New Year; Back To Business; Two Fuji X-T2 Issues

Belted Kingfisher; full image from JPEG (click to enlarge)
X-T2, 100-400mm lens @ 400mm; 1/2000th sec. @ f/8; ISO 2500; tripod mounted; IS off
This is ideally how each of the 102 images I made of this bird should have turned out

As I mentioned in my post on the wildlife weekend I recently took, I discovered two issues with my Fuji X-T2.  Are they really bag things?  I don't think so but I thought I would show everyone that, even with the newest, most sophisticated digital cameras, they always don't perform as we would wish.

The first has to do with focusing capability and the second with image quality.  I'll talk about the first issue here and highlight the second issue in my next post (Wednesday).

100% crop of the above image (click to enlarge)
Detail and sharpness holds up pretty well for such a small subject but the bokeh on this lens is terrible!

In mid-December I was on Virginia's Eastern Shore, in Chincoteague National Wildlife Refuge, photographing migrating birds, waterfowl and other found wildlife.  Its an annual trip with some photo friends.  One small bird I photographed was a Belted Kingfisher.  The closest I could get to it without it flying off was about 30 yards (27 m).  This is a small bird at a much greater than optimum distance, but I was hoping to get some decent images of it.

The camera/less combination produces sharp images (click to enlarge)
This is a crop of 25% of another frame taken the same day—handheld.

On the first day I tried, I handheld the X-T2 with the 100-400mm f/4.5-5.6 lens attached. I had my ISO set for 200, shutter speed 1/2000th sec. and aperture at f/7.1. Autofocus was set to a single point, at its smallest size. The focusing square was placed directly over the chest of the bird, so there was contrast between the white and dark feathers. Image stabilization was on.

I made several exposures and noticed upon looking at them on the LCD at 100% that they seemed out of focus.  I'm not a young guy any more, but I think I can still hold a camera and a lens this size pretty still for short periods of time at a shutter speed of 1/2000th sec.  What gives?

This is typical of most of the images I made as described.  On tripod or off, IS on or Off, high shutter speed.
Nothing in the image anywhere is in sharp focus. I really don't know where the camera focused.  (click to enlarge)

Plan B.  Same setup but turn the image stabilization off as common wisdom says we don't need it over 1/500th second to 1/1000th sec.  Same results.  Frustrated, I drove off to photograph other wildlife.

Next day.  I see the same Belted Kingfisher in the same location in the same tree, different branch.  This time i take out my huge, heavy Induro 400 series tripod with my Really Right Stuff B55 ball head, a setup that I have used for years and is steady as a rock, to make more images.

Tripod mounted, 1/2000th sec. @ f/8; ISO 2000 (click to enlarge)

A lot less light this next morning so I turn up the power on the X-T2!  1/2000th sec. @ f/8; ISO 2000.  Image stabilization on and then off to check if there is a difference. Hit rate is about the same. Maybe 10% of my images are sharp.  Hmmm.

It really bugged me so I tried analyzing my technique and couldn't find any way to vary my settings or conditions so I came to the conclusion that technique was not the issue here.

After getting home and looking at things closely in Lightroom, my other images of larger birds, waterfowl, ducks, eagles, ponies, landscapes, etc. with the same lens tells me the camera and lens aren't defective.  Tack sharp. Further analysis is necessary.

After thinking about it for a few days, I have two theories as to why I didn't achieve adequate focus on this bird in most of the images I made.  First, the bird is too small a target for the autofocus system.  The bird provides a target of approximately 500 X 500 pixels out of a 6000 X 4000 pixel image area.  Very small.  approximately 1% of the entire image area.  Maybe that is too small for the focusing system in the camera.  I don't know. Maybe I should have varied the size of the focus square at the time I was photographing, but I didn't think of that.  That still is an unknown.

Second, as is often the case in many digital cameras, maybe the actual focus point is not precisely under the square as depicted on my focusing screen.  We assume the visible squares cover the focusing points precisely but in many, many tests, that turns out not to be the case.  This deserves more experimentation to find out if it is a factor.

(click to enlarge)

One third consideration.  When the bird was turned sideways to the camera, the contrast of the feathers went to almost nothing.  That may have been a factor in the profile photos as well.

I'm curious if anyone has any additional technical information on the focusing system's size, placement, sensitivity and ability to focus on very small targets.  Please let me know.

Overall, I was extremely happy with the combination of the X-T2 and 100-400mm lens.  I look at this particular instance as an anomaly and no cause for concern.

(click to enlarge)

I've posted a variety of the images that are as in-focus as I could get under these circumstances.  I have mixed feelings about them as well.  They just seem a bit "off" to my eye, but it may just be the less than optimum bokeh in the background that distracts me from the bird itself.  These images represent about 10% of the overall frame.

This is a good example of knowing your gear, its capabilities and its potential limitations. Only when we fully understand our tools can we get the most out of them and achieve expectations as well as avoid disappointment.

As I said, this is nothing that I am worried about.  i believe there is a logical explanation for why I wasn't able to achieve consistent focus.  But the camera and lens combination—wonderful!

Next post, I'll show you another issue I discovered when photographing the Christmas Parade in the small town of Smithfield Virginia just before Christmas.  Come back, it is interesting.

Thanks for looking. Enjoy! 

Dennis A. Mook 

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