01-04-2015, 10:00 AM
LenScore uses a 200MP SuperDuper lab-only sensor. For EVERY lens the same sensor. While PZ uses for each lens a normal body which in most cases are not the latest fashion in camera-technology. Their D3x from 2008/2009 still has the same MP as your D750 - but they haven't tested the Sigma 24-105/4 A on that body.
That's also the reason why DxO gets different results for the same lens (if it's a 3rd party product from Sigma, Tamron, Tokina etc.) The Tamron gets less points on a D610 than on a D810 - not to mention the even lower resolving Canon sensors. But while LenScore gives the best possible comparison (imo), that doesn't matter much if the AF module of the body and the lens' AF drive don't fit well together.
Of course, depending on your way of shooting, a weak AF system might not be a huge issue - but people who go for a zoom lens try to save time: No lens change, maybe no tripod, maybe phase detection AF only or most of there time - all that can make the optical second best your personal best purpose lens.
Also, an important part but not tested is reliability of the AF: How many shots out of 100 are sharp? In which conditions? Testing labs use a best shot method (focussing manually, with light variations and get the best resolving out of it). In daily use, things can be different. For me, reliable and well-performing shake reduction is a benefit - I've not always a tripod with me. Some samples of that you can find in this test shot gallery.
And we didn't talk about sample variation yet. Lensrentals.com made a couple of resolution (only) tests, just to see how big the difference between the worst and best lens of a lot (same manufacturer and type) is. Sometimes tiny sometimes you'll get the impression the manufacturers use some kind of random production
How long will the AF work reliably? What about cold weather? How important is weather resistance to you? From the whole value of a lens, the optical bits are a major part, but what good is the best optics if the AF misses half the time? Or there's no AF and you have to rely on your focussing skills? Also, for Nikon owners, the Sigma zoom and focussing rings do the opposite what I'm used from Nikon zooms. So, if you have only one zoom, no problem, if you have a mixed collection, it can be a little bit confusing.
My advice would be: See if a dealer would borrow you the lens in question or you can rent it and get your own pictures. For my personal use the Sigma appears to be the best because my standard lens is either 35 or 50 when I walk around with two or three lenses with me (mostly primes). For travel the Sigma is pretty okay and performance wise on the level of the Nikon 24-120/4, if not better. (Another lens to consider, sorry)
That's also the reason why DxO gets different results for the same lens (if it's a 3rd party product from Sigma, Tamron, Tokina etc.) The Tamron gets less points on a D610 than on a D810 - not to mention the even lower resolving Canon sensors. But while LenScore gives the best possible comparison (imo), that doesn't matter much if the AF module of the body and the lens' AF drive don't fit well together.
Of course, depending on your way of shooting, a weak AF system might not be a huge issue - but people who go for a zoom lens try to save time: No lens change, maybe no tripod, maybe phase detection AF only or most of there time - all that can make the optical second best your personal best purpose lens.
Also, an important part but not tested is reliability of the AF: How many shots out of 100 are sharp? In which conditions? Testing labs use a best shot method (focussing manually, with light variations and get the best resolving out of it). In daily use, things can be different. For me, reliable and well-performing shake reduction is a benefit - I've not always a tripod with me. Some samples of that you can find in this test shot gallery.
And we didn't talk about sample variation yet. Lensrentals.com made a couple of resolution (only) tests, just to see how big the difference between the worst and best lens of a lot (same manufacturer and type) is. Sometimes tiny sometimes you'll get the impression the manufacturers use some kind of random production
How long will the AF work reliably? What about cold weather? How important is weather resistance to you? From the whole value of a lens, the optical bits are a major part, but what good is the best optics if the AF misses half the time? Or there's no AF and you have to rely on your focussing skills? Also, for Nikon owners, the Sigma zoom and focussing rings do the opposite what I'm used from Nikon zooms. So, if you have only one zoom, no problem, if you have a mixed collection, it can be a little bit confusing.
My advice would be: See if a dealer would borrow you the lens in question or you can rent it and get your own pictures. For my personal use the Sigma appears to be the best because my standard lens is either 35 or 50 when I walk around with two or three lenses with me (mostly primes). For travel the Sigma is pretty okay and performance wise on the level of the Nikon 24-120/4, if not better. (Another lens to consider, sorry)