MAXIMISE YOUR IMAGE...

Sony CineAlta Cameras
Compatible Sony CineAlta cameras include:

• HDW-f900/3
• HDW-f900/R
• HDC-f950
• PDW-f800
• SRW-9000
• HDC-1000
• HDC-1500
• f23
• f35

Please make sure to order the correct Gamma Curve versions when ordering.

It is strongly suggested that you read this independent article written by Alfonso Parra, AEC, where he looks at the original Light Illusion Gamma Curves, as well as his story on the shooting of The Bicycle, shot with Light Illusion Gamma Curves.

Pre-Built Gamma Curves
The selection of curves provided by Light Illusion range from ones aimed to generate a pleasing image 'in-camera' without the need to perform too much (any in some cases) post-production colour correction, through to curves that generate extremely low-contrast, high-dynamic range images that emulate the capture process of film negative, and require post-production manipulation (just like film printing!) to generate a final usable image.

The low-contrast curves are recommended primarily for when capturing to low compression, high bit-depth recorders (such as D5, HDcam SR, or to disc), with f900 cameras. With the 10bit 4:4:4 cameras there are no issues (although see note on f950 at the end of this page.) The reason for saying this is to minimise any issues with banding and other potential artefacts due to low bit depth and compression based recording.

However, having said that, a lot of f900 8bit (internal HDcam tape recording) work has been done with the full low-contrast curves - just ask Geoff Boyle

As always, test and evaluate the curves prior to using them for real jobs. Just be aware, as said above, it is possible that the stretched nature of the high-dynamic range, low contrast curves may push the image data beyond the spatial resolution available with the 8bit capture system employed with HDcam....

The curves are provided as a Zip files, and when extracted will show the necessary file structure format for the curves to be copied to a memory stick for camera use.

For additional information on these curves please contact steve@lightillusion.com.

You may be interested to know that the BBC have, on a couple of occasions, requested modified curves to meet their specific requirements for their wild-life programs. See Planet Earth for an example of what they shoot!

These second generation curves build on the previous ones which have become something of an industry standard.

Further camera testing, and feedback from real-world users, has resulted in these new improved curves.

Contents of pre-built Gamma Curves
The following diagrams show the various pre-built Light Illusion Gamma Curves contained in the four memory cards worth of curves.

There are a maximum of 5 Gamma Curves allowed per memory card, and there are four card's worth of files for each camera or camera range.

Cineon profile Curves
These first curves are for use where the maximum DR range of the camera is required during capture, with all images requiring later post-production grading to generate a final deliverable images, just as with film capture to negative requires grading and printing.

Light Illusion Gamma Curves - based on the Cineon/dpx format

The steeper the curve the more output change there will be for a given change of input. Hence the lower-contrast curves will generate stretched blacks, showing more shadow detail than the normal Rec709 based curves, combined with progressive highlights to prevent early detail clipping.

Compare the initial slope of these curves with the following MegaGamma curves, which are Rec709 based...

Cineon Curve Details (NON-f900 Range)
• DP-CIN-150c - 18%grey@50; 150%DR, Clip109%
• DP-CIN-250c - 18%grey@50; 250%DR, Clip109%
• DP-CIN-400c - 18%grey@50; 400%DR, Clip109%
• DP-CIN-625c - 18%grey@50; 625%DR, Clip109%
• DP-CIN-1000c - 18%grey@50; 1000%DR, Clip109% (requires +6db to prevent early clipping)

Cineon Curve Details (f900 Range)
• DP-CIN-150c - 18%grey@50; 150%DR, Clip109%
• DP-CIN-205c - 18%grey@50; 205%DR, Clip109%
• DP-CIN-285c - 18%grey@50; 285%DR, Clip109%
• DP-CIN-410c - 18%grey@50; 410%DR, Clip109%
• DP-CIN-600c - 18%grey@50; 600%DR, Clip109%

MegaGamma profile Curves
The MegaGamma curves provide extended highlight detail, while retaining the Rec709 shadow and mid-tone. For more info on the results there curves generate please see George Hupka's comments on the Projects & Endorsements page. It was George who first asked for these curves to be developed. Thanks George!

Light Illusion Gamma Curves - aimed at generating a usable image in-camera

Please note that curve 4 (green) is the maximum DR of the cameras in their default state. The fifth curve will require +3dB extended range to prevent early image clipping of the output.

MegaGamma Curve Details (NON-f900 Range)
• DP-MG-250c - 18%grey@45; 250%DR, Clip109%
• DP-MG-350c - 18%grey@42; 350%DR, Clip109%
• DP-MG-450c - 18%grey@39; 450%DR, Clip109%
• DP-MG-650c - 18%grey@36; 650%DR, Clip109%
• DP-MG-850c - 18%grey@33; 850%DR, Clip109%

MegaGamma Curve Details (f900 Range)
• DP-MG-150c - 18%grey@45; 150%DR, Clip109%
• DP-MG-205c - 18%grey@42; 205%DR, Clip109%
• DP-MG-285c - 18%grey@39; 285%DR, Clip109%
• DP-MG-410c - 18%grey@36; 410%DR, Clip109%
• DP-MG-600c - 18%grey@33; 600%DR, Clip109%

Log profile Curves
These curves are a mid-way house between the above two extremes, using a Log profile to provide an image that is pleasing to the eye, while offering good shadow and highlight capabilities.

There are two versions of these curves, with only one different between the two sets of curves - on the first set has 18% Grey scaled with curve's DR value, while the second set has 18% Grey is fixed at 42% of the output value.

Light Illusion Gamma Curves - 18% Grey scaled with DR value

LOG Curve Details (18% Grey Variable - NON-f900 Range)
• DP-LOG-150v - 18%grey@50; 150%DR, Clip109%
• DP-LOG-250v - 18%grey@45; 250%DR, Clip109%
• DP-LOG-350v - 18%grey@42; 350%DR, Clip109%
• DP-LOG-450v - 18%grey@40; 450%DR, Clip109%
• DP-LOG-650v - 18%grey@38; 650%DR, Clip109%

LOG Curve Details (18% Grey Variable - f900 Range)
• DP-LOG-150v - 18%grey@50; 150%DR, Clip109%
• DP-LOG-250v - 18%grey@45; 250%DR, Clip109%
• DP-LOG-350v - 18%grey@42; 350%DR, Clip109%
• DP-LOG-450v - 18%grey@40; 450%DR, Clip109%
• DP-LOG-600v - 18%grey@38; 600%DR, Clip109%

Light Illusion Gamma Curves - 18% Grey fixed at 42% output value

LOG Curve Details (18% Grey Fixed - NON-f900 Range)
• DP_LOG_150f - 18%grey@42; 150%DR, Clip109%
• DP_LOG_250f - 18%grey@42; 250%DR, Clip109%
• DP_LOG_350f - 18%grey@42; 350%DR, Clip109%
• DP_LOG_450f - 18%grey@42; 450%DR, Clip109%
• DP_LOG_650f - 18%grey@42; 650%DR, Clip109%

LOG Curve Details (18% Grey Fixed - f900 Range)
• DP_LOG_150f - 18%grey@42; 150%DR, Clip109%
• DP_LOG_250f - 18%grey@42; 250%DR, Clip109%
• DP_LOG_350f - 18%grey@42; 350%DR, Clip109%
• DP_LOG_450f - 18%grey@42; 450%DR, Clip109%
• DP_LOG_600f - 18%grey@42; 600%DR, Clip109%

The following images show the variation and help understand the benefit of a low contrast, high dynamic range image.

'Default' camera video settings

Mid range Log curve

Full log curve

In the above images the difference is fairly obvious between the first image, which has no room for grading, with crushed shadows and clipped highlights, while the second two images show good shadow detail and highlights that are not clipped. These images can be graded to look exactly as required as all the detail throughout the whole dynamic range has been captured. The difference between the final two images is less, with the shadow detail and highlight being a little further extended in the second image.

Images curtesy of Geoff Boyle, CML, who is a great believer in Steve's Gamma Curves .

Any user feedback on these curves will be greatly appreciated, and any necessary adjustments made to improve their use, as has been done with these second-generation curves. Obviously Light Illusion can't guarantee the use of these curves, so individual tests must be carried out by the user prior to any real work being performed.

Curve Loading - Sony f900/3 & f900R; f23/f35
The following is the procedure for loading the Gamma Curves into a Sony F900/3, or similar capable CineAlta camera. Once loaded the curves will disable some menu options, and it is best to set all other to off, or to their default. To check you have all the curves loaded connect the camera to a monitor and cycle through the curves; it will be obvious the curves are loaded by the various different looks you will see.

Please note that there is a bug with the Sony f950 CineAlta camera that will effect any Gamma Curves used with this camera - not just the Light Illusion curves. The problem is that in 4:4:4 mode the output image data levels get re-mapped to 4:2:2 levels when a CVP Gamma Curve is applied. This is not a serious problem as there is no clipping, just re-mapping of the output data. When loaded into a post system that expects 4:4:4 data to be valid from 0 to 1023 this will result in lifted blacks and lowered whites - which can easily be adjusted to be correct during any grading process.

f23/f35

• Un-zip the downloaded zip file directly to a Sony formatted memory stick
• Load memory stick into camera slot
• Load the gamma table data via a memory stick using the (USER GAMMA) page of the FILE menu in Custom mode
• Position the menu pointer to READ (MS t CAM)
• push on the MENU SEL/ENTER dial
• Select USER on the first line of TABLE on the (GAMMA) page of the USER (PAINT) menu and display the desired user gamma

f900/f950

• Un-zip the downloaded zip file directly to a Sony formatted memory stick
• Load memory stick into camera slot
• Top Menu FILE - Go to page 4 (user Gamma) and LOAD memory stick.
• Top Menu PAINT - Go to Page 3 (Gamma) - scroll down to Table - you see Standard and User options - select User - you will now see the files as a drop down option list - select curve and enjoy :o)
• Select each curve once to see your favoured setting compared to the others.

f800

• Un-zip the downloaded zip file directly to a Sony formatted memory stick
• Load memory stick into camera slot
• Top Menu FILE - Go to page FILE and LOAD memory stick.
• Top Menu PAINT - Go to page GAMMA - scroll down to Table - you see Standard and User options - select User - you will now see the files as a drop down option list.
• Select each curve once to see it compared to the others.

See here for projects and endorsements for the Light Illusion Gamma Curves.

For additional information on Gamma Curves please contact steve@lightillusion.com.