Originally posted by peso54 The K1-II brochure suggest that its FF sensor will be automatically cropped to cope with these lenses using an effective resolution of 15.36 megapixels, compared to the 24.32 sensor on the K3-II.
You can set the K1 and K-1 II to not automatically crop, and depending on the particular lens you may see a lot of vignetting or very little with your DA lenses.
I use the HD DA AF rear converter 1.4x AW quite a lot with my D FA 150-450 on the K-1, and whilst there is some vignetting, to me it isn't a problem. I almost always crop in post to arrive at an acceptable final image which is better than having the camera crop. I should add that whilst I find the vignetting of the 1.4x TC only a minor issue others have described it as serious, so it's a YMMV issue I think.
Check the lens database, many of the DA lenses have information on their performance (vignetting) at various f stops, on a FF camera.
Cheers,
Terry