52
votes
Accepted
Canon geometric overexposed quadrilateral shapes in all of my images
It looks like you've got a problem with the shutter. Possibly one of the "blades" in the second curtain is missing and allowing light to strike the sensor between the time after the second curtain has ...
- 169k
50
votes
What would be causing a thick black diagonal line in front of my camera's sensor?
From what I see this is element from the shutter. And my humble advise is to send your camera to repair shop, give it in to the hands of professional, do not try to repair it.
- 9,721
46
votes
Accepted
What's the point in covering the viewfinder?
On SLR cameras, the optical path is connected to the viewfinder. Even while a picture is being taken and the mirror is up, blocking the viewfinder path, it's possible the seal/gasket between the ...
- 31k
42
votes
Is it true that the best images from all digital cameras can be obtained at ISO 200?
There is an ISO which is not necessarily 200 that is the native sensitivity of the silicon from which the sensor is made. That sensitivity depends on the sensor itself, so will vary between cameras, ...
- 101k
39
votes
Why do photos with different settings produce different spots?
Let me just complement Xenoid's answer.
In this diagram, you can see how a bigger aperture produces a diffused shadow, that sometimes is hard to see.
And when you use a smaller aperture, the shadow of ...
- 21.3k
38
votes
What am I photographing INSIDE my camera?
First, understand a couple of things:
Even though we call these things "digital cameras," the process of turning photons into numbers is entirely analog. Analog circuits pick up all manner of noise ...
- 5,432
34
votes
Are Nikon DSLR sensors actually better than Canon's?
The DxO Mark scores are misleading, but that doesn't mean the gap in performance isn't real!
Several Nikon bodies (D800, D600 many of the D3xxx and D5xxx series) are using Sony Exmor sensors which ...
- 117k
34
votes
Accepted
Why don't cameras offer more than 3 colour channels? (Or do they?)
Why don't cameras offer more than 3 colour channels?
It costs more to produce (producing more than one kind of anything costs more) and gives next to no (marketable) advantages over Bayer CFA.
(Or ...
- 4,049
34
votes
How many pictures can you take with a Sony mirrorless camera before the sensor fails?
Unlike a mirrored camera, there is little likelihood of the sensing system
in a mirrorless camera suffering a catastrophic failure so it is really up to your "taste" to determine when a sensor is too ...
- 1,969
28
votes
Can the sun damage the camera sensor? Under what conditions?
At very wide angles the danger is much less and taking photos with the sun in the field of view doesn't normally harm the camera or lens. When the sun is very low on the horizon the energy is also ...
- 169k
28
votes
Accepted
Signal to Noise Ratio over the years
This data was iffy then — not really enough data points, and the trendline is dubious:
Source: a very timely xkcd
That said, the company DxOMark does measurements of camera sensors all the time, ...
- 140k
27
votes
What causes these squiggly lines in my photos and on my sensor?
Looks like fungus on the sensor (possibly under the low-pas filter). Some examples:
https://www.flickr.com/groups/canondslr/discuss/72157604712577076/
https://www.dpreview.com/forums/thread/3556906
- 17.2k
24
votes
What am I photographing INSIDE my camera?
Maybe it represents the small variation of the temperature of the sensor.
A hot sensor produces more noise than a cool one.
The small temperature difference can be explained by the presence of ...
- 417
24
votes
Accepted
Is it true that the best images from all digital cameras can be obtained at ISO 200?
The information your friend gave you was essentially correct for most digital cameras, particularly compact digital cameras with very small sensors, made about 15-20 years ago. Digital imaging sensors ...
- 169k
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 ...
- 12.6k
22
votes
Accepted
How can I find the sensor position on my camera?
Most DSLR cameras have a sign on the top (Plimsoll mark) which looks sort of like
The line indicates the position of the sensor plane.
I googled for pictures of the 600D. It also has this indicator ...
- 2,853
22
votes
Why do electronic shutters expose row by row?
So, why can't the sensor's image data downloaded to the processor, globally? Why is it downloaded row by row?
It's a matter of physical limitations and simplicity. The physical limitation is that ...
- 31.2k
22
votes
Why do photos with different settings produce different spots?
This is typical of sensor dust, the spots are more visible at small apertures. In fact taking a picture of the sky with a small aperture (large f-number) is the usual way to check for dust spots...
So ...
- 17.2k
21
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 ...
- 1,848
21
votes
Accepted
RAW files store 3 colors per pixel, or only one?
Raw files don't really store any colors per pixel. They only store a single brightness value per pixel.
It is true that with a Bayer mask over each pixel the light is filtered with either a Red, ...
- 169k
21
votes
What would be causing a thick black diagonal line in front of my camera's sensor?
The item obstructing the sensor is a shutter blade. Your shutter has failed and needs to be replaced. There's no hack or DYI solution for this problem. This is a hardware problem and not something ...
- 644
20
votes
Accepted
What are physical causes of clipping?
What exactly limits modern digital camera sensors in capturing light intensity beyond certain point?
In terms of the physical properties of the sensor itself:
The number of photon strikes and the ...
- 169k
18
votes
Is there any point in using automatic sensor cleaning on my DSLR even if I never remove the lens?
Several models of zoom lens are designed in such a way that they likely inhale dust and may vent it into the body of the camera. How big a problem this is remains debatable (see this discussion for ...
- 618
18
votes
Why don't cameras offer more than 3 colour channels? (Or do they?)
A few notes from this long-time optical systems engineer. First, there are things called "hyperspectral" cameras which use gratings or equivalent to break the incoming light into dozens or even a ...
- 1,847
18
votes
Why doesn't digital Large-Format exist?
It depends on how you define camera. In a sense, digital large format does exist, just not exactly in the way we might expect.
There are commercial products called 'Digital Scanning Backs' that fit ...
- 169k
18
votes
How to build an attachment to support lens?
I am using a D5200 and wish to find the height of the centre of the sensor from the base of the body.
I don't know the number, but you should be able to measure the distance easily enough. It's a ...
- 31.2k
16
votes
Accepted
Why does BRIGHT red in direct sun come out orange?
How can this be explained technically?
Auto Exposure and Auto White Balance.
The camera is trying to expose the image properly, but there's a huge difference in brightness between the shaded areas (...
- 31.2k
15
votes
Why does BRIGHT red in direct sun come out orange?
It's because the red channel has completely blown out, whereas the green channel hasn't. (Nor blue but that's not having any effect, here.)
Suppose the true colour of the car is five parts red to one ...
- 1,309
15
votes
Accepted
Hot, stuck, or dead pixels. What's the difference?
Excitingly, these terms mean different things to different people. I think the most useful distinction is like this:
Stuck pixels are always completely bright, as if they're fully overexposed
Dead ...
- 140k
14
votes
Accepted
What camera companies make their own sensors?
The underlying technology is broadly the same for all sensor makers and is the same technology used to produce other chips (such as CPU's). Manufacturers tend to be coy about where a chip was made (...
- 9,440
Only top scored, non community-wiki answers of a minimum length are eligible