Knee point, Slope & Cinegamma questions at DVinfo.net

Go Back   DV Info Net > Sony XAVC / XDCAM / NXCAM / AVCHD / HDV / DV Camera Systems > Sony ENG / EFP Shoulder Mounts

Sony ENG / EFP Shoulder Mounts
Sony PDW-F800, PDW-700, PDW-850, PXW-X500 (XDCAM HD) and PMW-400, PMW-320 (XDCAM EX).


Reply
 
Thread Tools Search this Thread
Old November 28th, 2009, 08:37 PM   #1
Trustee
 
Join Date: Jul 2007
Location: Australia
Posts: 1,321
Knee point, Slope & Cinegamma questions

Ok, I'm playing around with my Sony F350 and trying to get the top end whites from clipping but still keeping enough luminance in the over all shot.

I see some beautiful footage on Australian Tv where the overall skin tones are still bright but with the top end whites not completely blown out, something I what to achieve in my shooting.

I have search high and low for some info on the Sony f350 Cinegamma's with the Knee, slope engaged but have come up with nothing that I'm after.

Question: With the knee point, turned on and at a setting of 90 does this soften the image? and what shoud the knee slope be set at?

Any other info on this subject would be great.
I have looked at the Alan Roberts setting for the 700 and thought maybe I could mimic this on the 350 or something similar.

Cheers
Simon Denny is offline   Reply With Quote
Old November 29th, 2009, 02:52 AM   #2
Inner Circle
 
Join Date: Dec 2005
Location: Bracknell, Berkshire, UK
Posts: 4,957
The 700 and F350 are very different and 700 settings don't really work with the F350.

The Knee does not work with the cinegammas. Cinegammas are designed to be graded, they maximise dynamic range while keeping mid tones reasonably neutral to make grading easier. The images they produce, straight from the camera however often look flat and uninteresting, this is a result of taking a high contrast scene and compressing the highlights and lifting the blacks. If your after a "look" straight from the camera you are probably better off with the standard gammas.

The knee is crucial to highlight handling with the standard gammas.

The image beneath the knee will not be softened. The detail in the parts of the image being compressed by the knee is controlled by the knee aperture setting. Standard gamma 1 is a little noisy and gives an image with deep blacks. Standard 2 gives a less contrasty image than 1 but has less noise. Try bringing the knee point down to 80 or 85, I normally leave the slope at 50.
__________________
Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com
Alister Chapman is offline   Reply With Quote
Old November 29th, 2009, 05:19 AM   #3
Trustee
 
Join Date: Dec 2003
Location: Malvern UK
Posts: 1,931
Quote:
I see some beautiful footage on Australian Tv where the overall skin tones are still bright but with the top end whites not completely blown out, something I what to achieve in my shooting.
Depends on how they shot it and whether they used reflectors etc to help them out and whether they graded or not.

If you are using the STD gammas then using the knee point switched on is a good idea. As Alister suggested around 85 is a good setting. But be careful to tally this with your skin tone exposure. You don't want skin tone to fall above that 85% exposure or the tonal range will be compressed.

There isn't really one gamma to use for all situations though.
Simon Wyndham is offline   Reply With Quote
Old November 29th, 2009, 06:17 AM   #4
Trustee
 
Join Date: Jul 2007
Location: Australia
Posts: 1,321
Thanks guys,
I have noticed that using anything lower than 85% as you mentioned Simon produces compressed images and that using around 90% seems to retain some detail in the top end.
Yeah I realize there could be a host of other factors in producing these shows but the one show that stood out for me was a cooking show shot by channel Ten here on the beach. The
images being produced really held together over the whole range and this got me thinking that some sort of keen settings had to be used to retain such a clean image as our skies here in Oz are not very forgiving with shooting in at times and especial on the beach. Also they would have been using 2/3rd in chip cams as opposed to the 1/2" f350.

Forgot to say that using the gammas is a great place to start and that most of my shooting seems to be outdoors. I have had great success in cinegamma 1 but at times cinegamma 3 I also use


Thanks
Simon Denny is offline   Reply With Quote
Old December 4th, 2009, 08:08 AM   #5
Major Player
 
Join Date: May 2006
Location: Germany
Posts: 565
i just invested into a field lcd + waveform monitor - very helpful, because you will see how and what elements do clip in your picture.

What I found with my pdw330 as well: my blacks were always to high, but there is no way to correct that onlocation without a waveform monitor.

Since that experience I take a battery driven lcd+wave with me if possible.

Also, german broadcasters (they start HD production now) recommend using a waveform monitor for "better" programs.

Regards

Uli
Uli Mors is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Sony XAVC / XDCAM / NXCAM / AVCHD / HDV / DV Camera Systems > Sony ENG / EFP Shoulder Mounts

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 11:36 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network