Originally posted by PentaxPoke .. Shooting outdoors at 50 mm I compared my Pentax glass to my Tamron 17-50. Camera settings were identical. Whenever I looked at the shots from the 17-50 the WB seemed a bit "off." Sort of yellow. None of the Pentax glass did this. ......
There's a fair bit of on-line comment that the Tamron 17-50mm has a warm cast.
This lens has a big user community because its also used on Canon/Nikon/ Olympus etc.
I have a Tamron 28-75 and it also has a bit warmer tone than Pentax glass. Likely related to the different coatings used. My guess is its too subtle to see anything in RAW, but it confuses the AWB for JPEG.
Haven't used it on the K-7 yet, probably try it over the weekend...
So far, I'm aware the K-7 makes use of Pentax lens-embedded data to optimise for Program line (if you use P-mode in MTF), Autofocus, Distortion/CA correction (if you turn it on). Haven't seen anything on AWB. These cameras may be getting "too clever" by a bit - doing things without your realising it.....