crazy question how does the 16-55 f2.8 compare to the 50mm f2?

It probably most depends on what you shoot. I have both the 50mm and the 16-55mm. I haven’t made an IQ comparison between the two, because they’re very different lenses and not interchangeable - sorry for the pun

If you want to read a proper technical review on both and compare them, check out lenstip.com. They already reviewed the 16-55mm some time ago and should have the 50mm F2 review up in a couple of days - that’s how long it usually takes them to translate from Polish (http://www.optyczne.pl/index.php?test=obiektywu&test_ob=416).

If you travel a lot, want to shoot everything and are often in challenging weather conditions - the zoom is the way to go. I just spent a week with it in Iceland and couldn’t be happier. The range was nearly enough to cover everything, my 50-140mm spent most of the time in the backpack. With the winds and rain, changing lenses was almost only possible in the car, so a no go for primes. I just downloaded the pictures to my computer, so a deeper evaluation has to wait, but from first looks the sharpness, contrast and color look great. It handled long exposures, northern lights, running horses and hand held landscapes just fine.

The 50mm lends itself due to size and weight more for light travel and places where you know what you want to shoot . No tripod, inconspicuous, considered fun. Together with the 23mm F2 they make a beautiful combo and weight together with the X-T1 only 200g more than the 16-55mm alone. The AF is IMO even a little bit faster than on the zoom, but not by much - both are more than sufficient for my needs. The IQ of the 50mm is beautiful. As with most primes, it has a little more character to its rendering than the zoom - probably a question of (micro-)contrast.

One last thing: if you mostly carry a backpack/shoulder bag, the weight difference isn’t very noticeable. If however you want to carry it mostly on a shoulder strap or in your hand the 450g make a ton of difference. Either of the X-Ts + 16-55 aren’t really heavy, but it’s a front heavy package, which means on the strap the camera doesn’t lean on your body with the LCD but tilts, making the experience less than optimal. The same thing goes for hand carrying - I barely notice my X-T1 with the prime, but after some time with the zoom my wrist gets tired…

Good luck with your decision,

Mike