It has been a while since I looked in here , but having finally got myself a K-1 exactly a week ago , thought I'd drop in to see what was happening . After four years or so of using my K-3 , which I'm keeping , I expected the K-1 to be a straightforward transition - actually it's VERY different - besides a few new buttons and switches , things in different places and a whole new menu system - the operation of the camera is quite different , so this last week has been quite a learning curve . My first challenge was finding the best lens to use on it . While I've been shooting Pentax since 1975 and have more than a few SMC-M series lenses , I don't have so many FF AF lenses . I fist dug out an old SMC-F series 28-80 macro lens which I thought might work quite well ( it did on my MZ-S ) but it was somehow disappointing - but maybe some of my other settings were off ... Then I tried a Sigma 28-135mm consumer grade lens - this one has produced some stunning photos on the K-1 , so I'm well pleased with it ; I also went out with a Sigma EX 15-30mm lens I've had for a while , and photographed a castle nearby , trying out the HDR and pixel shift modes on a sunny day - these turned out really well also ... I have three Metz 54 MZ-4 flashes , with the correct SCA modules , which always worked well on my K-3 , and the *istD before that - but at first wouldn't play well with the K-1 . I tried dropping the sync speed down from 1/200 to 1/180 and the results were a bit more consistent - on the K-3 I always shot in X mode and selected aperture manually ; this at first didn't seem so great on the K-1 ( I had set the Metz from APSC to FF ) but then it seemed to start working . I also recently got four Cactus V6ii transceivers , and had them working pretty well with the K-3 , but it took a bit of fiddling around to get good results with the K-1 . I also have one Metz 70 MZ-5 and three 45 CL4 Digital flashes , which all worked with the K-3 but I have yet to try wth the K-1 . I seem to be generally getting there , but it is a lot of trial and error , which I hadn't expected . When the pictures come out though , they are stunning and the image quality is streets ahead of the K-3 , so I'm well pleased with the camera and just need to put more time and practice into it .