xf-300 vs sony EX1R sensor size?

[David Heath]

Originally Posted by Steve Phillipps

I'm used to 2/3" cameras too, and I never seem to have this ND juggling problem. .........
Say you're at f2 and the light changes a bit, stop down to f2.8, no big deal. If it changes more.......

It depends on what you are filming. If GVs etc out of doors then depth of field issues aren't likely to bother you much anyway. But an example of what I'm thinking about may be such as an interview situation indoors. The geography of the room may define lens angles, (and may mean relatively wide angles) and it's normally desirable to soften the background relative to the subject. Hence, it's often a good idea to juggle ND/gain to work extremely close to wide open - even then, and even with 2/3" chips, the background may still be sharper than desired.

1/2" chips will only make the issue worse. 1/3" will make it worse still. Cost etc may exclude the use of a 2/3" camera, but if there's no cost advantage to a 1/3" camera over 1/2", then in this respect the 1/3" camera is at a clear disadvantage.

[Steve Phillipps]

All things being equal yes. But, what if you could have a 1/3" instead of a 1/2" but the lens would be much better as they can make a better performing lens to cover the smaller chip for less money than the same performance lens would cost to cover 1/2"? That seems like it may be the case with the Canon, and that the 1/2" to 1/3" difference may be smaller than the difference made by a better quality lens.
Just a thought.
Steve

[David Heath]

It's a good thought, Steve, and the quoted figures for max aperture (if you believe them) are f1.9 for the EX, and f1.6 for the Canon. That half stop does mean that if both cameras are used wide open, the difference half negates the 1/2"-1/3" advantage in respect of both depth of field and low light performance.

But it is now becoming a camera v camera discussion. Does a good lens (and a heavier price tag) at all make up for an inherent 1/3" v 1/2" disadvantage? And it doesn't get away from the fact that if the new Canon had 1/2" chips, but still a f1.6 lens, it would be much better still. Instead of being an EX1 challenger, a definate EX1 beater.

[Paul Doherty]

Originally Posted by David Heath

And it doesn't get away from the fact that if the new Canon had 1/2" chips, but still a f1.6 lens, it would be much better still. Instead of being an EX1 challenger, a definate EX1 beater.

Alan Roberts who did those tests had exactly the same thought. Comparing the EX1 and the XF305 he said that "If Canon go on to make a 1"/2 version it'll be a real killer."

[Peter Moretti]

Originally Posted by David Heath

It's a good thought, Steve, and the quoted figures for max aperture (if you believe them) are f1.9 for the EX, and f1.6 for the Canon. That half stop does mean that if both cameras are used wide open, the difference half negates the 1/2"-1/3" advantage in respect of both depth of field and low light performance.

...

BTW, the Canon lens ramps from 1.6 to 2.8. I believe the EX-1's is 1.9 for the entire range. So if you are zoomed out all the way to get as blurry a background as possible, the EX-1 actually gives you effectively a 2 stop advantage in terms of creating shallow DoF. That is definitely significant.

[Steve Phillipps]

Is the lens ramping not partly due to the fact that the Canon is 18x vs 14x for the Sony? When does the Canon start to ramp, maybe around 14x?
Also, at telephoto range like that the dof would be pretty small even at f2.8. At max zoom and f2.8 and the subject at 20 the depth of field would only be just over 1 foot.
Steve

[Stephen Crye]

Originally Posted by Bo Sundvall

Hi

A wild guess from me is that the diameter of the optics doesn't matter so much. Think of it this way: Point your camcorder to an object which fills the screen, for example a wall of a house. The light that falls in to the camcorder from that wall is not dependant of the lens diameter. It does not become more light from the wall if the diameter is larger, the amount of light is only dependant of the source.

I guess that a larger diameter on a lens gives less optical problems within the zoom range, for example chromatic and spheric aberation, and also gives the manufacturer larger room for compensating for such problems and also build a more rugged system with higher quality. A larger diameter might reduce for light loss within the lens system though, so perhaps it does matter in some cases.

As I don't have a degree in optics this is only wild guesses as I said. :-)

Regards,

/Bo

Sorry to disagree, but the size of the lens is one of the biggest factors in light-gathering power.

Go to a big observatory. Notice the HUGE telescopes. Size matters when it comes to light-gathering power.

Steve