Renegade, I wouldn't have believed it myself, except that I was going back and forth between live view, and the eyepiece...focusing on something relatively close, of course...less than 5 feet (using my 58mm Voigtlander f/1.4) I first noticed it on the much-reviled 1.3x crop camera I rented. It was more pronounced on it...but it's certainly still there on my 1.6x camera too. I guess that's why they offer focusing screens for fast lenses, but that seems like a bandaid, because there could still be a degree of effective focus shift going on...going from something as small as your pupil, to something the size of the sensor. (I know lenses have focus shift themselves, but given just how fine we can magnify the image these days...and given just how shallow the focal plane is via a fast lens at close distance...you never know. This is also likely why those who shoot fast lenses of people "on the go" or "street photography", might be happier to not view their images at 100%. Just a guess.)
Wombat, I agree. I've posted in their blog section at times. Lensrentals are very professional, and very kind. I highly recommend them.
Glongstaff, interesting. And again, they were nice pictures! I may just try to ask Lensrentals if they've MTF50 tested the 50-500 Sigma lens. Probably haven't. I have to wonder why they would charge 40 to 50% more to rent it, than the Canon 100-400L, even given the extra reach...if the resolution truly is overly soft, especially towards the long end. The comments they have on the lens say it is sharp:
(Roger's Take): "After playing around with it for an afternoon, I’m totally impressed (obviously on limited data but totally impressed nonetheless). It is as sharp as the original 50-500, which is sharp indeed. The OS is spectacular and really does appear to be 4 stops worth. We have some nice 500mm images shot at 1/125 second. Autofocus speed is adequate to the task and accuracy has been good, up until the items discussed below. My summary: once again Sigma has designed a spectacular lens, and while the price isn’t cheap, it’s a good value for what you get."
They seem to have cut off the "items listed below"...I believe it initially had a high electrical failure rate...and some focus shift issues that required AFMA. I am not scared to use mine, as long as the setting is consistent at all focal lengths and focus distances...which it almost never is!
After a quick search, I am seeing the street price for the Sigma at $1509 at the usual places, and $1399 from Amazon marketplace. The Canon 100-400 seems to be $1499. I suppose the difference in rental price, could be due to the fact that so many more people rent the Canon, and they stock more of them. I believe I read somewhere that it is their most often-rented lens.
I really wanted to try a big zoom, but I'm just not that enthusiastic about the 100-400. I guess I should be. I know it's a fine lens.
Looks like Superdigitalcity, who offer coupons via a Lensrentals rental, have the same price of $1509, and have a sale price on the 150-500 OS, of $1019. The 120-400 is on sale for $949. If I was going to buy something, a price of under $1000 would be preferable...along with the smaller size and weight of the 120-400. But again, neither LR or Borrowlenses rents the 120-400. And I'm not ready to buy anything just yet. But the robins will be passing through here before the end of February.
I recall seeing a test of the 120-400 lens somewhere, and it looked bad. Could have been thedigitalpicture.com, I forget.
Given the combination of the low rental cost, combined with widely known and consistent performance / image quality, it looks like the Canon 100-400 may be my best choice.
I do want to rent a faster lens also, a month or two later...and that looks like it's between the (as yet released) "Art" version of the Sigma 120-300 f/2.8 (said to have two fluorite elements, the 2011 version has none)...or the version 1 Canon 300 f/2.8...or the version 1 Canon 400 f/2.8 (given what you get for the reduced rental price, it's hard to not want to rent the big heavy old 400.)
