Originally posted by Digitalis This is actually a really good point. I have a considerable amount of Pentax lenses, sending my camera in to get it adjusted for the AF inaccuracies of one lens - and take the risk of throwing out all the calibrations for all the other lenses I own, is a risk I cannot take.
I'm pretty sure that Sigma calibrates the lens to the body...not the body to the lens. I don't know if you meant to imply that it is the other way around, but that's what it sounded like to me.
The other guy was saying that ideally, lenses and camera bodies would be calibrated to the neutral point. That sounds great in theory, but I'm not sure how I would go about actually getting that done. I would not have confidence that I would be able to get a Pentax service center to actually do such a thing, and do it right.
Has anybody here actually had that done at a Pentax service center? I think they would be likely to say that the body is already within acceptable range, but if somebody has first-hand experience with this, I would love to hear it.
Originally posted by Digitalis Yes, there is a chance of camera bodies being the culprit of AF accuracy issues, however the lenses can also be at fault.
But you made a good point that calibration is not all in the lens. Manufacturing tolerances also apply to the camera bodies. I witnessed this first hand when I upgraded from my K-x to my K-30...calibration was drastically different. So in my experience, Pentax is not better than lens manufacturers in this regard. Which is why I found it useful to have my lenses calibrated to my specific body.
In fact, this whole calibration thing is something I hate about DSLR's, and is one of the reasons I have not upgraded to the K-30, and have been looking hard at mirrorless.
I sold a Sigma 100-300mm f4 to someone on the forum last year, and on my K-30 it worked beautifully with perfect focus. But the buyer, who had a K-5, claimed that it was too far out of calibration to correct on his body, and forced a return through PayPal, even though I had discussed possible camera body calibration issues with him before the sale. I then resold it on eBay as "for parts or repair" at a significant discount since I didn't want to deal with a second return, and the second buyer used it on his K-3 without any issues and was delighted with it and left gushing feedback. So yeah, I'm pretty sore on the subject in general, and it seems to me that Pentax bodies are a moving target in terms of calibration.
I recently bought a Panasonic GX7 to test the waters before committing to the GX8, and so far I've been enjoying it thoroughly. I've picked up the Panasonic 20mm 1.7 and Olympus 75mm 1.8, and they've been great, with no need to worry about calibration since focusing is performed on the image sensor itself. To me, this is the way of the future, and I will be happy to never have to mess with calibration again.
BTW, it seems like I remember reading something about how one of the big manufacturers (can't remember if it was Nikon or Canon) has made it so that when using their newer lenses on their newer DSLR bodies, there is some kind of feedback loop such that takes place so that the camera can detect and correct for calibration discrepancies between the lens and body, and you end up with perfectly focused images. Does this sound familiar to anyone else? It seems like it was an article written by lensrentals.com. It would be nice if Pentax could incorporate a similar system in their AF.