Older vs Newer production of same lens.

[jolyonralph]

I have been wondering how much difference there is between a modern production run of a lens that's been on the market for a while (eg the 50mm f/1.4) and older production of the same model.

While the optical formula is the same, one thing that has clearly improved in the time is the general production testing methods and I would assume that inter-copy variation between 50mm f/1.4s would be lower with current production runs than with those made back in the 90s.

Has anyone done any real analysis of this? I know that subjectively my new(ish) 50mm f/1.2L seems a lot sharper than an older model I was playing with in the past - but that may simply be wishful thinking.

 

[LonelyBoy]

I can't help with analysis of sharpness or AF accuracy, I can tell you that there are changes over time - the 24-105L that came with my 5D3 has a different body than the early ones. It's subtle, but for example the raised rectangular bumps for the AF and IS switches are much lower-profile than the earlier examples. Even car manufacturers sometimes make subtle changes in the same model and year with the same nominal options. It wouldn't be surprising at all if they managed to become much more consistent with their copy variation over time as well, just like semiconductor chip yields.

To really tell this you'd need to ask Roger really nicely to test an early batch and a later batch. And hope that it's a high-enough volume lens that they did make running changes to the production.