50L and focus shift, theory vs practice

Does is focus shift? doesn’t it? yes, no, maybe, maybe not...

The question of whether the 50L focus shifts seems to come up every other day (week maybe…) so I thought I would provide my perspective on the matter. I've written up a bit of a blog here to help people judge for themselves whether this really is an issue.

http://wskbrooks.zenfo​lio.com …-shift-theory-vs-practice


Obviously these are my personal conclusions using my own equipment, and they may not apply to every camera and lens combination. But essentially, my conclusions are that, Yes, it does focus shift, but No, isn't just not an issue. In pretty much all scenarios (test charts and real life), what I wanted to be in focus, was in focus.

Have a read if you're interested. I hope you find it helpful.

Well, on your particular lens.

Well said! This lens is intended to shoot real life situation. It is not intended for shooting papers, walls, and bricks. If you buy this lens for just shooting bricks, this lens is not for you.

Sorry, but as you said, your test was on an extremely small sample size of 1 - the 50L you own. So your results, while applicable and good for you, don't mean much to anyone else. on such a test, you cannot make blanket statements like...

Wissigle wrote in post #14535291
my conclusions are that, Yes, it does focus shift, but No, isn't just not an issue. In pretty much all scenarios (test charts and real life), what I wanted to be in focus, was in focus.

the 50L focus shifts by design. depending on the copy you get, this focus shift can be extreme enough to be troublesome, or manageable (which is my case), or not noticeable at all.

So while it's great you have a good copy you're happy with, your experience doesn't really provide any basis for people "judging for themselves whether this really is an issue".

Sol95, which you are right, I shouldn't make blanket statements, but the fact that you took my statement out of context is a bit misleading. The exact preceding sentence was quite clear, I'll repeat it: "Obviously these are my personal conclusions using my own equipment, and they may not apply to every camera and lens combination."

I'm not trying to say this post covers all lens samples in existence, it clearly does not. What I'm am trying to say is that the focus shift issue is real, but it's not necessarily a problem, and in my case, it is not. I suspect many others have the same conclusion.

sol95 wrote in post #14536186
Sorry, but as you said, your test was on an extremely small sample size of 1 - the 50L you own. So your results, while applicable and good for you, don't mean much to anyone else. on such a test, you cannot make blanket statements like... "my conclusions are that, Yes, it does focus shift, but No, isn't just not an issue. In pretty much all scenarios (test charts and real life), what I wanted to be in focus, was in focus."

the 50L focus shifts by design. depending on the copy you get, this focus shift can be extreme enough to be troublesome, or manageable (which is my case), or not noticeable at all.

So while it's great you have a good copy you're happy with, your experience doesn't really provide any basis for people "judging for themselves whether this really is an issue".

Cheers Maximus! Another commonly misunderstood perception made by some who get this lens - it has many flaws, but is also pretty wonderful!

maximus_73 wrote in post #14536166
Well said! This lens is intended to shoot real life situation. It is not intended for shooting papers, walls, and bricks. If you buy this lens for just shooting bricks, this lens is not for you.

Most people that bash this lens don't own it, or did own it, but didn't take the time to learn to use it.

When I first got mine, I freaked out about focus shift. Then I put away the focus charts, stopped sitting in front of my computer pixel peeping, and started taking real pictures. I went from being sick to my stomach that I had spent this much on a focus-shifting POS to realizing it works great in the real world and does exactly what it's supposed to.