Alley in Pisa, Italy

by Lars Kotthoff

submit your photo


Hall of Fame
View past winners from this year

Please participate in Meta
and help us grow.

Tag Info

Hot answers tagged

22

The mirror has to be a lot bigger for 4x5, particularly at 90 degrees to the axis the mirror flips about. The shutter also gets bigger in the direction it has to move (there's a reason the shutter moves up and down not left to right). This means a slower moving mirror and shutter. Another consequence of the bigger mirror is the lens mount has to be further ...


19

There are a variety of ways to display highlighted focus point indicators in the viewfinder. One of the earliest (yet still common) methods is to direct light back through the pentaprism to reflect off the rear-surface of reticles etched on the focusing screen or dedicated "superimpose plate". Displayed information is limited to highlighting the etched ...


18

Sounds nice but apparently there are currently some technical limitations: An electronic shutter requires the sensor to be equipped with what is commonly called "snap shutter" circuitry. Basically, this is a second set of diodes, as big as the light gathering photodiodes, but shielded under a dark cover, and some additional switches. To shoot, the ...


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

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. ...


16

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 ...


15

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 ...


15

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 ...


14

Some good readin' here. Some key notes... Cameras, typically smaller point-and-shoot cameras, that use no mechanical shutters typically use an interline transfer sensor. An interline transfer sensor dedicates a portion of each pixel to store the charge for that pixel. The added electronics necessary to be able to store the charge for ...


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

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 ...


12

ac·tu·ate [ak-choo-eyt] –verb (used with object), -at·ed, -at·ing. 1. to incite or move to action; impel; motivate: actuated by selfish motives. 2. to put into action; start a process; turn on: to actuate a machine. You pretty much have it. A shutter "actuation" is the opening and closing of the shutter when a picture is taken. It should ...


11

To get the definitive answer you can try to find and study the service or repair manuals for some cameras. For the stupid secrecy of the camera makers they are usually removed from the public access, but can be found elsewhere. This is a page from the Pentax K10D service manual; I don't know if you can figure from it how the LEDs themselves are positioned. ...


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. ...


11

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.


10

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 ...


10

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 ...


10

It's generally at the bottom of the camera body. The reflex mirror permits some light to pass through it, which bounces off a secondary mirror which hangs underneath the main mirror, through a lens, off another mirror though another lens and into the AF sensor: The reason for all of this bouncing around off mirrors is that the AF sensor has to be exactly ...


9

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. ...


9

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.


8

I think black is primarily chosen to be discrete, and because that's what people expect. Whilst some people like to be different, most want their camera to look like a camera. On the first point, a shiny camera would be a liability for nature photography, as light reflecting off it could scare away animals. People tend to use camo coverings over Canon's ...


8

I think you're right: I'd say it's a combination of aesthetics (black is perceived as more professional) and reflection considerations (less distracting in reflected surfaces, subjects' eyes, etc.) The fact that some DSLRs do come in colours (like the Pentax K-r in white and red) would seem to support the view that body colour makes no difference to picture ...


8

In my experience the shutter tends to fail gradually, i.e. it becomes unreliable shooting at high speeds, the first and second curtains can get out of sync, giving you inaccurate shutter speeds. It can fail completely in one go, but you usually get some warning. The shutter is very light and delicate so it's unlikely to do any damage when it goes! And yes ...


8

I think, basically, there's not enough of a difference. These give you about 12% greater height in exchange for about 5% in the other direction. That's not worth the risk of putting something "weird" into the market.


8

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 CCD/CMOS, 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 the autofocus ...


8

Russell, large companies like Sony do not work the way as you would expect. They have executive planning, and they usually respond to already existing needs gathered from the field. The larger a company and the more shareholders are there, the more conservative approach they take. So your options are: You patent, you create a prototype, you create a ...


7

Probably the reason for using mechanical shutters is that their disadvantages are easiest to live with; competing technologies are not clearly superior. There have been electronic shutters used for higher speeds on some older Nikon DSLRs, like D1 or D70. On these cameras, grid-like patterns were reported to sometimes appear on plain tonal areas with shutter ...


7

Video does not use the mechanical shutter. The shutter remains open. Something called rolling shutter is used to scan the sensor. This takes time, and is not instantaneous like a 1/4000th exposure with the mechanical shutter where all sites on the sensor record at the same instant. At 30 fps, each frame is effectively 1/30th of a second, so this type of ...


7

Image quality and possibly expense Introducing yet another element in front of the sensor will degrade quality of the pictures, and for various reasons. a) being outside of protection of the shutter will mean that it is constantly in contact with the air and dust. This will mean it will require more constant cleaning than a sensor would. How often do you ...


7

Most lenses have one or more lens elements behind the diaphragm also. I actually haven't seen one that doesn't. http://en.wikipedia.org/wiki/File:Tessar.png From: http://en.wikipedia.org/wiki/Photographic_lens_design



Only top voted, non community-wiki answers of a minimum length are eligible