74

A picture is worth a thousand words, here. This is a Twin Lens Reflex camera: The two lenses are linked together so they focus as a set (either the whole front panel moves, or the lenses are linked by gears so that they turn together to focus). The top lens — the "viewing lens" — has a mirror which bounces the view to the ground-glass viewfinder. The bottom ...


54

Single lens means that there is only one lens attached to the camera at once. This is to distinguish it from a twin-lens reflex camera, which has two lenses - one used for the viewfinder and one used for actually taking the photo.


36

In lens stabilisation contains a servo activated rear element which acts to move the image projected by the lens in order to cancel out the camera shake. In body stabilisation moves the sensor in order to counter camera shake. No method is clearly better, and discussion tends to turn into a brand war as Canon and Nikon don't offer (and are not likely to ...


28

In actuality, a cross type AF sensor is just two "normal" AF sensors, one with the lines oriented in a vertical direction and the other with the lines oriented in a horizontal direction, that are superimposed over the same area. Non cross-type AF sensors can be either vertical, horizontal, or even diagonal. Some very early AF film cameras with a single ...


25

Shutters are probably more accurate/reliable now, but more importantly with digital photography you get instant feedback so you can tell right away if there are any exposure problems, you're not going to ruin several rolls of film before you find out. I had a 1DsII that had a shutter which suddenly became unreliable at anything faster than 1/500s, I ...


24

The main reason is that it is low powered. An raster LCD - color or not - requires much more power and most of them need a permanently on back-light. New OLED display do not need the back-light but still pull more power than a segment-based LCD which has much fewer electronic circuits. Most current top-plate LCDs mirror what is shown in the status line of ...


22

As was said, the mechanical shutter has speed limitations. As to the slit, try to imagine without it. Suppose the shutter opens by moving from top to bottom of frame. And then of course, it has to close from bottom to top. So it is open longer on the top side than on the bottom side, which is uneven exposure. Modern fast curtains might move about 7 ...


22

There isn't. Once you have the basics needed to make a digital camera work, the incremental cost of additional features is very small, so there is a very strong incentive to cover at least the most common and popular features people expect — and a lot of competitive pressure. Even "retro" cameras like the Nikon Df have all the bells and whistles inside. (...


21

Weather Sealing is protection of the internal parts of a camera from external influences such as moisture, dust, and humidity. The degree of this weather sealing varies between manufacturers and also within models by each manufacturer. The protection is provided by both rubber sealing with silicon rings and gaskets as well as design considerations such as ...


21

Phase detect autofocus in DSLRs works by comparing patterns of light coming from each side of the lens using pairs of detectors which are separated a certain distance on the AF sensor. This distance is called the baseline, and the greater the baseline the more accurately the distance can be measured. The need for a wide baseline and for light to travel from ...


21

Thought experiment time. Assume we'd like a minimum exposure of 1/2000 of a second (500 microseconds) on a 35mm full frame camera. We have a single 'shutter' to move out of the way, and back. We'll tolerate one side of the picture being 10% more exposed than the other, so that means we allow 50μs to move the shutter back and forth. So the shutter has to ...


18

It's important to realize that you don't actually look directly through the lens with an SLR! If you did, a periscope style arrangement would do just fine. What you are actually doing is looking at an image projected onto the focussing screen by the lens. This image is flipped left/right and up/down by the lens, and then up/down again by the main mirror. ...


18

Hitting the DOF preview with a stopped down aperture should make it obvious: what you see can be very dim, dim enough it can be very difficult to compose and focus. That's why cameras have the lens wide open until actually taking a picture, so you can get the brightest image by which to setup your shot.


17

Magnesium alloy is one of the most preferred material used in DSLR Bodies, Laptops and other Gadgets. It is a mixture of Magnesium and alloy which is often aluminum, zinc, copper, silicon, zirconium and other minerals, and to answer your question why not aluminum? Well, not only aluminum but a combination of the said minerals. This mineral is also used in ...


17

if I use the auto-focus, does it adjust the lens focus, or is there a secondary lens in the body that gets adjusted? No, there's no secondary lens. The lens attached to the camera contains a motor that moves the lens elements as required by the autofocus system. Same with the aperture settings, is this changing on the attached lens, or is there another ...


16

The diaphragm is not at the back of the lens but in between optical elements. Forcing it to be at the back would be severely restrictive in terms of lens design and wide-angle lenses would become impossible on most a sensor-size and flange distance combinations.


16

Phase detect autofocus works by measuring the horizontal displacement between brightness patterns projected onto the AF sensor. To measure the displacement, pairs of 1-dimensional arrays of monochrome pixels are used. This is what the AF sensor in the Canon 5D mkIII looks like: You can see lots of different lines of pixels used by different user selectable ...


15

Probably the reason for using mechanical shutters is that their disadvantages are easiest to live with; competing technologies are not (yet) clearly superior. The major problem is that electronic shutter affecting whole sensor at once is rather easy to be implemented on CCD sensor, while for CMOS (preferred on new DSLRs) it requires additional circuitry in ...


15

I suspect the major reason this is true for DSLRs is to get the lightning-fast focus times that point-and-shoot cameras don't have. The autofocus mechanism is not actually part of the main CCD/CMOS sensor, but a separate device in the camera body, and the mirror splits the light coming through your lens so that half goes to the viewfinder and half goes to ...


14

Andrea at SAR has plenty of contacts within Sony. They wont listen to you though. Large companies have extensive procedures and policies relating to design which is why it takes so long and the results are such a mess. Your best bet would be via some up and coming camera manufacturer like Blackmagic, or do it yourself (or by partnering with a developer) by ...


13

As mentioned by the answers by @matt and @rowland, the price is directly linked to the the area of silicon used to create the sensor. Ideally a sensor with twice the area should cost about twice as much. Since all production of electronics on silicon (and other substrates) will have flaws, not all the produced chips/sensors will work. The yield rate (as it's ...


13

The biggest functional difference between a leaf shutter and a focal plane shutter is the ability of a focal plane shutter to precisely allow the same amount of exposure time for the entire field of light collected at the front of the lens and to allow the practical use of faster shutter speeds. Due to the fact that leaf shutters are open in the center ...


13

I expect that a company gets attempts like this every day. And most of them are totally useless crazy ideas. Your idea very well may be the exception, but odds are — speaking impersonally — it's not. That's why the system which makes it difficult to speak to anyone exists. It is protection. Additionally, if the idea is as great and inevitable as you suggest,...


13

Pros of using an EVF as opposed to the rear LCD screen: It is easier to see in direct sunlight. Holding the camera to the eye increases stability and comfort (especially with heavier lenses). EVFs offers diopter correction so users don't need to wear eyeglasses.


13

Why do we need a DOF preview button? So that you can see how much depth of field you'll get when the shot is actually taken. Why not just show the effective depth of field, by default? Because your eyeballs don't have variable shutter speed or auto ISO. And because autofocus systems need plenty of light to work well. Try setting your camera to f/22, ...


12

The Bayer filter passbands are designed to be make the sensor have a reasonable match to the human eye, while not costing too much. They're fairly leaky even in the visible part of their stop band, and pretty much uncontrolled in the IR. To increase their blocking in the IR a more expensive recipe in a thicker layer would be needed. The thicker layer isn't ...


12

You definitely have to change the design of the camera. This HowStuffWorks page explains how instant film develops well enough. Essentially, the film cassette contains rollers that roll out the developer to begin developing your film. Until this happens, the film is still light sensitive. This is why the cassette begins with a plastic, light blocking layer ...


11

Sigma DSLRs have this feature instead of dust-reduction which almost all others have. In the case of these Sigma DSLR, this also block IR light from reaching the sensor while other DSLRs have a filter right in front of it to do that. The suggestion of @rfusca is one I thought of before. It would probably not be complicated to have a protective cover in ...


11

Sensor price is more proportional to the physical size of the sensor, than the number of pixels within it. There are full frame sensor with lower pixel counts on some of the older models (for instance, the first Canon 1Ds). It's worth noticing that the sensitivity is lower than modern sensors - not because the pixels are larger, but due to other advances. ...


11

Very Unlikely There is a lot of R&D going on in sensor technology right now, even the examples you give are at best misleading. You only talk about megapixels, there are a lot of improvements that can be done without increasing the pixel count. For example, just compare pictures from a 8MP cell-phone camera from a new model to a 4 year old model. APS-C ...


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