Decentered lenses

[John Mitchell]

I recently bought a new Sony a6000 with the 16-50mm kit lens. Love the camera so far, and I even like the 16-50 kit lens more than I thought I would. It is very compact and and nice and sharp in the central region, even with the 24MP sensor, making it great for casual walk-around photography. However, while I didn't expect perfection from an inexpensive kit lens like the 16-50, I am disappointed by the fact that it appears to be somewhat de-centered. The far right side of images is noticeably mushier than the left. It can get really bad with distant subjects. From what I've read online, this is a common problem with this lens, especially on the right side for some reason. People on some forums have complained that they have had the lens replaced only to find that the new copy has the same issue. Some speculate that Sony's OSS (built-in image stabilization), not decentering, might be the real culprit. My question is, should I bother going through the hassle of exchanging the lens (and most likely the camera as well) or just switch to another lens in situations where I want corner-to-corner sharpness? Any thoughts on this?

[Inchiquin]

I can't say I've ever noticed this with my 16-50.

 

Alan

 

[John Mitchell]

37 minutes ago, Inchiquin said:

I can't say I've ever noticed this with my 16-50.

 

Alan

 

 

Good to know. As mentioned, it's most noticeable with distant subjects -- e.g. landscapes, skylines, etc. The left side of images shows an acceptable decrease in sharpness, but the right edges tend to turn to chaotic mush, making some images basically unusable. Think I'll be making a trip back to the camera store. I also have the original SEL 18-55 kit lens, and it seems fine. There's a slight imbalance in sharpness, but nothing to be concerned about

 

P.S. I've read that even some of Sony's expensive lenses show this same problem.

[Martin P Wilson]

33 minutes ago, John Mitchell said:

 

Good to know. As mentioned, it's most noticeable with distant subjects -- e.g. landscapes, skylines, etc. The left side of images shows an acceptable decrease in sharpness, but the right edges tend to turn to chaotic mush, making some images basically unusable. Think I'll be making a trip back to the camera store. I also have the original SEL 18-55 kit lens, and it seems fine. There's a slight imbalance in sharpness, but nothing to be concerned about

 

P.S. I've read that even some of Sony's expensive lenses show this same problem.

 

In that case could it be the sensor out of alignment, not square to the optical axis? Have you tried the lenses with other bodies? Just a thought ...

 

Mind you is that were the case I would expect it to be more pronounced with longer lenses which have smaller depth of field/ focus.

[John Mitchell]

1 hour ago, Martin P Wilson said:

 

In that case could it be the sensor out of alignment, not square to the optical axis? Have you tried the lenses with other bodies? Just a thought ...

 

Mind you is that were the case I would expect it to be more pronounced with longer lenses which have smaller depth of field/ focus.

 

I haven't  yet tried the 16-50 on another camera body. However, I've used other Sony lenses on the a6000 and haven't notice any problems.

 

Perhaps (?) it's field curvature with 16-50. It's a "pancake" design, and there are some pretty heavy optical corrections being applied to the RAW images.

[Ed Rooney]

I can't make the decision for you, John, but I do suggest you wait awhile before you do anything. 

 

Do you see the problem on every frame? Do you have other lenses you can use? 

 

I've had half the frame show up soft on a 24-85 zoom I had for my Nikon DSLRs. I occasional see this on an image from my Sony RX10. And when I first got the Sony 10-18, it did that once in awhile. The problem in each case fixed itself. Loosing a very occasional frame when shooting stock? I wouldn't worry about that. 

 

Edo

[John Mitchell]

15 hours ago, Ed Rooney said:

I can't make the decision for you, John, but I do suggest you wait awhile before you do anything. 

 

Do you see the problem on every frame? Do you have other lenses you can use? 

 

I've had half the frame show up soft on a 24-85 zoom I had for my Nikon DSLRs. I occasional see this on an image from my Sony RX10. And when I first got the Sony 10-18, it did that once in awhile. The problem in each case fixed itself. Loosing a very occasional frame when shooting stock? I wouldn't worry about that. 

 

Edo

 

You're probably right, a somewhat unusual lens like this -- or just about any lens for that matter ---  is bound to have some weaknesses. Switching it for another copy probably wouldn't help matters much. One just has to get to know its idiosyncrasies. I came across some useful-sounding advice here.

[Ed Rooney]

Do you still have the Sony 20mm pancake? I sold mine to Adorama long ago, and wish I had not. But I'm resigned to using a small shoulder bag with my a6000, since I keep the Sony 10-18 on it most of the time. 

[Bryan]

Not had this problem with my 16-50 John, it's actually reasonably sharp at the edges, possibly better, in that regard, than my Sigma 19 mm f2.8.  However the overall clarity of the images lacks sparkle, my old film era glass produces bigger (file size), crisper JPGs after processing from raw. I still use it when cycling, or when I don't want to carry a bagful of stuff, but it's not my fitment of choice.

[John Mitchell]

2 hours ago, Ed Rooney said:

Do you still have the Sony 20mm pancake? I sold mine to Adorama long ago, and wish I had not. But I'm resigned to using a small shoulder bag with my a6000, since I keep the Sony 10-18 on it most of the time. 

 

I've never owned that lens. It was supposed to be a good one. I have the original 16mm pancake lens to which I keep Sony's "ultra wide-angle" converter attached. Haven't tried this combo with the a6000 yet. Should be helpful to have the extra megapixels for cropping, etc. 

[Ed Rooney]

That's the one I meant, John -- the 16mm.  

 

 I like having the 24megs with my 10-18. It means I can make use that that good zoom from ultra-wide to normal. 20megs is fine, and I downsize some from there, but 24megs gives a feeling of confidence. Must I have bigger and better? Nah . . . I only shot for Alamy editorial stock, no News, no events, no special access, and I'm not holding my breath for a big advertising sale. Sony mirrorless is my friend. 

[davidhu]

Not had any problems with my 16-50 on the A6000, John. In fact I find it much sharper than the kit lens on my Pentax DSLR. Interesting article, by the way. 

[John Mitchell]

3 minutes ago, davidhu said:

Not had any problems with my 16-50 on the A6000, John. In fact I find it much sharper than the kit lens on my Pentax DSLR. Interesting article, by the way. 

 

Hmmm... perhaps I should take my copy back after all. How do you find this lens with distant subjects -- i.e. focused at infinity? I took some distant city skyline shots, and the right side turned to total mush, while the left side was fine. Perhaps I'm just not using the lens correctly.

[spacecadet]

The QC on kit lenses is supposed to be hit-and-miss and my 18-55 (A) sometimes misses focus- when it does the entire image is off, it's not just an AF miss. So I think the focus racking isn't dead on. I'd be taking it back.

*sometimes I put them through at 3250px with extra sharpening if I need the picture.

[spacecadet]

3 minutes ago, John Mitchell said:

 

Hmmm... perhaps I should take my copy back after all. How do you find this lens with distant subjects -- i.e. focused at infinity? I took some distant city skyline shots, and the right side turned to total mush, while the left side was fine. Perhaps I'm just not using the lens correctly.

I have this with a 55-200- it's worse wider than f8. But QC don't seem to mind if the centre 80% is sharp.

I wouldn't put up with it on my short zoom, though.

[John Mitchell]

1 minute ago, spacecadet said:

I have this with a 55-200 wider than f8. But QC don't seem to mind.

I wouldn't put up with it on my short zoom, though.

 

Yes, that's somewhat expected with long zooms. I'm going to have to do some more experimenting with the 16-50. I didn't have this problem with the Sony SEL 18-55 kit lens that I've been using, although it wasn't great at either 28mm or 55mm, but still passable. 

[John Mitchell]

26 minutes ago, spacecadet said:

The QC on kit lenses is supposed to be hit-and-miss and my 18-55 (A) sometimes misses focus- when it does the entire image is off, it's not just an AF miss. So I think the focus racking isn't dead on. I'd be taking it back.

*sometimes I put them through at 3250px with extra sharpening if I need the picture.

 

Interesting. I did some Googling and couldn't find any info on "focus racking" (new term for me).

[spacecadet]

I just mean the focussing elements moving back and forth, on something resembling a rack and pinion gear. Never occurred to me that it was an obscure term. Perhaps it's more of a film term.

[Bryan]

A test I conducted many moons ago shows the Sony 16-50 to perform reasonably at the edges

 

http://bryansphotographs.blogspot.co.uk/2013/03/sony-16-50-versus-pentax-28mm-m-f28.html

 

Here's another

 

http://bryansphotographs.blogspot.co.uk/2013/01/sony-e-lens-test.html

 

Manual focusing with the 16-50 does improve the results, but the lens still lags woefully behind a decent ancient prime

 

http://bryansphotographs.blogspot.co.uk/2014/05/50-mm-lenses-on-sony-nex-6.html

[John Mitchell]

20 hours ago, Bryan said:

A test I conducted many moons ago shows the Sony 16-50 to perform reasonably at the edges

 

http://bryansphotographs.blogspot.co.uk/2013/03/sony-16-50-versus-pentax-28mm-m-f28.html

 

Here's another

 

http://bryansphotographs.blogspot.co.uk/2013/01/sony-e-lens-test.html

 

Manual focusing with the 16-50 does improve the results, but the lens still lags woefully behind a decent ancient prime

 

http://bryansphotographs.blogspot.co.uk/2014/05/50-mm-lenses-on-sony-nex-6.html

 

Thanks for this, Bryan. My 16-50 certainly doesn't look this good on both sides of the frame. I've decided to take the lens back and try another copy. Hopefully, it won't be worse than the first one. Shall find out tomorrow ater I pick up lens #2.  My manual focusing skills ain't what they used to be, but I do use direct manual focus (DMF) when time allows to try to fine-tune the AF. 

 

BTW, do you use a lens hood with the 16-50? For some reason Sony doesn't supply one. Perhaps they wanted to keep the lens as compact as possible.

 

P.S. Regarding the 16-50 at 50mm. That does seem to be the worst focal length with this lens -- around f/10 seems to get the best results.

[Bryan]

4 hours ago, John Mitchell said:

 

Thanks for this, Bryan. My 16-50 certainly doesn't look this good on both sides of the frame. I've decided to take the lens back and try another copy. Hopefully, it won't be worse than the first one. Shall find out tomorrow ater I pick up lens #2.  My manual focusing skills ain't what they used to be, but I do use direct manual focus (DMF) when time allows to try to fine-tune the AF. 

 

BTW, do you use a lens hood with the 16-50? For some reason Sony doesn't supply one. Perhaps they wanted to keep the lens as compact as possible.

 

P.S. Regarding the 16-50 at 50mm. That does seem to be the worst focal length with this lens -- around f/10 seems to get the best results.

I don't use a hood with it, the only lens in my collection without a hood. Never researched the topic, got me interested!

 

Did you keep your original Sony standard zoom, possibly better than the 16-50?

[Johnnie5]

I just bought a used copy of the 16-50 from KEH and have had no problems with it.  I bought the Fotodiox lens hood for it and am very happy with it. The hood snaps off by pulling on it and can be reversed.  The only downside is it doesn't lock in position so you have to keep checking that it is aligned properly as a little bump may knock it out of position.  The good news is even when out of position at 16mm the edges of the hood don't seem to appear in the photo.  https://fotodioxpro.com/products/rvrshood-405-52-cap 

 

John

[John Mitchell]

9 hours ago, Bryan said:

I don't use a hood with it, the only lens in my collection without a hood. Never researched the topic, got me interested!

 

Did you keep your original Sony standard zoom, possibly better than the 16-50?

 

There seem to be plenty of hood options available. I was thinking of trying a 40.5mm --> 49mm step-up ring and a collapsible rubber hood to keep the "pancake" thing going.

 

Yes, I kept the original 18-55 zoom and the NEX-6 for backup. I was going to sell the NEX-6 but decided to hang on to it  (for now anyway) as a backup. I hate travelling with only one camera body in case it conks out. Have to say, I really like the compactness of the 16-50. I'm heavily into light these days, and the 18-55 is much bulkier. The 18-55 is less finicky, though. Is it better optically? I don't know.

 

 

[John Mitchell]

1 hour ago, Johnnie5 said:

I just bought a used copy of the 16-50 from KEH and have had no problems with it.  I bought the Fotodiox lens hood for it and am very happy with it. The hood snaps off by pulling on it and can be reversed.  The only downside is it doesn't lock in position so you have to keep checking that it is aligned properly as a little bump may knock it out of position.  The good news is even when out of position at 16mm the edges of the hood don't seem to appear in the photo.  https://fotodioxpro.com/products/rvrshood-405-52-cap 

 

John

 

That's encouraging to hear. I'm hoping the replacement 16-50 will be not as decentered. Perhaps I'm being too picky, though. Guess I'll find out.

 

Thanks for the link. I'll have a closer look at the Fotodiox hood.

[John Mitchell]

Just by way of an update, the replacement 16-50 lens seems fine -- no obvious decentering or other issues. There is none of the blurriness that I saw with the original lens when focused at infinity. So sometimes it pays to take things back. As mentioned, I'm liking this little lens so far. Sony seems to have done a good job of packing a lot into a very compact package. It's also much easier to use than I thought it would be.