Can I connect the ThirdEyeVideo dental camera to my laptop or computer ?
Can I show and grab a still image with the ThirdEyeVideo dental camera ?
The ThirdEyeVideo is an analogue camera, why not digital ?
Why the ThirdEyeVideo dental camera has no zoom lens?
Why the ThirdEyeVideo has no autofocus ?
What is the difference between the ThirdEyeVideo dental camera and a webcam ?
Can I connect the ThirdEyeVideo dental camera to my laptop or computer ?
The ThirdEyeVideo dental camera is an analogue camera. To connect the camera to your computer or notebook, you´ll need an av-digital-converter (= analogue-video to digital converter). The conversion into a digital format needs a so-called encoder, a programme, which converts analogue signals into digital signals. There are plenty of such softwares on the market, offered by many different providers. But a MPEG-2 video (a file format used for DVD videos) might not be equal to another MPEG-2 video !!! The quality of a digital video depends highly on the quality of the encoding software and the quality of the encoder itself (= coding method). To get the optimal conversion of the analogue camera signals, we recommend professional software-codecs, developed by renown manufacturers of broadcast equipment (= professional tv and camera equipment). Our favorite is Canopus, a subsidiary company of Thomson-Grassvalley (www.canopus.com). Canopus offers the analogue-digital-firewire converter ADVC55, a cigarette box format device, which can be connected to any computer or laptop with a firewire (or I-Link) interface. There are some av-usb converters from Pinnacle, Terratec (AV Grabster) and other manufacturers to connect our camera to your computer or laptop via usb (2.0) port. Unfortunately most of the amateur av-usb converters have a preset method of encoding the analogue video (and audio) signal. Many of them convert the analogue signal into a MPEG-2 or MPEG-4 (DivX or H.264) signal, which formats are apt to burn a video to dvd or video cd. Unfortunately MPEG-2 and MPEG-4 signals are not well suited for video editing in most (if not all) video editing softwares.
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Can I show and grab a still image with the ThirdEyeVideo dental camera ?
The simplest way to "freeze" a still image, e.g. to show some caries to the patient, is to use the still image function of your lcd monitor together with its remote control. However, the image will be lost when returning to the live preview. If you want not only to freeze the images, but to grab and save them to your hard disk to have them integrated and ready in your dental office software archive later, you´ll need a so-called framegrabber card together with a framegrabber software. Alternatively, if you already own an av-digital converter and a video editing software, you can use the grab function of the software to grab and save the desired still images. A small but mighty software is WinAvi Video Capture (www.winavi.com), which can be controlled intuitively and which can grab still images and capture videos in many different formats and save it to hard disk. WinAvi also offers many different possibilities to grab or capture your files for different applications (e.g. video streaming in the web )! Of course, you can use the software of your intraoral dental camera, which is, if an older model, certainly an analogue camera, too.
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The ThirdEyeVideo is an analogue camera, why not digital ?
The ThirdEyeVideo is an analogue camera, the ThirdEyeHD is a pure digital camera. Unfortunately many dentists interested in our ThirdEyeVideo dental camera believe a digital signal being superior to an analogue signal. That´s a big error ! The mass of data carried by an analogue signal, e.g. on an audio tape, a 35mm slide or a 35 cine film is sheer infinite. Who may be able to count the numbers of magnetic particles on an audio tape or the silver cristals on an exposed 35mm film. Therefore the mass of data in a digital format, which shall be saved to a hard disk, has to be reduced massively. The procedure to convert an analogue signal into a digital one is the so-called sampling. Sampling means, the software or hardware takes samples of the analogue signal in concrete intervals, which time (measured in Hertz, kilohertz or megahertz) is called the sampling rate. All intermediate values, e.g. the pitch of an audio signal, the grey scale or the color shades, are lost during conversion. So a digital signal always is an approximation to the original (analogue) signal only ! It never is as good as the original. The fact, that we think a digital signal is better than the analogue original has to do with our limited senses. So we can hear only limited audio frequencies and we can see only limited grayscales and pixels (the resolution of the human eye is limited). To pack the data on a hard disk, the digital data have to be reduced furthermore, they are compressed. Digital pixels with similar brightness or colors are summarized. You all know the pixel conglomerates when watching a formula 1 race on a lcd or plasma monitor. That´s digital ! A digital signal, which did not undergo the compression algorithms is called an uncompressed digital signal. The mass of data which arise from an uncompressed digital signal stream are immense. Thus one second of uncompressed HD signal (1.920x1.080 pixels) needs 140 megabytes of hard disk space. For one hour of uncompressed HD video you´d need an extra hard disk (504 gigabyte) !
The advantage of a digital signal lies in its ability to be regenerated when being copied (=dubbed) or transmitted over long distances. That means, that the original digital signal can be restored even when you replicate it over and over for many generations or when you transmit it around the world. An analogue signal would loose its quality eventually with every dubbing generation or along the distance.
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Why the ThirdEyeVideo dental camera has no zoom lens?
We admit, it would be great, if we had a zoom lens corresponding our requirements. But a zoom lens has some drawbacks, which made us decide not using a zoom lens ! Zoom lenses need additional lenses or lens groups to zoom in and out. Now, additional lenses need more light. Less light falling on the CCD or CMOS chip means, the iris (or the electronical iris) has to widen. The wider the aperture the smaller the depth of field will be. Another drawback: Additional lens(groups) may cause additional lens faults (abberation et cetera) The optimal lens with the best imaging properties a lens designer can design is a telephoto lens ! A telephoto lens has only two lenses. However sophisticated a lens design may be, it never can be equivalent to the optical qualities of a telephoto lens. Another disadvantage of a zoom lens is it´s inertia regarding the speed changing from zoom in to zoom out and vice versa. For all these reasons we have decided to abandon the idea of integrating a zoom lens in our ThirdEyeVideo dental camera, but to use a telephoto lens instead. Thus the depth of field is 8cm to 15cm depending on the illumination and the working distance. I you want to put is that way, our ThirdEyeVideo camera has a "manual" zoom by using the dental light to change working distance and thus changing the maginfication of the lens. This you can do much faster then changing the focal length of a zoom lens. What should an intraoral camera be capable to show ? Full mouth and a single tooth. If you have your dental light in a working distance of 80cm the ThirdEyeVideo camera can show the whole (full) mouth, if you go closer (about 20cm), the ThirdEye camera can show one tooth with its neighbors. This compares to a 4-fold zoom with its corresponding magnification. If you want to have an even higher magnification, you should use our microscope lens, which has a 12-fold up to 32-fold magnification.
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Why the ThirdEyeVideo has no autofocus ?
Yes, a properly working autofocus would be nice. But an autofocus has its disadvantages, too. An autofocus lens makes sense with a digital still camera. The subject is not moving or it is moving parallel the focal plane. Thus the focus is not changing during the exposure. But, what if you are busy with your fingers, turbine or mirror in the mouth of the patient ? Or if you move your head into the beam path of the dental light ? The autofocus would adjust back and forth to find the focus all the time. This would result in an unstable and out of focus image ! With a depth of focus of more than 10cm our ThirdEyeVideo dental camera will not have any problem at all. At a certain working distance - don´t all of us prefer certain working distances of our dental lights - you focus once by turning the outer lens ring. The image will stay focussed, even if the patient turns his head or you change dental light positions. Handling the mirror or any other instrument will not affect the focus of the camera. Believe me, a professional cameraman never would use an autofocus !
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What is the difference between the ThirdEyeVideo dental camera and a webcam ?
On dental shows we sometimes are asked, if a dentist could not use a webcam instead of the ThirdEyeVideo dental camera. At least webcams have up to 2 megapixels of resolution, now. My answer is: Basically yes ! If you are satisfied with the poor results ?! And: Pixels are not equal pixels and resolution does not equal resolution. So, a 12 megapixel cheapo-camera is unable to hold a candle to a 5 megapixel branded camera (e.g. Canon or Nikon). The ThirdEyeVideo dental camera was especially developed for the use in your dental surgery. All its components are optimized for this purpose. To shoot the best possible videos and still images. An example: A webcam is about 30 Euro. Two of our cable plugs alone cost 30 Euro. That makes them suitable for the sometimes harsh operation in a dental surgery. These differences in quality apply to all of the components used in our dental cameras...CCD chips, lenses, cables... It´s the components, which make the difference. You can buy a cheap camera lens for a few Euros, but you can buy a camera lens for 30.000 Euros also ! You might as well ask a professional cameraman, why he is shooting with a 50.000 Euro Digital-Betacam instead of using a 800 Euro HD consumer camcorder.
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