Digital Switching
by Larry Lemm
MXProDV Digital Video Mixer
($2,495)
Videonics
1370 Dell Ave
Campbell, CA 95008
(408) 866-8300
www.videonics.com
In response to a world that is quickly going digital, Videonics has introduced the MXProDV, a product targeted at DV videographers who want to edit in a linear fashion, or switch high quality DV live. The MXPro (standard version) is a popular stand-alone video mixer that allows users to combine up to four analog input sources in either a live, or post-production setting. We reviewed the MXPro in August 1998 issue of Videomaker, and reviewed a slightly upgraded model in the June 1999 issue of Videomaker. The MXProDV is very much like the standard MXPro, except that in addition to the standard analog inputs found on the MXPro, it adds two FireWire (IEEE 1394 or i.LINK) inputs and one FireWire output. You can mix analog and digital sources, and get a digital output.
Who would want to use a FireWire-equipped stand-alone mixer? Wedding and event videographers who use multiple Mini DV camcorders and want to do all-digital live switching, certainly. But users can also combine a Videonics AB-1 edit controller with the MXProDV for an all-digital linear editing suite. This combination would be good for those who create programs that are longer and needing fewer edits than is reasonable for a nonlinear editing system.
Getting Hooked-up
Hooking-up the MXProDV is a simple operation. For our first test, we used two Mini DV camcorders as sources, and a third Mini DV camcorder as a record deck. For our sources, we used a Canon XL1 and a Panasonic AG-DV950 (which isnt on the list of MXProDV-compatible devices, see sidebar). A Canon GL1 served as our record deck. All of the digital camcorders we used were hooked into the MXProDV using FireWire cables.
For monitoring, we hooked a TV to the "preview out" jack on the switcher using an RCA cable (the preview function doesnt support S-video). We used the LCD monitor from the GL1 as a final output monitor.
You might have noticed that we hooked up only two digital camcorders as sources. Even though it can support four analog video sources, the MXProDV allows for only two IEEE 1394 (digital) inputs, making the idea of live all-digital 3-camera shoot a dream, at least for now.
Four Meters of Freedom
One of the downsides of using IEEE 1394 cables in a live shooting situation is the 4-meter limit of the cable. Because they simply dont make IEEE 1394 cables longer than about 12 in length, you can get your camcorders only about 12 away from the MXProDV, spanning just 24 in total possible width with the camcorders straight out to the sides of the mixer. However, there are aftermarket IEEE 1394 extenders that you can buy if you need to put your digital camcorders further from the mixer than an IEEE 1394 cable allows.
Roll Transition
The MXProDV, like the MXPro, comes with 501 transition effects. These include standards like fades, wipes, slides and dissolves. The transitions in the MXProDV, like the MXPro before it, occasionally suffer from a bad case of the uglies. This is especially true when you use a colored edge on a wipe. The bordered edges tend to look rather blocky, a less-than-desirable fact in this day of antialiased 3D graphics. Your best bet is to use soft edge borders or avoid colored edges altogether. Transitions are performed in one of two ways. You can play them automatically, using the "play" button, or manually using the T-bar. We suggest sticking to the auto play mode. The T-bar on the MXProDV suffers from the same unresponsiveness we reported in both previous reviews of the MXPro. Transitions displayed a lag of about a second before catching up to the T-bar. After the delay, the transition would jump to match the position of the T-bar, then would move as the T-bar did through the rest of the motion. The only way to use it well was to jiggle the T-bar to get the transition started, then back it off until the transition was barely visible. Only then did the transition run smoothly, in correlation to the T-bars position. To be completely fair, we went through the process of re-calibrating the T-bar according to the instructions in the manual, and the operation improved slightly. However, even after the re-calibration, the T-bar remained frustratingly unresponsive.
Keyed Up
A function that the MXProDV performs well is chromakey. Using a green wall, we were able to key a subject well. Even with our quick lighting job, the MXProDV performed clean keys, without leaving the edges of the subject looking rough. Good job on the chromakey Videonics. MXProDV users will be pleased.
The rest of the functions that the MXProDV performed in our tests, such as color correction, time base correction and Picture-in-Picture, it performed well.
Whats the Deal?
The MXProDV has a manufacturers suggested retail price of $2,495, just under $700 more than the MXPro at $1,799. What do you get for that additional $694? Two FireWire ports, a basic audio mixer function and the ability to convert analog footage to digital. This may be the most attractive aspect of the MXProDV. Plug in three camcorders (in any combination of analog and digital) and record the mix out to DV. You leave with a master tape that is top notch, and youll have the ability to make lossless copies for distribution.
In our tests, we found that there was a noticeable quality difference between IEEE 1394 and analog inputs, as you would expect. We ran DV, S-video and composite outputs from a single camera simultaneously to three inputs on the mixer. This allowed us to accurately see the difference in quality between the DV and analog inputs. Footage routed into the box via FireWire was noticeably richer in color depth. Even so, the cameras we routed through the analog inputs looked very good. Anyone using the unit to mix analog with DV sources will be confronted with this visible difference that is inherent in the formats.
Next we attempted to match the color of three different camcorders using analog and DV inputs. Videonics has included a color balance feature that allows you to tweak the color balance of each input, but we found the feature difficult to use when we attempted an exact match between cameras. Heres why. While the unit does allow you to adjust color enhancement for each channel, all color correction is "temporarily disabled" during transitions: a fact stated plainly on the Videonics Web site. Because color correction is disabled during transitions, you cannot use a half wipe to see two cameras on the screen at the same time while you adjust color balance. The only way to compare cameras is to cut back and forth between them. While this is a relatively minor inconvenience when color balancing your cameras, it severely limits the usefulness of the unit. Cameras stay matched only during cuts-only switching. They become unmatched for the duration of any other type of transition.
All in all, the MXProDV works well as a live switcher. The ability to mix your different digital and analog sources to a second generation without appreciable signal loss is great. If Videonics added a couple more IEEE 1394 inputs and fixed that pesky T-bar the MXProDV would be a great product. As an editor, the MXProDV-AB-1 combination may have a hard time competing with similarly priced nonlinear editing computers. However, it is a great solution for the videographer who wants to continue to use his analog camcorders and tapes, add a digital camcorder and master to DV.
TECH SPECS
Inputs 4x S-video, 4x Composite video (RCA), 4x RCA stereo audio, 2x IEEE 1394 (FireWire, i.LINK), GPI minijack, headphone minijack
Outputs 3x Composite video (1x preview), 2x S-video, 2x RCA Stereo audio, 1x IEEE 1394
TEST RESULTS
strengths
weaknesses
summary
