Yes, I've read about the diminished aperture too, somewhere here on BF.
I wonder why it's not 42 mm.
Still, when the Swarovision überbins 10x42 appear next year, I'd be looking forward to a comparison with the Canon 10x42 L IS, and I suspect, so are many others here.
That would be a real test of the IS system, IMO.
Ronald
If you look at all other IS bins except for the 10x42 IS L, the largest exit pupil is 3.3mm.
So I was surprised when Canon came out with the 10x42 IS L, because of the 4mm exit pupil. That's what they need to attract birders and even more so with hunters.
It appearas that correcting "the shakes" in a larger exit pupil bin is beyond the current technology.
Perhaps 3.7mm was the best that Canon could do while keeping the correction angle within the acceptable range of people's tolerances.
If the 10x42 IS is actually a 10x37 IS, you've dropped almost a full configuration size, just above the Nikon 8x36 Monarch and 10x35 EII. Yet, you are carrying 2.3 lbs (w/out the batteries) near mid-sized bin.
I like the 10x30 IS (though it was the most stable out of several samples, the worst of which gave me nausea), but I found the 3mm exit pupil lacking on cloudy days, winter days, and while using the bin in heavily wooded areas.
From what I've experienced and read, there's sample variation among IS bins in terms of stability, and depending on how well you can tolerate the image "swimming" around the field, you might or might not be able to use an IS bin w/out unpleasant side effects (from merely annoying streaked or "swimming" images to nausea and headaches).
There's also the issue of the warranty. I think they are up to three years now, they used to be two years.
From what I read on CN, repairing an IS bin that is no longer under warranty can cost almost as much as buying a new one.
Many manufacturers of electronic consumer products offer extended warranties. I think Canon should back up their bins with extended warranties too.
If I pay $1,1000 for a bin, I expect it to last me longer than three years.
I realize that because of the electronic circuitry, Canon cannot offer 25-year warranties like Nikon or lifetime warranties like Swarovski (it will be interesting to see what kind of warranty Swaro offers on its IS bin), but they certainly could offer extended warranties for a reasonable price and stand behind their products.
New technology that would allow larger exit pupil configurations such as 8x32, 8x42, 10x42 and 10x50 plus extended warranties would help make Canon IS bins more competitive with non-IS alternatives for birders and hunters.