I'm about to make quite an about-face opinion on my experience with the XT-1 and its ability to be used in fast paced sports photography with continuous focusing mode engaged. For those who are familiar with my previous posts I have been quite critical of the XT-1's ability to function well in continuous mode with the XF56 1.2 for sports shooting. Upon reflection I have been really quite biased in my evaluation of that combination given the size of the lens, elements/glass involved, and the crazy F1.2 aperture I was shooting in for most shots. After shooting the same circumstances except with the XF18 instead I can see why I was setting very unrealistic expectations for the XT-1. Heck, how many Canon shooters out there use the 85mm 1.2 behemoth for sports shooting with such an insanely shallow depth of field? Not many if any.
As per usual, let's talk shooting specifications. For this bit of casual shooting I was using the XF18mm in Continous mode CH burst, set to ISO1600, varying the shutter between 1/200-1/500sec, and mixing the aperture up between F2.8-F4. These were all shot in JPEG normal with my beloved Chrome setting followed up with some quick tweaks of my own and some radial filters. For a tiny lens this thing produces some darn sharp images that have a beautiful 3D pop to them and awesome resolution that allows for some pretty heavy crops.
So in case you're a bit new to focal lengths, aperture, and their effect on depth of field (DoF), let's look at a comparison of the XF18 and the XF56 and the average aperture I was using on each occasion, and why the XF18 performed substantially better for very logical reasons.
XF18 @F2.8 at a subject distance of 8 feet = 8.23 feet of depth of field
XF56 @1.2 (because that's what you buy the lens for!) at a subject distance of 8 feet = 0.29 feet of depth of field
These two distinctively different levels of DoF explain a lot, particularly why I found continuous focusing mode to be so frustrating in the past. The XF18 didn't hunt around like the XF56 because it didn't have such a dramatically shallow DoF to work with so naturally continuous focusing mode is going to perform considerably better. That said, the XF56 did work well in single shooting mode and even if I shot at an aperture of F2.8 I'd only be getting a DoF of 0.69 of a foot = struggle town for focusing.
Something else that I found quite remarkable though when using the XF18, which probably has a lot to do with how much glass had to be moved around or rather not, is that with 619 photos on a single battery, the indicator hadn't even dropped to the less than 50% remaining mark!
Read that again!
619 photos on a single battery! And plenty more to spare.
After a solid browse through the 619 photos I took, I also noticed that the across bursts the XT-1 DID NOT miss focus mid shot. Amazing!
So why can't the Fuji perform well for sports shooting at wide apertures like my Canon 6D and 135mm F2?
The Canon 135mm F2 L has been my go to sports lens for a while now and was the first lens I owned on my 7D and continued to use on my 6D as well for various purposes. It's well documented that the 135mm F2 L is an exceptional fast focusing lens, and the most underrated piece of L series glass around, so naturally, comparing a Fuji XF56 lens to it is probably unfair. I know from experience that the 85mm 1.2 won't keep up with the Fuji though. I guess I'll just have to wait until the XF90 F2 arrives and see if it'll be the Canon killer!
My recent experiences with a borrowed XF18 lens (sorry Luis! I'll get it back ASAP!) have convinced me yet again that Fuji are making an exceptional product that meets all my needs as a photographer. The fact that I can walk around the streets with the XT-1 and XF18 inconspicuously yet use it to shoot close-quarter sports like Muay Thai, MMA, and BJJ demonstrates its versatility. It's truly hard to fault it as a camera system, particularly being able to use the EVF to get real-time exposure previews across different settings. I think it may be time to sell my X100s to fund a second body with my own XF18 lens or similarly wide lens.