Originally posted by Rmagers jatrax. I use a Sigma 18-50 2.8 and Tamron 70-200 2.8. I was under the impression these lenses would work on either. Is that not the case?
I am really only familiar with Pentax lenses. However, I can say both of those lenses will
work on the K-1 or KP as long as they worked on your k-x but they might not be the best choice. I would think the 70-200 would work just fine on the K-1 but the 18-50 will most likely vignette badly. It might be usable at 24mm or so but you would have to test.
Only you can decide what is acceptable for you but if you are going to go with the K-1 I would suggest you also budget for a 24-70 lens of some sort. The DFA 24-70 is excellent but there should be older Tamron or Sigma ones out there in similar focal ranges. Or if f/2.8 is not critical think about the DFA 28-105.
Originally posted by dakight Let's be really clear... it is not mandatory to upgrade to full frame lenses.
No it is not mandatory, but IMHO rather silly to spend the money on a FF camera and use old APS-C lenses. If anyone is going to make the commitment to FF I think they are just fooling themselves in thinking they will be satisfied with APS-C lenses. Considering where the OP is coming from (k-x) then the KP (or the K-3II as you suggest) would be a huge upgrade, would use his existing lenses and be far cheaper.
I would suggest that, given a certain budget, buying a KP or K-3II and a top notch lens will result in better performance than buying a K-1 and sticking old APS-C glass on it. This is especially so in the OPs given use case, portrait sessions with studio lights. In that case the low light ability of the K-1 is not a factor and the lower weight of the KP or K-3II would be an advantage. Of course if budget is not an issue then go all in and get the K-1 and DFA 24-70.