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director of photography, peter gray, dp, cinematography, dop, cinematographers, lighting cameraman, videographers, dv, high definition, 24p, digital films, HDW-F900, CineAlta, Varicam, AJ-HDC27F, Viper, 70mm, independent films, lighting directors, filmmakers, filmmaking, HDW-700AHDCAM TIPS and TRICKSfor Sony HDW-700/A High-Definition Camcorder
STABILITY: The CCD is extremely flat and dimensionally stable. In terms of flatness, the CCD is made to within a tolerance of one twenty-thousands of a micron. This means that any variation in lens coatings will tend to show up as a chromatic aberration in the resulting HD image. By comparison, lenses made for film cameras are less critical in some respects. This is because the emulsion itself is always weaving in the gate, and therefore cannot resolve similar coating errors. Certain aspects of HD lens design have to be made to much finer tolerances than equivalent lenses used on film cameras. WITNESS MARK: Focus measurements for the Fujinon and Angenieux lenses now reference to the witness mark on the camera, while the Canon lenses are measured from the front lens element. SQUARE PIXELS: The HDW-700 camcorder has 1035 lines of vertical resolution, while the newer model HDW-700A, has 1080 lines of vertical resolution. The extra 45 lines of resolution is barely perceptible. The reason for upgrading the CCD from 1035 to 1080 lines, is that the latter produces Square Pixels. Images composed of square pixels interface better with computer technology. EVS: Extended Vertical Resolution. Good for product shots, table-top work, shooting photographs etc. SENSITIVITY: f8,0 at 2000 Lux (@ 89.9% reflectivity). DCC: Dynamic Contrast Control is essentially an automatic Knee- Point adjustment circuit, designed to protect loss of highlight detail in bright or contrasty lighting conditions. BLACK GAMMA: Turn Black Gamma "ON" (factory preset is "off") to divide the gamma range into 3 sections (blacks, mid-range, and whites) with independent control of each part of the range. With Black Gamma turned on, you have about a 15% latitude of adjustment, plus or minus, of overall Gamma (Master Gamma), before effecting the blacks at all. GAMMA CROSS-OVER POINT: The factory setting is 55 (%) IRE. Best to set your Gamma Cross-Over Point (also referred to as "Average Picture Level") a little lower to say, 50 (%) IRE, to get an even relationship between your "blacks" and "whites" i.e. so you don't compress or stretch the available range in either direction. Or alternatively set it a little lower to increase overall color saturation. Kodak Color Film is the equivalent of about 47 (%) IRE, and this value is therefore a good setting for a more film-type of "look". BLACKS: In DTV (Digital Video/Television) systems, Blacks are at Zero, rather than at 7.5 (%) IRE. The latter is an older (analog) standard used to protect broadcast transmitter overload. BLACK BALANCE: Re-do the Black Balance if you change any of the black levels while setting up the camera LATITUDE: The Sony HDW-700 has a full 11 stops range before black saturation. This is not quite the same as a full 11 stops of latitude. In terms of usable dynamics in relation to film, the HDCAM really has about a 9-stop latitude. The difference is that the HDCAM can electronically force the angle of the toe in order to produce gradations of black in the extreme lower end of the brightness range being recorded. Then the HDCAM can record gradations of blacks, two stops below the level that the current Kodak Vision stocks begin to record anything above the film emulsion's base fog level. CCD's are linear devises. The gamma curve of CCD's are normally modified to give a little more in the mid range. This is to compensate for the non-linear response of the phosphors in television screens and video monitors. GREY CARD: It is necessary to use an 11-step Grey Card in setting up the HDCAM, rather than a 9-step card. DOWNCONVERTING: If downconverting HD to other video formats, always choose a Scanning Frequency 59.94Hz (rather than 60Hz) because the downconversion process is technically much simpler, and therefore significantly cheaper. At 59.94Hz there is only line interpolation in the conversion process, and no (read, very expensive) time conversion processes also involved. So as a general rule of thumb, it is currently better to shoot 59.94 for all production at this time, as downconversions are more cost effective and are without the associated motion artifacts with the 60Hz process. (A Scanning Frequency of 60Hz is the original HDTV standard, but a new ATSC standard allows for both 60Hz and 59.94Hz during the transition period between SDTV and HDTV production.) ASPECT RATIO: It is interesting to note that the decision for the 16 : 9 aspect ratio was made some 27 years ago. It was based on the best possible compromise in preserving the maximum image area across the popular existing formats in the early 1970's. In other words, a 16 : 9 extraction gives the least loss of image area across the most common aspect ratios i.e. 1.33, 1.66, 1.75, 1.85, and 2.35 STUDIO VTR: The Sony F500 HD-Studio VTR has a 1080/24p output, 1080/60i output, and has a 480/30i or 480/30p selectable outputs. 24P: The first six prototypes of the new "24 frame" Progressive Scan camcorders from Sony (HDW-F900) will be delivered end of October, 1999, for testing purposes. This model is also switchable between 1080/23.96p, 1080/24p, 1080/25p and 1080/60i. (As of the end of August, 38 units have been pre-sold before its release early next year). ENHANCEMENT: It is important to remember that you can always add Image Enhancement after shooting, but you can't always take it away. As a general rule of thumb, it is better not to over Enhance your image unless completely sure of your requirements, and extra especially if considering a conversion to film. It is usually better to simply turn Enhancement off, if converting to film or for general Green/Blue Screen work. Alternatively, it can benefit the image to have some subtle enhancement (about 3 (%) IRE) as it helps to smooth out edging and avoid some aliasing. MONITORS: The new "D Series" 24inch and 32inch Monitors from Sony are dual system. They can display both SDTV and HDTV signals in their full resolution "SPOT METER": The #2 Auto Iris setting can be effectively used as a 10 degree spot meter (reading in the center of the frame). CLEAR SCAN: Used for shooting computer monitors. Range is 30 to 7000 Hz. FAN: The camcorder has two in-built cooling fans. The front one is normally always on, but you can turn it off momentarily if necessary (via the appropriate menu). It is variable speed, and changes according to temperature. The rear fan only comes into operation during playback. COLOR SPACE: TAPE: HD cassettes have an Orange Band to distinguish them from Digital Betacam cassettes, which are (almost) identical in shape, size and construction. The HD tape itself, differs slightly from Digital Beta tape ...... by having finer particles in the magnetic coating. In an emergency, you can use a Digital Betacam tape in a HDCAM at the expense of reduced signal to noise ratio (about 10%). However, the indentations present on the HD tape, need to be duplicated (i.e. drilled) on the Digital Betacam before it will function in HDW-700/A camcorders. Duration is 40 minutes, and the current list price is US $81.25 per cassette. BEST LENS: The Fujinon 20x Lens seems to have the performance edge over the other available long-lens options right now, by as much as 30% MTF. (The Canon 18x lens is prone to "breathing" effects.) PEAKING: Turn up the Peaking Adjustment on the viewfinder to add image enhancement to the viewfinder display to help make critical focusing adjustments easier (this setting has no effect on the recorded image). POWER CONSUMPTION: The camcorder draws approximately 40 Watts of power in operation. AUDIO: Is uncompressed. Sampling Frequency is 48kHz, Quantization is 16bits per sample, and the Frequency Response is 20 to 20kHz. DEPTH OF FIELD: The image area on the two-thirds inch CCD on the HDW-700 camcorder is almost identical in size to a Super 16mm frame i.e. 11mm diagonal for the CCD compared to 11.2mm diagonal for Super16. So using 16mm Depth of Field tables/calculations for lenses on this camera are a very close approximation. LESS DOF: Consider using the -3db gain setting if it is desirable to have less Depth of Field. STEADICAM: Generally speaking, Steadicam monitors, accept a standard Bi-Level Sync signal. Sony's HDCAM works with a Tri-Level Sync signal, and therefore the camera output doesn't work with normal Steadicam monitors. I understand that Cinema Products have a special Steadicam monitor that will work with the HDCAM. COLOR CORRECTION: White Balance adjustment is linked to aperture, and therefore doesn't track with changes in exposure (i.e. with routine changes to the iris setting). It is better to do Color Correction on the HDW-700 camcorder via the 6-way Matrix system, as this will ensure your dialed-in color correction, will now track properly with changes in aperture. EXTERNAL MENU DISPLAY: To display the in-camera Menus on your monitor (when attached) ...... first, turn the camcorder off, then while holding the Menu Cancel Switch down, turn the camcorder back on. MAIN MENU: The Top of Menu (or Main Menu) is displayed by holding in the Rotary Encoder Button and flicking the Viewfinder Switch from the "OFF" position to "MENU" GHOSTING & BUZZ: DTV does not suffer from any problems with ghosting. Also no problems from "sync buzz" on the audio track (i.e. in a situation where the whites are cranked up). Copyright © Peter Gray Peter Gray |
