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LensRentals on two new Sigmas - so-so and oho!

Quote:A chart stays the same - but lenses usually are corrected for ∞ . With a 50 × fl (50 × 14 mm = 700 mm) as a distance to the chart, one has to run into problems such as more vignetting and distortion at closer range.
No, we tested both. Distortion barely changes and has no influence on the results anyway, because we don't correct it. Vignetting is also not an issue in the analysis (unless it is really extreme, as it happens for example to be for many wide angles on the Leica M).

Also, loo at the focus scale on your lens: the test distance is much closer to infinity on that scale than MFD. So far I have not found any evidence that testing at this distance and the results I get from there contradicts the results I get with tested lenses "in the field".

Quote:Let me be the one to spoil the party: what I see in the Nikkor shots is not PF, but LoCA, IMO. So, to me, the Nikkor shots look out of focus.

I didn't quite get how you focused. Did you use LV to focus on the corners, or especially the crops you're showin? And did you do some focus bracketing or stacking to see if you hit best focus?

With both lenses, I used LiveView at max enlargement. This means, the focus field has to go down to the right corner - what you see in the crop was the spot I focused on. Additionally I checked with a LCD loupe. Don't know if you already saw the LCD of the D850 - it's the best so far and I really doubt if focus bracketing would come up with a better result.


You can defend that Nikkor - as I said, as a zoom it's still a marvel. But I will not redo these unscientific rows. I might be wrong with one focusing, but not with three. And the focus row, I just did quickly, was worse - even at step 1 (of 10) it's not fine enough. Next step could be using a focus rail and move the camera mm by mm - but honestly, Klaus I leave that to the fans of Nikon   Wink I've seen enough to come to my conclusion and I did this kind of comparisons also often enough. And you? Any experiences with the 14 mm Sigma?  Tongue

No, no experience with the Sigma yet, sorry. Only a 3-digit number of other lenses and a bit of practice in reviewing Wink

But seriously: looking forward to being able to get my hands on the Sigma, for sure.

I was prepared to see the Sigma worse, especially after it fell down and I never heard that kind of incidents ever improved anything. I really tried to get the best out of the Nikkor, but I also admit: if it would be a better performer in terms of flare, I would not have thought of getting another 14 mm - the f/1.8 is nice, but easily overrated. And a tough challenge for AF, too.


In regards of stars wide open, the Nikkor is still doing better - so I think I should send the Sigma in to have it checked and the hood replaced. It's just, I don't trust their one-man workshop too much. I've seen their gear and I'm not sure it won't come back worse than I send it in.

Just mentioning - you are comparing a 2 1/2* rating on 50mp with a 4* rating on 24mp?

I did also provide a 3 1/2* rating for 21mp ... which you seem to ignore altogether in your argument although it's the one that you should take here if at all ...

The rating reflects the degree of a lens’ capability to cover the potential of a sensor in full across the image frame (besides other criteria).
No, I'm not comparing your ratings - I was just wondering, how two lenses I own compare to each other  Big Grin


I'm thinking about ratings and their impossible comparisons and the more I think about (as well as about better ways to do comparable ratings) the more I understand your troubles.


Besides, 3 ½ ★ for a prime with less distortion, less flares and IMO same or better resolution wide open than a 4 ★ rated zoom - well, I just skip the rating bit.


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