I exclusevily used the 18-55 mm kit lens which has a maximum aperture of f/2.8. Here are my first impressions on the X-T1.
I JUST LOVE IT !!!
It's solid yet lightweight. It has interchangeable lenses. Even the supplied 18-55 mm kit lens lives up to Fujifilm's reputation of being one of the best lens manufacturers in the world. It's sturdy : when you zoom, it has just the right resistance. It is sturdy built and certainly doesn't feel like a kit lens, which is all too often a plastic thing supplied in kits of several DSLR manufacturers.
As to the X-T1 itself : it is fast. You turn it on and by the time you look at the LCD or through the EVF, it is ready to shoot. It's autofocus is rapid. It never let me down during this shoot, nor did it cause me any delay or did I have to retake images. Of course, these subjects are static. I hope to shoot some dynamic, moving subjects shortly and get back to you on that.
Does the X-T1 have drawbacks ? Not a lot. For my personal taste the locking of the ISO-dial is unnecessary and a bit difficult.
The EVF is certainly adequate. It takes some time to get used to looking at an electronic image when compared to shooting a DSLR. On the other hand, the big advantage is that you really see what your photo will look like in terms of exposure and white balance. And that proves very efficient. I can't wait to shoot with the X-T1 in a pit lane, where you are not allowed to glance at your LCD monitor without stepping out of the pit lane in a garage box for security reasons.
All shots were made under one of the most challenging white balance conditions : mixed light sources like tungsten spots, daylight and warm incandescent, natural light, ... The results you see were made with the White Balance setting on Auto. I love the color rendition.
Most shots were made on ISO 3200. Fujifilm has already been rewarded for it's high ISO image quality and the X-T1 is certainly no exception. Well done, Fujifilm.
Eagerly awaiting your new 10-24 mm for yet other photo adventures !