F3: Wtb: Cbk-rgb01

Peter G. Johnson

Peter G. Johnson

Active member
Wish I hadn't sold the s-log function (CBK-RGB01) now that the Pix 240i connects via 3G. Anyone out there who wants to sell their key? (Even prepared to return the SxS card after installation.) Have PayPal; trustworthy (etc)
 
Ouch! You just can't cop a break with SLOG and this camera can you Peter.



A reenactment of your travails:
:nads:
(SLOG in green)
 
That's sums it up! I read extensively, experiment proficiently to learn, very careful with finances, think all things through... but the the s-log issue keeps on stinging.
 
Peter, have you been digging around enough to find anything conclusive regarding RGB 444 (de-bayered) versus YCbCr 422 ?
 
Have you seen anyone's tests online - even if just a static shot of a yellow rubber duck of SXS vs 10-bit 422 vs RGB 444? I would really like to see this. (not the duck, I mean some tests)

Right now I'm doing tests on 8-bit SXS vs 10-bit 422 prores and even vs 10-bit 422 uncompressed and on a static shot at least, the difference is nothing staggering on an un-graded image and zooming in 200%. When I grade it extensively pushing tones from separate channels in a way that would never earn you a pay check - again they hold up quite identically.

I will do more conclusive tests by shooting more scenes with drastic gradients in them as well as some high contrast scenes, perhaps then things will get more interesting.
 
Sony hasn't helped by only providing scant details on what the F3 can and can't do. (Planned) firmware updates have demonstrated that the F3 can magically do lots of things, but the most significant thing is s-log, followed by it's output signal. The fact that no-one can definitively explain what comes out of HD-SDI is testimony to that. With the F5 and F55 due to come out soon, the F3 will be all but forgotten, other than by those who can't afford anymore upgrades.

Having said that, the CBK-RGB01 will probably become redundant, so.... if you've got a copy, I'll buy it for no more than $500. It may be worth nothing in the next few months.
 
starcentral said:
Have you seen anyone's tests online - even if just a static shot of a yellow rubber duck of SXS vs 10-bit 422 vs RGB 444? I would really like to see this. (not the duck, I mean some tests)

Right now I'm doing tests on 8-bit SXS vs 10-bit 422 prores and even vs 10-bit 422 uncompressed and on a static shot at least, the difference is nothing staggering on an un-graded image and zooming in 200%. When I grade it extensively pushing tones from separate channels in a way that would never earn you a pay check - again they hold up quite identically.

I will do more conclusive tests by shooting more scenes with drastic gradients in them as well as some high contrast scenes, perhaps then things will get more interesting.
Click to expand...
Just under expose al least 3 stops and do the test.
 
I definitely will, the last few days was just sorting out the shuttle. Off topic: but I had NO IDEA the shuttle had a built in battery that lasts a good hour! That is awesome!
 
Shoot a blue sky and pull both the 8bit and 10bit into premiere and add contrast. The smooth gradients in the sky is where you will see it (banding/blocking in the 8bit). Also make sure you have the sequence to display maximum bit depth otherwise it will just show you 8bit. Like Douglas said you'll also have more in the lower ire's to work with.
 
yeah I will try on some new images with gradients and see what happens, but honestly when you do compare of straight footage from SXS 35mbps to prores 220mbps there is not a lot of difference, if any. Check out the video below, some small change in color but without seeing side by side you could not guess if one was 35mbps or 220mbps. As for pushing 3 stops, I will try that test too but god forbid I miss my exposure by so much. Mostly I shoot slightly higher middle grey so it is lowered in post improving noise and crushing blacks nicely again reducing noise.


lexicon said:
Mathew Allard:
"A simple comparison between recording 4.2.0 35Mb/s as opposed to 4.2.2 10 bit Apple ProRes 422 (HQ) to a Cinedeck Extreme.

Amazingly the 35MB/s codec stands up much better than you think it would. You should never judge a codec purely by a number. 4.2.2 10 bit is sharper and slightly cleaner but it is very hard to pick the difference.

The night time shots were all shot on +12DB."

Click to expand...
 
starcentral said:
I really want to know how different ungraded RGB 444 looks against YCbCr 422 - anyone, just a quick test shot?
Click to expand...

Here's the most useful comparison I've found: http://blog.mxr.at/422-vs-444/

The images themselves don't tell you much, but the difference matte at the bottom of the page paints the picture a little clearer - there is a fair bit more colour depth to be found in the 4:4:4 output (as well there should be!).
 
Grug said:
Here's the most useful comparison I've found: http://blog.mxr.at/422-vs-444/

The images themselves don't tell you much, but the difference matte at the bottom of the page paints the picture a little clearer - there is a fair bit more colour depth to be found in the 4:4:4 output (as well there should be!).
Click to expand...

From this I wouldn't call the difference as "highly visable", however recognizing that there is definitely some more color saturation and less breakup or posterization in certain parts of the image.
 
Eventually received a copy of the CBK-RGB01, free with another purchase. (Won't sell this time!) The Pix 240 recognises 3G S-Log as 'RGB (10 bit.)' I'll be recording a movie with students very soon. I'll handle the camera. They'll do the acting and then edit it for themselves using FCPX. Good learning all round and I can finally do something constructive with all this equipment.
 
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