Originally posted by beholder3 The onyl difference in wording needs to be that since the mFT lens already only fills the tiny mFT image circle, it is cropped already from the beginning. It doesnt happen as a second step by using a smaller sensor behind a large image circle lens.
Of course, but then again I am assuming that if you nééd to get in that close (close like 400mm on 4/3), you would be cropping in post with a FF or even APS-C camera anyhow with a lens of similar cost and weight (ánd lose pixels doing so). And indeed, I almost always find myself cropping images from the DA560 on the K3II. What makes the Olympus 150-400 f4.5 a very interesting lens, is the ability to switch from 500 to 400mm with the flick of a switch, and if still too long, zoom out. That means that you can always make sure that you have the maximum amount of pixels in your image,without the need of mounting or removing teleconverters, and avoiding the bother of cropping and lowering your pixeldensity. If this lens turns out very good optically, I will be very tempted to consider it.
Originally posted by beholder3 That sound a litle bit strange, since all the crying for 600mm F4 lenses is ALL about light gathering not much else. So a 800mm F9 (FF equiv.) lens is just that.
There are cheap short 1000mm F10 FF mirror lenses out there, nicknamed "russian barrels" here. I'd like to see a direct comparison between them.
600mm f4 lenses are totally impractical for me, weight, size and cost-wise. I am looking for a similar priced lens like the DA560, but still lighter and smaller. F9 at 800mm is ok., and don't forget f5.6 at 600mm!! I don't see a russian mirror lens do that.
---------- Post added 02-06-19 at 04:01 PM ----------
Originally posted by mecrox The only metric which really matters is how many pixels can you put on that thar bird at acceptable levels of DOF, aperture, speed and ISO. It’s a very practical matter, as is the thousands of dollars which unfortunately have to leave one’s bank account to achieve it. The sensor limits on the Oly will be OK for some and not for others. I would certainly rent for a week myself to see where on that scale I really was. I suspect in the end I would plump for the value/IQ compromise and go and see Mr Nikon (D500 + whatever).
According to the info from people that saw the lens for real, it will not be very large and heavy, and
allegedly an Olympus rep. shared that Olympus does not plan to price it sky high. The lens is smaller than the big beasts out there, it may be a similar package to the Nikon 500PF, a bit larger and heavier, but if not too much, it may be a very nice alternative to the 500PF on the D500. And by the time that the 500PF will finally be available, the Olympus lens will not be far away from launch anyhow....