Originally posted by Paul the Sunman Pentax Distributors: "Hey Boss, we have a request for an inspection copy of the DFA 70-210 from Font-of-all-knowledge.com". Boss: "Great. Go into the store room and find the most de-centred copy we have to send them. And if you can't find a de-centred one, pick any and drop it from head height. Then send it off to them straight away; we want to see those MTF charts out as soon as possible."
Is that what really happens? It would seem so, given the regularity of the "they had a bad copy" mantra here on PF. As someone with a cupboard full of Pentax lenses and not one dud, I find it strains credulity that these review sites cop the bad copies so often. Indeed, surely distributors should test any lens before sending it for review, just to be safe.
Two lenses is exponentially better than 1 for testa, doubling the amount of information and therefore reliability, so starting to build a consensus. If bdery and Digitalis came to the same conclusion I think we could call it a wrap. The score is 2-0 for the Tamron, but it's only the fourth inning.
If it were baseball, you'd say "With the score two nothing and 4 innings left to play, my team still has chance to win." Those of us who follow sports know you can't just run to a betting site and place a bet because one team has a lead, and claim you're going to win your bet. You'd be wrong good portion of the time.
I'd be more worried about making an error in judgement based on too small a sample than giving Pentax a break by suggesting bad copies caused the problem.You look at the tests, the images etc. you make an informed decision.
But honestly, everyone trashed my 18-135 and I love the lens, so I give no credibility to any of these clowns. They know what their measurements tell them. That has no correlation with whether or not people might like the lens. It's a public service that they publish their results, it's on the people who read the results that think a lens is unsatisfactory because of them if they judge a lens to be unsatisfactory because of them.
What's worse, people who suggest it might be a bad copy, or people who suggest Pentax is building an inferior lens based on two copies?
In my opinion, when users results are contradicted by the internet sites, the user is always right
from their perspective.
The sites run their tests, but clearly, in the case of the 18-135 and many other lenses, their tests are often irrelevant to the users.
I know people have a hard time with this but, the only test that matters is whether or not you like the images.
The test charts don't predict how popular a lens will be.
Price/performance costs.
Affordability counts.
Handling an ease of use count.
Overall rendering counts.
My issue is not with those who are enamoured or dismissive of test scores.
My problem is with people who look at these scores and try and draw conclusions about the utility of the lens from them.
My experience is that when I look at test site scores, then look at the images I like, I'd caution against posting anything negative about a lens because of test scores. You still have to try out the lens. Given the generally positive reviews the lens had, a few people jumping on resolution and CA scores who haven't used the lens is frightening.
My own polls have suggested most people can't tell the difference between reduced size K-3 and k-1 images, and yet people want me to believe they would be affected by the difference between the Tamron and Pentax versions of this focal length. When you're ready to run blind test if DFA*70-200 and DFA 70-210 images @ ƒ5.6 to see who can tell the difference let me know. I'll be interested.
Sorry if I'm dismissive, but I go with blind testing with polls of usually 75 or more respondents. In blind tests, people don't think what they think they think, and they don't know what they think they know. My 18-135 received far worse reviews, on tester rating it 1.5 out of 5. Yet it's one of my most used lenses. Why would I have any faith at all in the meaning of their tests? Keep an open mind, you may find something you like despite the meaningless rumination of test numbers.
A bit of balance please.
Incredible we'd be criticized for being prudent by someone who appears to be so impulsive.
As for the test scores, as published, a lot of people are happy with a lot worse even if the current test scores hold up.