Robert Peters and Scott Hull RAW VS. JPEG

 When you take a JPEG picture:  The sensor resolves 10 to 14 bits/pixel  Camera sees what color correction is necessary to get an 18% grey and applies corrections  Applies sharpness and noise reduction  May apply contrast corrections to contrast  Reduces bits/pixel to 8 bit/pixel  Applies JPEG compression (dropping some information, is a “lossy compression)  Saves compressed image. JPEGS

 When you take a RAW picture:  The sensor resolves 10 to 14 bits/pixel  Camera sees what color correction is necessary to get an 18% grey and saves corrections  Records Noise reduction and sharpness settings  May save contrast corrections  May apply “lossless” compression  Saves all sensor information at 10 to 14 bits/pixel.  Examples of RAW file formats CR2 (Canon), NEF (Nikon), ORF (Olympus), PEF (Pentax), RW2 (Panasonic) and ARW, SRF, SR2 (Sony) RAW PICTURE

 JPEG  Opens picture  RAW Camera Vendor Software  Reads sensor data  Reads and applies “corrections” but leaves sensor data unchanged  Non-Camera Vendor Software  Reads sensor data  Analyzes data and develops own correction to color, contrast and sharpness VIEWING PHOTOS

 Applying some changes after taking picture is equivalent to making changes before taking picture  Can apply ISO changes, almost equivalent to changing ISO prior to taking picture (software only works on RAW, calibrated in f-stops).  Can apply color and contrast changes any time after the picture is taken with same result as if applied when picture was taken.  Get 12 to 14 bits/pixel, gives greater recovery of under or over exposed pictures and detail in deep shadow.  No compression artifacts.  JPEG compression can reduce sharpness ADVANTAGES OF RAW

 Consistent color corrections, noise reduction, contrast is independent of software (may be consistently wrong…)  Smaller files than RAW, typically 2 to 10 times smaller  More pictures per memory card with JPEG  More pictures per burst (before filling camera buffer), faster transfer from camera memory to memory card with JPEG  JPEGs are universally readable by many programs  Every Camera vendor has proprietary RAW algorithm, can even vary by model  No universal RAW reader  Most web cites will not accept RAW, need JPEG (e.g. Facebook, Flicker, Blurb,) Have to convert from RAW to JPEG for these sites. ADVANTAGES OF JPEG

ORIGINAL PICTURE (5 STOPS UNDEREXPOSED) JPEG size: 1,688 kb RAW size: 10,224 kb

JPEG EXPOSURE CORRECTED (COLOR CORRECTION NOT POSSIBLE WITH NIKON VIEW)

RAW EXPOSURE AND COLOR CORRECTED (USING NIKON VIEW)

CROPPED JPEG VS RAW (WITH NEAT IMAGE NOISE REDUCTION)

COLOR CORRECTED JPEG VS. RAW

ANOTHER EXAMPLE RAW VS. JPEG RAW: 12.4 MBJPEG: 5.3 MB Olympus E-5; 12.3 MP camera (MD Renaissance Festival, 2011)

RAW VS. JPEG CLEANED UP IN PSE 10 RAW JPEG

FEATHER CLOSE-UPS (AFTER PSE 10) RAWJPEG

 …JPEG…is…best on photographs and paintings of realistic scenes with smooth variations of tone and color. For web usage, where the amount of data used for an image is important, JPEG is very popular. JPEG/Exif is also the most common format saved by digital cameras.Exif  …JPEG may not be as well suited for line drawings and other textual or iconic graphics, where the sharp contrasts between adjacent pixels can cause noticeable artifacts.  As the typical use of JPEG is a lossy compression method, which somewhat reduces the image fidelity, it should not be used in scenarios where the exact reproduction of the data is requiredlossy compression  JPEG is also not well suited to files that will undergo multiple edits, as some image quality will usually be lost each time the image is decompressed and recompressed, particularly if the image is cropped or shifted… FROM WIKIPEDIA

 If photo does not need significant correction, JPEG uses less memory and is a universal format to share with friends  RAW gives the ultimate flexibility but requires special software and has larger files. More information CONCLUSIONS