102
votes
Accepted
Took my first ever 4k picture; Why is it so disappointing?
4K might be the next big thing in video, but for still photography that's just 8 megapixels, which is quite low for most cameras, and I think around the resolution of the iPhone. I have a Nikon D5300 ...
- 1,059
47
votes
Took my first ever 4k picture; Why is it so disappointing?
Most cameras already have a resolution going far beyond 4K. Assuming you mean Ultra HD (3840x2160) opposed to "true" DCI 4K (4096x2160) you get a resolution of about 8MP (DCI 4K would be about 8.8MP). ...
- 571
46
votes
Accepted
Why does the Canon 1D X MK 2 only have 20.2MP
All pixels are not equal Larger pixel wells, such as those found on a 20MP full frame sensor, are able to capture more photons than smaller pixels like those on a high resolution phone sensor. The ...
- 175k
34
votes
Accepted
Maximum useful resolution for scanning 35mm film
According to Ken Rockwell:
Fuji Velvia 50 is rated to resolve 160 lines per millimeter. This is the finest level of detail it can resolve, at which point its MTF just about hits zero.
Each line will ...
- 26.9k
28
votes
Why does the Canon 1D X MK 2 only have 20.2MP
Compromises are made in everything. Look a little harder and you can find "top" DSLRs with many, many more pixels. Hasselblad H6D-100c has 100 MP, for example.
But looking at only megapixels gives ...
- 12.5k
27
votes
Are online photos safe from damage?
one of my Facebook accounts seem to have lost a significant amount of resolution
Facebook (and other social media sites) compress photos while storing/displaying. Considering the amount of data that ...
- 556
25
votes
What does a client mean when they request 300 ppi pictures?
I'm having trouble understanding what it means.
What it means is that whoever wrote the request probably doesn't have a clue how JPEGs are rendered using most current image viewing applications.
PPI (...
- 175k
24
votes
Accepted
Does aliasing occur in film photography?
No. Aliasing is result of sampling, taking discrete samples or readings of a signal, at a low enough frequency that the frequencies in the input signal are confused for other frequencies, such that ...
- 32.3k
21
votes
What is the resolution of a satellite image when measured in centimeters and meters?
Spatial resolution in Remote Sensing is normally expressed in distance per sample rather than samples per unit distance. The same information is there, it's just expressed as the reciprocal of what ...
- 311
19
votes
Took my first ever 4k picture; Why is it so disappointing?
Whoever told you about 4K probably mislead you. At least, you have the resolution right. You see, 4K at 3840x2160 is a resolution term used for video, signifying almost 4000 pixels in width. The ...
- 103k
19
votes
Accepted
What is a resolution unit?
This is in the Exif standard for metadata, on page 26:
ResolutionUnit
The unit for measuring
XResolution
and
YResolution.
The same unit is used for both
XResolution
and
...
- 143k
16
votes
What does a client mean when they request 300 ppi pictures?
While other answers are correct regarding the general usage of ppi/dpi in digital images, there is a specific and important usage that may apply here. As you said it's for an archaeological project, ...
- 261
14
votes
Accepted
Can a blind person resize a photo independently?
The image I uploaded was rejected because it was under 300 DPI.
The DPI is just a number which has no relevance to a digital image. It relates only to printing and not the quality or resolution of ...
- 6,385
14
votes
What does a client mean when they request 300 ppi pictures?
What does a client mean when they request 300 ppi pictures?
It means that they have no idea what they're talking about.
Deliver full-size images as you would to any client. You can change the ...
- 11.7k
13
votes
Is it better to crop in Raw than JPEG?
Note that you can crop JPEG images without having to reencode them if you use tools that work with the JPEG format, such as jpegcrops, ...
- 233
13
votes
What is the resolution of a satellite image when measured in centimeters and meters?
"Resolution: <whatever>" means that the image contains sufficient detail to resolve an object of size <whatever> on the ground. There are multiple definitions of exactly what it means to be able ...
- 21.8k
11
votes
Accepted
Does the detail in an image affect how large the image file is?
This is not only possible, but extremely likely, when you're using a compressed image format such as JPEG. Data compression methods in general become more efficient as the data to be compressed ...
- 5,404
11
votes
Is it better to crop in Raw than JPEG?
When shooting JPEG you usually have to option to select the size and quality of your image. For instance with Nikon cameras you can select Large and Fine. This option will give you the maximum ...
- 472
11
votes
Are online photos safe from damage?
Short answer: no. Especially not in the case of facebook, where you explicitely give them the right to use your images almost as they want. From their terms:
Specifically, when you share, post, or ...
- 3,161
10
votes
Why does the Canon 1D X MK 2 only have 20.2MP
Quoting from DPReview's spec sheet for the 1D X Mark II:
Continuous drive 16.0 fps
That means that the 1D X Mark II is pushing 20 MP × 16 = 320 MP through its pipeline every second, which is a ...
- 21.8k
10
votes
Why does the Canon 1D X MK 2 only have 20.2MP
Imagine yourself at the side line of a major sports event. Yeah it's bloody dark despite the stadium lights and you cannot send in your assistant to chase the athletes with a flash. You'd rather have ...
- 8,504
9
votes
Accepted
Determining the size of the smallest resolvable detail for a given camera
If you want tens to hundreds of pixels per 50 micron area, you need a microscope. Based on your object size, with that resolution, you want at least 10px/50um * 3000um/50um a 600px wide view of your ...
- 2,445
9
votes
How to determine the actual or "true" resolution of a digital photograph?
You could compute the Fourier transform of the picture and analyze it in frequency space. If the image was upsampled, higher frequencies will be missing in the transformed image.
Note that the ...
- 739
8
votes
Accepted
How to resize a photo?
Use a copy of your file, do not resize your original photo.
You can use this free program: http://www.gimp.org/
Using Gimp:
Open your file.
Use the rectangle select tool. (Define some initial ...
- 23.8k
8
votes
I am going to advertise on a billboard. Is 127 kilobytes good enough?
Would an image of 127 kilobytes be good enough for an advertisement that size?
You really need to know the dimensions of the target billboard in pixels. It's possible that you've got a highly ...
- 31.7k
8
votes
By what mechanism does a camera change its output resolution?
Let's say that with your 24 megapixel digital camera, you have selected an output size of 6 megapixels.
Usually what this means is that the camera captures the scene at the full 24 MP, performs some ...
- 751
8
votes
Accepted
Do high export resolutions compromise image safety?
An image doesn't have a DPI until you print it.
All it has are dimensions in pixels.
Anything else is simply an interpolation of one system to another in order to display on your screen... which is ...
- 23.1k
8
votes
Accepted
What does "12MP + 12MP Camera" mean in the specs of a mobile phone?
A quick search indicates that that "12MP + 12MP" means exactly that: two 12MP cameras. One is a "standard" camera, for the other several possibilities exist (depending on maker): monochrome, wide ...
- 3,161
8
votes
Are online photos safe from damage?
The photos on one of my Facebook accounts seem to have lost a significant amount
of resolution after they had already been posted.
This is not damage, this is facebook deciding to not store the ...
- 383
8
votes
Accepted
Lumix G7: Raw photos only in 1920x1440, no higher res available
Don't worry — the RAW files are the full resolution. They contain all of the data recorded by the camera. The option to change resolution is grayed out because there's no in-camera way to reduce it, ...
- 143k
Only top scored, non community-wiki answers of a minimum length are eligible