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Your night vision uses the new EMCCD technology. Can you provide some background information?

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Our FrogEye and SharkEye cameras use a night and low light vision technology called 'Electron Multiplier CCD' or EMCCD.

EMCCD address approximately the same market as image intensifier tubes. The attached Powerpoint presentation provides some background information and comparisons between EMCCD, image intensifier tubes and low-light video technology.

In summary, EMCCD compare to image intensifier tubes as follows:

1. The effective resolution of EMCCD improves as light levels go up. Above a certain sensor-specific light level (about 125 microlux to 1 millilux for the TC-253 chip used in some of our cameras), that contrast will be better than intensifier tubes and continues to improve until perhaps a 3x advantage is reached. As a result, for long-standoff work in urban environments you can often get much better target detail with an EMCCD. This translates to a longer available stand-off distance and its associated benefits.

2. The contrast available in EMCCD is similar to that of regular CCD and as such significantly better than intensifier tubes. Target detail is thus easier to recognize.

3. The EMCCD can be used day or night. During the day, software will switch the on-chip intensifier circuitry off, effectively converting the device into a regular CCD. This enables 24 hour operation, and contrasts with the burn-out that intensifier tubes suffer when operated in bright light.

4. The high sensitivity of EMCCD can be used during the day or in low-light situations to operate with a very short exposure time. This reduces motion blur and is of advantage in applications such as sea floor photo surveying, free-hand operation with a long telephoto lens, or obtaining crisp images of rapidly moving targets.

These are the disadvantages of EMCCD as compared to image intensifier tubes:

1. While image intensifier tubes require virtually no support circuitry for direct viewing devices, EMCCD require very significant circuitry. That translates to higher power consumption. Our FrogEye and SharkEye cameras consume about nine watts in EMCCD mode, and more if the thermo electri cooler is activated. For this reason, EMCCD are not a good choice for direct viewing devices such as night vision goggles unless the superior contrast and resolution of EMCCD is strictly required.

2. The sensitivity of EMCCD is device specific, and some devices are not as sensitive as image intensifier tubes. For example, we found that we need at least 12 microlux on the sensor plane to obtain a very rough image with the TC-253 EMCCD. When using a GEN3 OMNI4 intensifier tube, we managed to do the same job down to about 4 microlux. However, the TC-246 EMCCD chip (soon to be available as an option for FrogEye and SharkEye cameras) should yield an approx. 5-10 time advantage over the TC-253 according to our preliminary tests. If verified, the TC-246 will be more sensitive than GEN3 OMNI4 tubes.