A sensor is the digital camera's equivalent to film. It contains millions of tiny light-detecting areas called photosites, which convert light into an electric charge. After exposing the sensor to light, this charge is read from each pixel and converted into a digital image.
61
votes
7answers
18k views
When do the differences between APS-C and full frame sensors matter, and why?
I'm trying to decide on a higher-end digital SLR, and I'm down to choosing between an APS-C model and a full-frame model.
I understand that the sensors are of different sizes, and as such have an ...
39
votes
6answers
21k views
Can the sun damage the camera sensor? Under what conditions?
I want to experiment taking photos where the sun appears. I'm afraid of what might happen if I take one with a narrower angle (where sun would be bigger). Can the lens act as a magnifying glass and ...
20
votes
5answers
2k views
Do megapixels matter with modern sensor technology?
Are more megapixels good?
Are more megapixels bad?
Do more megapixels increase detail? Do they make my images sharper? On the other side, is there a point that is too much? Do megapixels cause ...
24
votes
11answers
2k views
What is the best way to clean the sensor on a digital SLR?
I've got a couple of spots of dust on the sensor of my Canon 20D - a rocket blower isn't shifting them, and I'm ridiculously scared of some of the more direct methods for cleaning sensors -- what ...
32
votes
8answers
8k views
What does “expanded ISO” mean?
The ISO specification for the Canon EOS 7D reads as follows:
High ISO
For handheld shooting in low light, the EOS 7D offers ISO
speeds of up to 6400. Expandable to
ISO 12800, for low light ...
14
votes
4answers
5k views
Why does a bigger sensor lead to a shallower depth of field?
It has been mentioned at a few places that a larger sensor results in images with a shallower depth of field.
Example image: http://www.mattgrum.com/FF_vs_APS-C.jpg
APS-C Canon 30D left, FF ...
15
votes
4answers
727 views
Does the dpi number reported by camera in JPG have any meaning?
I have two cameras, a 6mpix Panasonic FZ8, and 14mpix Canon A2200.
When I compare shots from two cameras, one of differences I notice is
dpi number that camera reports in JPG info:
FZ8 reports ...
7
votes
5answers
871 views
How does taking lower-resolution pictures with a higher-resolution sensor affect image quality?
Does taking a picture with 8 megapixel resolution with my Canon IXUS with a 1/2.3" sensor and 12M max resolution provides the same or worse image quality (particular, noise) as if the picture was ...
13
votes
6answers
2k views
Why are blown highlights particularly bad in digital photography?
I've heard that digital sensors are less "forgiving" of blown highlights than film. Why is this?
There's something called "characteristic curves". How does this related, in film and in digital?
Can ...
17
votes
3answers
3k views
What is meant by the “native ISO” when talking about DSLRs?
The new Nikon D7000 is out, and a lot of previews has touted the "native iso" of D7000 to be 100.
What does this actually mean? I'm assuming it means it performs at its best at iso 100, which means ...
10
votes
4answers
2k views
When shooting in mRAW or sRAW, how does the camera generate smaller files?
Most mid- and high-end DLSRs offer two or three sizes for RAW capture. When the camera is generating the medium or small sized RAW files, how does it make them smaller? Does it capture less ...
19
votes
2answers
1k views
Why use a small aperture when trying to see sensor dust?
Here and there I read of people who set their lens to a small aperture while testing their sensor cleanness, supposedly to get the best image of dust speckles. However, the image of the on-sensor dust ...
10
votes
3answers
665 views
What are differences between Bayer mosaic and Foveon 3 layer sensor?
To filling my appetite on camera things hunger I've came across to Sigma website and found this 3 layer sensor stuff.
Can anyone really explain this based on their experience or research about this?
...
7
votes
1answer
2k views
How to fix an image sensor damaged by long sun exposures?
I took a number of shots of the sun during mid-afternoon and now all my images have pink spot where the sun was. Is there anyway to fix this, or is it permanently damaged?
The camera was pointed at ...
17
votes
2answers
443 views
What are the basic workings of the Lytro light-field camera?
lytro.com describes their new light field camera as being able to capture the entire light field, rather than just one plane of light, thereby allowing for a whole new set of post-processing ...
16
votes
2answers
1k views
What are the advantages or disadvantages of a back illuminated CMOS sensor?
The iPhone 4s uses a backlit CMOS sensor, and I have noticed that some other point and shoot cameras do as well. What does that mean for photography, and if it is a benefit why do DSLR cameras not use ...
9
votes
6answers
2k views
What happened to Foveon sensors?
It seems like the Foveon sensor should be able to produce better images, because it's not dependent on the separate red, green, and blue pixels as exist on most digital cameras. However, cameras ...
5
votes
1answer
3k views
What effect does UV filter provide?
I know that I should always use a filter on my lens to protect the camera lens, however, exactly what impact to the picture does using a UV filter have since that is the one most often used? Do I ...
4
votes
1answer
116 views
What characteristics make a digital sensor good?
Generally, the technical image quality of a digital image (before we get to the post-processing stage) is the product of the characteristics of the lens and the recording medium, with an important ...
14
votes
7answers
498 views
Why do cameras use a single exposure rather than integrating across many very quick reads?
I have never understood why cameras need a shutter with a specific speed and why this cannot be adjusted in postprocessing. I think that present sensor works in an integral way: they save the amount ...
14
votes
3answers
3k views
What is the Nyquist Limit and what is its significance to photographers?
The Nyquist Limit is frequently mentioned in the context of lens and sensor resolution.
What is it and what is its significance to photographers?
Here is an example of it being used by DPReview.com ...
17
votes
6answers
3k views
How many stops can a digital camera capture?
How many stops can a digital camera capture?
I wondering if some one know, or have measure, the stops also for the negative or positive film, the human eyes, the monitor, the television, etc...
...
13
votes
3answers
4k views
Can a laser pointer damage the sensor in a digital camera?
I once experimented with standing in a dark room and directing a laser pointer towards my digital camera with a long shutter speed while moving the two about. I made a few images that way; one was ...
9
votes
2answers
2k views
What is “pixel density”?
Apparently megapixels aren't a good way to measure the camera quality, so some people are referring to a relative measuring system called "pixel density".
What specifically is this? What information ...
10
votes
3answers
2k views
Should I clean my camera sensor, or take it to a professional?
Possible Duplicate:
Best way to clean the sensor on a digital SLR?
Can anyone offer me advice on how to clean my camera's sensor?
Should I do this myself, or take the camera to a ...
7
votes
4answers
871 views
How many bits of data are typically actually captured by a digital camera sensor?
In a comment on this question someone suggested that camera sensors typically only output 12-14 bits of data. I was surprised because that would mean that 24 bits of color is only useful for doing ...
4
votes
1answer
327 views
what's the relation between sensor size and image quality (noise, dynamic range)?
I'm reading this description on sensor size:
Digital compact cameras have substantially smaller sensors offering a
similar number of pixels. As a consequence, the pixels are much
smaller, ...
4
votes
2answers
761 views
Is it sensor damage? Or dust?
I have been trying to shoot partial solar eclipse today with my Nikon D3100, and later noticed this spot on images:
http://pix.academ.org/img/2011/01/04/70baea815d1557594f096a82ab05704f.png
I do not ...
3
votes
2answers
312 views
Assuming a perfect sensor, what is the physical limit of ISO/pixel area?
Assuming that camera manufacturers can eventually make the perfect sensor that introduces no electrical noise to the signal, at what point (measured in ISO/area of a pixel) will shot noise be so ...
18
votes
3answers
2k views
Why are larger sensors better at low light?
The top answer of What point and shoots are good in low light conditions? says that (1) a fast lens/wide aperture (2) reasonable ISO 400+ handling and (3) a large sensor when put together are critical ...
12
votes
2answers
2k views
How come a 1" sensor is 13.2 x 8.8 mm big?
I'm wondering how sensor sizes are calculated. The Sony RX100 reportedly has a sensor size of 1" which is 13.2 x 8.8 mm according to the press release and various sites.
How does that work? That's a ...
9
votes
4answers
706 views
Why is sensor sensitivity called “ISO”?
I was curious to know how the term "ISO" was coined for referring the image sensor's sensitivity. Is there any reason or circumstance that contributed for terming "ISO"?
Also, does ISO has a literal ...
8
votes
4answers
1k views
What are the pros and cons of different Bayer demosaicing algorithms?
Bayer sensors use a pattern of red, green, and blue pixels, and merge those together into a final color image, with one pixel for every single color sensor. This could be done through a "naive" ...
15
votes
3answers
990 views
How can dynamic-range be larger than sensor bit-depth?
Found something that confused me and so I thought the crowd here can probably answer this one since its camera-related and technical at the same time.
How can dynamic-range be larger than sensor ...
9
votes
2answers
1k views
Why don't comparisons of aperture take sensor size into account?
When one compares focal length, many times we use the 35mm equivalent length. A 50mm lens on an APS-C sensor camera(1.6x) would be a 80mm equiv. length on a full frame camera.
But when we state the ...
6
votes
4answers
695 views
Is a self-cleaning sensor necessary when using only one lens?
The Canon 1100d lacks a self-cleaning sensor.
If I use this camera without ever exchanging the lens, is the absence of a self-cleaning sensor a bad 'feature'?
Are the bodies of modern DLRS cameras ...
2
votes
1answer
510 views
Why does my Nikon D90 make a strange sound during built-in sensor cleaning, when my friend's D90 doesn't?
I noticed a quiet sound (like squeaking) when using the built-in sensor cleaning of my Nikon D90. In some forums I read about many people having this behavior with the Nikon D700 and some Canon ...
1
vote
2answers
360 views
Dust on the sensor, should I be worried?
I did a 30 second long shot without the lens and checked the sensor and saw some dust on my sensor (even though camera has sensor cleaning). I didn't see any defects on photos yet, but is it something ...
26
votes
6answers
1k views
Do sensors wear out?
We all know that shutters wear out and they have a limited number of actuation's.
The question I have is, do sensors wear out too? Do they suffer any kind of damage after each shot?
Should I be ...
11
votes
3answers
371 views
How does the D800E reverse the effect of an antialiasing filter by adding another filter?
According to http://mansurovs.com/nikon-d800-vs-d800e the D800E differs from the D800 in that one of the layers of the filter reverses the effect of the initial low-pass filter. How does this work?
...
11
votes
5answers
258 views
Does it matter which way the camera is orientated for the sensor cleaning to work?
With the advent of sensor cleaning in newer bodies - does it matter which way up you hold the camera whilst it is cleaning? I understand that the sensor cleaning works by vibrating the sensor to knock ...
10
votes
3answers
628 views
What advantages does a pure black and white camera have over colour cameras?
Now that Leica has released a pure black and white camera, the Leica M-Monochrome, I started to think about the advantages a pure black and white camera has compared to a colour camera.
I guess you ...
9
votes
0answers
340 views
What does expanded ISO mean?
Especially with regards to image quality.
I am particularly interested in when you expand to a lower ISO, say 50 rather than 100. Generally the standard high ISO is too noisy, with the expanded ISO ...
8
votes
4answers
2k views
How effective are in-camera integrated sensor cleaning systems, and have they improved?
Few years ago, Canon introduced some sort of internal sensor cleaning system that (as far as I understand it) shakes the sensor off any dust it collected during use. This shake is very high frequency.
...
7
votes
3answers
207 views
Is Poisson Noise (“Shot Noise”) a significant source of noise for typical photography?
In this answer, @jrista states that even a camera with a perfect, noiseless sensor would still have noise due to "Poisson noise" aka "Photon Shot Noise" - noise caused by the random variations of ...
7
votes
2answers
547 views
Why are sensors less sensitive to blue light?
This is a followup question to Why is the blue channel the noisiest?. The simple answer to that question is that sensors are less sensitive to blue, and therefore require more amplification, which ...
7
votes
7answers
967 views
Why has no one invented a 4:5 aspect ratio APS-C/35mm-sized DSLR?
People keep inventing different form factors and formats for cameras, but none seems to have hit on what seems (to me) like an obvious one. Why doesn't somebody build a camera with a sensor that has a ...
6
votes
3answers
455 views
Fancy technology cropped vs old technology full frame - Which will give better images?
After selling my 1Dmk2 last year the time has come to get myself a new body, all along I'd decided that I wanted to do more "wow" pictures, big landscapes and do some more portait photography (up ...
5
votes
1answer
185 views
Where is the AF sensor located in a DSLR?
As I understand every DSLR has a separate, smaller sensor that handles phase detection focusing. Where is it located?
If this location is different for every DSLR, and therefore this broad question ...
5
votes
5answers
357 views
What companies offer an IR camera filter?
I'm planning on converting a Nikon D50 to dedicated infrared, replacing the internal IR cut filter with one that will block visible light, and pass infrared.
Google has turned up a couple sites, and ...
