While I trust their methods and unbiasedness at Photozone, as several have pointed out, the sheer number of lenses not tested is also an important aspect to consider when reading the different reviews.
How many lenses does TDP, DPReview, DXO use for tetsing lenses?
You make a fair point. From the reviews I've read, it appears that each site has strengths and weaknesses:Roger at LR
is king of sharpness data from my perspective, b/c he tests all of LRs stock of the same lens (in some cases, dozens of the same lens). That trumps most everyone out there for data, but he's not the thoughtful tips/feedback/insights guy that Bryan Carnathan is. Roger also has (IMHO) massive street cred on being a camera nerd first and a fanboy last. He'll blow any design out of the water if it underperforms.TDP
-- Carnathan does test multiple copies but not a huge number. He brings up copy to copy variation when something odd occurs and obtains new glass to verify odd findings. See his Tamron 24-70 IS and new Mk II 24-70 reviews -- fishy stuff came up and he itemized the differences.
Further, his site is more of a broad read of useability and his personal (though admittedly expert) take on things. His site excels at fun image-level comparisons of all the lenses taking the same shot (or test page) from a tripod, and then allowing you to mouseover to see what's going on: L vs. non-L vs. Sigma, aperture, ISO, etc.
I read his site fairly religiously for all-around reasons. It's thoughtful, useful commentary from a knowledgable user. But his is a world of insight and adjectives
-- it's not a lab-like mountain of details.Photozone
has the most nicely broken down sharpness data that I can read easily. They have middle/border/extreme resolution data for many focal lengths on a zoom, and they report it for most common apertures selected. Very helpful. This is a site opens your mind a bit as you tend to comparison shop. At a site like this, you see non-L glass punching its weight brilliantly against L glass if you stop it down just a shade. Big limitation? I believe it's only one lens they test.DXO
s interesting angle is having combinatorial data of bodies + lenses. No idea how many lenses they actually test. I don't read this site much as DXO has (groan) their own metrics on their own hardware that I haven't bothered to learn how to read. I still don't understand their data fully.
I don't read DPreview
reviews as they require a dozen page turns to get ad views. Fail. They are wasting my time versus their competitors.
I don't read Ken Rockwell
much, but my goodness, if you want a fine detail about metal vs. plastic, if the front element rotates during focusing, how many points on the sunstar created when stopping down, etc. then he's your guy. Absurd little details for the nerdy camera lover. TDP has some of this, too, but it's inconsistently reported from review to review.
For me, I trust:
- TDP for everything but data -- it's just there, easy to find, and thoughtfully explained.
- Roger at LR for hard sharpness numbers. End of story.
- Photozone for quick, easy comparison of two lenses I might be considering