Technical FAQ

Basic CCD Characteristics

---

A CCD chip is an array of light-sensitive elements and very small electronic capacitors. These capacitors are charged by the electrons generated by the light. Each light element (photon), that reaches the CCD array's atoms displaces some electrons. This displacement provides the current source. These current sources are localized in small delimited areas (the capacitors) called pixels. Common CCD chips are composed of thousands or millions of pixels.

A single Output

---

The capacitors are discharged in lines and control gates allow the transfer of one pixel line into the next one. The last line of the array is transferred into a horizontal shift register. This shift register allows the transfer of one pixel to the next one, and the last pixel of this horizontal register is connected to the output gate.

Taking a Picture

---

Clean the CCD array by reading the picture. Wait for a defined time ( the exposure time) to allow the light to charge the capacitors. The output gate of the CCD array can either be connected to an analogue or to a digital converter in order to digitize the picture, or it can provide a standard video signal if the clock's timing is according to the video norms. If the image is digitized, it will be easy to store it in a computer memory. So, its processing will be easy to perform.

Standard Fabrication Lowers Costs and Enables On-Chip Integration

---

CCD sensors rely on specialized fabrication that requires dedicated—and costly—manufacturing processes. In contrast, CMOS image sensors can be made at standard manufacturing facilities that produce 90% of all semiconductor chips, from powerful microprocessors to RAM and ROM memory chips. This standardization results in economies of scale and leads to ongoing process-line improvements. CMOS processes, moreover, enable very large scale integration (VLSI), and this is used by our “active-pixel” architectures to incorporate all necessary camera functions onto one chip. Such integration creates a compact camera system which is more reliable and removes the need for peripheral support chip packaging and assembly, further reducing the cost.

Low Power Usage Extends Battery Life

---

Active-pixel sensor architectures consume much less power—up to 100x less power—than their CCD counterparts. This is a great advantage in battery-dependent portable applications, such as laptop computers, hand-held scanners, and video cellphones. CCD systems, on the other hand, tend to be inherently power hungry. This is because CCDs are essentially capacitive devices, needing external control signals and large clock swings (5–15 volts) to achieve acceptable charge transfer efficiencies. Their off-chip support circuitry dissipates a significant amount of power. CCD systems require numerous power supplies and voltage regulators for operation, whereas active-pixel sensors use a single 5-volt (or 3.3-volt) supply, reducing power-supply inefficiency. A CCD system typically requires 2–5 watts (digital output), compared to 20–50 milliwatts for the same pixel throughput using an active-pixel system. For example, a CMOS digital camera system operating from a NiCd camcorder battery could operate for a week, while a CCD arrangement would drain the battery in a few hours.

Random Access to Pixel Regions of Interest Adds Flexibility

---

In CMOS active-pixel image sensors, both the photodetector and the readout amplifier are part of each pixel. This allows the integrated charge to be converted into a voltage inside the pixel, which can then be read out over X-Y wires (instead of using a charge domain shift register, as in CCDs). This column and row addressability, similar to common DRAM, allows for window-of-interest readout (windowing), which can be utilized for on-chip electronic pan, tilt, and zoom. Windowing provides much added flexibility in applications that need image compression, motion detection, or target tracking.

No Artifacts, Smear, or Blooming Means Higher-Quality Images

---

With our active-pixel architectures, the RMS input-referred noise is comparable to very high-end (and expensive) CCDs. Both technologies provide excellent imagery compared with other CMOS image sensors. Our active-pixel architectures use intra-pixel amplification in conjunction with both temporal and fixed-pattern noise suppression circuitry (i.e., correlated double sampling), which produces exceptional imagery in terms of dynamic range (a wide ~75 dB) and noise (a low ~15 e-RMS noise floor), with low fixed-pattern noise (<0.15% sat). Our active-pixel sensors achieve a quantum efficiency (sensitivity) that is comparable to high-end CCDs, but, unlike CCDs, they are not prone to column streaking due to blooming pixels. This is because CCDs rely on charge domain shift registers that can leak charge to adjacent pixels when the CCD register overflows, causing bright lights to “bloom,” leading to unwanted streaks in the image. In our active-pixel architectures, the signal charge is converted to a voltage inside the pixel and read out over the column bus, as in a DRAM. Our sensors have built-in anti-blooming protection in each pixel, so that there is no blooming. Smear, caused by charge transfer in a CCD under illumination, is also avoided.

Intra-Pixel Amplification and On-Chip ADC Produce Faster Frame Rates

---

CMOS active-pixel designs are inherently fast, which is a particular advantage in machine-vision and motion-analysis applications. Active pixels can drive an image array’s column buses at greater speeds than is possible on passive-pixel CMOS sensors or CCDs, and on-chip analog-to-digital conversion (ADC) it eases the driving of high-speed signals off-chip. A separate benefit of on-chip ADCs is the output signal’s low sensitivity to pick-up or crosstalk. This facilitates computer and digital-controller interfacing while adding to the system’s robustness.

On-Chip Integrated Circuitry Enables “Smart” Camera Functions

---

CMOS active-pixel architectures allow signal processing to be integrated on-chip. Beyond the standard camera functions—AGC, auto-exposure control, etc.—many higher-level DSP functions can be realized. These include anti-jitter (image stabilization) for camcorders, image compression (before and after readout), color encoding, computer database interface circuits, multi-resolution imaging, motion tracking for perimeter surveillance (“smart image sensing”), video conferencing, and wireless control.

One-push White Balance

---

Setup > Video Source Properties > One-push
To get the most precise and consistent white balance results, adjust the white balance rectangle to a background region (where the color temperature of the illumination is reflected) and then click the One Push button. The size of the rectangle does not matter, but the area contained within the rectangle must be white.

Optimize Image Settings for Frame Rate

---

1. Setup > Video Source Property > Exposure > Un-check Auto Exposure
2. Setup > Video Source Property > Exposure > Set Exposure Time to the minimum value that still produces an image with sufficient light
3. Setup > Video Source Property > Misc > Set Frame Speed Level to High

Lower the Image Resolution

---

1. Setup > Video Stream Format > Select Lower Resolution

Increase the Frame Rate without Disabling Auto-Exposure

---

Sufficient illumination is needed to provide short exposure times. If the frame rate seems slow, trying increasing illumination, for example, by using a fiber optic illuminator.

If the software opens properly but the live image display is all black, the computer likely does not have enough USB bandwidth to display the image. This occurs most often when a camera requiring a USB 2.0 connection is connected to a USB 1.1 port.

Connect the Camera to a USB 2.0 Port

---

To resolve this issue, connect the camera to a USB 2.0 port. On some older computers, the ports in the front are USB 1.1 and the ports in the back are USB 2.0. Modern computers no longer have USB 1.1 ports.

Lower the Image Capture Resolution

---

If using an older computer that only has USB 1.1, you may be able to get a live image display at a lower resolution. Select:
Setup > Video Stream Format > Choose the lowest resolution available.

If the ToupView software opens without error, but the camera does not show up on the list of devices, please try the following solutions:

Ensure the proper device driver is installed

---

1. Visit our downloads page: http://www.bigcatchusa.com/downloads/drivers-and-software/
2. Download the driver matching your camera model
3. Install that driver
4. Disconnect and reconnect the camera

Try a different USB port

---

Sometimes a specific USB port may have problems. Try a different USB port, if possible on a different part of the computer (i.e. front vs back)

Camera Care

---

All eyepiece camera internal components are sealed within the housing and require only occasional cleaning outer to maintain their optical integrity. It is recommended that these instruments be used and stored in a clean, cool and dry environment and that care be taken to keep them free of dust and other contaminants.
Avoid exposing to fumes and extreme temperatures and never immerse or rinse in water. Also it is advised to use the plastic or other scope or eyepiece cover when not in use.

Cleaning

---

If cleaning is required then first attempt to gently blow off any dust or other contaminants with compressed air. If no compressed air is available then try to lightly brush off any lose debris with a fine brush (a makeup brush will work well). If it becomes necessary to clean the lens then we recommend using a standard optical lens cleaning solution. To make your own optical lens cleaning solution, mix one part alcohol (C2H5OH) with three parts ether ((C2H5)2O). Simply saturate a cotton swab and gently wipe the lens surface clean.

Caution!

---

Avoid touching the surface of the lens with your finger tips. Never disassemble or open the scope or camera body. This will introduce dust and other contaminants and may cause permanent damage.