Canon lens M39 (LTM) 50mm/1.8

[@atf2940]

Good instruction. The fungus/haze is only on the rear double element, aperture side. So it suffices to unscrew the outer ring at the back, take out the complete lens assembly through the front and then unscrew the double element as shown in the video. (When unscrewing elements its always a good idea to make an alignment mark.) Try wetting the glas surface only, since the paint comes off easily. I cleaned mine with complete (!) success in 30 minutes, including disassembly and reassembly. I used 10% peroxide with a dash of ammonia 24%. Easy job.

[@monochromes]

Thank you! Valuable feedback and I agree, an alignment mark helps. 👍

[@ADRIANPRADA]

yes, there are definitely several versions of this lens, mine does not have the small screw, nor the screws on the back

[@yam2k]

Great video! I have an issue with my 50mm 1.4 ltm, not sure if that's the right place to ask but it looks like you know your stuff! There's some play/wobble between the part that threads into the camera an the rest of the lens.. I disassembled the lens as far as possible for me and it appears the play is inside the helicoid gear. I wasn't able to disassemble that further though.. Would it be sufficient to apply new grease to the helicoid gear or is it more likely that there's something loose/worn inside of that gear?

[@monochromes]

Sounds like something needs to be tighten up. When you attach the lens to the camera, are there any parts that rotate more than they should, e.g. the aperture ring? If it does, check the rear lens if it loose. I wouldn't apply more grease, it won't solve the problem.

[@oldgittarist]

Excellent! I have this lens and this info may be invaluable.

[@Minerva___]

Great video. Thanks for sharing! Going to attempt this on a lens I just picked up :)

[@tannergagliardo503]

I was curious what tool you used to get the front element out. I have the same lens and I can find anything thin enough to fit between the filter threads and the metal ring.

[@monochromes]

Once you get off the metal ring the front lens should be loose. In you case, is it stucked?

[@tannergagliardo503]

monochromes no mine is not suck I was more curious about the tool you used to get the actual metal ring off. It looks similar to a screw driver.

[@tannergagliardo503]

monochromes it is the tool you used in the very first part of the disassembly, to take off the metal ring. If you know what tool that is, please let me know it would be a great help.

[@monochromes]

@@tannergagliardo503 The one at 0:20-0:36 is a flat screw driver 1 mm wide.

[@tannergagliardo503]

monochromes thank you so much!

[@mbenavides]

thanks for your videos, is it possible to clean the inside of the part on min 5:00 ?

[@monochromes]

Hello Martin! Thanks for watching. Using a lens spanner, you should be able to dismantle the lens barrel even further. I never did that since the fungus was located on one side of a lens element. Cheers!

[@jediviking2012]

Thanks! I think I've got some haze on the same element.

[@hashsteezy]

Can I just use a spanner wrench to access the 2nd rear lens instead of removing the front? Also it seems I have oil on the rear lens. Will alcohol wipes clean it? Thank you.

[@andredematosalves]

Thanks for sharing, could you tell me a brand of these screwdrivers you use?

[@crimsonred9207]

I did the same thing and my haze/fungus still remains. Any help ?

[@Danistb]

Hello! I recently removed the rear element to clean up som haze and I lost track of which side is which. I noticed that the edge is rounded of on one side while being sharper on the other. Do you have any tips? Regards, Daniel

[@monochromes]

Not sure, I would guess the rounded edge should be facing the film. At 1:44 you can see the shape of the lens. If you use the lens on a digital camera it will be easy to judge how the proper orientation.

[@Danistb]

@@monochromes would images come out blurry or something if it is the wrong way?

[@monochromes]

@@Danistb I'm pretty sure the will. They may be sharp in the center but blurry in the corners. At least, it's worth trying. :-)

[@kalenderquantentunnel9411]

Why is it, nobody is showing how to disassemble regrease the helicoid in these lenses (1.8 and 1.4)? With most LTM lenses it is a straightforward operation? Is there any catch to that on the Canon lenses? 😮

[@monochromes]

Have a look at this video kzbin.info/www/bejne/iX2phZt3Z9hmiqc He can probably help you.

[@clipsTL]

Just picked up a Canon 50 1.8 LTM but it back focuses a few inches- seemingly at all apertures. Any tips on how to fix this? Thanks!

[@monochromes]

Sorry for a late reply. I'm not sure how to correct a back focus really. Did you find a solution for this?

[@clipsTL]

@@monochromes i haven’t, unfortunately. I think the lens will be relegated to use with my Sony a7.

[@Pentaxmarine]

What if the haze/fungus is in between the middle two middle elements?

[@monochromes]

It's still doable. Have a look at: jimshomeplanet.com/lensglue.html I don't know how the lens elements are glued in the Canon lens but I restored once a SMC-Pentax 100/4 lens that was very cloudy: It turned out the cement between two lens elements was the culprit. So I stored the glued glass element in acetone for a week, after that it was easy to separate then and re-glue them with Canada balsam.

[@scottgubbins5940]

Hi! I don’t seem to have the little screw above the aperture ring to remove the first element. I’m sure I have the same lens as the rest followed the guide, minus this one screw! I need to fix the aperture blades! Do you know if there is a different model or any tips on removing it?

[@monochromes]

Not sure if there are different versions out there. For some Pentax lenses, you can see variation if they look the same. The screw will secure the first element so you should be able to just remove it?

[@FalseDigital]

I can't seem to figure out how to remove the rear lens group in the same way you have. When I try to screw off the back it doesn't move at all. Is there a screw holding it in place that you didn't show in the video? Any help would be appreciated. Thanks!

[@FalseDigital]

Also, do I need to disassemble the whole front element to remove the rear group or is it possible to simply unscrew the rear elements by themselves?

[@monochromes]

Hi Graham! No need to remove front element in order to remove the rear group. All you need is a lens spanner to untighten to ringt holding the rear lens element in place. I really recommend a spanner if the ring is stucked. A screw driver can easily slip and scratch the lens. Do you also have a Canon 50mm/1.8 (LTM)?

[@FalseDigital]

Thanks for the response. I ended up figuring it out. It just happened to be on there really tight. After using a rubber grip (for jar lids) I was able to twist it off. I've got a lens spanner, so it was just the twisting motion that I was stuck at after that.

[@monochromes]

Happy to hear that! Good luck!

[@ataabax]

I have a problem with my 50mm 1.8 chrome version, I couldn't reach the rear elements, anyone tried to clean that version?

[@ChefAlexSocci]

Is there a reason you prefer to use the peroxide/ammonia solution rather than alcohol? Seems most people use alcohol so im curious. Thanks!

[@monochromes]

Just a coincidence actually, I stumbled on the recipe when searching on fungus. Honestly, alcohol would be good as a first an option since it is a more gentle treatment. If that is not sufficient, go for my alternative.

[@ChefAlexSocci]

@@monochromes cheers, seen some people use windex which contains ammonia but not this combo, this seems less likely to affect coatings if done gently and at proper dilution.

[@monochromes]

@@ChefAlexSocci in my case the lens was very cloudy and the coating was not affected after the treatment - at least what I could see.

[@joelfetzer8738]

Worked like a charm. Thanks!

[@bigstick5278]

I just picked up a Canon f1.8 35mm LTM up for $1.00 and original lens cap and brown case Salvation Army.. I notice a little strange ring on the rear inside element but looking through the lens it is clear no haze. I shot a few shots on my Sony a6000 and found it to have amazing IQ and super compact on the Sony. Perfect for street photography candid shooting. Looks like easy dissembling but I always fear I will put it back together wrong. How do you get the infinity lock off?

[@monochromes]

I haven't tried it myself. When I look at the lens I pressume the infinity lock can be untightened by turning it anti-clockwise. I'm not so fond of the infinity locks either. $1 for the lens! That's a bargain!

[@bigstick5278]

$1.00 that's more like a sin!! Lol!! and it wasn't even half off day!! (0:} I shot some more shots and I see no effect on the IQ, may just leave it alone for now.. It basically has the same mechanics as your 50 so popping out the rear elements shouldn't be a huge task.. Anything I should know other then having the orientation of the elements back in the same way they came out?

[@monochromes]

Nothing I can think of. The lenses are probably constructed in a similar way. Take your time, have the proper tools. I'm jealous about your 35/1.8! :-)

[@bigstick5278]

Then you will be jealous that the a6000 I am using was another deal of the decade at $8.50 and kit lens.. It was a filthy high shutter mileage kit lens wasn't working but after some persuasion cleaning and tapping on it worked won't manually zoom the ring just spins. Didn't have a battery so I got it for half of what they wanted.. $15.00 battery and charger and it's in my hands all the time except when I am sleeping. And now i posses a butt load of 50mm and other brand name lenses. My poor D700 is sitting i need to work with that again for true Full frame work.

[@monochromes]

That's an easy life! :-)

[@ryankevin]

The aperture ring on my lens is pretty sticky and difficult to move. Would I need to fully disassemble the lens to lubricate the ring?

[@monochromes]

Ryan Kevin Yes, I would disassemble the lens in order ro clean the aperture blades with isopropanol and lubricate the barrels. It's fairly straight forward. :-)

[@jaldert76]

Do you still clean these lenses. I got one that needs service ;)

[@monochromes]

I don't dare to do this for others! :-) If I mess things up, I would feel terrible to return it.

[@bert98deer]

I don't know if your still responding, but i'm having trouble unscrewing the front and rear part of the lens. It's almost like its stuck, do you have any recommendations for this issue?

[@monochromes]

Still around! ;-) What kind of tool are you using? It should all be very straight forward.

[@bert98deer]

@@monochromes awesome, im using a lens spanner wrench. The 2 holes in the front and rear lens element that you have to unscrew to get the lens out are difficult to move and seem stuck. Im debating if I should get vacuum pads to get a better grip on it.

[@bert98deer]

@@monochromes nevermind I got it off using the vacuum pads and a bit of elbow grease 👍

[@monochromes]

@@bert98deer Happy to hear that!

[@BennyCFD]

Is there a Canon FD to M39 ltm adapter

[@monochromes]

Yes, have a look at the Novoflex adapter at BH photo.

[@utube321piotr]

Most of these lenses suffer something far worse than fungus coating the middle, small lens element, which on a lens cross-section diagram is #4. The haze in 2 copies of the lens that I happen to have seems to be caused by a strange "coating" that sits on top of the glass surface and it is mighty hard and resistant to acetone and isopropyl alcohol as well. I had spent a good amount of time with 10kRPM mini grinder/polisher equipped with a rotary felt pad using a cerium oxide water slurry compound to get rid of this nuissant optical impediment. It seems to me that this "coating of haze" is not something that would naturally develop on a glass surface, but rather as if someone tried to change the lens character and make it render dreamy and soft. I have not tried the ammonia/H-peroxide mix since I don't have such compounds readily available, but will attempt it soon enough in my quest to figure out this anomaly. Thanks for sharing your videos.