Nikon has a competing system and they are not really designed for the pro's looking for full frame etc. I have a generation old olympus pen and am very happy with the camera and lens options. yes I could have gone dslr... but my equivalent setup would weigh 4x as much. body and 5 lenses and filters etc.. i would not discount the current generation of micro 4/3rds which is an olympus/panasonic offering. lenes are interchangeable between the 2 mfgs. i have 2 panny/leitz lenes and 3 olympus ones.