Hi there!

There are new Sony lenses in.

First Look: Sony Announces Two New E-Mount Lenses: the 12-24mm F/4 and 16-35mm F/2.8 (http://www.dvinfo.net/news/sony-introduces-two-new-wide-angle-full-frame-e-mount-lenses.html)

I always get confused here, it says they are full frame, but on a FS5 you have to add 1.4 to the range? I use Canon lenses now with a metabones adapter, but this would not be a same as a 16-35 Canon, right? Or...?

Cheers.

Focal length is focal length...

The point here is that these cover the full 35mm still frame area, so if placed on an A7 or A9 camera (with a sensor much larger than that on the FS7 or FS5) the field of view is that much wider...

I'm fairly amazed by just how wide the field of view is at 12mm in the demo photos! (Of course the demo photos have the sun in mid-frame, so it's hard to tell if there is any exposure fall-off as you approach the corners of the full frame area..)

Focal length depends on the camera and not on the lens, and since the FS5 is not a full frame camera, well...

No, focal length is still focal length. It is a characteristic of the lens, not of the camera.

If no other optics are added (ie - no speed booster optics) a 24mm lens will always be 24mm.

So a Sony 16-35 will be the same as would be a Sigma, Nikon or Canon 16-35 as long as they're mounted on the same camera with no additional optical elements added.

It will make different size pictures on different cameras if they have different sensor sizes (or film frame sizes)

Field of view for a specific focal length will of course vary for different sensor sizes.

Yes, you are right of course! But in order to use Canon glass on the FS5 we need a speedbooster or something else. Like the one I have, and then my question is what the difference between the two would be?

Thanks.

When used with a Canon or Nikon full-frame lens, a Speedbooster will give you one f-stop more light than an equivalent e-mount lens -- plus the field of view would change by a factor of .71x.

For example, an f/4 10mm e-mount lens would perform exactly like an f/4 10mm lens on your FS5.
But a Canon f/4 10mm full-frame lens with a speedbooster would perform like a f/2.8 7.1 mm lens on your FS5.
And with an ordinary lens adapter (not a speedbooster) the Canon lens would perform exactly like an f/4 10mm lens on your FS5.

BTW, on the FS5, it doesn't matter whether an e-mount lens is full-frame or not because both types of lenses will have identical performance on the FS5.

Ugg.....I really wish Sony would standardize placing iris rings on every lens like this. They do it on a couple of models but not many. I think they definitely deserve iris rings based on their price. Hell, I'll even be happy with a fly by wire ring if it was reasonably smooth.