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-   -   F3 BBC Report (https://www.dvinfo.net/forum/sony-xdcam-pmw-f3-cinealta/493829-f3-bbc-report.html)

Tony Brennan March 30th, 2011 04:25 PM

F3 BBC Report
 
Alan Roberts BBC test report for the F3 is now available at BBC R&D White Paper WHP034 - Alan Roberts

Nate Weaver March 30th, 2011 05:30 PM

Re: F3 BBC Report
 
So by his measurements, the S/N ratio is -48ish?

And the AF100 is -49ish?

What?

I'd sure really like to understand his methods better, because his results don't match my eye. In addition by his own admission, he states that because pretty much all cameras have gamma correction before any sort of output that you can measure, direct measurements won't be accurate. I don't know if this is really true, or?

Anyway, sure glad I tested both AF100 and F3 before I bought, because if all I did was read this document to make a choice, I'd be missing out on a whole lot.

Erik Phairas March 30th, 2011 05:35 PM

Re: F3 BBC Report
 
Yea and the EX1/3 are -47db at +3db gain on their report.. Kinda odd.

Doug Jensen March 30th, 2011 05:39 PM

Re: F3 BBC Report
 
I don't mean to nit pick too much, but I see two errors right on the first page:

". . .but the supplied BP-U60 has a nominal capacity . . ."
Unless they are bundling a battery in the UK, the camera does not come with one.

" . . .the lens mount is standard PL, and has hot connections for the supplied Sony lenses . . ."
Does he not realize he's looking at an adapter? The native mount is an F3 mount.

Erik Phairas March 30th, 2011 05:43 PM

Re: F3 BBC Report
 
I'm wondering now if he has a typo and ment to say the F3 is -58.5db.

Dennis Dillon March 30th, 2011 06:15 PM

Re: F3 BBC Report
 
I have recorded 56 hours of F3 material on both Nano and internal. Only once did I see aliasing, and it was from a tight patterned shirt a grip was wearing during my last trip to London. It showed up in a fold of the shirt, changing the presentation of the H/V pattern more diagonal. This seems to make sense from Adam Wilt's Mega Trumpet test. See ProVideo Coalition.com: Camera Log by Adam Wilt | Founder | Pro Cameras, HDV Camera, HD Camera, Sony, Panasonic, JVC, RED, Video Camera Reviews .

Ill be returning to London and hiring the same grip with the same shirt. I will try to repeat the situation. I'll set Detail Level to 0, Detail Frequency to +99, and Aperture level to +20 as per pp10-11 Roberts Addendum 68 and see what we get. If it is still pronounced, I'll buy his shirt and burn it :) .

Mean while most of the material from the F3 has been posted for three network prime time programs (Sorry no frame grabs due to property rights), with very favorable reviews.

Nate Weaver March 30th, 2011 06:59 PM

Re: F3 BBC Report
 
Quote:

Originally Posted by Doug Jensen (Post 1633442)
I don't mean to nit pick too much, but I see two errors right on the first page:

". . .but the supplied BP-U60 has a nominal capacity . . ."
Unless they are bundling a battery in the UK, the camera does not come with one.

" . . .the lens mount is standard PL, and has hot connections for the supplied Sony lenses . . ."
Does he not realize he's looking at an adapter? The native mount is an F3 mount.

There was some other factual errors like not being able to be remotely controlled (RMB-150 & 750 both work with F3). Maybe his criteria for "remotely controlled" is more stringent? Overall it seems like his time with the camera was really limited and he didn't do much research along the way.

Anyway, I don't want to pick his paper apart in fanboy fashion, because I really do believe by the tone of his writing that he doing his best to be scientific and impartial. There is however that one big head-scratcher with the noise level....

Erik Phairas March 30th, 2011 07:12 PM

Re: F3 BBC Report
 
I still say it has to be a typo. That is a HUGE difference from the claimed S/N ratio. Greater than any other camera he tested I bet.

Carlos Molina March 30th, 2011 08:31 PM

Re: F3 BBC Report
 
Roberts is also claiming that "the sensor has approximately 12.9 Megapixels, typical of a digital stills camera." Sony's F3 brochure states that the 'effective resolution' of the sensor is 3.3 Megapixels (2.4K)? What's going on with this report?

Doug Jensen March 30th, 2011 08:38 PM

Re: F3 BBC Report
 
Here's another error:

"Sensitivity was not measured directly. The specification claims it to be T/11 at ISO800, and since ISO800
corresponds to 0dB gain, this means that the sensitivity is very . . ."

0db corresponds to ISO 400 not 800.
And even that is bogus. The ISO varies depending on the paint settings.

Doug Jensen March 30th, 2011 08:40 PM

Re: F3 BBC Report
 
Quote:

Originally Posted by Carlos Molina (Post 1633501)
Roberts is also claiming that "the sensor has approximately 12.9 Megapixels, typical of a digital stills camera." Sony's F3 brochure states that the 'effective resolution' of the sensor is 3.3 Megapixels (2.4K)? What's going on with this report?

Apparently he missed it when Sony clearly said the pixels are 4 times bigger than a typical SLR's pixels.

In fact the whole report is riddled with typos and mistakes including this one: " . . . and audio via SLR connectors."
Sloppy work.

Seems odd he says "The lens mount is standard PL, and has hot connections for the supplied Sony lenses and for the Cooke /I range of lenses." but hen he makes no mention of the Arri LDS interface.

Tony Partamian March 30th, 2011 11:27 PM

Re: F3 BBC Report
 
he also says " Noise performance is good, 18dB gain may be reasonable for best quality programme-making."

So forget about dbs and numbers

Brian Drysdale March 31st, 2011 01:43 AM

Re: F3 BBC Report
 
Quote:

Originally Posted by Doug Jensen (Post 1633442)
I don't mean to nit pick too much, but I see two errors right on the first page:

". . .but the supplied BP-U60 has a nominal capacity . . ."
Unless they are bundling a battery in the UK, the camera does not come with one.

" . . .the lens mount is standard PL, and has hot connections for the supplied Sony lenses . . ."
Does he not realize he's looking at an adapter? The native mount is an F3 mount.

I think he's referring to the camera as supplied to him, rather than how you'd purchase the camera. I guess he's interested in the high end sector and how the camera is set up for his test.

The noise levels are interesting, his graphs indicate the same low figure. It could be his test equipment's calibration is off? In practise, no one has commented on the F3's noise levels, whereas the AF 100's have been commented on. The reference to "18dB gain may be reasonable for best quality programme-making" seems contradictory.

Alister Chapman March 31st, 2011 02:14 PM

Re: F3 BBC Report
 
I don't get the noise figures either. I don't quite understand why he off hand ignores the +2db bump in his noise plot at 0db say it's "not significant" when if you follow the otherwise reasonable looking noise/gain plot you would see an improvement of around 4db in the noise figure. The plot does not make sense, noise and gain almost always go hand in hand and most of the plot makes complete sense, the big bump at 0db is very odd. I would have a much easier time believing -52db (strangely close to that of the FS100) than -48db. Did he have +9db programmed and not zero db??


Alan is also implying equal R G and B pixels which is not typical of a bayer sensor which normally has 2 green for each red and each blue. Now Sony have not said that the F3 is bayer, so perhaps this is something different. Zone plates don't normally lie.

I also don't follow the pixel count logic:
quote
"implying that the sensor has dimensions which are related to those numbers, probably 2200x1238"
then
"and that the sensor resolution is probably much higher than 2200x1240"
and
"the native resolution of the camera does not reach the limits of the 1920x1080 format"

Now I know that a bayer sensor will produce a final resolution lower than the pixel count, but it all seems confused and the final conclusion that it must be a 12 mega pixel sensor because it has similar sensitivity to a 3 chip camera, well that's conjecture beyond belief. Also I don't see how 4,800 x 2,700 is a "reasonable fit" with 2,200 x 1,238, there is a pretty big discrepancy even if you do multiply 2200 x2. Anyway we know the sensor to be 3.5MP gross with 3.3MP active.

What we might be seeing is conventional conclusions about an un-conventional sensor?

Alister Chapman March 31st, 2011 02:59 PM

Re: F3 BBC Report
 
looking at the noise plot again, Alan is suggesting that the F3 is noisier at 0db than at +6db. That really does not tie in with my visual observations. It implies we should be using either +6db or -3db but not 0db.


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