101
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 ...
- 1,049
46
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). ...
- 561
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 ...
- 168k
33
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 ...
- 26.3k
29
votes
Accepted
How can I open a very, very large image to downsize it?
I used ImageMagick on Ubuntu to resize those big pictures.
convert -resize 10% source.jpg dest.jpg
It took awhile, but worked with 1 GByte of RAM, the tool created a 4.7 Gbyte swap-like file for ...
- 6,107
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 ...
- 12.3k
26
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 ...
- 546
23
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 ...
- 31k
20
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 ...
- 301
18
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 ...
- 101k
18
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
...
- 140k
15
votes
Why do different smartphones with the same megapixel camera resolutions have different quality of image?
There are a lot more to image quality than resolution (i.e. number of megapixel).
First of the light from the subject has to be gathered to the image sensor. This is done by one or several optical ...
- 8,138
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 ...
- 6,265
13
votes
How can I upscale a low-res image to make it appear higher-res?
I have found the free waifu2x very good for upsizing images. You can try an online demo. It uses "Deep Convolutional Neural Networks" to predict what the missing image data should be. It works better ...
- 231
12
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 ...
- 19.8k
11
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, jpegcrop, or jpegtran - these tools perform lossless operations ...
- 213
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 ...
- 3,113
10
votes
Why do different smartphones with the same megapixel camera resolutions have different quality of image?
Megapixels just tell you one thing: the number of individual tiny detectors on the sensor. They do not tell you anything about:
the size of the sensor overall
the sensitivity and size of each sensor
...
- 140k
10
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 ...
- 5,244
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 ...
- 19.8k
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 ...
- 8,334
9
votes
How can I open a very, very large image to downsize it?
Theoretically, most image formats could be downscaled progressively, without loading the entire image into memory, however I do not know any tools that really implement such feature, except for JPEG: ...
- 4,845
9
votes
Accepted
Is the camera sensor or the lens the limit to resolution?
There is no hard limit to resolution - details don't just vanish they fade out gradually as the contrast between light and dark is reduced. This reduction in contrast is expressed by means of the ...
- 117k
9
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 ...
- 422
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
Is the camera sensor or the lens the limit to resolution?
Lens resolution is much more complex than sensor resolution. It's not constant across the lens, and changes with aperture.
Here's a forum discussion that goes into the details of lens/sensor ...
- 4,544
8
votes
Accepted
Why does my Sony Alpha 77 II sometimes change to a lower resolution on its own?
The Sony A77 has a Digital 1.4x and a 2x “Smart Teleconverter Feature”.
This feature crops the image with no image quality loss, albeit, at a smaller size cropped from the centre
At full size of 24 ...
- 4,642
8
votes
How do I set up my camera to get a high enough resolution for printing at 300dpi?
There is no highest resolution as DPI is a meaningless without knowing the print size.
With a given camera, the smaller you print, the higher the DPI. If you need a certain DPI for some given print ...
- 101k
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 ...
- 31.2k
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 ...
- 19.7k
Only top scored, non community-wiki answers of a minimum length are eligible