Wobbly Canon LTM 50mm f/1.4 Lens

[AusDLK]

I have a very nice LTM Canon 50mm f/1.4 lens but it has some annoying play in the barrel when focusing or twisting it when holding the front and rear of the lens, maybe 1mm or so side-to-side.

I found a video on how to disassemble this lens but nothing specifically related to this issue.

It doesn't make the lens unusable but I'd still like to fix it -- or have it fixed.

Any advice?

 

[lukx]

There is a retaining ring screwed in from the back that holds the optical block down into the focusing mount. If that isn’t tightened it will cause the looseness you describe. It’s a rather easy fix, but requires a lens spanner to tighten. But you could easily check if it’s loose.

 

[AusDLK]

There is a retaining ring screwed in from the back that holds the optical block down into the focusing mount. If that isn’t tightened it will cause the looseness you describe. It’s a rather easy fix, but requires a lens spanner to tighten. But you could easily check if it’s loose.

that wasn't it. there are two rings in the lens around the rear element. both were tight.

 

[Duofold RF]

“I think the Canon 50mm f/1.4 price reflects its mechanical quality, its optical performance is excellent. It used cheap aluminum and was poorly machined and assembled. The play, is most likely due to poorly fitted helical components. You could try using thick helical grease to alleviate the play. My Pentax 50mm f1.4 has the same issue, no fix.

 

[AusDLK]

here is a video showing the issue:

 

[AusDLK]

“I think the Canon 50mm f/1.4 price reflects its mechanical quality, its optical performance is excellent. It used cheap aluminum and was poorly machined and assembled. The play, is most likely due to poorly fitted helical components. You could try using thick helical grease to alleviate the play. My Pentax 50mm f1.4 has the same issue, no fix.

i don't think this issue is related to the movement of the focus helical. this is smooth. see the video that i just posted.

 

[Duofold RF]

I have the same lens which has some degree of wobbly, you can remove the focusing knob which is fairly easy to do and check for issue. In general the parts of canon 50mm f1.4 are cheaply made and assembling tolerance is wide, hence the price is around $200-300.

 

[dexdog]

that wasn't it. there are two rings in the lens around the rear element. both were tight.

Just checked my copy of the 50/1.4, it does not move like your lens does.

 

[AusDLK]

I have the same lens which has some degree of wobbly, you can remove the focusing knob which is fairly easy to do and check for issue. In general the parts of canon 50mm f1.4 are cheaply made and assembling tolerance is wide, hence the price is around $200-300.

the lens does the same thing whether the focus knob is locked at infinity or not.

 

[38Deardorff]

the lens does the same thing whether the focus knob is locked at infinity or not.

Mine is rock solid....but my 28 LTM the front element group wobbles.... someone had it apart.... but it still works like a charm so i'm learning to live with it.

 

[Duofold RF]

You may need to disassemble it, to check what cause the side to side play.

 

[Duofold RF]

Check this post:

Canon 50mm f1.4 ltm disassembly

I've found and followed some instructions for cleaning the Canon 50mm f1.4 ltm lens, and initial disassembly is quite easy. However, the main part I want to clean and re-lube is the focus helical. Once the rear retaining ring is removed, the focus assembly slides off the back, leaving the lens...

rangefinderforum.com

The wobble may relate to these parts。 Do not over tight the ring.

 

[AusDLK]

Check this post:

Canon 50mm f1.4 ltm disassembly

I've found and followed some instructions for cleaning the Canon 50mm f1.4 ltm lens, and initial disassembly is quite easy. However, the main part I want to clean and re-lube is the focus helical. Once the rear retaining ring is removed, the focus assembly slides off the back, leaving the lens...

rangefinderforum.com

The wobble may relate to these parts。 Do not over tight the ring.

so far as I know I checked these rings and they are tight