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BUYING A USED "PROFESSIONAL" CAMERA OR CAMCORDER
So, what's so special about a "professional" TV camera?
Professional TV cameras make better pictures than prosumer or
consumer models. I'm sure you're not surprised to hear this. Some
say you can't see the difference once the image is duped onto
fuzzy old VHS tape or non-HD TV set, but the truth is, you can
see the difference, and it is quite obvious. Pro cameras make
sharper pictures than their lower-priced cousins, and that translates
into a sharper picture even when the image is hammered by:
1. Being changed from component colors (which are sharp) to composite video (which are relatively fuzzy). 2. Being duplicated down several generations. 3. Being converted to VHS which has a picture resolution of about 240 lines (SVHS has 400, DV has 500, DVD 550). 4. Being played over RF (i.e., channel 3 or 4) into a common TV set.
Another big difference between the pro cams and their little brothers: The professional models make a smoother (less grainy) picture. Put in technobabble, they have a higher S/N (Signal-to-noise) ratio.
Besides these big differences, pro cameras have some nifty features. Digital signal processing (DSP), for instance, allows you to make your camera adjustments via an on-screen menu, doing away with a lot of knobs and buttons that got dirty and erratic. Also, you can store the settings in memory and recall them instantly each time you fire up the camera.
Microlens technology works like an insect's eye to concentrate light over the CCD picture elements to increase camera sensitivity.
Then there's the way the camera moves the data from the image sensors to the outputs of the CCD chips. The camera manufacturers have been improving interline transfer (IT) and frame interline transfer (FIT) to further reduce vertical smears from bright objects in dark scenes. Picture resolution is high and dynamic range (the ability to handle very dark and very bright parts of the same picture) is far better than what you get from prosumer cameras and camcorders. Many of today's cameras can operate in Standard Definition (SD) or in widescreen High Definition (HD). Consumer models costing under $1000 can make widescreen shots, but the imagery is still SD, about 700 pixels per line times 483 scanning lines. True HD camcorders can record 1280 - 1920 pixels per line, times 720 progressive lines or 1080 interlaced lines. These cameras are much sharper, but cost $3500 up.
Camera Bells and Whistles -
All of the contemporary portable cameras appear to have a number of electronic shutter speeds such as 1/100, 1/125, 1/250, 1/500, 1/1000, 1/2000 second. These high shutter speeds are occasionally useful in stopping fast motion in sporting events for sharper still frames. (No camera yet has a fast enough shutter to stop a politician's lips.) A more popular use: The high shutter speeds darken the image, allowing you to use lower f-stops and decrease your depth-of-field, making foreground and background chaff in your picture go fuzzy. Camera operators used to use a neutral density filter to get this effect, in fact there's probably one on the camera's filter wheel. Changing the camera's electronic shutter, however, may be quicker and easier. Most EFP cameras have detachable viewfinders that rotate in various directions allowing the camera to be in an uncomfortable position while your eyeball is not.
Most of the zoom lenses have extenders allowing them to focus on objects 1" from the lens. Great for closeup shots of a raging rhinocerous.
Some cameras come with the recording deck built-in (one piece camcorder), while others allow various decks to be attached. Note that if you mount a deck from one manufacturer to the camera of another manufacturer, an unreasonably expensive interface adapter will have to be purchased to unite the two. Whether the camera is separable or one-piece, most units have component outputs that allow you to send signals to a backup VCR (in case your camcorder gets trampled by that rhino. Most EFP and ENG cameras have genlock capability, allowing their pictures to be synchronized and mixed with the images of other cameras, character generators, and effects devices in a multicamera shoot.
Newly designed viewfinders seem to offer higher resolution than their predecessors, living up to the standards of the higher resolution camera CD chips. Many of this year's viewfinders offer a feature called "quick start", yielding a picture within three seconds after the camera is turned on. Many have center markers and safety zones to remind the camera operator to keep the rhino centered on the screen.
Most of the camcorders have time code readers and generators, frame accurate backspace editing, built-in loudspeakers, and viewfinder playback capability. Also since the Betacam, MII, and SVHS formats allow four audio channels (two high fidelity, and two linear), the camcorders independently control these four channels.
Many camcorders have phantom power supplies (+48V, CH-1/2) to power professional condenser microphones.
Numerous cameras this year are sporting chroma detail circuits that sharpen images having highly saturated colors. Normally, high chroma areas of a picture appear fuzzy, especially in expanses of a single color, such as a blowup of a red carnation. These chroma detail circuits sift through the color mush and enhance differences within the color, drawing out detail.
Digital signal processing has brought the "film look" to video. Up to now, the dynamic range of video cameras has been quite limited. Now with the help of 2/3" Hyper-HAD frame interline transfer (FIT) CCDs with 520,000 or more picture elements, it is possible to get an unprecedented 80 dB dynamic range out of the camera. This translates to almost 11 f-stops of exposure latitude surpassing the 9-1/2 f-stops available on 35mm film insuring superb capture of high contrast scenes. This dynamic range combined with a 62 dB luminance signal-to-noise ratio allows low light scenes to be captured with detail not even possible on film. With the better camcorders such as the digital Betacam having a 62 dB signal-to-noise ratio, it is possible to faithfully capture the full dynamic range of the camera.
But they cost so darned much!
That's true. Maybe that's why they call them "professional" cameras because only the professionals can afford them. Solution: Buy a used model, maybe three years old. They'll cost about half what current models cost, yet they are still quite up-to-date. Many of the Pro rental shops sell off their gear after a couple years. The Networks also update periodically. And some production shops just go out of business. Check the trade magazines like TV TECHNOLOGY, VIDEO SYSTEMS, VIDEOGRAPHY, and AV VIDEO & MULTIMEDIA PRODUCER for used camera sales. Some to look for:
Sony BVW-300A Betacam SP One Piece Camcorder -
Besides many of the aforementioned features, this camcorder will operate for 75 minutes on a single NP-1B battery and can record 30 minutes on a single cassette. One unusual feature is audio confidence playback from the longitudinal tracks, allowing you to hear the sound off the tape just after it has been recorded.
Although you can play the camcorder's image back in its monochrome viewfinder, to play back color to another monitor you need an optional playback adapter.
Sony BVW-400A Betacam SP One Piece Camcorder -
This model sports most of the features of the 300A but has an additional selection of electronic shutter speeds allowing the camera to shoot computer screens without getting scanning bars or flicker in the image.
Panasonic F565 3CCD Digital Processing Camera -
This $7500 (new) camera (head only) seems designed for low light level use with a 1 lux minimum scene illumination. Like other cameras it switches to higher gain (up to +30 dB) in low light level, but further improves its sensitivity by teaming dual pixels together (2 pixels aborb twice as much light as 1). The 1/2" CCD chip has semispherical lenses over each pixel to maximize the light consentrated on the pixel (conventional CCDs have pyramid-shaped lenses that are slightly less efficient). Panasonic calls this HS-FIT (High Sensitivity Frame-Interline Transfer).
Third generation DSP (Digital Signal Processing) circuitry uses 10 bit processing as opposed to 8 bits, reducing the noise generated in the digital-to-analog conversion of the signal. Digital dynamic noise reduction has been around for a long time, but Panasonic developed a new algorithm for reducing blur or lag that is a typical byproduct of DSP.
The F565 has a chroma detail circuit to improve resolution of saturated colors. It also has a dark detail circuit that optimizes resolution in dark parts of the picture. This would allow you to, for instance, distinguish individual hairs from one another on a brunette.
As with other DSP cameras, on-screen setup menus allow the user to program various camera settings such as chroma gain, sharpness, dynamic noise reduction, contrast, 58 digital adjustments in all. These adjustments are stored in five files, three of which are presets for studio, ENG, and low light level applications; the other two you program yourself.
A digital High Light Color function reduces chroma washout in bright areas of the picture. Imagine sunshine on Chairman Frisbane's baldpate. You no longer see normal flesh tones up there; the reflection blooms into a chalky white. With the High Light Color function, the normal flesh tone color is restored.
Panasonic AG-DP800 DSP Camcorder -
This unit cost the same as the F565, but includes the built-in SVHS VCR. Like its brother, it has the High Sensitivity FIT 1/2" CCDs with 380,000 pixels. It also has DSP, chroma detail, dark detail, and highlight compression circuits to extend the dynamic range of the camera. It has six memories to store customized digital parameters and a high gain mode capable of seeing in two lux. Besides the usual variable electronic shutter speeds, it has inbetween speeds for shooting CRTs flicker free. Even with the VCR running, the camcorder consumes only 20 watts making it able to record up to two hours, the length of an SVHS videocassette.
A 26-pin backup VCR connector allows a second VCR to record the camera's component signals, starting and stopping when the camera does.
Panasonic F700 Digital Processing Camera -
This $12,850 camera was an upscale version of its brothers listed above. Its DPS circuits are on LSI (Large Scale Intergrated circuit) chips taking up minimal space. A two-dimensional low pass filter reduces cross color and other chroma problems. This is especially handy if you are shooting pinstripe shirts, herringbone jackets, and venetian blinds, all images that tend to drive color cameras crazy.
Twenty different digital adjustments can be set including gamma, knee-point, chroma detail, detail, matrix and shading. Some of these adjustments assist the camera in displaying dark or bright parts of the image with the same detail as the rest of the image; dark parts don't turn into mud and bright parts don't bloom into chalky white. You can program the camera with one set of parameters, or switch it to one of the three preset modes of operation: standard (studio lighting), low light level, and fluorescent. Under the fluorescent mode, the blue-green light from fluorescent tubes is tempered by the circuits, restoring a natural white balance to the image.
A built-in SMPTE color bar generator with date/time display provides test signals to simplify monitor and video tape playback adjustments.
Panasonic WV-F250B Camera -
The $4,650 WV-FW250BH camera docks to a $3,530 (prices new) AG-7450A SVHS VCR. The camera also docks with Betacam and MII VCRs and has component and separate Y/C outputs appropriate for each format.
The camera has an SMPTE color bar generator with time/date display, and a camera identifier in the display. Up to four separate cameras can be identified. The F250B also converts to a studio camera with optional camera control units. Although it is not DSP, the camera has a few DSP-like features such as a bright light compression circuit, detail enhancers, and two white balance memories.
JVC KY27B Camera -
This camera makes low light level performance with minimal vertical smear its claim to fame. Under normal lighting, the camera has 750 lines of horizontal resolution at 62dB S/N ratio. It is one of the few professional cameras offering a combination of automatic level control and full time auto white balance to allow smooth continuous shooting from dark hallways into bright lights. One of its field production configurations uses a low cost triax cabling system to operate the camera 5000 feet from its camera control unit, switcher, or VCR. The camera head costs $7540, but the whole ENG package brings the price up to $9761. It's also configurable as a studio camera for $10,764.
JVC KY-19U Color Camera -
This camera is similar to the 27B except that it has 1/2" chips rather than 2/3", yet maintains most of the same specifications. The head alone originally cost $5245, the ENG package, $7466.
To achieve its low light sensitivity of 2 lux, the camera has an electronic gain boost of 24dB plus a special pixel readout system (summing adjacent pixels over time) to provide an additional 6B for a total of +30dB.
The electronic iris has a continuously variable shutter obviating the need for an ND (Neutral Density) filter. Using the camera's automatic level control (ALC) one can give the camera an aperture priority, setting the iris for desired depth of focus; the ALC circuit will automatically adjust to the correct video level.
The full time auto white balance will adjust automatically from incandescent to outdoor lighting without making you stop and reset your white balance for each change.
The electronic shutter has the usual incremental settings up to 1/2000 second but also has a variable scan function to provide flicker free shooting of computer CRTs that refresh at the inbetween speeds.
Camera setup menus allow you to adjust contour (detail enhancement), pedestal (black level), and other camera settings through a menu, storing the results in memory. Optional adapters allow the camera to be remotely controlled through a camera control unit or an RS-232C data link from an IBM compatible or Apple MacIntosh computer.
JVC GY-X2B camcorder -
In 1995 the GY-X2B SVHS camcorder (originally $8,999 with 13:1 lens) replaced its GY-X2 brother. The X2B sports 50,000 more pixels (380,000), twice the low light sensitivity (1.5 lux), two more dB S/N ratio (62dB), and 150 more lines of resolution (750). It also replaced its brother's shallow shoulder pad with a deeper more comfortable one.
Neat features include continuous auto black balance, auto white, and extended auto level control, to accommodate carefree point-and-shooting over broadly varying conditions. It has a plug-in time code option, variable shutter speeds for shooting CRTs, a built-in speaker, genlock, dual outputs for a spare deck, including a Y/C output. The stereo XLR inputs can be switched from mike to line level. The standard button mike that comes with the camcorder is omnidirectional and monaural, and picks up a lot of echoes. A mountable shotgun mike is available and easy to install. Remember that when you are finished using an external mike, switch back to the camera mike before you break away to shoot other footage or you may not get any sound. Wedding videography friends of mine who have used the GY-X2 for their upscale customers, feel that it was worth their $7000 investment. Instead of using the JVC NB-J1 batteries, they preferred the long, skinnier, Sony NP-1A batteries that also fit the camcorder. The slimmer batteries are easier to slip into pockets. Each battery operates for 40 minutes and takes an hour to recharge. It is also possible to operate the camera off the 12 volt battery belts used for portable lights.
Hitachi SK-2000P Series Portable Digital Camera -
These cameras came in three models, the top of the line SK-2600P, the middle of the line SK-2000PW (capable of 4:3 and 16:9 aspect ratios), and the lower level SK-2000P. At the top end, Hitachi sports 13 bit digital video processing for all three video channels. And with 600,000 pixels, the SK-2600P has the highest resolution available today on a CCD camera. To send this high signal to its destination, the camera uses a wide band FM triax system with a 12 MHz bandwidth for the green channel and uses a 10 MHz bandwidth for the red and blue channels. For full 10 bit digital transmission or extreme cable lengths, a fibre optics system has been developed to send the camera's signal to the camera control unit. The digital signal can then be fed to a D1 or D2/D3 VCR making the entire camera chain digital.
Like some of the other digital cameras, it has special high chroma detail and adjustable detail circuits. Other circuits compress high video levels to provide additional sharpness in high contrast scenes. One special feature allows the adjustment of flesh tone details without effecting the remainder of the picture. This is useful for softening blemishes and wrinkles on the faces of talent without softening the rest of the scene. A similar feature allows one color in the image to be independently corrected without affecting the other hues.
With an RS-232C interface, the camera and its control unit can be operated by a computer.
With the optional SU-F300A setup control unit, it is possible to transfer the precise camera matching details from one camera to up to 12 other cameras.
Fixed pattern noise is always a problem with CCD cameras operating in high temperature environments. The Hitachi camera head has a thermoelectric CCD cooling unit that "refrigerates" the chips, decreasing the fixed pattern noise (blemishes that seem to stay in the same place even though the camera moves). A plug-in filter assembly provides 6 correction and neutral density filters. They may be removed to allow cleaning or for installing special effects filters. A four position filter wheel can be remote controlled.
The viewfinder has a unique PIP (Picture in Picture) feature allowing the camera operator to simultaneously see his own shot, plus second video signal (maybe the program feed) in one quadrant of his picture.
Hitachi Z2000 13 Bit Digital Camera -
Like its brothers the Z2000 had a circuit to soften the detail of flesh tones and another circuit to allow painting the hue and saturation of a single color in an image. Like several other cameras it has circuits to increase the deatail in high chroma parts of the picture as well as special gamma controls to improve reproduction in the darker portions of the scene. Like a few other digital cameras, the Z2000 can improve its low light sensitivity by doubling the readouts of its pixels. And like the JVC models, it has hands free automatic white balance as you shoot. Besides the fixed shutter speed, the camera has "lock scan" shutter speeds with incremental adjustments to match computer monitors.
Sony DXC-637 Camera -
The DXC-637 sports "Hyper-Gain" to stretch sensitivity down to 1 lux by reading out pairs of pixels. For bright light, Sony improved its "Dynamic Contrast Control" circuits to make colors look more natural under high contrast conditions. "EZ focus" is a feature that electronically reduces the depth of field to make focusing easier. Additional "EZ" controls automate other camera setup parameters.
Sony DVW-700 One-Piece Digital Betacam -
The $65,000 DVW-700 provided the first generation 4:2:2 component digital images ready for digital post production. Its DSP circuits permit setup infomation to be stored and retrieved easily. Its Lithium Ion battery packs the same punch as a NiCad at 1/2 the weight.
Sony BVW-D600 Analog Betacam SP Camcorder with DSP Camera Head -
The $62,000 BVW-D600 offers the setup convenience and stability of DSP, coupled with the popular Betacam SP format. The camera includes most of the features of its digital 700 brother.
Sony BVP-550 DSP Camera -
The BVP-550 offers the stability and convenience of DSP, and can interface with a PC for remote computer diagnostics and display of operational status. It has an "Integrated Imaging Capsule" allowing users to easily swap out the 4:3 aspect ratio CCD imager FIT block replacing it with a 16:9 block.
JVC KY-27C Low Light Camera -
Retaining the features of its predecessor the KY-27B, the KY-27C pushes the envelope further with 800 lines of resolution, 1 lux sensitivity with full video output, virtually no vertical smear, and improved auto white and auto gain circuits. The KY-27C can also operate remotely tethered by 5000 feet of low cost triax cable.
Panasonic AJ-D700 Camcorder, Part of DVCPRO Digital Component System -
The DVCPRO system acquires on digital tape, and edits nonlinearly on disk, staying in the digital realm from start to finish without quality-degrading analog-to-digital conversions along the the way. The camcorder records 4:1:1 digital component video on 6.35mm cassettes, similar to DAT tapes, employing 5:1 intraframe compression (which doesn't affect editing ability). The AJ-D700 has 3 half inch 410,000 pixel FIT CCDs, records 63 minutes, and uses only 20 watts of power (including recorder). To speed transferring data from tape to disk for editing, Panasonic will offer a 4X high speed transfer player.
TABLE 1
DSP (Digital Signal Processing) Features
1. Through the elimination of noisy, mechanical potentiometers, DSP provides highly reliable and stable performance. 2. Totally digital circuits suffer less drift due to changes in temperature and humidity. 3. Adjustments made through menus require fewer buttons and moving parts. 4. Camera adjustments are stored in a digital memory, maintained there for instant recall. 5. Camera adjustments which are quantified numerically require less test equipment. 6. The stored settings in one camera can often be transported to another camera, thus matching the two. 7. On analog cameras, the detail in light parts and dark parts of the picture is sometimes lost. A lot of effort goes into tweaking the camera to make the detail reappear. In DSP cameras, the dynamic range of the camera can be tailored to enhance the detail of bright or dark areas of the picture. This allows for crisper edges and more saturated colors and enhanced chroma detail.
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