Nikkor AF-D 35 f/2 or AF-S 35 f/1.8 or Tokina 35 f/2.8 macro ???

Started May 7, 2010 | Discussions thread
brightcolours
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Re: Nikkor AF-D 35 f/2 or AF-S 35 f/1.8 or Tokina 35 f/2.8 macro ???
In reply to moving_comfort, May 12, 2010

moving_comfort wrote:

brightcolours wrote:

pandalee wrote:

well, you really dislike slrgear.com but IMO, theirs the best tests then here DPR, I mean Lens tests , I dont need camera reviews but lens review some times needed since some lenses like zeiss 28 and 25 , I can never see them myself before ordering them on line.

there are many sites only test Canon or Nikon only but they are of fanboy kind , so I do not trust them at all.

that siad ,@ here or @ slr the reviewers sometimes answer to your particular questions , I know PZ guys comes over here to ansewer to some people that he does like but he also insults others who dislike his review in very bad manner, I read a few threads where he was coming out very agressively or insulting others that dislike his site or a particular review of his, this makes them less trusted ,imo.

The thing is this:

SLRgear's "findings", test data, often is not truthful. Why that is, I do not know. Whether they intentionally post fake results, whether it is because of their technical inability to test, or mess up test data in another way, I have no idea.

But it is demonstrably wrong, often.

.

If this is true, then you should be able to demonstrate an example of one or more of their errors?

OK, an example.

  • Canon EF-S 17-55 f2.8 IS USM.

SLR gear writes about its CA performance:
"Chromatic Aberration

CA is a bit of a weak point for this lens, at least at its widest focal lengths. At 17mm, maximum CA is quite high, although average CA is much lower, indicating that the worst CA is limited to the edges and corners of the frame. CA decreases as you zoom to longer focal lengths, reaching a reasonable level (but still higher than we'd like) at 28mm. CA from 35-55mm is acceptably low"/
And:

"The Tamron has better CA (sometimes much better) across the focal length range, as well as lower vignetting in all cases except 17mm above f/5.6, where the two lenses are close to equal. "

And about the Tamron then:

"Chromatic aberration is generally very good; a little high in the corners at 17mmm but decreasing to very low levels at longer focal lengths. (Go ahead and load up the interactive viewer for CA though, there are some odd behaviors some places within the operating envelope, minimum CA doesn't necessarily occur with the lens either wide open or fully stopped down.)"

Now that is all very nice. However, anyone knowing anything about both lenses knows that is factually just wrong, and how SLRgear comes to their findings of the lenses concerning CA measurements is anyone's guess.

Photozone finds concerning the Tamron:

"Chromatic aberrations (color shadows at harsh contrast transitions) are high towards the wide-end of the zoom range especially at large aperture settings with a peak of 2px on the average at the image borders. Stopping down reduces the issue but you will need to stop down to f/8 in order to suppress the problem to uncritical level at 17mm. CAs are a far lesser problem towards the long end of the zoom range. Please note that CAs can be quite easily corrected in most modern RAW converters or via tool support."

Lenstip finds concerning the Tamron:

"Unfortunately, the Tamron 17-50 mm did not impress us in this category. Tamron’s full frame substitute – the 28-75 mm model – is equipped with three low dispersion glass elements and in its worse performance the chromatic aberrations does not exceed 0.1%. The Tamron has only one dispersion glass element and probably this causes its poor behavior...

...For the most difficult combination of f/2.8 and 17 mm focal length, the chromatic aberration reaches a value of 0.15%, which is not a very impressive result. Fortunately, for all the focal lengths, stopping down the lens helps significantly. For 30 to 50 mm focal length starting from f/5.6 we are able to decrease the chromatic aberration to almost nothing."/

You can find any 17mm image online of the Tamron, and will notice the CA.

In the past I have noticed more odd results in some slrgear reviews, although other reviews seem to be spot on. Because of the odd results, and not knowing how and why they occur, has made me ignore SLRgear, as it is only possible to rely on their reviews when you actually know the product already (in case there are such odd results).

(Note: I don't have a strong opinion of either Pz or SLRGear, other than there have been reviews on SLR gear that have conformed to my own experience a bit more than PZ, although I do follow PZ pretty closely for the measured data.)

I think PZ is just as vulnerable to to sample variation as any other site, maybe more so, and many people mistakenly take their results as gospel a bit more than other sites. They are a resource, not a gospel.

That is what I always say too. Base your opinion on a number of resources. Just not SLRgear.

But sites like:
Photozone.de
Lenstip.com
Dpreview
Fredmiranda.com

.

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