74 votes

Why is there "single" in the term DSLR (Digital Single Lens Reflex)?

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 ...
mattdm's user avatar
  • 143k
54 votes
Accepted

Why is there "single" in the term DSLR (Digital Single Lens Reflex)?

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 ...
Philip Kendall's user avatar
  • 21.9k
40 votes
Accepted

Why can't my custom camera body focus to far distances?

If I have built my device with the correct distance between the flange and the optical plane, does this mean the (inexpensive) lens I am using is bad? If you had built your device using the proper ...
Michael C's user avatar
  • 175k
34 votes

Why isn't my camera body white?

This is purely speculation, so take it with a grain of salt. But the outside of a camera can benefit from being black for the same reason the inside does, to prevent light bounce. This may not be as ...
LightBender's user avatar
  • 3,181
28 votes
Accepted

Why do even high-end cameras often still include normal (non-cross-type) AF sensors?

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 ...
Michael C's user avatar
  • 175k
23 votes

Why do cameras use a slit between two curtains rather than exposing the entire sensor instantly?

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 ...
WayneF's user avatar
  • 12.9k
22 votes
Accepted

Is there a DSLR/mirorless camera with minimal options like a classic, simple SLR?

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 ...
mattdm's user avatar
  • 143k
20 votes

Why do cameras use a slit between two curtains rather than exposing the entire sensor instantly?

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 ...
Roddy's user avatar
  • 1,838
18 votes

Why do we need a DOF preview button?

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 ...
whatsisname's user avatar
  • 1,192
18 votes

Why isn't my camera body white?

From a marketing perspective, black tends to be a safe colour to choose because it's the least offensive and most subdued. From an manufacturing perspective, if a pigment is involved (such as the case ...
DKNguyen's user avatar
  • 291
17 votes
Accepted

How do SLR lenses connect to the body?

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 ...
Caleb's user avatar
  • 31.7k
14 votes
Accepted

Why is the IR filter present when there is already the Bayer filter on an image sensor?

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, ...
Chris H's user avatar
  • 3,812
13 votes

Why do we need a DOF preview button?

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 ...
Caleb's user avatar
  • 31.7k
11 votes
Accepted

Will a pinhole camera work with instant film?

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 ...
OnBreak.'s user avatar
  • 20.5k
10 votes

Why can't my custom camera body focus to far distances?

If not, do I move the lens away or closer to the optical plane to fix the problem? If the lens will focus on near subjects, but not on a subject at "infinity," then that means that the lens is too ...
Solomon Slow's user avatar
10 votes

In-body neutral density (ND) filters?

Just a guess, but I don't believe that ND filters are so widely used as you assume. A very large share of the users of a specific camera will never need an ND filter and therefore not be interested in ...
jarnbjo's user avatar
  • 3,007
9 votes

Why is there "single" in the term DSLR (Digital Single Lens Reflex)?

The more important letter in DSLR is the R, which stands for reflex. What differentiates reflex cameras from others is that the image is made to appear on a screen that's positioned in a way that's ...
Blrfl's user avatar
  • 5,532
8 votes

How do SLR lenses connect to the body?

As Caleb pointed out, all focus and aperture-related functions (as well as optical zoom when relevant) happen inside the lens, not in the body (in terms of lens components moving at least, not talking ...
jcaron's user avatar
  • 317
7 votes
Accepted

Are there any DSLRs that are only manual mode?

No. The incremental cost in actually providing modern features including priority and program modes is very, very small — but the reduction in potential market would be enormous. Because of this, ...
mattdm's user avatar
  • 143k
7 votes
Accepted

Is it technologically possible for a sensor to run two ISO's at once?

It should be possible but may require a specific hardware design to do so. Magic Lantern does something similar (but not the same) on standard Canon sensor with dual ISO, which means every other line ...
Gimli's user avatar
  • 196
6 votes
Accepted

Why are rangefinders not directly above the lens?

Rangefinders use two "viewports" in order to get the split image to aid in focusing. If you look closely you will see the second little window usually near the lens itself. It would be possible to ...
Mike Sowsun's user avatar
  • 12.2k
6 votes

Can we improve phone cameras using separate sensors for each of RGB?

Your idea is very interesting. But there are some very serious problems. Parallax. Because the sensors will be shifted to each other they will "see" different picture. And the process of creating one ...
Romeo Ninov's user avatar
  • 11.9k
6 votes

Is there a DSLR/mirorless camera with minimal options like a classic, simple SLR?

The closest thing might be the Epson R-D1 (only available pre-owned), a manual focus, manual shutter cocked digital rangefinder camera. Also, there are some similarly designed cameras from Leitz. ...
rackandboneman's user avatar
5 votes

Why do we need a DOF preview button?

Your confusion comes from a mixup of viewfinder and live-view use: Through the viewfinder, you physically, through purely optical means, see through the lens. The only way to get a bright image is ...
ths's user avatar
  • 7,152
5 votes

Why is there "single" in the term DSLR (Digital Single Lens Reflex)?

To me, the problem is with the word "lens"--I think it would be much clearer if it said "optical path" as it entails more than just light-bending elements. A single lens camera is one where you are ...
Loren Pechtel's user avatar
5 votes

Can we improve phone cameras using separate sensors for each of RGB?

Many video cameras already do just what you propose. But they use a beam splitting system between the lens and the sensors which essentially cuts the amount of light reaching each sensor by roughly ...
Michael C's user avatar
  • 175k
5 votes

Can we improve phone cameras using separate sensors for each of RGB?

Modern smartphone image quality is limited by their tiny sensor size, lens quality and diffraction, not the demosaicing process. Therefore, the idea does not seem to be useful. Note that ...
szulat's user avatar
  • 5,060
5 votes

Is it technologically possible for a sensor to run two ISO's at once?

An ND grad is cheaper and bracketing is cheaper still, almost the first limitation people would hit is they'd want to change the graduations (angle, depth etc); ultimately there's no incentive for a ...
James Snell's user avatar
  • 9,699
5 votes

What are the physical limits that determine a camera's flash sync speed?

Before electronic flash became the norm, we used flash bulbs. These were a one-time use bottle of sunlight. Typically they consisted of a glass envelope filled with oxygen. The bulb contained a ...
Alan Marcus's user avatar
  • 38.9k
5 votes

Why can't my custom camera body focus to far distances?

Potentially. It could also be that your measurements are slightly off. To find the perfect distance, you can focus on infinity, and then slowly move the lens nearer, until the picture is sharp. That ...
Aganju's user avatar
  • 2,022

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