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Next PZ Lens Test Report: Nikon AF 85mm f/1.4 D (FX)
[quote name='mst' timestamp='1281450844' post='1645']

Yep. Still, I have some hope the AF-S will be better. Not much, though. In fact, I usually tend to be rather pessimistic ... but prepared for the best <img src='<#EMO_DIR#>/wink.gif' class='bbc_emoticon' alt='B)' />



Quote:I see some potential for additional review work here <img src='<#EMO_DIR#>/wink.gif' class='bbc_emoticon' alt='Big Grin' /> Seriously though: from my experience the focus shift remains visible in normal working distances with these lenses. At least with the Sigma ...

I'm afraid it may vary from copy to copy. I tested two different Sigma 50s a few years ago (I think; first one about half a year after they first appeared on the shelves), spaced about 6 months apart.. Both had some focus shift, worst at F/2, of about 1 cm at a focusing distance of 50 cm. At F/2.8 no longer noticeable, and neither beyond about 1.5 m, but then at longer distances both frontfocused rather badly, one to a degree where anything beyond 5 m was unusable (couldn't focus further away), and the other from about 8 m.

Ah well. I did test 5 50Ls in order to get the one I currently own, over a period of a little over a year <img src='<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='Big Grin' />. My 85L II actually has a little more focus shift than the 50L, so I guess that is a very good score <img src='<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='Smile' />.

Quote:Nope, only focus miscalibration. The lens was simply backfocusing, and that becomes more obvious with larger subject distance.

Ah, ok, I was wondering already <img src='<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='Smile' />. However, one wouldn't expect that with an expensive Leica lens...

Quote:I haven't tested for focus shift, yet, but you're right about not being an APO lens ... at least not in the sense we usually look at it (truely apochromatic). It shows a considerable amount of LoCAs.

Well, I was just wondering, because I couldn't find really useful information.

Yes, difficult to find on the internet for sure. Most people do use longitudinal CAs for this, but normal CAs are sharp, these ones aren't, as they are in the OOF areas, and they have a completely different origin, hence my suggestion for the actual optical fault name.

Quote:However, to get to the point that's probably more important (people mixing up lateral CAs and LoCAs): maybe we should add some links to a lens test FAQ or place some short explanations within the reviews.

-- Markus

Maybe with some sample photographs to show the difference, including where they appear? Maybe also some for PF as well, as that is a different beast altogether too <img src='<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='Big Grin' />.

Kind regards, Wim
Gear: Canon EOS R with 3 primes and 2 zooms, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....

Messages In This Thread
Next PZ Lens Test Report: Nikon AF 85mm f/1.4 D (FX) - by nosingchum - 08-10-2010, 02:16 PM
Next PZ Lens Test Report: Nikon AF 85mm f/1.4 D (FX) - by wim - 08-10-2010, 08:40 PM

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