kiron 28mm f2 and it needs to be cleaned as well.

nice one! i made the same fix a lot of times! Works on stuck shutter blades as well! Not always of course but often. One Canonet QL17giii that i found on a local flee market did not work at all. Just take out the back Lens-assembly, some drops of Naphtha and clean it. And just like that the canonet was working perfectly again!

much more tips like this please!

@KNURKonesur

3 ай бұрын

yes! youtube needs stuff like that! stuff actually useful, not just review after review of new expensive (but sponsored) gear!

amazing tip

So much familiar problem😂😂 Especially for soviet lenses... Some people using WD 40 to release them, which is causing even more disaster which leading to complete disassembly of entire lens including glass elements washing and diaphragm mechanism taken apart😅 But this way you can get really cheap over-greased lens. For little money but with lot of work, which I am personally enjoying...

J'avais l'exact même problème sur l'exact même objectif il n'y à pas longtemps. J'ai par contre été un peu plus radical en enlevant aussi le bloc optique avant et en utilisant du dégraissant en spray. Au final, le diaph refonctionne parfaitement ( dommage que ma lentille arrière soit "vérolée" - mais ça c'est un autre pb :) ).

Can this decenter the lens?

This going to be a great solution

Nice!

Can you do more content on putting black material on your lenses?

Awesome

Thanks! I have this lens. The aperture works great, but the focus ring is very hard to move 😢,

@ChasWG

3 ай бұрын

That means you need to remove all the glass elements and clean out the helicoids of all the nasty old grease. I've been collecting vintage Konica Hexanon AR lenses lately and I've had to do this with three of the different lenses (57mm f1.4, 50mm f1.7 and 135mm f3.2) The 57mm lens was really sort of beat, dents in the filter ring, oil on the blades and a focus ring that was basically impossible to use as it was. That one was a real battle, but eventually you get all the old gunk out of the threads and it turns freely. Then its a matter of cleaning up all the solvent used and flushing it all out, then re-greasing the threads and reassembly. While what Mathieu showed us here seems like it only takes a few minutes, the reality is that it takes a little longer for the lighter fluid to actually get in to all parts and dissolve the oil and grease. But this can all be done! I have done this with many of my vintage lenses. I bought a fairly stuck Nikkor 105mm Ai lens for cheap and it is now a stunning lens and one of my favorite lenses to use when I can. Give it a try!

Brilliant job cleaning. Those are quite classic Rokkor lenses. MC1 I presume. although the 58XXXXX might be an MC2. Do you know? My minolta history isn't that good.

@KNURKonesur

3 ай бұрын

both are amazing anyway, doesn't really matter. people keep talking about the later versions of those lenses, I've got the first version (pre MC) and the MC version in the video, there is basically no difference between them, the newer ones is a bit warmer in tonality, that's it

Sometimes this is only a temporary solution. I have a Minolta rokkor 58mm 1.2, which is quiet complicated to open up. I took the aperture blades apart and cleaned them individually. 4 months later, completely stuck again. Its the grease from the helicoid that is shifting and making the aperture blades oily…. 😅

J'ai le même avec cet excès d'huile sur un Nikon 100mm 2.8

I have this lens too

Hi Mathieu, this can only be a very quick tipp. This repair will not work for a long time. You should eleminate the reason for the oil covered blades. That is mostly the helicoid. These blades will getting recovered with oil very qick.

@MathieuStern

4 күн бұрын

Yea, sadly, do you have a better solution ?

@Riffeldoc

4 күн бұрын

@@MathieuStern the only way i know is to disassamble the whole lens, seperate the helicoils swipe the old lube away und make it new. In the aperture system is no oil needed. The best way to remove the grease is to use isoprpylalcohol 98-99%. Please excuse my bad english

Usually this is a temporary fix. But yes, as a first approach to CLA is ok, first rule: do no harm 🙂

@MathieuStern

3 ай бұрын

yea, thats what I am saying at the end of the video, this is not the same as cleaning the blades like a pro, but it can help make it work again.

can 95% alcohol be used instead?

@Trevellian

3 ай бұрын

Spoken with some lens repair technicians about it. They prefer lighter fluid as it leaves less residue and doesn't damage aging plastics.

@michielbuse4386

3 ай бұрын

Yes you can for sure!

@michielbuse4386

3 ай бұрын

These older lenses have metal diafragm most of the time luckily​@@Trevellian

@Trevellian

3 ай бұрын

@@michielbuse4386 Yes, but often there are plastic components. And it has less residue.

Personally, i just use ethanol