"Bad" copy of PL 12mm f1.4 "fixed"... try at your own risk!

jeffharris wrote:

What does “RHS” mean? Never heard that one before.

I’ve always been in support of fully spelling out an acronym term (with acronym in parentheses) then resorting to the acronym going forward.

This was the first result when I Googled it... so it can't be that obscure in my humble opinion (IMHO).

Interceptor121 wrote:

Did you ever checked if the lens was decentered in the first place using a siemens star or other technique?

No... just practical usage. There are various causes, not just decentreing, for bad performance. I never proved it was decentred... it could have been tilted, off axis, spaced incorrectly. I just applied a technique I had read about that could produce a fix, and luckily it did.

Pete_W wrote:

glassoholic wrote:

A few weeks later, I thought about it again and this time tapped around the front/ filter mount.

Lens mounted and... amazingly, all is good!!!

Wow! This is quite amazing.

I had this lens, in fact I tried three copies of this lens and was dissatisfied with all of them due to softness along one side. It was really disappointing because I have two PL15 lenses and they are perfect, so I held high hopes for the PL12.

I don't think I ever would have been game enough to do what you did! But I am glad it worked for you.

Thanks. Sometimes I look at something and just go ahead... damn the torpedoes... another day and I would not have dared to do it. If I hadn't got the idea by reading about it, I wouldn't have thought of it. I figured that a pro grade lens, especially one without any stabilisation mechanism, and a prime (no complex groups of elements in a zoom moving around), should be able to withstand the forces I put it through... it would either "fix" something or do nothing further wrong... plus hope for some luck too that it did not exasperate the issue. Modern lenses have many glass elements and several sub assemblies, or tubes, holding groups of elements stacked, all retained by screwed in rings. I presume that there could be tiny amounts of free play or "give" in the assembly, and that when it all goes together, somewhere there might be a tiny misalignment or a speck of foreign substance that prevents everything from bedding or seating in the way it was designed, and doing what I did, encourages something to move into where it was intended to be.

Credit to lensrentals.com for the below screenshot:

jeffharris wrote:

glassoholic wrote:

jeffharris wrote:

What does “RHS” mean? Never heard that one before.

I’ve always been in support of fully spelling out an acronym term (with acronym in parentheses) then resorting to the acronym going forward.

This was the first result when I Googled it... so it can't be that obscure in my humble opinion (IMHO).

OK. Thanks for the explanation.

Cool trick fixing that lens!, BTW. 😉

Rectangular Hollow Section in my world. Generally grade 350, or 350 megapascals yield strength 😁

Gnine wrote:

jeffharris wrote:

glassoholic wrote:

jeffharris wrote:

What does “RHS” mean? Never heard that one before.

I’ve always been in support of fully spelling out an acronym term (with acronym in parentheses) then resorting to the acronym going forward.

This was the first result when I Googled it... so it can't be that obscure in my humble opinion (IMHO).

OK. Thanks for the explanation.

Cool trick fixing that lens!, BTW. 😉

Rectangular Hollow Section in my world. Generally grade 350, or 350 megapascals yield strength 😁

And the moment of inertia ...

Hey guys,

I have owned something like 50 m43 lenses. From my very own experience there is a HUGE sample variation between them. Even Olympus PRO lenses suffer from it.

For example I have had 3 Oympus 25mm 1.2 PRO lenses and just the last one that I still own can be described as an excellent piece. The other 2 were noticably softer than my PanaLeica 25mm 1.4.

So yes be aware of such a phenomen.

Cheers

Dunsun wrote:

Hey guys,

I have owned something like 50 m43 lenses. From my very own experience there is a HUGE sample variation between them. Even Olympus PRO lenses suffer from it.

For example I have had 3 Oympus 25mm 1.2 PRO lenses and just the last one that I still own can be described as an excellent piece. The other 2 were noticably softer than my PanaLeica 25mm 1.4.

So yes be aware of such a phenomen.

Cheers

Yes. For me, as long as there is not a one or other side soft issue, I can live with a copy that is a bit softer than hoped for. I too had a 25 Pro problem... left side soft, and Olympus under warranty did something to it and it came back very good. Lensrentals have some good articles and even the pro type lenses from other manufacturers have a range of sharpness in samples, but there seems to be a suggestion that m43 is generally worse in this regard.