There’s been an explosion of hidden cameras in recent years, with cameras now available in nearly every shape and form you can image. Everyday stuff such as clocks, desk alarms, computer speakers, power plugs, even kids toys have been discreetly turned into high-tech high resolution spy cameras.
Interestingly enough, there are not many hidden spy cameras in the form of a book. You would have thought that a book lying around is probably one of the easiest spy cameras to hide in plain sight and so manufacturers would be rushing to make tons of these. However, there are not many options around.
There are essentially two things a good hidden camera should be able to do – blend into the background and record video and audio/video reliably. So how does the Conbrov DV9 spy camera book fare? Conbrov kindly provided a unit for us to test, and we put it through its paces. Note that the model we tested has an upgraded 1080p sensor vs. the 720p model currently available on Amazon.
I must warn you at this point that we do not endorse any illegal use of these cameras. All testing carried out using this camera features the authors of this blog. Make sure you follow all local and national laws in your jurisdiction while operating this camera.
The DV9 comes in a high quality packaging that provides adequate protection to the contents. There is no branding on the box at all.
back to menu ↑
What’s in the box
1 x Book camera
1 x User manual
1 x Pin for resetting the camera
1 x Warning sticker
1 x USB cable
1 x USB Card reader
|Size||8.26 x 2.3 x 1.6 inch / 21 x 15 x 4 cm|
|Standby power consumption||10uA|
|Max day time continuous recording time||~30 hours|
|Day time recording power consumption||220mAh|
|Night vision recording power consumption||820mAh|
|Night vision continuous recording time||9-10 hours|
|Charging time (to 100%)||20 hours with a 2Amp USB charger|
|Max PIR standby time||24 months|
|Camera lens angle||75 degrees|
|Max MicroSD storage||32GB|
|Loop recording||ON/OFF software adjustable (Default is ON)|
|PIR (Mode MD) video length||2 minutes per file|
|PIR detection angle||60 degrees|
|PIR detection distance||15-25 feet|
Design and Features
The Conbrov DV9 is described as a book by the seller, and it does look like a vintage book as you can see below.
But inside it looks more like a file folder or a binder. I can see why they went for a binder style inside of a book – you need a place to hide the massive 10,000 mAh battery and all the electronics. The spline of the binder is the perfect location for this. If someone were to casually flip through the DV9, they wouldn’t notice the settings buttons unless they went past the last page.
A few pages are included in the binder but you may want to add more pages to make it more realistic.
back to menu ↑
There is a reflective glass cover at the top of the book concealing the InfraRed LED. Its noticeable only if someone is looking closely at the book. In operation, the IR LED glows a dim red. It is noticeable if you are looking for it, but is not so bright that it catches the eye.
Just below the IR LED is the camera lens. Even though the seller describes the camera as a 720p model, the video files I obtained from the camera were of 1080p resolution – a pleasant surprise! The camera has a claimed angle of view of 75 degrees and I verified this in my testing.
Further down you will find a very small PIR sensor with a detection angle of 65 degrees and a max range of 25 feet.
On the inside of the spline, you will find the MicroSD slot, a reset button, a microUSB port, activity LEDs, an audio On-Off toggle switch, and the mode selection switch. The camera supports up to 32GB microSD cards. The provision of a USB port allows you to connect the camera directly to a computer to download videos. This is much easier than removing the SD card and putting it in a computer using the included USB card reader device.
Even if you plug in a USB power cable, the battery does not seem to charge when the spy camera is in operation. This would be a good feature which would then let you use the battery as a power backup – potentially increasing the time you can keep the camera up and running if external power is available near the point of camera use.
Also missing are any wireless data transfer options. Why would you need Wi-Fi in a spy camera? So that you can retrieve recorded footage without having to physically access the spy camera. At the asking price, I would have expected to see a P2P Wi-Fi connection option. By the way this would also let you view a live stream from the camera.back to menu ↑
The camera has 2 operation modes – Motion Detection (MD) recording and Continuous recording (REC mode). In MD mode, recording is initiated whenever the PIR sensor detects motion. This is great because it prevents false recordings, helps conserve battery life and lets you record more on the microSD card. Audio recording is available in both MD and REC recording modes.
Date and time overlay is possible and you can turn on loop recording – but that’s it when it comes to configuring the camera. There is no way to adjust video quality settings such as the bitrate, or image quality adjustments such as brightness or contrast.back to menu ↑
The manual is written in very good English and is quite exhaustive in my opinion. There are clear illustrations showing the different parts of the spy camera and a clear summary of instructions. There are different sections that then detail each step of the summary.
A very helpful table of various LED indicator statuses is also provided.
So here are the steps I followed to set up the spy camera:
- Insert a 32GB Sandisk Class 10 microSD card.
- Charge the spy camera up using the provided USB cable and a 2 Amp charger.
- When its fully charged, put the spy camera in REC mode. The microSD card will show up as a removable disk on your laptop.
- Open the YW_TIME.txt text file and enter the date and time, and whether you want the automatic video loop on or off.
- Great 1080p video quality
- Records audio
- Night vision IR LED
- PIR motion sensor
- Very good user manual
- No Wi-Fi or live stream
- No IR cut filter, causing false colour at daytime
- No video or audio settings
- Cannot be charged while in recording mode
That’s it – there are really no other software settings you can control. On the camera itself, you can turn the audio on/off, and choose the recording mode.
The next challenge is positioning the camera. As with most spy cameras, there is no Wi-Fi or live stream feature. So you can’t know whether you are getting everything you want in your scene until you record and then play back the video. But that’s just a one-time exercise.back to menu ↑
Overall I was happy with the performance of the Conbrov book camera. Video quality is high at 1080p resolution and the audio quality is decent. The camera uses Variable Bit Rate (VBR) settings depending on the complexity of the scene – this helps optimise storage space. Sadly there is absolutely no way to control the camera video or audio settings.
There is some false colour during the daytime and that is because of the absence of an IR cut filter. But really that’s not an issue because the camera has a very low threshold for switching to night mode and then everything is black and white anyway.
Night time video quality
The following video was taken in absolute darkness, and you can see that the single IR LED is not powerful enough to light the whole scene and has a spotlight effect. The camera is around 10 feet from the wall.
Night time is grainy but I would take sharpness and detail over noise reduction any day (or night!).
Here's some technical info of the clip itself:
General Format : AVI Format/Info : Audio Video Interleave File size : 182 MiB Duration : 1mn 58s Overall bit rate : 12.9 Mbps
Video ID : 0 Format : JPEG Codec ID : MJPG Duration : 1mn 58s Bit rate : 12.9 Mbps Width : 1 920 pixels Height : 1 088 pixels Display aspect ratio : 16:9 Frame rate : 30.000 fps Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Compression mode : Lossy Bits/(Pixel*Frame) : 0.206 Stream size : 183 MiB
Audio ID : 1 Format : PCM Format settings, Endianness : Little Format settings, Sign : Signed Codec ID : 1 Duration : 1mn 58s Bit rate mode : Constant Bit rate : 128 Kbps Channel(s) : 1 channel Sampling rate : 8 000 Hz Bit depth : 16 bits Stream size : 1.81 MiB (1%) Alignment : Aligned on interleaves Interleave, duration : 512 ms (15.37 video frames)
Daytime video quality
While the room was not brightly lit in the next test video, there was ample daylight coming in from the window. You can see this in the first couple of seconds of the video, before the camera switches to night mode and turns on the IR LED.
What did I mean by the camera having false colour during the daytime? Check out this sample video shot outdoors – the leaves are not very green at all but actually they are very green, I promise:
Here's some technical info of the clip itself:
General Format : AVI Format/Info : Audio Video Interleave File size : 253 MiB Duration : 1mn 29s Overall bit rate : 23.7 Mbps
Video ID : 0 Format : JPEG Codec ID : MJPG Duration : 1mn 29s Bit rate : 25.2 Mbps Width : 1 920 pixels Height : 1 088 pixels Display aspect ratio : 16:9 Frame rate : 30.000 fps Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Compression mode : Lossy Bits/(Pixel*Frame) : 0.403 Stream size : 268 MiB
Audio ID : 1 Format : PCM Format settings, Endianness : Little Format settings, Sign : Signed Codec ID : 1 Duration : 1mn 29s Bit rate mode : Constant Bit rate : 128 Kbps Channel(s) : 1 channel Sampling rate : 8 000 Hz Bit depth : 16 bits Stream size : 1.37 MiB (1%) Alignment : Aligned on interleaves Interleave, duration : 509 ms (15.26 video frames)
What would you use audio in a spy camera for – to capture conversations. So it should be sensitive enough to pick up anything in the room. The DV9 is good enough – it easily recorded my baby crying downstairs and other bits of sounds outside the room through a closed door.
PIR Motion Detection
Software-based motion detection is the method employed by most spy cameras, so I was delighted to see that the Conbrov DV9 used a PIR sensor to detect motion. A PIR is far more accurate than software methods because it actually detects the presence of a heat radiating body in the scene. This means you have virtually no false recording triggers – which is the biggest issue with pure software based motion detection.
It detected motion in a range of 10 – 15 feet in our testing and never once missed a motion trigger. There is a slight delay before motion is detected but its very small, something like 1 second and is not a problem at all.
File Copy Speed
Plugged into a USB3 port with the included USB cable, it averaged around 5.7 MB/s which is fine. This was using a Class 10 Sandisk MicroSD card in the camera.
The battery takes a few hours to recharge fully and the yellow charging indicator LED will go off when its done. Conbrov says the 10,000 mAh battery should provide a standby time of up to 24 months in motion detection mode, but of course we can’t test that. But the battery held up over 2 weeks of intense testing.
There is no battery gauge so you can’t know how much juice is left in the battery. Its very much a top it up and let it discharge till it is dry type of device.
The high bitrate of the recorded clips limits the number of hours the camera can record. I found that it needs approximately 1.5 Megabytes per second of video and audio in night mode and around 3.0 Megabytes per second for daytime clips. So a microSD card with the maximum supported size of 32 GB can store up to 5.4 hours of night-time video or 2.7 hours of day-time video.
So to really take advantage of the massive battery capacity, you should use the motion detection recording mode, and this is what most people would probably use the spy camera for.back to menu ↑
So if you want a spy camera that does a nice job of melding into the background, but capture good quality full HD 1080p video and audio with a very long battery life, the DV9 is the spy camera for you.
A spy camera that does a nice job of melding into the background, and captures good quality full HD 1080p video and audio with a very long battery life.