Originally posted by tennjed Thanks Steve. So the fact that the K3 images appear noticeably softer on the MacBook (non retina) does indicate that the K3 has an AF problem?
Originally posted by stevebrot If normalized to the same degrees of arc, both the retina and a less capable display will appear equally sharp.
^^^^That is the most important statement.
There's a lot of math involved and I may not have it all down, but it starts with the 240 pixels per inch of both the K5 and K3 native sensor image.
You then have to equate the viewed image to the pixel density of the monitor, it might be something like 90 for your non retinal display and 130 for the retinal display.
There's a formula out there for monitor size and pixel density etc.
So basically until you can look at your monitor replicating 240ppi based on your MONITORS ppi you aren't comparing images equally.
At this risk of being really wrong, I feel it's akin to JPEG compression because at 90ppi you are seeing only 1 out of every 3 (rounded up) pixels of the native 240ppi image.
What this means is that your monitor at say 90ppi is using hardware to extrapolate an image that's at 240ppi. Some monitors do this better than others.
I think this means 240ppi images at 185% on a 4k monitor (130ppi) = 240ppi images at 267% on a standard monitor (90ppi)
What does that mean for your 50-200? I'm not sure because you are talking about MacBooks versus iPads and different resolutions. Pixel density is a factor of resolution AND diagonal so the different platforms are apples to oranges.
I also don't know how many images you took, at what shutter speeds and what apertures and iso, but if I had to make a guess, I'd say the 50-200 is not playing well with the K3. The K3 is very unforgiving of lenses and technique (you can find 3 dozen "K3 sucks..oh wait it was me" threads on PF). I had 3 lenses that played very well with a K5iis, a K30 AND a K-01, but they became unusable when put on a K3, no matter how much I tried to tweak them. I think the K3 may be exposing flaws in the 50-200 or your technique, or both.