Originally posted by Marc Sabatella Glad to hear it! Sorry, I posted my other reply before seeing this (I usually try not to do that), but I guess my comments there are probably still valid.
No problem. I added a redirect post.
Originally posted by Marc Sabatella Could be, but without controlled tests, it's going to be impossible to say. As I mentioned in my previous response, focus with ultrawides is always tricky, and not because of any specific fault with any cameras.
Focusing is tricky *on DSLRs*. It is not at all tricky with MILCs where you can zoom into the area you are attempting to focus on.
As for testing, it can be misleading too. If we compare two lenses and one scores a max of 40lpmm in one out of ten trial shots, while another scores the same in 8 out of 10 tests, they will both look equivalent in test scores, but the effort to get good results will not be revealed by their equal score.
It does not matter to me how sharp a lens is in lab conditions because my photography is not done in lab conditions - if I cannot focus a lens reliably under regular use, what good is its *potential* sharpness to me?
Originally posted by Marc Sabatella so there is no real point looking for verification every time someone posts something most people already believe or know to be true. It is when individual results vary from what is generally known to be true that one rightly *should* question those outlying results.
You should be careful with this line of thinking - it leads to
herd mentality.
Originally posted by Marc Sabatella The thing specifically relevant to lens testing, though, is that it is easy to stuff up a test to make a lens look worse than it actually is. Whereas it is next to impossible to stuff up a test to make a lens look *better* than it actually is. If one given controlled test shows great sharpness, then that lens *is* capable of great sharpness, period, and no further tests will cause that to not be true.
See above. Capability is not an indicator of performance. You can dig a trench with a spoon, but it's not going to be efficient. A sharp lens that misfocuses will be worse than a slightly less sharp lens that focuses perfectly. What matters more is the rate of keepers you get from a lens, or otherwise put, its reliability in producing high quality images.
In the specific case of the DA, there may be a combination of focusing issues with the fact that it is a relatively slow lens, so it will have a harder time nailing focus in low light. For example, in one set of tests, I tried focusing on a print and I used the ability to see the printing dots as a resolution bar. With the E-PL2 I could see the dots while focusing and could easily take images that had such detail. With the K-7, I couldn't get those dots to show up - I couldn't see them in the viewfinder and AF seems to have consistently failed to focus on the print surface. This was done late afternoon, so light wasn't great. I moved to a table with a lamp and I repeated the test - the K-7 was more reliable now and scrutinizing a crop, I could see all the detail I could hope to record.
My conclusion at this moment is that the DA15 is as sharp as I need it to be, but it requires accurate focusing to benefit from that sharpness.