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I took a whole series of photographs of local listed buildings, so I could add them to wikimedia - until I saw the results.

D5500 with Nikkor 24-120mm VR 3.5/5.6G 50mm ISO 100 1/320s f4.8

Full picture [jpg ⅓ actual size, click-through]

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detail - screen-snap at x2 zoom

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Pictures taken hand-held, but I'd say that's too much distortion to be motion-blur at 1/320, reinforced by the fact that all my pictures are similarly affected, even faster exposures. I was bracketing so some are at 1/600 or higher. VR was on. Also I had a polariser on to help with the clouds.

Detail of a similar picture taken the same day with just the kit lens at 18mm, 1/125 f4, also with CPL - same 2x magnification as above.
It's not perfect, but it shows nothing like the blurring of the 24-120

enter image description here

I've noticed this 24-120 showing bad colour aberration before, when using it on extension tubes for macro - so even under highly controlled conditions with good lighting & multiple manual exposures on a focussing rail, it still isn't good.

I would have otherwise blamed the CPL, perhaps giving some internal reflection, but I really have to come to the conclusion that this lens doesn't focus properly on my camera.
I have no means to tweak & save the auto-focus in-camera, it's not a feature on the D5500.
I would also perhaps blame the relatively wide aperture, maybe I should have stopped it down - but the kit lens turned out sharper at a wider aperture.

Is this just a "duff lens" in the broadest terms?
[I have to say I've never liked it much, but I was given it, so never look a gift horse in the mouth]

Is there anything in my admittedly newbie technique I can do to improve this, or is it just time to get a 'better lens'?

(Not used for this particular comparison, but I also have a 50mm 1.4 & a Tamron 70-300mm f4-5.6 neither of which shows such glaring focus-fail)

After comments:
I went back to the location to try some further experiments. I removed the CPL from the equation, but added a variable ND to my 50mm to reduce light & get longer exposures, just for comparison. These are [very] quickly assembled from my results...
[again, click to see larger]

24-120mm
a) one of the bracket -1 EV shots from the first session, with filter & VR [to eliminate long exposure shake from the equation]
b) through d) no filter, no VR
b) tighter aperture
c)/d) original aperture, fast exposure

enter image description here

50mm for comparison
a) 1/40 to show how steady I can hold the camera - not perfect but OK-ish.
b) similar settings to my problem pics
c) comparison at tighter aperture
d) comparison at wide open
enter image description here

  • Two things to try: 1) Use AF in Live View 2) Manually focusing at max magnification in Live View - the idea here is to see whether it's a PDAF, CDAF or just a general autofocus problem. – Philip Kendall Sep 26 '17 at 11:01
  • Based on the small preview image of the whole thing, it looks like there are other areas that are focused better than the are in your crop. What AF point did you use and where was it pointed when you (or the camera) locked focus? – Michael C Sep 26 '17 at 12:05
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    D5500 Reference Manual says (gray box page 163) the + button zooms Live View preview up to 8.3x. Move it around with arrow keys. It's very handy for focusing. – WayneF Sep 26 '17 at 14:10
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    @Tetsujin 1/3:2/3 still only has a single distance that is at sharpest focus. Everything closer and further is blurrier the further away from the point of focus they are. DoF calculations are based upon viewing the entire image at a reasonable distance, not upon pixel peeping. – Michael C Sep 26 '17 at 15:54
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    If you're going to zoom in on the bus stop sign to judge AF accuracy, wouldn't it make sense to actually tell the camera to focus on the bus stop sign? – Michael C Sep 26 '17 at 16:01
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I believe it is motion blur from being handheld, as your sample crop of the sign shows a double image with a sort of drop shadow effect. I've encountered nearly the same issue when a shot is taken while the camera was still being steadied- I steady my camera with my left hand and guide the camera up to the left of my left eye when I shoot handheld. This creates a diagonal blur like what I see in the image.

Otherwise, the image is in focus, about as best as it can be for your chosen aperture, and that crop is of details that are pretty close to the resolution capability of your camera. It would be hard to discern any faults other than global softness, as you point out.

Here's your image again, with the area of interest marked in pink (Note the text: 616 WS or 616 W8).

Original crop image, callout to 616 and WS text on signage.

It's a little easier to see the symptoms with a little increase in brightness and big increase in contrast (10% brightness and 40% contrast in Paint.NET).

Original crop image, callout to 616 and WS text on signage, image adjusted to show relief from likely motion blur.

Aside from the motion blur, everything else is okay with the image for what it is. I recommend testing again in a similar scenario with a bracket of shots, some with a tripod and and some without; and some with VR on and some with VR off (set VR to tripod mode if available when testing on the tripod too). There's a chance you may see continued softness or reproducible blur with VR on, which may suggest that VR is to blame on the lens instead.

  • See my additional shots, added to the question - inc one from the same session at 1/1000s showing a very similar issue. – Tetsujin Sep 26 '17 at 14:52
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    "motion blur from being handheld" is not motion blur, but shake blur. Motion blur and shake blur are quite different. – StephenG Sep 26 '17 at 23:38

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