[stoppingdown]

I just ran the test on my just arrived Sony 4/10-18mm... Former attachment is focused, latter is slightly defocused. It has been taken according to the suggestions, but I didn't use the tripod: I think it's ok because the lens is stabilised. The focused image doesn't look decentered, or at least too much; the defocused image looks it is. Your opinion?

 

Now, the practical question. I've bought through Amazon and I think they shouldn't contest a return because of a defect, and send me a replacement. But how many chances I have that the new lens is better (above all, how many chances about one which is worse)? I mean, if my current sample is just slightly decentered, is it worth while asking for a replacement? Does somebody have some experience about how many times Amazon would satisfy a replacement request? Thanks.

[Klaus]

It's probably too late but if this lens was mine I would return it for sure.

[stoppingdown]

Not too late, as I contacted Sony right after my latest post here and they asked for a proof... I'm just waiting for a LED panel to redo all the chart tests in decent light conditions.

[josa]

Hi Klaus, if I prit the template on A4 and put it on the wall, také the picture, will result be the same? Thanks.

[mst]

The resolution of the template might not be sufficient to give really sharp edges in an A4 print. However, you may give it a try.

On the other hand, it should be quite simple to create a similar pattern with a vector drawing program, which you can then scale to any size wanted.

-- Markus

[josa]

Thanks Markus!

[casual snapper]

Hello from Germany!

 

After some tests I managed to do a test with both planes in parallel with my brand new Fuji X-E1 & XF 18-55.

Result: I am able to focus to a point, where all four lines are almost equal, however a slight defocussing shows a rather worrysome result. Both are 100% crops from the center. Unfortunately I don't have a second lens for comparison. Hmm, what should I do?

 

- Frank

 

[Guest]

To everyone:

I had Sony SEL50 sample which passed this test perfectly but one corner was rather bad.

Be sure to check if all corners have same quality/resolution even if this test shows no issues.


Frank:

If you can exchange this lens with no question asked - just do it.

Getting some pictures that clearly show sharpness issues (like weak side/corner) should be helpful in most other cases.

[casual snapper]

Hi everyone,

 

what about the testing of the edges?

Focussing with the center AF-field on a distant object (approx. 100m) in maximum

wide angle setting and ma. aperture, then switching to MF and comparing how much the four edges

are out of focus in relation to each other (not absolutely).

 

How ist the accuracy and importance of this test compared to the "5° checkerboard" test?

 

- Frank

 

Edit 2 March 2014: I was able to exchange the lens. In fact I got two successive replacements. The checkerboard test was ok with both, however both showed unevenly sharp edges at wide setting. I kept the 2nd replacement, because I noticed the problem was a slightly inclined field, with could easily be compensated by a minimal refocussing or inclination of the camera and is almost not relevant in real world situations.

However, sad enough, I had three XF 18-55 and not one of them was ok in both tests.

By the way, my newly acquired XF 35 mm performs fine with both tests.

[TomPhillpotts]

Hi all,

 

I seem to have the same problem, I'd like to get some other's opinions on this. 

 

I have a Fuji XF 18-55, here's the results of my test. I think the problem is there, but perhaps not as serious as Frank's above, for example?

 

My question is, is this problem bad enough to be worth me exchanging the lens for another, considering that the replacement lens may be worse than what I have now?

 

Thanks for your input.

 

Tom

 

[ATTACHMENT NOT FOUND][ATTACHMENT NOT FOUND]