You can compare graphs with other 43 and m43 lenses. http://slrgear.com/reviews/showproduct.php/product/1741/cat/15 "Compared to other Olympus primes and zoom lenses, the 40-150 is top notch. At 40mm, the 40-150mm edges out the 12-40mm @ 40mm at ƒ/2.8 with better corner sharpness, for instance. At 70mm, the 40-150mm displays nearly identical sharpness characteristics to the well-regarded Olympus 75mm ƒ/1.8 prime @ ƒ/2.8. And at 150mm, the 40-150mm is very similar to, if not just slightly sharper than the Olympus 150mm ƒ/2 Four Thirds lens @ ƒ/2.8 and stopped down."
This is certainly very positive. I'm still not buying the 150f2 comparison given that the "little tuna" was tested with the E410, and the 40-150 was with the GX-1. My own feeling is that the 150f2 is better than the 75 f1.8, but then again this is just splitting hairs :smile:.
These sorts of tests are ultimately meaningless unless you use exactly the same camera; or you do what Roger Cicala does on Lens Rentals, who uses specialised equipment to assess the true qualities of a lens.
Luckily my money will be taken when I get the lens. And that is hopefully soon. Or at least before I go on a vacation to Spain next month...
Maybe, but this comparison isn't really new as Olympus themselves stated in their press release for the 40-150mm that the new lens was even better than their 150mm and 35-100mm F2, and posted the MFT charts to prove it.
I know that Olympus said it was the best ever and their MTF charts show better results, but that would be a given, they wouldn't be saying it's not the best. However, the MTF charts for the 4/3 lenses haven't been produced using the current sensor and I think they may even have been produced using the 5MP E-1 sensor, as that's around the time when the lenses came out. Olympus is not going to go back and re-test, and then say that their old lenses are better than the new ones. Marketing doesn't work that way.
I've got my copy and it's sharp, bokeh is nice and so is everything else, more than adequate for my purposes. but is it really so sharp that you'd give up your prime lens if resolution is the top concern? I don't think so.
All manufacturers that I know of use calculated values for MTF charts. Making measurements using charts, lenses and cameras give System Resolution numbers. System resolution numbers will always be lower than resolution performance numbers than any single component of the image capture system.
This is correct - the MTF charts that Olympus provides are *calculated* MTF charts and do not depend on any body or sensor. Same thing for Panasonic MTF charts. You can safely compare any Olympus MTF chart from 4/3 or m43. The various numbers that review sites *measure* do in fact depend on the body shot with. None of these test sites actually measure a lens MTF, this requires specialized test equipment. These sites test lens+sensor+processing resolution numbers and then call them MTF. One criticism of all manufacturers *calculated* MTF charts is that they are often rather rosy compared to an actual measured MTF. Very few lens manufactures provide measured MTF but Zeiss is one of them.
I tend to discount the manufacturers mft values, perhaps unfairly, but if rather see real tests. Unfortunately these are all system tests which present their own problems.
Completely agree. The one thing I find some value in the manufacturer calculated MTF charts is they can sometimes be useful in predicting if a new lens is better/worse/same as an existing lens you are already familiar with in some way (e.g. corner sharpness, astigmatism, etc.). As you say none of these measures is perfect...
The issue with real tests is that the data only is for that lens, on that body, focused to that distance for that test target. As Roger Cicala points out all the time, you really have to know what the different tests measure and how the numbers relate to what is visible. Real test results have this aura of verisimilitude, but may give less useful information than a set of calculations.
Well the other issue is that it has been shown repeatedly that calculated MTF curves from manufacturers often have little to do with real measured MTF curves. By which I mean actual MTF curves done with proper equipment on an optical bench, not the BS stuff that photozone et al. push out with Imatest using a lens attached to a body. Pick your poison of poor numbers but the calculated MTF curves are really just differently bad from the Imatest results. Measuring the actual MTF of the lens would be the most useful thing to do, but expensive and hard to do correctly. Though that is a service Roger is specifically trying to offer now!
