I really hate buying new. It's not that I don't lust after beautiful glass and cool looking new cameras, but I hate the process.
When I worked in a camera shop, I developed the habit of not buying before trying and two things happened. I either did not take to the new gear pretty quickly, saving the hassle, or if it suited my pre conceptions I would then test a potential purchase against several of it's siblings to make sure I got a good copy.
Often my rudimentary* testing could not clearly pick a poor lens from a better one and if this was the case, there was not a problem big enough to find. After a lot of this, I rarely found a bad copy but the fear was still there of spending my hard earned on a "dud". One of the reasons I switched to M43 was the consistency of the lenses, both in performance and variation.
Enter the 40-150 f2.8, bought on faith and without comparison. Nothing but good things have been said about this lens, but I was suspicious of it until proven otherwise. My first job with the lens, after some basic tests was a disaster (NEVER use new gear on a job until you are fully conversant with it). The images taken of slowly moving subjects on a bright day were soft- "soft focus lens" soft. Tests had proven the lens to be as sharp and clear as my 75mm (at close distances and indoors) but these images displayed a hazy fuzziness with blown out highlights that were unworkable (think mobile phone photos pre smart phone).
Unhappy with the lens, but having had it awhile, unused due to poor health, I felt like I was stuck with it. More testing pre sale, just to make sure.
All images were good !?!
It is a bit sharper and crisper than my much loved 75-300 and matches the 75. What to do?
Today I think I have nutted out the issue. Edit; looks to be a firmware issue to.
The two images were taken within seconds of each other with identical settings, but different focus pulls. The only thing that could be different is the point of focus. On checking, the hazy image has no better focal point closer to the lens (both are heavy crops), so the focus miss must be behind her and the slightly more coherent bokeh supports that.
On checking the original shoot images, the focal point is just behind the subject also.
When the lens misses focus to behind the subject (an issue with moving subjects on EM5's) , the resulting foreground bokeh is very soft and hazy**, almost glowing. This looks to be a mostly bright day phenomenon so far, greatly exaggerating brilliance and the lens also looks to over expose a touch which does not help.
I must admit, this has firmly relegated the two zooms to the scenery work they were purchased for as I just don't get the snappiness from them that I get from my primes and that outweighs the convenience benefits. Stopped down and used carefully they are excellent, but for wide open portrait use they are neither consistent nor fast enough.
*In the past I would do a bookcase test, viewing identical images at 100%, then I switched to corner tests as that looked to be the first indicator of trouble, but lately I just take images in good light hand held with the different lenses, but the same camera, choosing off centre focus targets. If the issues are bad enough to see this way, they are bad enough to matter. Remember, a lens as good as the best image it can take, not the worst, but consistency is key.
** Lightroom 6 has the new dehaze feature on both the brush and effects palettes, helping to negate the issue.