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 ...
- 3,181
23
votes
How do zoom lenses restrict their widest aperture at the telephoto end?
The entrance pupil is limited by the diameter of the front element, and that is what usually restricts the maximum aperture of telephoto zoom lenses - not the physical size of the aperture diaphragm.
...
- 174k
22
votes
Accepted
Why is my large format lens so much smaller (in length) than my 35mm-format lens?
The focal length is the distance from the (theoretical) center of the lens to the image plane. On the large format camera, there's a lot more camera between the lens and the film.
The lenses are also ...
- 143k
22
votes
Is a two-prime lens possible? E.g. 35mm and 50mm
Yes, it is possible and a "Lens Turret" is one way of accomplishing it.
It was very common to use a "Lens Turret" on film and movie cameras in the 1950's before zoom lenses became practical.
Source:...
- 12.2k
22
votes
50mm mirror lens. Does one exist?
The mirror lens design resolves two key optical problems:
All lenses suffer from chromatic aberration. This is color fringing due to the failure of the lens to refract (bend inward) all colors of ...
- 38.5k
20
votes
Accepted
Why do prime lenses have multiple lens elements?
Single lenses with real thickness refract the different wavelengths of light at slightly different angles. For anywhere other than the exact optical center of the lens, this causes a prismatic effect ...
- 174k
19
votes
Accepted
How do apertures which seem too large to physically fit work?
Your observations of the lens leads you to both a correct, and incorrect, conclusion.
Correct: the aperture (i.e., mechanical iris) of the lens is substantially smaller than the 10 cm it supposedly ...
- 32.2k
18
votes
What is the difference between the Canon 55-250 IS II and 55-250 IS STM lenses?
First, let's get a bit of nomenclature out of the way:
EF-S means a lens in the Canon EOS system that will only work on cameras with APS-C or smaller sensors (if any smaller than APS-C EOS sensors are ...
- 174k
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 ...
- 291
15
votes
How do manufacturers get to high (83x) zoom levels on hybrid cameras?
I think the use of the term 83X while true, is most misleading. The Coolpix does a remarkable job when it comes to its optical range which is 83X. This is actually called the zoom range. The math is: ...
- 38.5k
15
votes
Does a large mount diameter really allow design advantages for large aperture lenses?
First: Sony doesn't necessarily disagree with Nikon's claim. It's just that Sony designed their 'E' mount with a throat diameter of 46.1 millimeters at a time when it appeared it would be an APS-C ...
- 174k
14
votes
Why we can't use telephoto lens for macro objects?
There is no direct relationship between Telephoto focal lengths and Macro capability. There are some fixed focal length prime lenses that fall into the Telephoto range in terms of focal length and ...
- 174k
13
votes
I am getting a complete vignetting on my new canon 6D but only with the 18-270mm lens
From the "Recommended For" tab of the Tamron web page for that lens:
Tamron Di-II lenses are engineered expressly for digital SLR cameras with image sensors commonly referred to as APS-C, measuring ...
- 1,153
13
votes
Accepted
What motivated lens makers to now use 1/3 f-stops rather than say 1/4 or 1/2 stops?
Historically, the unit of exposure was a doubling or halving of the exposing energy. This is the origin of the f/stop. Initially, this adjustment was made by inserting a thin metal plate with a ...
- 38.5k
13
votes
Accepted
What's the opposite of a fisheye lens?
The opposite of a fisheye is a rectilinear lens.
You probably did not find one because your definition is wrong. Distortion of a fisheye lenses is not barrel distortion, it is that a different ...
- 102k
12
votes
How would a curved sensor change camera and lens design?
Digital image sensors used in modern cameras are essentially silicon chips:
Sensor dies are produced in large batches on silicon wafers. The wafers are cut into many pieces with each piece housing a ...
11
votes
Why there are so few lenses with small minimum focus distance?
Because most interchangeable lens cameras typically use larger-format sensors than 1/2.3"-format.
The close-focusing capability of most small-sensored compacts comes from the fact that small sensors ...
- 51.1k
11
votes
Accepted
What is the advantage of a lens with a curved focal plane?
The distinct "look" it provides. In addition to adding more pleasing bokeh blur to background objects near the edges of the frame, it also allows objects on the periphery that are in the same plane as ...
- 174k
11
votes
Accepted
Is a two-prime lens possible? E.g. 35mm and 50mm
Yes it is technically possible. The question is whether this will have practically same limitations as a zoom or not.
There are two objectives from Leica with stepped focal length adjustment: the 16-...
- 4,667
11
votes
Why do lenses for larger sensors tend to have shallower angles?
This is simply where the market is converging to at the moment. The typical kit lens is still 18-55mm on an APS-C sensor but most people find wider angle more useful, so some manufacturers made a few ...
- 102k
11
votes
Canon 18-55mm lens giving err01 after it fell down
whether lens could be repaired without loosing big amount of money?
Whatever the damage, repairing the 18-55 almost certainly isn't worth it. People upgrading sell them for not very much, just get a ...
- 21.6k
10
votes
Accepted
What are STF lenses?
STF stands for "Smooth Transition Focus", and is a Sony-specific* term indicating that the lens includes an apodization filter to create smooth bokeh (out-of-focus blur) — and smooth bokeh is ...
- 143k
10
votes
Is a two-prime lens possible? E.g. 35mm and 50mm
It is possible and Canon has done it, although in a different way than you'd expect - their EF 200-400mm f/4L IS USM Extender 1.4x. It's a zoom lens with a built-in teleconverter that could be toggled ...
- 2,044
10
votes
Accepted
Are there any 24-70 2.8 lens with no length change in zooming?
You need to look for a lens that uses internal zoom so that the length of the lens will not change during zooming. You also want a lens with internal focusing so that the length of the lens doesn't ...
- 174k
10
votes
What's the opposite of a fisheye lens?
A fisheye lens isn't designed to have extreme barrel distortion -- the distortion is the result of trying to map a sphere onto a plane.
A regular lens follows the equation ...
- 2,435
10
votes
Does a large mount diameter really allow design advantages for large aperture lenses?
Using your thumb and forefinger on each hand, make a finger frame, and hold it out at arms length.
Now imagine that your entire field of view is limited by the bounds of this finger frame. Anything ...
- 32.2k
10
votes
Canon 18-55mm lens giving err01 after it fell down
The black obstruction looks like a detached aperture blade. This is a seriously damaged lens. Repairing it would at least require it to be dismantled and the aperture blades replaced. Possibly there ...
- 4,045
10
votes
How would a curved sensor change camera and lens design?
Curved film planes were very common in low-end roll film cameras and even 35 mm simple cameras.
This is because they improve the image quality of a lens with a spherical focal surface, as is the case ...
- 7,102
9
votes
Why there are so few lenses with small minimum focus distance?
The focal length of a lens is a calculation made when the lens is imaging an object at infinity. This is a distance as far “as the eye can see” symbol ∞. As we focus on objects nearer than infinity, ...
- 38.5k
9
votes
Accepted
Why there are so few lenses with small minimum focus distance?
I've found that for interchangeable lens camera lenses (at least for Olympus micro for thirds lenses) the minimal focus distance in the specs is measured from the sensor, while for compact cameras ...
- 260
Only top scored, non community-wiki answers of a minimum length are eligible