[Since writing much of the review below in 2007 of the Canon HV20, Canon has introduced the similar HV30 as a replacement. Changed are the raising of the zoom control higher above the body surface, making the body color black, improving the 
off-angle viewing performance of the fold out panel viewfinder, adding 30P shooting capability, adding a higher-capacity battery choice (the NB-2L24H, which can also be 
used on the HV20 - but to fully recharge it on the HV20, it must be removed after the 
first charge cycle and replaced on the HV20 for a second charge cycle), and adding "Vixia" to the name...]

INTRODUCTION --
Canon certainly "got their act together" on this one - the HV20/HV30 is one heck of a good inexpensive small 1-chip HD (high definition) camcorder!

LENS CHARACTERISTICS --
The lens at the wide end is superb, producing a very sharp image to the corners. Zooming 
about 1/2 way through the (marked) zoom range on the VF (viewfinder) zoom scale away from WA (wide angle) gradually introduces a touch of CA (chromatic aberration) toward the image corners, but with nothing very bad and with nothing else to complain about. Zooming to about 3/4 of the way toward the tele end (as indicated on the VF zoom scale) introduces still more 
CA, but it is acceptable, and sharpness, while declining a bit, is still very good. Beyond that point, the image quality declines rapidly (the CA is excessive at the long end and sharpness, especially toward the image corners, isn't all it should be). Since I prefer WA, these characteristics aren't a "deal breaker" for me and in the zoom range that I will use most of the time, the picture sharpness is astonishing when viewed on an unusually sharp 42" LCD TV at 6.5', especially when it is compared with any SD (standard definition) camcorder output and with anything sold near the absurdly low price I paid for the HV20.

PICTURE CHARACTERISTICS --
The picture has excellent color, even with AWB (auto white balance), although the picture is a little light with the stock picture settings. Contrast appears good, although it can be somewhat high for some subjects without adjustment - and highlights burn out easily, a common problem with one-chip camcorders. Those and some other picture characteristics can be modified slightly in the menus for improving the picture when needed. There are no evident oversharpening effects or MPEG-2 compression artifacts, and it is surprising that even with the high picture compression used for putting an hour of HD picture (plus sound) on a standard small Mini-DV sized tape, commonly seen compression artifacts with motion do not appear (at least that I have seen so far on a good 42" 1080p HD TV). The picture remains sharp, smooth, and with good color down to roughly medium-bright interior light levels, below which "golf-ball" noise appears and the color loses its purity rather abruptly. Unlike with Mini-DV camcorders, it can be useful 
to drop the shutter speed of the HV20 to 1/30th second, with little degradation of the image resulting. With minimal camera or subject movement, even a 1/15th second shutter speed can look good. Occasionally, with jerky or rapid camera motion, CMOS rolling shutter picture distortion can be seen. To my surprise, the 24P mode is not so ugly with motion as earlier versions (30P) that I have seen. It also appears to increase the camcorder sensitivity a bit, an advantage in fairly low light (where the HV20 is better than I expected it to be, although it is a camcorder that definitely does not perform well in very low light levels). "24P", however, is not truly 24P, and editing with it can be tricky. The "cine look" mode (which "jiggles" contrast, saturation, etc. to simulate the look of film) helps with skin color under some lighting conditions that otherwise result in a too-red or harsh image - but for general shooting, I find that video shot in this mode is too low in contrast and color saturation to be pleasing. "Cine look" mode appears to smooth out motion in 24P mode, but at the price of softening the image considerably during motion.

SOUND CHARACTERISTICS --
The sound quality is acceptable as-is, but some undesirable camera handling noises and zooming hum can be heard in the recorded audio. The built in microphone is also very sensitive to wind noise. Unfortunately, when using an external microphone with the HV20, you cannot enable the auto "wind" LF (low-frequency) cut filter, and I like to shoot nature here and the wind is almost always blowing. I tried adding a stereo Sony 908C external microphone to the camera using a simple isolation bracket, which solved the first two problems, but I could not solve the serious wind noise problem when the wind was strong, even with two layers of foam windscreens and with added multiple layers of differing types of open cell foam wrapped around the windscreens. I have not tried a Rycote "furry" over the Radio Shack foam screen (RS part number 33-373A, which fits nicely over the 908C's own foam windscreen). I then tried, without success, my two mono short shotgun Sony microphones (with screens and wraps) mounted at diverging angles 
on a dual bracket and using a Radio Shack 1/8" dual-mono-to-stereo adapter (RS part number 274-375, $4.99) and a RS 1/8" right angle stereo adapter to get cords where I wanted them (RS part number 274-372, $3.99). Next up was my mono Sennheiser MKE-300 short shotgun microphone with its wind screen plus a Rycote "furry" over that, all mounted on a pair of isolators to raise the long and fat microphone package high enough so that it was out of the visual range of the lens zoomed wide with the Raynox .66X WA lens converter on it. This solved all the problems, but introduced another one - with the microphone's mono plug inserted into the HV20's stereo input, I got a mono audio image that hung noticeably toward the left side. I was able to achieve a centered mono image by adjusting channel balance during editing - and also by using a Radio Shack 1/8" mono-to-stereo adapter (RS number 274-374, $2.99). I eventually replaced the MKE-300's mono plug (which did not fit sockets reliably anyway) with a stereo plug with the "hot" wire connected to the plug's ring and tip. I added the right angle adapter to 
get the wire where I wanted it and also to better protect the camcorder socket from possible damage from side force on long adapters sticking out of the side of the camera. I looked at various solutions for converting mono sound to a simulated stereo sound, but I was not happy with any until I tried one of my own (see here). I have also found that this camcorder's AGC (automatic gain control) does not always prevent wave-form clipping distortion. (I do miss the Sony VX2000 microphone/audio which, with the Radio Shack perfect-fit windscreen [RS number 33-373A], was free of all problems and it just plain produced good ambient stereo sound for me without fuss.) When using the larger of the two batteries that were originally available for the HV20, I heard a frequent "thunk" in the audio. I recognized this immediately as being caused by the battery moving in its mounting area - and it was cured by adding patches of masking tape four to five layers thick to the backs of the batteries. The patches extend a tad short of the terminals, some short of the depression at the other end, and just short of both sides (clearing the mounting cut-outs). Afterward, I put the cap on each battery with the opening (indicating charge state) over the side opposite from the blue label and filled in the exposed 
area with a ball-point pen (blotting it afterward). Also, be very sure to switch from the default 
mini-plug "AV" output to the alternative "headphone" output in the menu when using headphones 
with the HV20!

RECORDING MEDIA --
Tape has advantages over the DVD, memory card, and hard drive recording systems used by some camcorders. The compression system used for tape is still generally better for image quality, and tape remains preferable for editing and storage practicality. Unfortunately, the first tape I tried was a rare defective one, and it pointed out a potential problem with tape: dropouts  (and an HDV MPEG-2 dropout causes the picture to freeze for about half a second). Many people report trouble-free use of standard Mini-DV tapes of various brands (and even with mixing brands), and I later had relatively few problems with the same kind of tape I had had many dropouts with. This experience did give me the opportunity to (painfully...) learn the differences in how three editing programs handled problematic source material. Higher grades of tape in the Mini-DV cassette format are available, but the prices are considerably higher (but for safety I will now use tape specifically designed for recording HDV with its MPEG-2 format, which is much more sensitive to the effects of tape dropouts than Mini-DV - and I now have a supply of Sony DVM-63HD tapes). DVD, memory card, and hard drive in-camera recording systems do avoid dropout problems, but for me, their several disadvantages far outweigh their one advantage.

MANUAL CONTROLS --
Manual controls can be accessed after the slider on the camcorder upper rear left side is moved from the full "Auto" to the "P" position. MF (manual focus) is done by pushing a small button next to a "roller wheel" near the front and turning the roller (the backlight compensation button is just above it). Pushing the MF button and holding it more than two seconds moves the lens to infinity focus, but only for the zoom setting already selected (any zooming defeats this setting). The "edge peaking" viewfinder MF aid appears quite helpful (accessed at the bottom of the viewing screen or in the menus) - but I found the 2X magnification option on the coarse-grained screens less useful than the peaking function alone, available separately in the menus. There are also useful "lock-and-shift" exposure and sound recording level controls (using the tiny joystick on the camera back), which serve well enough as substitutes for fully manual controls (although their operation can be confusing).

AUTO CONTROLS --
The HV20's auto controls work well, and for some people, the upper left rearward switch may be left at the "Auto" rather than the "P" position (but this is not my choice for the best picture...). The "instant AF" and "standard AF" modes give slightly different choices for how the autofocus works. I prefer to leave the camera in "I-AF" mode since the slower standard AF mode can't keep up with moving objects very well (including me with the camera) and it hunts for correct focus more often than in the "I-AF" mode. My current preferences for setting the picture bias controls (with my camera...) are: sharpness always at "o", exposure always at "-", contrast at 
"-" on sunny days and at "o" on cloudy days, and color depth at "o" unless there are saturated yellows, oranges, reds (then I use "-" to prevent these colors from "block-up", removing detail in these areas), or when there is skin tone in the sun (or at "+" if the light and color are "flat"). I use DWB outdoors in sunlight and SWB in shade/cloudy-conditions (or I set the adjustable white balance) for the best color balance and for avoiding scene-to-scene color balance variations. In addition to the picture biasing adjustments in the menus, there are also selections for smoothing skin tone and also for simulating a "film look". Selecting the custom settings locks out skin tone smoothing. Using "cine mode" results in a picture that looks too flat and lifeless for my tastes (although this mode can also be modified with the custom controls and manual exposure shift). Some added manual reduction in exposure may be useful under almost any condition to avoid loss of the appearance of image "richness", the loss of highlight details of light-colored subjects, and the blocking up of highly saturated yellows, oranges, and reds. Aperture-priority and 
shutter-priority auto exposure modes can be selected in addition to program auto, and all of these can be overridden using the "lock-and-shift" manual exposure control (which I now use more frequently, judging exposure with the eyepiece VF). I prefer using shutter-priority, using 1/60th second when shooting moving water, and 1/100th or higher for everything else outdoors unless the shutter speed blinks indicating that it needs to be adjusted to another shutter speed for correct exposure (image diffraction effects at the smallest stop available, f8, are not really a problem, and the lens is good at wide stops). Some of the special program modes can improve the picture characteristics under specialized conditions, but I very rarely use these. For me, the picture with the body side switch set to "Auto" mode is not what I like - but that is what the biasing controls, the aperture and shutter priority modes, and "lock-and-shift" mode are for, available with the body switch set to "P".

ADDITIONAL COMMENTS --
The menus are fairly easy to operate from the single button and "joystick" on the rear (many of the options are removed unless the slider on the camcorder upper rear left side is moved to "P"). The lowest level items are accessed by pushing the button and making selections with the joystick (pushing it in to fix them). The second level is accessed by holding in the button longer than two seconds - a neat system (but sometimes confusing in practice). Other options are accessed with the joystick directly, pushing it up or down for selection, then left or right to change the settings, but I find this VERY confusing in practice, simple as it sounds. There are outputs for FireWire, HDMI, component video, stereo sound, and headphones - and various inputs, including a stereo 1/8" microphone jack. I thought I would miss a Lanc input, but Canon has provided not only a nice zoom control (unusual for a small camcorder), but one with an unusually slow lowest speed available - very nice! And, there is a menu selection for choosing a fixed zoom speed (including the slowest) so that you can "mash" the zoom controller and still get a predictable zoom rate. The optical stabilizer is excellent, but since I now shake rather a lot, I use a handle that extends far out to the left side of this small and light camera, with a folding bar attached to it that rests on my left shoulder. Added to that are a firm grip with my right hand - and with pressing the top of the camcorder viewfinder to my eyebrow, I have four points of support (I also have a tank of a professional fluid-head video tripod, but I dislike using it). As a further method of image stabilization, I now sometimes also use ProDAD Mercalli Expert, a software stabilization program. For more on that, go here. A standard shoe for a light or microphone is also supplied on top of the camcorder, hidden under a snap-off (and easy to lose) cover (I leave it in my video gear cabinet so I know where it is...;-). Data is transferred by FireWire to a computer for editing, and some very inexpensive editing programs will now handle the HDV MPEG-2 material. The edited video can be transferred back to the camcorder for archiving, and HD disks can be made on Blu-ray blanks using some editing programs with appropriate burners.

SOME COMPLAINTS --
The HV20 has the usual full-auto-everything/program/aperture-priority/shutter-priority selections, but no fully manual exposure mode. Its "lock-and-shift" exposure mode can serve well enough for most manual exposure needs - but I still haven't gotten used to navigating quickly and easily the manual exposure level and sound level adjustments with the joystick (I always seem to push the control the wrong way and instead of modifying a setting, I wind up in a different function). I now favor often leaving the exposure control activated and using the eyepiece VF to judge exposure, and this has worked well. The barely adequate eyepiece VF is fixed in position and does not permit extending it or tipping it up (although it does easily clear the small battery packs available for this camcorder). The camcorder and VF eyepiece are (unfortunately for me) not left-eye friendly. I found it useful to put small sticky-backed bits of soft material at the VF top corners to protect eyeglasses from the hard VF surround material. The swing out VF panel screen is coarse and the apparent video image brightness changes considerably with viewing angle changes, making framing difficult and focus and exposure evaluations with it almost impossible outdoors (the HV30 panel is better). The HV20 (and HV30) VFs show quite a bit less than the full image recorded area (said to be 20% less, which makes it necessary to look carefully at what is in front of the camcorder to avoid shooting unwanted things - like your own shadow when a WA converter is installed...). Most of the various available VF grids and lines are too distracting (although using the single grey horizontal line choice may be useful when leveling the camera).  Unfortunately, the camcorder's VFs do not serve well enough as monitors to make reliable framing and picture adjustments on location easy, and this can be somewhat frustrating when the footage is viewed afterward (especially since modifying MPEG-2 in post is not desirable with the resulting quality-lowering but required additional compression pass). Other than using the often-OK settings given under "Picture Characteristics", above, I have found no "one set of settings does all" way to insure that most footage shot with this camcorder will be ideal (unlike with the Sony VX2000 - although much of this problem can be attributed to unavoidable differences between a good three-chip camcorder and a good one-chip camcorder). Most of the HV20's controls are surprisingly awkwardly placed and awkward to use. Handling the camera while taping can result in noise being picked up by the built-in microphone and zooming produces a low-level hum in the audio, but using an external microphone with even a simple isolation system can solve these problems. Unfortunately, the "windscreen" (really only low-frequency audio filtering...) cannot be turned off in "auto" mode when using the internal microphone, and it cannot be turned on when using an external microphone in "P" mode. Making some choices locks the user out of some other choices (this is necessary for simplicity in the menu and operational organization, I guess, but....). As mentioned above, the large cover for the accessory shoe snaps off for removal, and it can be easily lost. Other covers on the camcorder are attached with material that looks stressed when it is bent to open the covers (one hopes that these hinges will last...). Some jacks/plugs are tiny and a bit finicky (and one cord with a tiny plug is quite stiff), although I suppose that this is necessary to permit so many connections to be made to such a small camcorder. Related to this is the unfortunate necessity for manually switching in the menus from "AV" to "headphones" since they share the same jack (although for most purposes, "headphones" can be left selected). While commendably tape based, using even the highest quality Mini-DV tape in the HV20 risks dropouts, so expensive HDV-specific tapes should probably be used (experience with this varies, and many people report reliable results with cheap Mini-DV tape). Battery selection for the HV20 is very limited, with the two largest ones being almost identical in run time (and these do not have very long run times - but a larger one is available for the HV30 that will fit the HV20 although it requires two charging cycles on the HV20 for a full charge). Also, while this camcorder may be inexpensive, the remote for it is unnecessarily tiny, weak in signal output, and the camcorder receiving end is unfortunately placed under the camcorder's lens, so the remote's operation is not very reliable. 

CONCLUSION --
The above complaints notwithstanding, the HV20 (and HV30) can produce excellent image quality and acceptable-to-good sound quality, and for the money (or even much more), you cannot improve on its performance. The picture quality is a huge improvement over even the 
best Mini-DV (or any other camcorder SD format), and while it is well short of the very best broadcast HD, it appears to me to be the equal of "average" HD broadcast picture quality 
(at least when the HV20 is used near the wide angle end of its zoom range and in good light), 
not a small thing for such an inexpensive and simple camera. This camcorder is amazing!

THE CANON HV20 WITH WIDE ANGLE LENS CONVERTERS --
I went through my shelves full of WA lens converters, trying them on the HV20, and I was surprised how good four of them are, even in HD - but they are all a bit less than perfect. One generic fisheye adapter of the many I have is quite sharp and extremely wide (although it is not 
at all zoom-through), but my particular camcorder's sensor is decentered top to bottom, so the cropped circular image is not satisfactory without further cropping in post (the stabilizer should, 
of course, be turned off when using these cheap fisheye lens converters, or the cropped edge of the image will move around in the frame). The VERY wide Sony ES-06 is very slightly softer in the corners at wide stops (only) than the two less wide converters and it has some slight CA and a considerable amount of barrel distortion, but it is very compact and light (although it is also not at all zoom-through). The fairly light-weight Raynox (HD6600) .66X is quite good and it has the least amount of linear distortion, but it is not fully zoom-through and at the wide end it is bettered very slightly by the Canon WD-58 in the corners at wide stops (although this one is also not fully zoom-through). (The WD-58 .7X was designed for the Canon GL-1, but it was excellent on 
the various Sony 58mm front-threaded Mini-DV camcorders - see comparison frame grabs at www.donferrario.com/ruether/WA-converters.htm from various 58mm WA converters on the VX2000.) The WD-58 is rather large and heavy, and it has very noticeable barrel distortion on this camera's lens (see the sidewalk in the frame grab below), so I now tend to favor the slightly wider and lighter Raynox .66X (which is also the only one that will accept a filter and shade). It may still be worth trying the $200 Canon .7X made specifically for this camcorder. I did not try my Sony 58mm .7X WA or 1.7X tele lens converters since these are FAR too large and heavy for the small HV20 camcorder (but they are top-quality converters - maybe I should try them just for fun...;-).

COMMENTS ON SOME HDV EDITING PROGRAMS --

COMMENTS ON USING THE MERCALLI VIDEO STABILIZER PLUG-IN --

SOME FRAME CAPTURES FROM SOME HD VIDEOS I'VE PRODUCED USING THE HV20 --

SIMULATING STEREO AUDIO WITH A MONO SOUND TRACK --