[robbiec]

Yes, once you have done two things:

(1). Bought the lens (or rented it for a longish time),
and
(2). Used the lens for long enough, in enough different situations, to "recognise ... [the] lens' strengths".

Good tests (what this thread is looking for) come in earlier,
when you're trying to decide whether it's worth your while to do (1) and (2).

Unfortunately, most of the tests out there have their flaws and gaps,
so they don't really help you that much.

All the tests have weaknesses and I personally believe if you have a K-1 are meaningless (possible exception of Ephotozine as they have tested the new DFA zooms on the K-1) save as a guide only. If you buy a lens purely on resolution as suggested by the OP then what about colour rendition, flare handling, bokeh, micro contrast? - I would argue that they are just as important as pure resolution - if that was the case then the only Pentax 50 to buy is the D(FA)50/2.8 Macro, followed by the DA50/1.8 followed by the FA50/1.7, A50/4 Macro and then the A50/1.2 (which actually in real life stomps on the 1.7 for scene rendition) and then finally you will get to the 50/1.4 - now who is going to tell me that the OOF handling of the 50/1.7 is better than the 50/1.4? Someone mentioned the Zeiss 2.8/25 which tests pretty badly but used out in the wild is a fabulous lens that belies its test results (I can personally attest to that but I bought it because I researched it properly and then bought on a gut feeling despite the test results), how does one cater for the exceptional exceptions?

You have a hankering for a certain lens for whatever reason. You will research, possibly there will be a couple of online tests, you can search on here and might find a lens club solely for the lens in question or search on Flickr for example. If it passes the research phase then you are 3/4 qtrs of the way down the Buy route. What do you do next? you have possibly the choice of renting (doable in the UK and maybe certain states in the US, a couple of days with a lens is more than enough to find out the basics of what a lens is capable of with the shots that you will be using it for) or buying one. Easiest thing to do is pick one up 2nd hand, try it out and if you don't like it sell it on. If you lose money that is your research rental fee, if you break even, you've had experience of a lens for free, if you make money all the better.

One potential thing we could do on here would be to create a Lens Test club with a reference guide on the imaging tests to perform which could be created via the poll system - i.e. flare handling, high contrast handling, close up, near distance (i.e. reportage), landscape, and whatever anyone else chimes in that could be useful. An Imatest suite is not possible for the vast majority on here so you won't a resolution test as such but there must be a couple of hundred photographers on here that are more than capable of stress testing a lens without pure scientific numbers.

[normhead]

You can run tests, but can you determine what in individual user might like? Different people like different things. The point being, it doesn't matter what you test, if you pick a favourite, 70% won't agree with you. Every image posted on the forum is a test. Some people are looking for shortcuts. There aren't any.

Tests will be important when there is linked data that can predict which people will like which lens. Until then, they are just a bunch of numbers.

35mm find that prime. - PentaxForums.com