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 ...
  • 172k
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 ...
  • 26.7k
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 ...
  • 12.4k
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 ...
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 (...
  • 172k
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 ...
  • 31.6k
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 ...
  • 102k
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 ...
  • 142k
17 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, ...
  • 271
16 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 ...
  • 8,268
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 ...
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 ...
  • 10.7k
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 ...
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, jpegcrop, or jpegtran - these tools perform lossless operations ...
  • 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 ...
  • 20.5k
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 ...
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 ...
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 ...
  • 3,133
10 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 ...
10 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 ...
  • 118k
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 ...
  • 142k
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 ...
  • 20.5k
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 ...
  • 8,464
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

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 ...
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 ...
  • 102k
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 ...
  • 22.1k

Only top scored, non community-wiki answers of a minimum length are eligible