14

Digital sensors are very linear for the vast majority of the response curve, with deviations at the very bottom (due to noise, depending on where the black point is set) and at the very top near saturation. Digital sensors are particularly linear when compared to film, which has a pronounced 'S' shape response curve. The reason for this is that incoming ...


14

Horizontal and Vertical Banding Noise (HVBN) is caused by sensor readout, downstream amplification, and ADC. There can be multiple sources of HVBN, some of them cause a relatively fixed pattern, others can cause random pattern. External signal interference is often a source of softer and more random banding. Exactly which causes banding in which sensors ...


13

Aesthetic considerations of the image aside, it's just mechanically obvious that a square fits inside of the image-circle produced by the camera's lens a lot better than a rectangle does. The short answer to all of this is that this premise seems logical, but is actually incorrect. It's true that a square is the most area, but that's only the best use of ...


13

An unfiltered CCD or CMOS sensor looks very similar to any other silicon integrated circuit that has a very regular/repeating structure of similar structure size - semi-metallic gray (from silicon, quartz and aluminum) with some iridescence probably resulting from diffraction grating effects in the fine, repeating structures. Compare a bare DRAM or flash ...


12

The largest CMOS sensors available commercially for photography are "medium format" and measure about 44mm x 33mm. CCDs exist in slightly larger sizes up to 54mm x 40mm. Larger sensors for scientific applications may have been produced. Sensors are produced by projecting a mask onto a large wafer of silicon using UV light. The wafer is then cut into ...


11

Looking at those images/calculations it seems right to me. You might have enough silicon to make another sensor, but it's not in the right place. There's not another 24mm x 36mm spot anywhere on that wafer to make an additional sensor, hence the waste. Additionally, you'll get some bad sensors (I once was given an Intel CPU keychain that was from a dud). ...


9

The 14 bit depth is the limit of the physical sensors capabilities, it isn't just that the engineers decided to throw away useful data. An increasing number of bits available in a sensor reflects an increasingly larger complexity of circuitry and precision needed to resolve those progressively finer and finer details. Complexity and precision don't come ...


8

TLDR; Do this at your own risk! The compressed gas is formed from a liquid propellant in the canister which under certain conditions can spray all over your very delicate electronics leading to short-circuits which cause lots of damage up to and including fire if the battery is shorted. It will cool (possibly freeze) parts of your camera and that can ...


6

They're very common — to the point that I wouldn't bother to check in advance. This will be especially true for longer exposures, as the sensor heats up. So, I just assume they're likely and plan to run the built-in pixel mapping function if I notice any. Or, if I were to shoot RAW all the time, I'd wouldn't worry about it at all, since most RAW converters ...


6

There is nothing that stops them putting smaller sensors on the wafer. It is rather doable. Some concerns are: Too close to the edge the mechanical processing introduces stress and dislocations so don't consider the entire wafer having the same quality... The best bet is that on the perimeter you will have higher failure count. That is why on your left ...


6

If it's only compressed air (and not compressed refrigerant that is used in typical "canned air" products), then ideally it is no different from using a rocket blower, other than different air velocities due to the pressure of the compressed air. EDIT: Practically, however, there are reasons to be concerned. Cheaper cans of compressed air are sometimes ...


5

There are even bigger sensors. If you look closely to the image in the top-right corner of that page you'll see that the biggest sensor there is 'Medium Format Kodak KAF' sensor. Ok, I understand that it isn't quite easy to figure this out because one can easily take that the background of that image is gray while in reality the image has a white ...


5

No, it is not normal. These stripes look a lot like Newton's Rings, even though they aren't rings. Did you use some filter in front of the lens, which might have created those patterns?


5

With a CMOS sensor, the analog-to-digital converters (ADCs) is on the same die as the imaging sensor. With a CCD, you get analog signal out of the chip, and an external analog-to-digital converter (ADC) needs to be used. There are benefits and drawbacks of each approach. For example, you can pair CCD with a really good ADC having high dynamic range, and ...


4

The closest thing I know to what you're thinking of is what Fujifilm are doing with DR mode in their EXR sensors, as seen in the X-10 and X-S1) - half the pixels are deliberately underexposed by a stop (or two) and combined with the "normally" exposed pixels before the image is output. For more detail, see DPReview's X-10 review - what you're interested in ...


4

Firstly, I think this is off topic. Secondly, I can't directly answer specifically for silicone, but I did work in circuit board manufacture. I assume the same the same points apply. When preparing the job it costs twice as much to two panel on one board. When manufacturing board we normally had production set up for one specific board. Switching between ...


4

Some more things that can limit what's practical to below what can be manufactured: weight (of the resulting system). A very large sensor needs a very large image circle, which means large lenses, and a large camera. power consumption. A large sensor needs more power than a small one, thus battery life is decreased (unless you again increase the size and ...


4

NEVER. All the other answers apparently missed that you've removed the IR/UV cut filter from on top of the sensor. All the standard cleaning methods assume this protective glass is in place. You are in essence attempting to clean a bare printed circuit, and this is a very delicate and complex type of circuit at that. I would recommend non-contact methods ...


4

You're getting a little confused. Un-boosted ISO Or what you're calling "native range." There's a native ISO setting, which is what the sensor uses without any amplification, and you can consider this the "base" ISO setting of the camera. All of the unboosted other ISO settings are achieved by amplifying the gain on this native signal. Boosted ISO ...


4

What is preventing me from sampling it at a higher rate? Every discrete step in the operation takes time. Changing the value of inputs to a logic gate takes time. Once those inputs have stabilized, getting a stable output from the gate takes time. Placing a new value on a data bus takes time, and then signaling the other device(s) that the data is ready ...


4

It can be about either the sensor's sensitivity to specific portions of the visible spectrum or about the algorithms used to create color from the monochromatic luminance information collected by the sensor. But it is almost always about how both are combined to produce a viewable image. You can take the same raw image data from the same camera and run it ...


3

Here are some of the ways: http://www.image-engineering.de/iq-products/iq-tools/measurement-devices/camspec http://www.image-engineering.de/iq-products/iq-tools/measurement-devices/camspecs-express I use a monochromator, light sphere, and a photodiode. You can find most of those supplies at Edmund Optics http://www.edmundoptics.com/ and similar shops. You ...


3

I'm sure somebody more knowledgeable than me will give an extensive answer, but the short answer is: It refers to the technology of the image sensor, see active pixel sensor on Wikipedia. Roughly speaking, there are two kinds of image sensor technologies used in most digital cameras: CCD or CMOS. The former stands for charge-coupled device, the latter stems ...


3

There are CMOS-based cameras with electronic shutters (basically all cameras with video mode have electronic shutters) but the technology does have its limits. When the camera reads from a CMOS sensor it reads the data line-by-line, not all at once, this means that, if the subject or the camera moves fast enough you can get very interesting effects. CCD ...


3

For high value chips, like imaging sensors or i7 CPUs, it generally isn't worth it - silicon real estate isn't the major part of the costs. You would need the other chips to be smaller, but have a similar number of mask layers and the same etch chemistry. It's likely that your smaller sensors are an older design and the processing has evolved. ...


3

(Note: Though you explicitly asked about DSLR sensors, I though that, for completion, this could be of interest) In CMOS sensors, every sensel has its own amplificator, so the sensor's response can in theory be tuned up on a per-pixel basis. In fact, there are already HDR sensors in the market whose answer is non-linear to allow for higher dynamic range. ...


3

The working principle is the same in both systems. Light makes electrons in silicon 'jiggle about' and the silicon is etched in a way that the jiggling makes those electrons move in the same direction. This process is the same as occurs in solar panels. When the image is 'read' from the sensor, each pixel has the charge measured (how this happens ...


3

It is more like an S curve, where the low end is mostly cut off by subtracting the dark current, but it starts saturation before hitting the MAXVAL. In an 8bit image I have sometimes found the true saturation to start around 200 rather than 255. This is the reason why HDR images is more complicated to make than to sum(Wn*In), where Wn is given by the ...


3

Well, as people have pointed out, they are very common. Heck, 1 bad pixel in 1 million pixels is an error of 0.001% -> i.e. tiny. Now in most cases hot or dead pixels will be mapped out by the camera's firmware of by the RAW editor and should not cause any problems. In this respect, it can also be quite difficult to find a hot pixel as you would need a way ...


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