I would like to know what are the available (industry standard) CCD sensor resolutions for cameras in the visible light. What is the highest CCD resolution that can be found in the industry?
CCD resolutions in camera
ccd
Related Solutions
I don't see too many issues using a standard USB camera in a vacuum. Your two largest issues are likely to be heat dissipation, and outgassing from the camera components.
Depending on how high a vacuum you need, you may need to package the camera in a hermetic container. There is almost inevitably going to be at least a small amount of soldering flux/VOCs left on the PCBs from production, and it will outgas when you pump the system down.
If you have sufficient pump capacity, or don't need extremely high vacuum, it shouldn't be too much trouble.
You could also try removing all the plastic from the camera, and baking the PCB assembly at a low temperature to speed up the out-gassing (~100°C?).
Second, at least some of the USB-cameras I have used do dissipate a fair amount of power, so depending on the camera, you may have localized heating issues due to the lack of convection cooling. It should be possible to deal with this using proper heat-strapping, though I think it would probably better to just pick a device with low dissipation.
Lastly, you can certainly buy some pretty interesting USB cameras, which do support all sorts of fun things like variable ISO, and variable shutter time. It mostly depends on your budget.
If you don't mind experimenting, I would say go to your local electronics store, and just buy a webcam, and see what happens (and post pictures!).
The hardest part, I think, is probably going to be hermetically sealing the cable feed-through. You can't just stick the cable in a cable gland, as you will get leakage through the cable, both between the strands, and between the individual wires and the sheath. You will need hermetically rated bulkhead connectors.
For CCDs: - It's hard to clock the horizontal shift registers of a CCD much faster than 40 MHz without having a drop in you CTE (Charge transfer efficiency) as there is a limited drift velocity for electrons. The fastest I've even worked with is ~ 45 MHz, and I was cheating. How this problem is solved is to use a "tapped" architecture in which a subset of columns feed a shortened horizontal shift register each being run at the higher rate. So instead of trying to force those outputs out one amplifier you have them come out of 4 or 8 or more.
In your example above that would likely a 4 tap architecture.
I've used sensors that had as many as 256 Taps and an aggregate pixel rate of ~ 10 GPixels/s.
For NON CCD sensors (APS, CIS, APS etc. - how ever you label them) i.e. CMOS image sensor. It's much more easy to run at higher speeds with outputs running at 80 MHz or more. Faster than than become problematic with power and noise levels. So indeed these two end up being tapped.
Best Answer
Pixel size and the area that they are occupied is the key parameters of a CCD sensor Dynamic Range, the SNR, the Spacial Resolution and the Modulation Transfer Function (with a given optics).
However if pixel size is reduced, sensitivity to light reduced accordingly. So there is a clear tradeoff between spatial resolution and light sensitivity. So be cautious when read pixel size. Some manufacturers also use the sub-sample pixel but this is done after some process.
With the CMOS APS technology of 0.3μm (that was some years ago and I don’t know if it is changed), the optimal pixel size is 6.5μm. That is 35 line pairs per mm Nyqist limit (i.e befor aliasing). Technologies like 0.17μm may be allow down to about 4μ pixels.
High resolution industry standards -especially for medical applications- is 2.5k x 2.5k and 4k x4k.
A good list is here