Online Sensitometry for Digital Intermediate Calibration Author Ujwal N. Nirgudkar Alfa Imaging Systems Pvt. Ltd. INDIA H.P.A.-2009
Motion Picture Film Laboratory Process Original Negative Processing Negative Scanning Color Management System Recording Digital Intermediate Digital Intermediate Processing Printing from D.I.Negative Positive Processing Print ready for Exhibition
Wet Processes-Uses Chemicals Original Negative Processing Negative Scanning Color Management System Recording Digital Intermediate Digital Intermediate Processing Printing from D.I.Negative Positive Processing Print ready for Exhibition
Quality Control by Sensitometry Original Negative Processing Negative Scanning Color Management System Recording Digital Intermediate Digital Intermediate Processing Printing from D.I.Negative Positive Processing Print ready for Exhibition
Consistency in Film Processing can be achieved using Sensitometry Let us understand SENSITOMETRY
Light Stopping Ability of a Sample
Opacity and Density
Typical Sensitometer Produced 21Step Wedge
Conventional Sensitometric Graph-Density v/s Exposure This Graph is known as D log E Curve H & D Curve(Hurter & Driffield) Log I*t Curve
Characteristic Curve for Black&White Film
Sensitometric Strip for Negative Processing Sensitometric Strip for Positive Processing As per current procedure These Strips are Processed at fixed intervals (1hr OR 2hr) & compared with Reference Strip for QC.
Machine Speed v/s Frequency Film Speed Ft/Min 100 200 300 400 500 600 700 800 900 1000 Frequency 10.00 5.00 3.33 2.50 2.00 1.67 1.42 1.25 1.11 1.00 Frequency of Sampling reduces with increase in Machine Speed
Machine Speed v/s Frequency 12.00 10.00 Sample Frequency 8.00 6.00 4.00 2.00 0.00 0 200 400 600 800 1000 1200 Speed Ft / Min Frequency of Sampling
New Methods of Sensitometry
New Methods of Sensitometry Wedge should be Exposed by Film Manufacturer for Entire Film-stock
New Methods of Sensitometry Wedge should be Exposed On the Portion Between Sprocket-holes
New Methods of Sensitometry Wedge should be Exposed on the Opposite side Of Bar-code Registration
New Methods of Sensitometry Advantages Frequency of Sampling Increases from 1 to 3000
New Methods of Sensitometry Advantages Direct Link Between Bar-code & Densitometric Reading
New Methods of Sensitometry Advantages Enhanced Density Measurement Accuracy
New Methods of Sensitometry Advantages Easy Monitoring of Quality for Laboratories
New Methods of Sensitometry Advantages Savings in Cost & Time
New Methods of Sensitometry Advantages Easier Color Corrections
New Methods of Sensitometry Advantages Quality by Default and Not Quality by Choice
History of this Technology Chemical Engineer with 27 years experience in Filmlab in India, worked on SMPTE committees F-2 & L-6, & first SMPTE Fellow from India. This Technology was First Presented at SMPTE Technical Conference in Oct-2002 at Pasadena. U.S.Patent No, 6,849,366 granted on 1st Feb.2005. U.S.Patent No, 7,254,324 granted on 7th Aug.2007 Selected by Dept. of Science & Technology, Govt. of India for Incubation & Support in 2007. Alfa Imaging Systems Pvt. Ltd. was incorporated in April 2008 to promote this technology.
U.S.Patent 6,849,366 issued on 1 st Feb.2005
Who will benefit from this Technology 1)Online Sensitometry on Camera Negatives- Cinematographers / Studios 2)Online Sensitometry on Print Films- Laboratories 3)Online Sensitometry on Digital Intermediate- D.I.Facilities
1)Online Sensitometry on Camera Negatives- Cinematographers As the sensitometric readings are available on the Camera Negative itself,it gives a very good reference for Cinematographer Studios Get a right to know how their Negatives were processed
2)Online Sensitometry on Print Film- Film Laboratories Film Laboratories can easily monitor the quality of print processing around the world at different locations. As the sensitometry is online, the data can be scanned online & made available at one central location e.g. Hollywood, using a dedicated network.
3)Online Sensitometry on Digital Intermediates- D.I.Facilities What are the Benefits???
Online Sensitometry for Digital Intermediate Calibration
Fights between DI People & Lab People,over who went wrong
Fights between Digital Technology & Chemistry
We need consistency between Recording & Processing Image courtesy ARRI
Characteristic Curve for Black&White Film
Simulated Sensitometric Patches created for Digital Intermediate as DPX Files. These files were recorded in the soundtrack area along with the picture.
What more we need??? 1)Scanner To scan these sensitometric Patches 2) Software To convert the readings in to meaningful actions
The New Patches can be also read separately on the Analyzer & R,G,B corrections can be easily applied for changes in D.I.Negative Processing. Image courtesy FILMLAB & RTI
If the Film Manufacturers also decide to use this technology(?) This is how the D.I.Negative will look in future.
Current Status of Technology 1)Protorype Ready 2)Scanner Manufacture Ready to tie-up 3)Software Manufacturer Ready to tie-up 4)Should be able to take a commercial trial in Hollywood in the next three months
Acknowledgements Thanks To
Acknowledgements Thanks to All Of You
Online Sensitometry for Digital Intermediate Calibration Ujwal N. Nirgudkar ujwal@alfaimages.com www.alfaimages.com U.S.Cell- (323) 350 7864 Alfa Imaging Systems Pvt. Ltd. INDIA