Originally Posted by divamum First reviews finally out: http://www.ephotozine.com/article/ta...s-review-19056 It's looking good, although $1299 is a higher initial price than I was expetcing :-/ Still waiting and watching as this one hits the streets.... :)

same link as above ;)

Oh man, this thing has me drooling. Lemme know if any of you find ISO chart shots with it...

Sorry Manfred - was posting in haste and didn't see yours before doing so! They are indeed the same.... :)

Anyone have a view how this lens will compare with the canon 24-105L? Like so many other owners of a 5d2 I have that lens and would step "up" to a 24-70 providing the f2.8 gives me the necessary quality of shallow DoF, bokeh, etc + sharper + IS/VC. I can trade off the longer length if I get all the prior three

Here's the MTF data:

http://www.lensrentals.com/blog/2012...24-70-mtf-data

Originally Posted by Pupator Here's the MTF data: http://www.lensrentals.com/blog/2012...24-70-mtf-data

That link also has a brief review and comparison to the Canon equivalent. Recommended reading.

Can somebody here who's good at interpreting the numbers enlighten us as to what those MTF charts are likely to mean? ~hopeful look~

Also, what about those "onion" highlights? I only saw one particular highlight which did that in the sample - I'm curious as to why it WAS only one higlight in the image (which seems weird), and also what that kind of bokeh indicates.

Originally Posted by divamum Can somebody here who's good at interpreting the numbers enlighten us as to what those MTF charts are likely to mean? ~hopeful look~ ...

The problem with MTF charts is that there is no single standard or even a single agreement on MTF testing methodology or testing limits. In other words MTF charts only allow comparison between lenses from the same manufacturer or tests at the same testing facility. You cannot directly relate MTF from one source to another source.

To drive home how important this is, almost every manufacturer of lenses does optical MTF testing for quality control and versional testing. Canon uses "calculated" MTF methodology for it's public MTF tables, which only loosely compares to optical methods. Both results can be valuable, but only in the context of each manufacturer and not between each manufacturer.

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In general, the horizontal scale is lens center to lens edge, while the vertical scale is contrast and resolution (global contrast versus micro-contrast).

The dotted and dashed lines represent the visual OOF qualities and generally the closer the dotted and dashed lines follow each other, the better the bokeh will appear.

Here is a pretty good video explanation of MTF charts and what they mean:

http://youtu.be/DjCoD0_V2RM

If anyone is interested, there are ISO crops up on the digital picture:

http://www.the-digital-picture.com/R...mp=0&APIComp=0


The reviewer mentioned he had some problem with bad lenses, so IDK how accurate these shots are, but.... they don't look too hot. At every focal length except 70, the Canon 24-70 is sharper at f2.8 than the Tamron is at f8 :x

Am I reading it backwards? I'm jut looking at it now, and it looks like the Tam is sharper in the center (although, granted, not at the edges). The mouseover is the Canon, right?

Originally Posted by divamum Am I reading it backwards? I'm jut looking at it now, and it looks like the Tam is sharper in the center (although, granted, not at the edges). The mouseover is the Canon, right?

At 24mm, I see that too. (... That the Tamron is sharper in the center than the Canon.) The difference is not great, however.

Overall, I agree that the Canon has a better showing. The Tamron images do look like they might respond very well to post-processing sharpening techniques.

I've read elsewhere (photozone, etc) that when reviewing the Tamron's they get very mixed results depending upon the lens copy they are testing...moreso apparently than Canon. This really worries me. It's easy to get stuck with a an underachieving copy or that it could have been better (unless you buy multiple copies, test the heck out of them, and return the others - if even possible). I guess I'll wait for the Canon 24-70 II and see what sort of results it achieves. In the meantime, I've rented the Canon 24-70 twice now for concerts while waiting for the II.

The photozone review said that the focus shifts at higher apertures... making me wonder if this test was done correctly (or if it was a really wonky lens). I'm looking at the corner crops for 35mm and 50mm on the Tamron and they're actually WORSE at f5.6 than f2.8. Can that be right?

The new Canon should be nice, but truthfully I was happy with the original. I was just really hoping to see something around its level with IS :(