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|Nov 5, 2009, 10:19 PM||#1|
Join Date: Nov 2009
Aiptek PocketDV T100LE review (too dark!, need firmware, questions)
I bought on German eBay a used Aiptek mini camcorder which appears to be a "Pocket DV T100LE". It came with no accessories. Fortunately it has at least a standard mini USB jack (no matter of course) which works well with the cable of my Hama USB2.0 SD-card reader and a driver downloaded from Aiptek. The focus lever was missing, so I had to dismantle it and make my own from copper wire and cable insulation. Now it seems to work correctly, but I am very dissatisfied with it, since it records video even worse than my lousy digicam "Jenoptik JD 4.1 x z3" (which has only 320x208 in MPEG2 with bad colours and almost inaudible sound), despite a dedicated "camcorder" should be expected to do that better. E.g. the colours are even less accurate, the MPEG4 looks grainier (Jenoptik behaves much more analogue despite snow) and the picture jerks somewhat during fast pan. But worst is that it tends to film unusably dark.
By the lack of accessories I am not sure if I identified the model correctly (e.g. T250LE looks the same); the grey case looks very much like the PocketDV IS-DV and the bottom sticker label is "DZO-V3TS". But also other eBay vendors sold this type as "PocketDV T100LE". According to Amazon it was released in 2007. Generally Aiptek seems to consider these small camcorder rather a kind of fashion item than an utilitarian device, since they release them in a ridiculous variety of variants those only differ in case style despite very similar technical features. Many of them are not mentioned at all on the Aiptek website, so they can be hard to identify when the case has no model name. Regarding the poor quality, Aiptek's rapid product change cycles smells like a foul trick to avoid too many bad internet ratings by simply changing the model names every few weeks and also use other brand names once a model was rated poor. (Early Aiptek camcorders e.g. filmed only in resolutions far below VGA with jerky 7 or 13fps, which IMO really doesn't deserve the term "camcorder".)
So here is my review of the Aiptek PocketDV T100LE (or whatever it is genuinely called). Regard that this is my first tapeless mini camcorder, so I am not sure how far the described flaws and properties are typical for them and also exist in other cheap models or brands.
- too dark picture / exposure bugs
Its worst flaw is the horrible low light performance, which makes it almost completely unusable indoors after dawn.
The black level of the CMOS image sensor is way too low, so in areas with dim incandescent light (42W halogen in my living room) where I can still nicely read newspapers, the picture turns black. I consider this a severe firmware bug, since it is not just overly snowy or grainy by video amplification like with other poor camcorders, but fully black. Even the white frame of my TV set (a Nokia 417TV highend CRT TV) turns almost invisible, so I only see the (not overly bright) TV picture on the video. In my kitchen illuminated by the 15W kitchen hood incan bulb the cam can see nothing beyond 80cm away from it. Only my light grey tiled bathroom (60W incan ceiling lamp) looks fairly well visible, however already my own shadow looks grainy and almost black despite in reality it is barely darker than the rest of the wall. Setting "exposure" to maximum doesn't help against black pictures, since the algorithm apparently already switches internally to the highest available step when dark.
As a fix there is a so-called "night shot" mode built in, which however reduces the frame rate to something unusable like 5 fps with all moving objects drawing long comet tails (tripod very recommended) because it only increases exposure duration. But even in this quite useless mode the light sensitivity is not better than the daylight mode of average normal camcorders. Also without nightshot the T100LE blurs fast motion and pan noticeably more than a real tape camcorder. This may be result of the MPEG4 data reduction, but likely also of longer exposure time due to its very low light sensitivity. (The only other camera I yet saw with that low sensitivity was an antique Eumig B/W tube video camera from 1970th.)
I am fully aware that there are physical limitations since the tiny 3mm lens of such mini camcorders can in no way compete with the light intensity of the several cm large lens of professional SLR or highend video cameras. But a properly programmed "night shot" should change video amplification, gamma curve and possibly increase noise filters, or at least simply multiply the numerical video output brightness values with a scale factor once the picture turns too dark. Reducing the frame rate is no solution. E.g. even my old webcam "Aiptek HyperVcam" (with similarly cheap fixfocus hardware) offers plenty of different controls to adjust the internal values of its OmniVision CMOS image sensor to produce a properly contrasted (although snowy) picture at low light. The T100LE offers even in webcam mode (of Windows 98SE) only a single slider that reduces the frame rate to increase brightness exactly like the night shot mode.
Apparently Aiptek knew how poor it was, so they added as another silly feature a so-called video lamp consisting of 2 fairly bright 5mm LEDs (in yellowish warmwhite) those only produced a greenish circular spot in the center of the video picture; unless fully (4x) zoomed, their spot is way too small to fill the filmed area, and at close distance the lamp even overdrives the CMOS sensor, causing a plain white circle in the center of the picture unless the LEDs are partly covered by fingers (which tends to happen unintentionally). I carefully treated the lens-like transparent plastic cover of the lamp with fine sandpaper to scratch fine vertical (important!) grooves into it. On the one hand this makes the spotlight dimmer, but on the other hand it spreads the light over a larger and more oval area, which fits much better into the 4:3 screen ratio than the tiny circle of the unmodified state and reduces overdrive. (Do not scratch horizontally, else the light beam will spread vertically instead.) But in a dark room the camcorder can anyway see a white wall with that lamp only in 1m distance; even night shot mode makes it reach not really farer. Photographing my face with it closely in the dark makes very hard contrast; many parts remain black despite the LEDs are bright enough to blind me unpleasantly. During webcam mode the lamp can not be switched on or off.
In camcorder and photo mode the exposure setting in the menu has only 5 steps [-2, -1, 0, 1, 2], and unfortunately the internal resolution of it doesn't seem to be any higher. No matter how it is set, the automatic exposure control (which can not be turned off) switches the video picture darker and brighter in noticeably coarse steps (unless it is at the range end) when ever the mean brightness of the viewfield changes. This is particularly annoying when the light condition is at the threshold between 2 values, which makes the picture continuously switch brighter and darker like a disco music light, which looks really stupid. (I read that this flaw exists in many other Aiptek camcorders.)
When filming out of the window with daylight, the zero setting was way overexposed (too pale), so I had to set exposure to -2. This reveals that there is obviously a severe firmware bug in the exposure control algorithm, that likely also causes the horrible low light behaviour.
High exposure settings or bright objects (e.g. lamps) make the picture locally overexpose into a slightly pink tinted plain white area. Although such flaws also exist in my Jenoptik digicam, with the T100LE they are much more visible, because the dynamic range of its CMOS sensor is obviously much lower. In the menu a histogram can be enabled to estimate in a bar graph how much of the picture is under- or overexposed.
- low colour depth & distortion
Despite video colour resolution is claimed to be 24 bit, it looks much lower. Particularly in dark areas video often contains visible grainy colour steps those rather look like 16 or even 12 bit colour. I am not sure if this is a limitation of the image sensor or caused by too high video compression. Fast panning also makes a kind of picture distortion (tearing or temporary change of width/height ratio) that I never saw on analogue tape camcorders. The video is recorded as ASF files instead of plain MPEG4. I read complaints that this is a proprietary Microsoft format that is difficult to use on non-Windows (Mac and possibly Linux) operating systems.
- bad pixels
The 3 megapixel (2048x1536 pixels) CMOS sensor of my specimen shows a dozen green and blue pixels spread over the picture. They are mostly visible when zoomed in. Bizarre is that in normal mode the digital zoom produces a grainy preview picture on the TFT without these pixels, while the higher resolution preview mode is called "smart zoom" and needs to be activated in the menu every time the camera is turned on. I am not sure if it is disabled by default to save battery (it may consume some CPU capacity) or to hide these bad pixels from customers during sales demonstration.
- photos - no zoom during playback
In photos of course any bad pixels are visible. Suspicious is that one can not zoom into recorded photos during playback to find and delete blurred ones or see details, which may be another trick to fool customers. Also the claimed interpolated 10 megapixel are nonsense regarding the 3 megapixel sensor. The camera also has a flash with red eye reduction, which is no matter of course for a camcorder. But due to the reddish overexposure sensitivity of the CMOS sensor it is of limited use, because it tints photos pink. Generally the fixfocus CMOS photos have a Polaroid appeal. My old Jenoptik with CCD and optical zoom does that much better.
For me particularly a lack of photo playback zoom would be a complete disaster because I tend to use my digicam also as a notebook to document electronic circuitry during repair or DIY and need the zoom to see details to put parts correctly back together.
With the T100LE the lowest photo resolution is 1 megapixel, which takes still 200 to 300kB per photo. My Jenoptik can take VGA photos with each only 50KB, which is my most used resolution; I tend to take many hundreds of these when I document electronics. They are fully sufficient for my music keyboard website to illustrate enlarged details. Only for photos with many small details (e.g. the main photo of a keyboard) I choose a multi-megapixel resolution (something like 1400KB) and manually compress it further.
- no file date stamp
A very annoying flaw of the T100LE is that it saves no file time and date stamps. Files are numbered, but they always share the same date "01-01-01 00:00", which makes this device unsuited for any diary-like long-term applications (those otherwise would make sense by the voice recorder feature). Although it can be annoying to set the time after every battery change (capacitors exist to avoid that), it it state of the art that modern digicams can even save GPS position with their pictures and videos, and to get rid of manual clock setting, a proper camera driver could easily be designed to copy the system clock setting from the PC through USB every time the camera is connected.
- SD card data corruption
After my repair, the camera suddenly refused to recognize the SD card (hama 2GB) and only showed its internal flash memory contents. When inserted into my Hama SD card reader, I discovered that the entire card was "unformatted"; the hex editor HxD showed that the FAT and entire contents was partly overwritten with multiple copies of its directory and zeroes, so even recovery programs failed to find any intact files on it. I am not sure if this crash was just a dirty card contact, bad battery contacts or a firmware bug, but with my Jenoptik I yet never had any incidents of complete data loss on an SD card despite the Jenoptik often also accidentally saves only to internal flash memory or records a video file faulty when powered off or empty battery. (The T100LE also records a damaged video file when battery fails.) This is another reason not to use the Aiptek as a video diary.
The T100LE has a digital picture stabilizer against shaky hands. With video the effect is noticeable, however I don't know if it reduces the frame rate (like I read elsewhere). During panning it might jerk slightly more, but IMO it doesn't really reduce the anyway low video quality.
- digital zoom
It has been written much about digital vs. optical zoom. Everybody knows that the digital one makes the picture grainy when the sensor resolution is too low. However with consumer cameras the mechanism of optical zoom tends to be of very fragile plastic parts (I repaired a Canon Ixus 800IS objective) those are extremely sensitive to strong mechanical shocks and dirt. Thus for a toy or sports or action camera digital zoom definitely is a technically reasonable solution. It also doesn't decrease picture brightness when zooming in, which can be theoretically (not here) a benefit with low light. Digital zoom can also theoretically zoom very fast without loss of sharpness or mechanical wear, and by the lack of motors it consumes less battery power, so it isn't generally bad.
With the T100LE the digital zoom moves somewhat jerky and IMO too slow. It can be speeded up by rapidly pressing the zoom buttons, however the mechanical button click noises are also recorded by the internal microphone (noiseless soft rubber contacts would help here). In webcam mode zoom can not be used.
- no macro mode (near objects blur)
A small mechanical sharpness slide switch rotates the lens among 2 fixed positions for far and narrow. Unfortunately the range is way too small; the narrow setting is intended for 50..70cm and starts to blur narrower objects. Technically it is no problem to rotate such a lens further to focus tiny objects in only 1cm distance; my HyperVcam can do that, and also moving the lens holder manually during repair (I replaced the switch handle) focussed the lens much closer. A completely manually operated focus ring with feelable stopper at the far setting would be much more useful than the silly switch.
- screen always on
The Aiptek T100LE is switched on by opening the TFT monitor lid and turned off by closing it. You can not film with closed lid or TFT turned off, which makes the camera unnecessarily bulky and fragile when used as an action camera (e.g. on a helmet mount). Unlike later models, the T100LE also can not flip the screen around to make self-photos or -videos.
- strong magnet
Another annoyance is that the power-off switch is magnetic sensor in the TFT frame that is triggered by a magnet in the top right of the case rim. I really can't understand why they added this stupid construction which may easily damage cassettes, diskettes or bank cards in a pocket or bag, not least because the employed magnet is much stronger than needed to trigger the sensor. It e.g. can easily lift a screwdriver (the internal speaker magnet is much weaker outside the case) despite a weak magnet triggers the switch also. (Hold the upper screen rim against any magnet to test.) The magnet sensor on the PCB seems to be a small coil, that is likely part of an oscillator that changes its frequency in the magnetic field. Possibly the inventors initially used that oscillator as the TFT backlight transformer which protection circuit turned it off to prevent fire when the frequency changed by failing parts, and as an evolutionary side effect they accidentally discovered that so a magnet could be used to turn the unit off without wiring a switch.
With magnetic radiation there should be a general code of minimization to avoid damage to property and health. So this magnetic switch constitutes a completely unnecessary hazard.
- nasty chemical odour
After using the camcorder, my hands stink badly of electronics. It reeks like a mixture of epoxy, solvents and motor oil odour that is certainly unhealthy. I wiped the case with soap water to clean it, which reduced the stench but could not eliminate it. Particularly the rubber jack lid (may be some acrid plasticized soft PVC compound) keeps stinking.
- hands up! do not kill me!
This shiny mini camcorder (and many similar models) is handheld almost exactly like a pistol. So only its uselessness in low light may prevent policemen or watchmen from confusing it and though accidentally kill filmers of e.g. political demonstrations with a firearm when they believe to see a pistol attack.
Otherwise the similarity with pistols raises the question whether it would be more ergonomical to place the shutter or video button like a pistol trigger or add a simple gunsight as viewfinder on top to permit aiming with closed screen lid to save battery. Possibly the screen should be also placed on top instead of the left side for more stable two-hand operation.
- usable sound quality
Although mono, the recorded video sound from the microphone isn't too bad (but has some static) and also the internal speaker (a 2cm yellcoin) is of appropriate quality for the tiny camcorder. (My Canon Ixus 800IS has only a 12mm yellcoin that has lower volume. My Jenoptik even has no speaker and records sound with something like 3bit 8kHz; even speech was impossible to understand with that thing unless you speak very loud.)
- long battery life
Nice is that the T100LE runs on 2 standard AA size batteries. Of course rechargable NiMH batteries are recommended for any serious use, but in emergency it can indeed run many minutes on regular alkalines. (My Jenoptik strictly needs highest quality "ready to use" NiMH and crashes with alkalines or worn out NiM after only a minute due to extreme peak current and moving motors.)
Despite it makes the case bulkier, I clearly prefer standard NiMH cells over proprietary Li-Ion rechargeables. Lithium ones are often expensive and hard to find (especially some years later when the original goes bad) and especially cheap ones have the fatal tendency of violently exploding in the charger, hands or face like firework rockets and release severely poisonous smoke and residues (hydrofluoric acid, cobalt etc.). I consider lithium rechargeables arson timers and want to keep as few as possible of them in my apartment.
The camcorder has only 2 jacks - a standard mini USB jack and a 3.5mm stereo output. When a plug is inserted, the camcorder asks on its screen how to use them. The stereo jack can either be used as a stereo headphone or A/V output jack (i.e. analogue CVBS video on right channel, mono audio on the left). My standard stereo jack plug works only when slightly pulled out; else it shorts audio and video, producing hum and rolling picture, so I am not sure if this was intended for a proprietary plug with more than 3 contacts. USB can be used in webcam or usb drive mode. Unfortunately there is no video input for an external (helmet) camera.
Unusual is that you can exchange SD cards when powered on. (Windows file manager and playback mode window automatically update the shown directory.) However I would not recommend this due to the tendency of data corruption.
|Nov 5, 2009, 10:22 PM||#2|
Join Date: Nov 2009
I examined the hardware whether the CMOS image sensor can be placed on an external cable (e.g. head mounted on eyeglasses). Unfortunately it has no simple serial data or analogue line; the sensor sits on a small PCB ("DZO-V3T SENSOR, FOR SPECTEK REV:B, 59-418-0500-000W", which also contains the LED lamp and shutter button switch) with a very narrow 36 pin plug connector that would be severely difficult to modify. Also the TFT screen PCB has an 18 pin foil cable, which would make it hard to add a longer cable for placing it externally to see what I film. (The screen front pane is simply glued with double sided adhesive tale. To dismantle it, carefully pry at its rim with a screw driver. There are no screws under the metal badge.) The main board ("DZO-V3T MAIN BOARD, 59-418-01000-000, REV:B") is dual sided SMD. It is based on a square CPU that seems to be something like "ZORAN, ZR36460BGCF, A2 X6CM3634HB, COACH-8M". (The label was partly damaged by sticker glue, so the 2nd number row may be wrong.) On the back there is the flash ROM with green sticker "DZO-V3T, V" followed by handwritten mark "1208"(?) and a RAM(?) "hynix 635A, HY5DU561622ETP-D43, KOR, N7EE5493SQ1". There are also a some small ICs and many discrete components.
At least this electronics does not consist of only one COB chip (black blob - like a melody greeting card), as I first expected when I saw the performance of this battery operated Chinese plastic toy.
- plastic case
The case of the T100LE is partly grey and partly metallic silver plastic, which scratches easily. By the use of AA batteries it is somewhat thicker than slim lithium powered Aiptek camcorders; especially the bulged "Aiptek" metal badge on the back of the screen lid makes it unnecessarily bulky and may scratch in the pocket. But otherwise it is quite stylish and looks somewhat military-like. (I remember that few years ago certain mobile phones looked similar.) USB jack and SD card slot are only covered by an odorous grey rubber lid that is flimsy and awkward to stuff back into place. Some people complain that the battery cover was hard to open, but at least my used specimen makes no problems. Unfortunately the screen can not be turned around for self-photos (which however may make it slightly less fragile than swivel screens).
Annoying is that the 3mm lens has no protective glass pane. Although this may reduce internal reflections, it is inappropriate for such a simple mini camcorder that may rumble around in pockets or handbags, because collisions with hard objects like keys may easily scratch and ruin the lens. The aluminium ring around it looks even like when the objective was originally designed to have a glass pane that was omitted to cut cost. (Photos of similar Aiptek models on the web look like when they include it.)
To make it short, this camcorder is only a toy. When it competes with anything, than with camera mobile phones and not with any "real" camcorders. I am disappointed that the video despite 30 fps VGA looks worse than my old Jenoptik, which 320x208 resolution looks more honest and "analogue" although that digicam turns warm and empties NiMH batteries quicker. (With the Jenoptik even playback mode with only TFT lit draws much battery power.) Gimmicks like the 10 "picture frames" stress the toy nature of the thing. For people those by ideological reasons strictly avoid to carry a brain fryer with them (like me) or need additional cheap cameras for things like sport, hobby action filming, camera tossing or uncontrolled experiments (e.g. with risk of camera loss, theft or damage) it is ok, and it can record fairly long video in YouTube quality on a cheap 2GB card.
The T100LE was new only 60EUR and you can find them used even cheaper. But when you rate prices of Aiptek and similar mini camcorders, always compare them with similarly equipped digicams; digicams without optical zoom nowadays tend to be extremely cheap (below 40EUR) and may record video in similar quality, which can make it questionable whether a brand new Aiptek camcorder is really a bargain. (I am not familiar with their HD camcorders, but I read that they suffer of similar problems like my T100LE.)
WANTED: head mounted camera
My main purpose for the mini camcorder should be use as a point of view camera to film e.g. my own bike ride or do art with it. I don't do extreme sport, so it doesn't need to be extremely robust, but I clearly prefer digital zoom because it shouldn't break when it drops, and it should be possible to make it rainproof (plastic bags...). Especially it must have a TFT screen to see what I film. (Most cheap spy- and action cameras have none.) Best for me would be an SD card operated mini camcorder with good low light performance, at least VGA resolution with 30 fps and video input jack to connect an external camera. Particularly I would like to connect a glasses camera or forehead/ helmet camera; the thing doesn't need to be invisible, but shouldn't restrict head motion or vision too much. And it should be cheap (something like 40EUR). I guess a small security camera could be used; they tend to be optimized for much better low light performance than mini camcorders itself.
The simplest method would be of course to mount the T100LE (as is) on the peak of a plastic hardhat, using the screw part of a cheap mini tripod. But by its flaws I think I need something different.
Is there a firmware upgrade?
The horrible low light performance of my Aiptek PocketDV T100LE (or "DZO-V3TS") is unbearable. Is there a firmware update to fix its automatic exposure control or brighten the picture to make it usable indoors? Also file date stamps would be important.
My T100LE displays as the "camera" icon a different mini camcorder with blue case and silver front, which shape resembles an Aiptek MPVR or Z series (e.g. Z300HD-V, AHD Z500 Plus) camcorder. It also does not displays any brand or model name anywhere, which makes me conclude that the same firmware was likely used for various models (and possibly other brands) those differ mainly in the case shape.
- Has anybody examined this or made a list of technically identical variants?
- Has anybody made a firmware hack utility or add-on software for Aiptek camcorders (like CHDK for Canon digicams) to tweak internal parameters or unlock hidden features?
I don't care much about toy gimmicks like the MP3 player or eBook reader found in other Aiptek models, but I'd like to tweak internal parameters of the image sensor or compression algorithm (resolution, fps, ratio) and mask out bad pixels to improve video quality. Best would be of course a hack that turns the 3.5mm jack additionally into an AV input to connect a helmet camera, so far the PCB can be really software controlled on that level. (I read that other Aiptek camcorders use their jack this way.)
On eBay I saw a no-name mini camcorder named "DV-1 digital player" (written on its screen frame) with 2GB internal memory, 2.5 inch swivel screen, claimed 16 megapixel and only QVGA video at lousy 15fps, which had lots of gimmicks including MP3 player, calculator, calendar, notepad, eBook reader and a NES ROM video game player.
- Are any Aiptek (export model?) camcorders known with that famiclone (Nintendo 8bit) video game player in its firmware?
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