70-300 Canon or Sony

I have two idle cameras sitting around. A Canon 7D and a Sony a7. I would like to employ one of them with an image stabilized 70-300 and need to decide whether to go with the Canon 70-300 L or the Sony 70-300 G OSS. I would prefer the Sony because of the better sensor on the a7 and also because I want to complete my migration to Sony asap. But if AF with the a7 is inadequate I'll have to get the Canon.

It is intended for both, static and moving objects. Any thoughts? Advise appreciated.

The AF in the 70-300 is good and being native you have access to all of the AF modes, something you won't have with an adapted Canon 70-300. The Canon 7D doesn't have very good AF to begin with but the a7 bodies don't have good AF for moving subjects either. You would need an a6300 for that which has much much better AF fro moving subjects.

Thanks E.J. Your reply confirms what I expected. I just couldn't find any reviews for this lens with the a7 attached, which shouldn't surprise since the a7 had been replaced with the a7II long before this lens arrived.

I did find a lot of conflicting reports regarding the sharpness of this lens. Some praise it for being tack sharp, others say it's mediocre. And both show images to prove their point. This may indicate sample variations. I guess I need to have a copy in hand and test it myself. So I ordered one this morning. I hope I don't have to return it.

The lens is every bit as good as the 70-300L from Canon.  People are going to publish whatever their preconceived notions have decided about the lens.  Real bench testing shows it to be the equal to the Canon.  In fact I am incredibly impressed by its ability to render very fine detail.  A lot of so-called testers never normally shoot with anything over 85mm or at best a 70-200 and have no idea how to shoot a 300mm (or 450 equivalent on an a6300) to insure sharp shots.

100% unsharpened crop - a7R Mk II, 70-300 @160mm, handheld - click on image to see actual size:

That's pretty convincing, E.J. If I hadn't already, I'd be ordering the Sony right now. Thanks again for your help.

Well, the lens arrived last Thursday and I learned since that it is not fully compatible with the Sony a7. Which is consistent with what Sony states in this  compatibility information.  Only, they don't really tell you what can go wrong, which is about everything.

Mostly, pictures were partially or completely out of focus. I first suspected a bad sample except, once in a while it produced a tack sharp image. Also, the image in the viewfinder was always sharp, only the copy saved to disk was bad.

Surfing the net for an answer, I eventually came across a report that stated that the image stabilizer with this combo can not only be ineffective, it actually will make things worse. So I turned it off and, voilá, all images are tack sharp.

I took this combo to an event this morning and got wonderful, problem free images. At a price, though. Even in bright day light I had to set ISO to 800 to get blur preventing shutter speeds. Just the opposite of what prompted me to buy this lens, getting image stabilized long reach.

So I'm looking at getting an a6300, as soon as the stores have it in stock again. Which means I will have to find something else to do for the a7.

According to the compatibility page, as long as the firmware in your camera is on the latest version it should work normally.  Is this not the case?

Installed firmware version is 3.10. And yes, the "shake compensation switch" is available. I can hear the gyro rotating when I turn it on (and I can still hear it rotating when I turn it off), but the images come out sharp only when I turn it off.

I find the wording here interesting. It reads "you can use the focus range switch…" and that one works. It also reads " you can use the focus hold button…" and that one works as well. But the shake compensation switch is only "available". Which it certainly is, but without the desired effect.

Focusing is slow in shady areas - as expected - but surprisingly quick in bright sunlight, even with continuous focusing.

Bought an a6300 for this lens and all is well now.

But, boy this camera is tiny. Attached to the 70-300 it looks more like a lens accessory than a camera. And trying to "reach" some of the controls occasionally gives me cramps in the hand. But that's a different story.