223
votes
Accepted
What does an unprocessed RAW file look like?
There is a tool called dcraw which reads various RAW file types and extracts pixel data from them — it's actually the original code at the very bottom of a lot of open source and even commercial RAW ...
- 144k
67
votes
Given an image how to identify whether it is RAW file or not
Once I've a JPEG photograph image file, how can I find out whether it is a RAW file or not?
If you have a JPEG file, then it is not a RAW file.
RAW isn't a single format, but rather a collective ...
- 31.7k
47
votes
Why do we use RGB instead of wavelengths to represent colours?
The goal of the imaging engineer has always been to capture with the camera a faithful image of the outside world and present that image in such a way that the observer sees true to life picture. This ...
- 39.7k
36
votes
Why do we use RGB instead of wavelengths to represent colours?
You said,
this is the information that is captured at first by digital cameras.
That is not correct. By themselves, sensors on most digital cameras respond to a broad band of frequencies of light, ...
- 33.3k
35
votes
Accepted
Changing JPEG to RAW to use on Lightroom?
In my opinion, none of the other answers addresses the obvious misconception in the question:
There is no use in converting a JPG (comparatively low quality) to a RAW file (high quality), because you ...
- 446
33
votes
Can you "open" RAW camera files?
It's linguistics.
Of course you can open a raw file, as the term "to open a file" has a very broad spectrum of different, but related meanings.
On a low level, "to open" just ...
- 1,359
27
votes
Do raw images of the same camera have the same size?
A picture being worth a thousand spreadsheet cells, here is an histogram of the size of the RAW files from my camera for 2018 (EOS 70D, 20Mpx). Sizes are in 1000's of K (not really MB).
For the ...
- 22k
26
votes
Do raw images of the same camera have the same size?
Many digital cameras use lossless compression with raw files. That means the size of raw files from the same camera is somewhat content dependent.
The more detail and different colors a scene ...
- 176k
25
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, Green,...
- 176k
23
votes
Given an image how to identify whether it is RAW file or not
Unless somebody frivolously renamed a RAW file, it will never have a file name with the .jpg/.jpeg/.jfif extension. Typical extensions for RAW files will be .raw, .arw (Sony), .dng (Android phones etc....
- 7,252
23
votes
Is it normal for RAW files to have lens distortion? How best to deal with it?
Is this normal for RAW images?
Yes, it is normal.
Based on my experience with Canon cameras with different lenses, the RAW image remains uncorrected w.r.t. to the corresponding JPEG.
This means that ...
- 8,763
19
votes
Changing JPEG to RAW to use on Lightroom?
In the absence of real raw files, the JPG is your "raw". Most image editors, including Lightroom, can open or import JPGs. You may choose to save in another format while editing, but do not lose or ...
- 27.1k
18
votes
Accepted
Does converting image file formats affect quality?
Going from JPG (which is a lossy format) to any lossless one (like PNG) does not.
Going from any format to a lossy one, yes, including JPG to JPG. It could be too little to notice, and using the same ...
- 25.4k
15
votes
What makes RAW files difficult for manipulation?
Nothing makes raw files difficult to manipulate for someone with the right expertise and tools. It's just that there aren't many folks around who have those tools and expertise.
The tools needed to ...
- 176k
15
votes
Accepted
Why does the histogram of an image depends on the software that opened it?
It's all to do with the profile applied to the raw files and guesses other software makes as to what that profile ought to be...
RAW is not an 'absolute' format in terms of the image displayed, it's ...
- 23.4k
15
votes
Accepted
Is it better to continue shooting in JPEGs instead of RAW if you are not planning to do post processing?
"Better job" is subjective. We certainly get lots of questions like
Why does this camera generated JPEG look better than the software generated one?
Why do RAW images look worse than JPEGs in editing ...
- 144k
15
votes
Accepted
How sharp are RAW photos before processing?
Are RAW images by nature slightly blurry prior to processing? If I open them up in Lightroom and zoom into the photo, my photos are not tack sharp but a bit blurry. Once I process, it comes out ...
- 144k
15
votes
Can you "open" RAW camera files?
It is all already said, I just want to make a meme and a philosophical exercise.
Here is a JPG file opened... on a program that does not make a "preview" of the file.
I prefer one that ...
- 25.4k
13
votes
Why do we use RGB instead of wavelengths to represent colours?
The reason cameras and displays work in RGB is because our retinas work that way.
Since our eyes encode colors with those components (RGB), it is a very convenient system (although certainly not the ...
- 231
13
votes
What does an unprocessed RAW file look like?
It's a really really big grid of numbers. Everything else is processing.
- 271
12
votes
Why do we use RGB instead of wavelengths to represent colours?
An attempt to answer simply:
We cannot practically capture enough information to store a complete breakdown, frequency by frequency, of all the different wavelengths of light present, even just ...
- 13.7k
12
votes
Accepted
Why do we use RGB instead of wavelengths to represent colours?
I think there are some misconceptions in prior answers, so here's what I think is true. Reference: Noboru Ohta and Alan R. Robertson, Colorimetry: Fundamentals and Applications (2005).
A light ...
- 136
12
votes
Accepted
How does one actually *use* a dark frame?
Straight away I should mention that lunar photography is different that astrophotography of deep-sky objects. The types of frames you are describing (calibration frames) are extremely helpful for ...
- 3,987
12
votes
Accepted
Can RAW image files deteriorate over time?
RAW files no more deteriorate over time than a DOC file would. As long as you store them correctly (with backups of course) the file will be fine.
It's true that the software that you use to process ...
- 511
11
votes
Do I need in-camera HDR if a camera can take RAW?
Yes and No.
Taking a single RAW, you have more dynamic range than a single JPG, so you have a limited 'high dynamic range', depending on the camera's capabilities.
For a less limited HDR, you need ...
- 2,032
11
votes
Accepted
Why can software correct white balance more accurately for RAW files than it can with JPEGs?
Why can software correct white balance more accurately for RAW files than it can with JPEGs?
There's a fundamental difference between working with the actual raw data to produce a different ...
- 176k
11
votes
Given an image how to identify whether it is RAW file or not
Trivial ways to recognize whether a file is a RAW or a JPEG:
File ending: JPEGs end with .jpg or .jpeg, RAWs end with different ...
- 6,478
11
votes
Accepted
Opening NEF files on windows initially open fine but then change contrast
Anytime you open a raw file and look at it on your screen, you are not viewing "THE raw file." ¹ You are viewing one among a near-countless number of possible interpretations of the data in ...
- 176k
10
votes
What is the purpose of gamma correction in today's screens and how does it relate to graphics and photography?
I am a former broadcast engineer, and I currently work in feature films and television as an editor and VFX supervisor.
Many statements on here are incorrect. Gamma in the signal path is a desired ...
- 582
10
votes
When is it better to use HDR rather than just pulling extremes from a RAW file?
It is appropriate in situations where you can't capture the dynamic range in one shot and in situations where lifting the shadows would reveal too much noise. Certain landscape shots and night time ...
- 5,223
Only top scored, non community-wiki answers of a minimum length are eligible