23mm 1.4 decentred?

[Phil]

I was shooting a wedding yesterday and dropped my X-T1 with the 23mm 1.4 attached. It fell about two feet down onto a carpeted floor. It landed more or less on its side, I think, but the lens cap had been pushed onto the lens and was difficult to get off.

 

I found this shot from later in the day, at f/4. The 100% crop in the Lightroom panel is from the centre of the frame, and the cropped view in the middle is from the upper portion of the frame.

 

Does this look like its decentred? I'm Canadian and bought it from B&H, so trying to get it serviced under warranty could be a hassle (I do live right on the border at least).

 

Screen Shot 2016-02-01 at 12.29.07 AM by Phil Babbey, on Flickr

[darknj]

It looks so to me, although the fall shouldn't have been that bad, unless it was an over 5 feet (1,5m) fall.

 

But if the lens cap was pushed inside, it really is not a good thing for the front element of the lens.

 

I would certainly try to send it in and claim innocence about the fall.

[Phil]

That's where I thought I might be alright, because the lens focuses internally and the cap wasn't hit so hard that it took any permanent damage. The fall was under 1 metre. I'm not very tall and the camera was hanging at my side when I dropped it (I unclipped it from my BlackRapid strap for a photo and since I could still feel the strap on my shoulder, forgot and just let the camera fall at my side when I was done).

 

I'm going through the day's photos and doing some tests right now and centre sharpness seems to be fine, but I'm not sure about the edges.

 

In that photo above, is f/4 shallow enough that the top of the wall could just be falling out of focus? I was angling the camera to keep the wedding party near the bottom of the frame.

[darknj]

In that photo above, is f/4 shallow enough that the top of the wall could just be falling out of focus? I was angling the camera to keep the wedding party near the bottom of the frame.

 

That is very possible, since I haven't handled the 23mm that often I wouldn't be certain of its out of focus parts. And it makes for me try to compare it to the 35mm F1.4 neither.

 

Have some more tests and see if that bothers you, if it does, send it back in under warranty saying that you strangely noticed the out of focus area and feign ignorance when asked about the fall, that MIGHT work.

[quincy]

[...]

In that photo above, is f/4 shallow enough that the top of the wall could just be falling out of focus? I was angling the camera to keep the wedding party near the bottom of the frame.

 

That's just a bit of math, i guess.

Depending on the size of the people on your picture (a bit less than 1/3), and your camera's angle of view of about 63°, I'd estimate your distance to about 5 m from the heads of your subjects.

Assuming that your camera was at about the same height as your subjects heads, 19° of your FOV point downward, 44° upward. This gives us about 5 m of additional wall on top of your subjects. That wall is about 7 m away from your camera on top of the frame.

 

If your camera was focused at the faces (5 m), your DOF at f/4 ends at about 2 m behind the subject, assuming an acceptable circle of confusion of 0,009 mm. That'd be right where the wall is on top of the frame.

Taking into account the loss of sharpness towards the edge of the frame every lens has, your image might just be what is to be expected, or slightly worse.

[milandro]

I think that how each one of us would react to something like this happening ( to lens AND camera)  is a very personal thing.

 

Some people would react in a  nonchalant way. If it is not , obviously, broken, and it works, go on living with it.

 

Others, and that includes me, would not feel good about it and from now on start obsessing that every little thing which will happen in future will be the product of what has happened.

 

From what I see and if you are person type A, don’t do anything, everything works as it should.

 

However if you are person B, as I am, send it in to have it checked .

[Phil]

Thanks for the feedback guys.

 

I'm thinking things are okay. I did a rough measurement today and it fell pretty much exactly 2ft onto a carpeted floor (with a wood subfloor). Since I was holding it before I let it go, if fell accessory door first. I didn't notice how it landed, but since the lens cap was pushed on harder, I'm hoping it absorbed some of the impact. The AF doesn't sound any different or seem any slower, and my photos from the rest of the day don't seem soft - but it was a wedding and I mostly shoot people anyway, so it's mostly centre frame.

 

I'll keep a close eye on it and shoot it often but try not to worry. With no external moving parts and a (more or less) pro build, it should hopefully be fine. Thankfully it wasn't the 35 1.4. I'm not normally one to obsess over little things, but money is tight and I use this lens for work, and it would be a big hit to have to get it repaired - I'm guessing it would be an expensive fix. I'll shoot it some more after work and update here if I find anything interesting.

[Phil]

Not to bump a boring thread but I shot a brick wall, and even at 1.4 only the far corners are soft. Stopped down to f/4, there's a tiny bit of softness in the most extreme corners, but even at 100% it's hard to catch. I think the left corners may be a little softer than the right, but it's hard to even find the softness, so I'm going to go on with my life and try to forget about it. It very well could have been that way when I bought the lens.

 

Definitely the last time I buy internationally, though. With gear this expensive it's not worth the risk IMHO.

[frod]

Well, even if it is slightly off, you now have a unique lens that will produce shots that nobody else's 23mm f/1.4 will!