Mark Schubin, HPA Technology Retreat, 2006 February 23 1 Small Format HD Acquisition Part 1 – What’s Out There Part 1 – What’s Out There Part 2 – The Optical Format Factor Part 2 – The Optical Format Factor Part 3 – Hierarchical Analysis Part 3 – Hierarchical Analysis

Mark Schubin, HPA Technology Retreat, 2006 February 23 2 Current Small-Format HD BrandModelImagerCoding4=GOP/BRLensMSRP Canon XL H x1080 M 4:2: /25 I 20x5.4/1.6 $9000 JVCGR-HD x720 M 4:2: /19 F 10x5.2/1.8 $3500 JVCGY-HD x720 M 4:2: /19 I 16x5.5/1.6 $6300 JVCJY-HD x720 M 4:2: /19 F 10x5.2/1.8 $4000 PanasonicAG-HVX x540 D 4:2:2 1280/9601/100 F 13x4.2/1.6 $6000+P2 SanyoVPC-HD x720*AVC? ?/9 (30f) F 10x6.3/3.5 $800 SonyHDR-HC x1080 M 4:2: /25 F 10x5.1/1.8 $1800 SonyHDR-FX13-960x1080 M 4:2: /25 F 12x4.5/1.6 $3700 SonyHVR-A x1080 M 4:2: /25 F 10x5.1/1.8 $3100 SonyHVR-Z13-960x1080 M 4:2: /25 F 12x4.5/1.6 $6000 * all imagers 1/3-inch except Sanyo 1/2.5-inch For about twice the highest price above and somewhat larger size, there are also the Grass Valley Infinity (2/3”) and Sony XDCAM HD (1/2”). Panasonic records on P2 card, Sanyo on SD card, all others DV tape Coming soon: Samsung SC-HDX15, Sony HDR-HC3 4: luma samples BR: bit rate D: DV coding F: fixed lens GOP: group of picture length I: interchangeable lens M: MPEG coding /: maximum aperture

Mark Schubin, HPA Technology Retreat, 2006 February 23 3 Optical Format Factor: The Basics lens image Ø x y x y Ø Ø normal imager widescreen imager imager Ø AR x y S : inch 16 4: inch 1616: /3-inch 11 4: /3-inch 1116: /2-inch 8 4: /2-inch 816: /3-inch 6 4: /3-inch 616:

Mark Schubin, HPA Technology Retreat, 2006 February 23 4 The Format Factor Divide equivalent factors of one format by another’s. e.g., 2/3-inch imager 11-mm diagonal divided by 1/3-inch imager 6-mm diagonal yields a format factor of 1.83.

Mark Schubin, HPA Technology Retreat, 2006 February 23 5 Acceptance Angle Based on focal length and imager size: Based on focal length and imager size: 13.5 mm lens, 16:9 aspect ratio, horizontal: 13.5 mm lens, 16:9 aspect ratio, horizontal: 55° – 1-inch (wide angle) – 10.3’ shot at 10’ 55° – 1-inch (wide angle) – 10.3’ shot at 10’ 39° – 2/3-inch (normal) – 7.1’ shot at 10’ 39° – 2/3-inch (normal) – 7.1’ shot at 10’ 29° – 1/2-inch (tighter) – 5.2’ shot at 10’ 29° – 1/2-inch (tighter) – 5.2’ shot at 10’ 22° – 1/3-inch (tighter still) – 3.9’ shot at 10’ 22° – 1/3-inch (tighter still) – 3.9’ shot at 10’ O I DF O I – = – D F

Mark Schubin, HPA Technology Retreat, 2006 February 23 6 Applying the Format Factor 13.5-mm lens in 2/3-inch format divided by 1.83 yields 7.4-mm lens in 1/3-inch format for equivalent acceptance angle mm lens in 2/3-inch format divided by 1.83 yields 7.4-mm lens in 1/3-inch format for equivalent acceptance angle. 4.8-mm lens in 2/3-inch format yields 2.6- mm lens in 1/3-inch format, but that focal length is not available in that format. 4.8-mm lens in 2/3-inch format yields 2.6- mm lens in 1/3-inch format, but that focal length is not available in that format. Failure of the Format Factor

Mark Schubin, HPA Technology Retreat, 2006 February 23 7 Sensitivity Based on individual Based on individual sensor (not imager) size: Range of 1/3-inch sensor (“pixel”) sizes: Range of 1/3-inch sensor (“pixel”) sizes: 2/3-inch comparison: 2/3-inch comparison: full output 1/4 output 1280 x x1080 2/3-inch 1440x x x540 2/3-inch 1920 x 1080

Mark Schubin, HPA Technology Retreat, 2006 February 23 8 Applying the Format Factor For equivalent H & V resolutions,f/4 in 2/3-inch format divided by 1.83 yields f/2.2 for equivalent sensitivity. For equivalent H & V resolutions,f/4 in 2/3-inch format divided by 1.83 yields f/2.2 for equivalent sensitivity. f/1.8 in 2/3-inch format yields f/1 in 1/3- inch, but that aperture is not available. f/1.8 in 2/3-inch format yields f/1 in 1/3- inch, but that aperture is not available. Dynamic range is proportional to sensor size, so even wider apertures are limited. Dynamic range is proportional to sensor size, so even wider apertures are limited. Failures of the Format Factor

Mark Schubin, HPA Technology Retreat, 2006 February 23 9 Depth of Field Range of distances appearing to be in focus with the lens focused at some particular distance Range of distances appearing to be in focus with the lens focused at some particular distance Complex equations based on f-stop*, focal- length*, shooting distance, and “circle of confusion*” (visually indistinguishable from a dot) Complex equations based on f-stop*, focal- length*, shooting distance, and “circle of confusion*” (visually indistinguishable from a dot) * format-factor-related

Mark Schubin, HPA Technology Retreat, 2006 February Depth of Field Less allows attention direction Less allows attention direction Is more DOF better for news? Is more DOF better for news?

Mark Schubin, HPA Technology Retreat, 2006 February Applying the Format-Factor At DoF-related distances*, for same viewed resolution & framing, DoF is that of a different format with the f-number and focal length adjusted by the format factor: At DoF-related distances*, for same viewed resolution & framing, DoF is that of a different format with the f-number and focal length adjusted by the format factor: 2/3-inch 14.6-mm f/3.3 = 1/3-inch 8-mm f/1.8 2/3-inch 14.6-mm f/3.3 = 1/3-inch 8-mm f/1.8 * not macro, not in the hyperfocal range 2/3-inch 6-mm f/1.8 = 1/3-inch 3.3-mm f/1, which is not available 2/3-inch 6-mm f/1.8 = 1/3-inch 3.3-mm f/1, which is not available *except microlens aperture issue Failure of the Format-Factor

Mark Schubin, HPA Technology Retreat, 2006 February Introducing Contrast Do you see a curve across the top?

Mark Schubin, HPA Technology Retreat, 2006 February Modulation Chart contrast resolution

Mark Schubin, HPA Technology Retreat, 2006 February Modulation Chart contrast resolution curve varies with retinal angle and observer

Mark Schubin, HPA Technology Retreat, 2006 February Modulation Transfer Function contrast resolution “sharpness” is proportional to the square of the area under the curve curve shape varies due to such factors as filtering, diffraction, etc.

Mark Schubin, HPA Technology Retreat, 2006 February Combining Vision & Technology contrast resolution invisible not reproduced available & visible

Mark Schubin, HPA Technology Retreat, 2006 February Understanding Diffraction Airy disk MTF reduced, resolution unaffected

Mark Schubin, HPA Technology Retreat, 2006 February Diffraction and MTF Monochromatic diffraction-based MTF Monochromatic diffraction-based MTF MDMTF = 1 - (1.22 x λ x f x lp/mm) MDMTF = 1 - (1.22 x λ x f x lp/mm) For diffraction-limited resolution: For diffraction-limited resolution: MDMTF = 0 MDMTF = 0 Rayleigh Criterion: Airy disks one radius apart Rayleigh Criterion: Airy disks one radius apart almost 100% MTF

Mark Schubin, HPA Technology Retreat, 2006 February Violating the Rayleigh Criterion f/8 f/11f/16f/22 Canon EOS 20D – 6.4 µm sensor pitch originals 232 x 173

Mark Schubin, HPA Technology Retreat, 2006 February f/8 (f/3.4) f/11 (f/4.6) f/16 (f/6.7) f/22 (f/9.3) (1080-HD 1/3-inch equivalent)

Mark Schubin, HPA Technology Retreat, 2006 February Diffraction & the Format Factor Diffraction rarely significant in SDTV Diffraction rarely significant in SDTV Format factor applies Format factor applies f-number at MTF:0% 50% 75% 2/3” 1088 pels/line /3” 1088 pels/line /3” 1920 pels/line /3” 1920 pels/line /3” 1920 pels/line /3” 1920 pels/line /3” 1920 pels/line /3” 1920 pels/line /3” 1920 pels/line /3” 1920 pels/line worst-case: λ = 630 nm (red) best-case: λ = 400 nm (blue) 100% 92%

Mark Schubin, HPA Technology Retreat, 2006 February Lens Characteristics vs. F-stop Lower f-stop: less diffraction, more sensitivity Lower f-stop: less diffraction, more sensitivity Higher f-stop: less aberrations, ghosts, flare, vignetting, better relative light distribution Higher f-stop: less aberrations, ghosts, flare, vignetting, better relative light distribution Sweet-spot: 2-3 stops below maximum open Sweet-spot: 2-3 stops below maximum open simple-lens aberrations reduced in smaller formats simple-lens aberrations reduced in smaller formats Do lens corrections result in the 2-3 rule of thumb? Do lens corrections result in the 2-3 rule of thumb? If so, small formats may lack the sweet spot. If so, small formats may lack the sweet spot. Canon EF75-300/4-5.6 IS 300-mm closest focus, shot on EOS 20D not a video lens or camera

Mark Schubin, HPA Technology Retreat, 2006 February Lens Quality & the Format Factor Lens MTF often uses line-pairs/millimeter (lp/mm) as the resolution axis Lens MTF often uses line-pairs/millimeter (lp/mm) as the resolution axis Smaller formats have fewer mm so higher lp/mm at equivalent image resolution and, therefore, need higher-quality lenses for equivalent MTF Smaller formats have fewer mm so higher lp/mm at equivalent image resolution and, therefore, need higher-quality lenses for equivalent MTF 100 lp/mm in 2/3-inch format x 1.83 format-factor yields 183 lp/mm in 1/3-inch 100 lp/mm in 2/3-inch format x 1.83 format-factor yields 183 lp/mm in 1/3-inch

Mark Schubin, HPA Technology Retreat, 2006 February LP/mm Line-Pairs per Millimeter 100 MTF % Relative MTF of HDTV and SDTV 2/3-Inch Studio Lens Measured at Picture Center F-4.0 HDTV SDTV 16:9 5.5 MHz SDTV Band-edge 1080/60i HDTV Band-edge Optical Reference 56 From “The Central Role of the lens in HDTV Imaging,” Laurence Thorpe, Canon, PBS Technology Conference 2005

Mark Schubin, HPA Technology Retreat, 2006 February LP/mm Line-Pairs per Millimeter 100 MTF % Format-based Lens MTF Points “HDTV” “SDTV” 2/3-inch SDTV 544 lp in 9.6 mm ≈ 57 lp/mm (30) 2/3-HDTV lp in 9.6 mm = 100 lp/mm (81) 2/3-HDTV lp in 9.6 mm ≈ 67 lp/mm 1/2-XDCAM HD 960 lp in 7.0 mm ≈ 138 lp/mm (110) 1/3-inch lp in 5.2 mm ≈ 122 lp/mm 1/3-inch lp in 5.2 mm ≈ 184 lp/mm (149) B&H Photo Prices: Canon XL H1 HDV cc w/20x lens - $ 9K Canon J17Ex7.7BIRS 2/3” lens - $11.5K Canon HJ17Ex7.7B 2/3” HD lens - $19K (not from B&H and much older): Canon HV12x12 1-inch HD lens - $112K 1-inch HDTV lp in 13.9 mm ≈ 69 lp/mm (56) 1/3-inch SDTV ~427 lp in 5.2 mm ≈ 82 lp/mm (55) 184/100 ≈ 2/3-to-1/3 format factor format factor

Mark Schubin, HPA Technology Retreat, 2006 February 23 26Conclusions The format factor allows conversion of focal length, aperture, and depth of field between formats, but it fails when the limits of the lens/prism are reached. The format factor allows conversion of focal length, aperture, and depth of field between formats, but it fails when the limits of the lens/prism are reached. Dynamic range is based on sensor area. Dynamic range is based on sensor area. Lenses for smaller-format cameras need to be better than lenses for larger-format cameras, by the format factor, for equivalent MTF. Lenses for smaller-format cameras need to be better than lenses for larger-format cameras, by the format factor, for equivalent MTF. And, now, heeeeeeere’s Larry! And, now, heeeeeeere’s Larry!