Originally posted by LeDave I had issues making adjustments due to poor lighting as the AF adjustment varies, when I finally got the chance to do it in sun-light, I was able to single it out to a +9 for perfect AF. I learned the hard way, never adjust your AF in poor lighting conditions. And no, really bright in-door light-bulbs do not count. It can vary from +5 to even +9 when you try to adjust it in really poor conditions. I didn't believe it before but I do now, the K-5 has issues with fluorescent lighting. If you are planning to keep it all the way, as in not planning to resell it in the future like me, then you can consider in keeping it. But if you are someone who likes to switch lenses a lot or is unsure about whether you want to keep it in the long run, then I suggest you send it back for a better copy for higher re-sell-ability/trad-ability. But as this can vary by the specific person, some cannot tolerate that much of a back-focus at all even if they plan to keep it for many years down the road while some can. It all depends on how you feel about it. Also I know how you feel about the weather, where I live right now, the weather is going crazy. It snowed a lot yesterday also and cars were slipping off the road. Good luck adjusting your AF, don't let the +10 fool you until you actually test it out in the light, it could be better or worse, and if anything you should return it if you can't find a good lighting a few weeks before the return policy expires.
LeDave,
Funny, you read my mind. I just did some more testing indoors with using two bright light bulbs illuminating the chart, but I had a suspicion this is not making for an accurate test at all. I'm hoping for a sunny day tomorrow. As for the selling/keeping the lens long term, I tend to be a keeper, like you, until the thing dies. Once I have something, I convince myself to make the best of it, for better or for worse (hence the waffling in making an exchange). Usually, everything works out. It's only as a result of using this lens that I've begun to question so many things about the K5, focusing, and lenses in general. Up until now I was satisfied, but perhaps I've just climbed a steep learning curve in becoming more particular. The crazy narrow depth of field combined with focal length makes autofocusing a real challenge, don't you think? Or is it just me? Also, low contrast seems to challenge this lens more than either of my two lesser lenses. By the way, did you use the same testing chart I mentioned? If not, how did you test?
Also, have you tried any AF-C, high speed tracking (continuous frame-high) with this lens? One reason I got it was for getting super sharp outdoor shots of dogs, kids, things in action, as well as for some use indoors (after all, it's supposed to be fast at 2.8). I understand it's a bigger lens to move around, but the AF-C seems much slower than my kit. My choice was between this lens and the 70-200 Tamron, and I'm very satisfied with the range, build, weight, bokeh, colors and IQ (when in focus) of this one, but have learned that I'll have to plan better when shooting fast moving objects.
Did I read somewhere that you had this lens, sold it, and then got a new one? If so, any differences between the two?
I'm going to call B&H and see what my timeframe for exchange is. Their answer may nudge me one way or another.
Stay warm in your snowy climes!
Pam