What Is Raw File Format

by -116 views

Virtually all cameras will accept a menu pick that lets yous choose the quality and size that images are saved at. On well-nigh higher end cameras (DSLRs, MILCs, and some Span cameras), along with various JPEG options, they volition also have an option to save in RAW.

RAW is an image format that records the data from the camera sensor, and doesn’t apply any manipulation (or only applies a minimal amount of manipulation) to this data. The camera as well saves the sharpening, saturation, etc settings in the file, just does non apply them.

Yous and then use a RAW conversion program on your computer to catechumen the RAW into a JPEG or TIFF file. As part of the RAW conversion process, y’all can employ the settings saved in the file, or you tin can alter the settings.

JPEG meanwhile, has all the sharpening, saturation, etc. settings practical in camera, which means you lot tin can’t hands change or undo these settings later.

This is the bones process that happens when you take a photo with JPEG vs. RAW:

With JPEG:

Light hits camera sensor > Analog to Digital conversion > Sharpening, Saturation, White balance etc. settings applied > Compressed to 8 scrap colour space > Saved equally JPEG

With RAW:

Light hits camera sensor > Analog to Digital conversion > Sharpening, Saturation, White balance etc. settings recorded (but not practical) > Saved as RAW

Settings not ‘broiled in’

So RAW files are much more than flexible than JPEG files. If you take set the sharpening setting too high on your camera, with a JPEG file in that location is not a lot you tin practise. With a RAW file, the underlaying data has not had any sharpening applied, so you just set the amount of sharpening you want when converting it to a JPEG.

The aforementioned affair is true with any other photographic camera setting: white balance, saturation, contrast, noise reduction etc. JPEG has these settings ‘broiled in’, while RAW format will allow you to change them at the time of conversion.

8bit vs. 14bit

The ‘bits’ referred to here, are how many levels of tone are recorded in each color channel (R,One thousand,B) of an epitome. eight scrap means that each color channel has 256 different levels of tone that can exist recorded. All JPEG files are 8 $.25 per channel.

RAW files meanwhile, usually record in 12 or 14 bits per channel. 12 bits is four,096 tones, while xiv bit is 16,384 tones. And then the higher the bits per channel, the more tones it can record, and the smoother gradations volition be.

Most monitors are 8 bit (some LCDs are 6 flake), and so you are unlikely to detect any divergence betwixt an 8 bit JPEG and xiv bit RAW on your screen. Where it does come up into play though, is if you want to do whatever manipulation to your image.

If yous perform an adjustment that modifies the tones values e.chiliad. a curves or levels aligning, in an viii bit image you will come across gaps appear as the tones are shifted.

8 bits per channel photo vs 16 bits per channel histograms after applying contrasty tone curve

I saved a 12 bit RAW file as eight scrap and xvi bit TIFFs. (Saving equally 16 bit doesn’t magically create more data – it only contains the bodily data of the 12 fleck file). And then I applied the same very stiff contrast tone curve to both images. Y’all can come across the histograms of the images in a higher place, the eight bits per channel file has lots of gaps in the data where tones have been compressed together, only the 16 bit file does not.

In real life, y’all will need to be applying some quite farthermost adjustments to see any difference. Merely it is always worth having that extra data there, only in instance you do need it.

Highlight headroom

RAW files allow you to pull back the exposure or utilize highlight recovery when converting the file. This means you can recover detail from blown highlights that would but be recorded as pure white in a JPEG file. See this post for more information and an example: Why Use RAW Image Format?.

No compression

JPEG files are compressed, while RAW files are not. A small-scale amount of information is lost as role of this compression procedure. RAW files are non compressed (some cameras offer losslessly compressed RAW), so yous do non loose whatever image detail as role of compression.

Of course, this fact means that RAW files are usually much larger (in MB) than JPEG files. This ways that they take longer for the camera to tape to the retentivity carte du jour. Then you cannot normally shoot as many shots in a single continuous burst using RAW format every bit you can using JPEG format.

Information technology also means that your memory card will fill up much quicker, and RAW files volition take up more space on your hard drive. With the toll of memory cards and difficult drives, this is not an effect for most people though.

Improve conversions

Equally RAW convertor software improves, you may be able to re-process older RAW files, and get a amend outcome than you could originally. This is not something that you tin practise with a JPEG, which is stuck with the in-camera RAW conversion from when you took the photograph.

In theory, the much more powerful processor that a computer has should be able to perform a amend chore at RAW conversion than the camera tin can today also. Withal, I have not seen whatsoever show that this is true.

Unlike RAW formats

Dissimilar photographic camera manufacturers use different file extensions for their RAW formats:

  • Nikon: .NEF, .NRW
  • Canon: .CR2, .CRW
  • Sony: .SRF, .SR2, .ARW
  • Pentax: .PEF, .PTX
  • Fuji: .RAF
  • Panasonic: .RW2 .RAW
  • Olympus: .ORF
  • Sigma: .X3F
  • Samsung: .SRW
  • Adobe: .DNG

The .DNG format created by Adobe is an ‘open’ format, and some photographic camera manufacturers also allow you to salve RAW files in DNG format, as well as their own proprietary format.

Although camera manufacturers usually proceed the same file extension for RAW files between ane camera model and the next, the format that each new camera saves the information in this file tends to have some differences. Often when a new camera model is released, in that location is a period of fourth dimension before a RAW converters are updated to support the RAW format saved by the new model.

Then, if yous get a new (just released) photographic camera, ensure that the RAW conversion software yous use supports the photographic camera earlier you shoot RAW. Or simply shoot RAW + JPEG. Then you lot have the JPEG files for immediate use, and the RAWs for when the RAW conversion software is updated.

A potential problem with this habit of changing the RAW format for every new photographic camera, is that in the future, information technology is possible that RAW convertors will stop supporting older formats. This would exit you with a load of RAW files y’all tin’t do annihilation with. Every bit far as I’m aware this has non happened so far – RAW files from the 1999 Nikon D1 can still be opened in Adobe Camera RAW today.

This potential trouble is function of the reasoning behind Adobe’s DNG format. Every bit well every bit some cameras allowing you to save files direct in DNG format, Adobe also offer a convertor to convert other RAW formats to DNG.

RAW converters

There are a large range of different RAW conversion programs. The well-nigh popular are:

  • Adobe Photographic camera RAW – part of Adobe Photoshop / Lightroom (both utilise the same RAW conversion engine)
  • Capture One Pro
  • DXO
  • SilkyPix
  • OnOne Photo RAW
  • Digital Photo Professional (Canon only)

Typically, RAW conversion software produced past the manufacturer of your camera will convert a RAW file (with no adjustments made) so that it looks exactly the same as if you shot a JPEG in camera.

Other RAW conversion software though, will usually requite the epitome a slightly dissimilar look. This is because the photographic camera manufacturers do non normally release the precise information on the settings recorded in a RAW file and how they should be interpreted past a RAW convertor.

Nikon NEF RAW file converted in Capture NX 2

Nikon NEF RAW file converted in Capture NX two

Nikon NEF RAW file converted in Adobe Camera RAW

Nikon NEF RAW file converted in Adobe Camera RAW

Both the above files are from the same RAW file. The file was merely opened in the RAW convertor and saved, without making whatever changes to the settings. You can see in that location are some slight differences in the way the two programs converted the image.

The version converted in Adobe Camera RAW has a slighter college contrast. There is also a noticeable difference between the two images in the effulgence and saturation of the green block on one of the posters, and the woman’due south red jacket.

Most RAW conversion software supports saving presets. So if y’all similar your photos to have more contrast or less dissimilarity than the program defaults, you can increase the contrast, and then salvage it every bit a preset. You can and so employ the increased contrast preset whenever you convert a file.

Ease of use

Unless you lot are emailing a photo to another photographer, you cannot merely email a RAW file and expect the recipent to be able to view it okay. Nor practice most photo sharing websites accept uploads of RAW files. Instead, you must outset convert the RAW file to a JPEG.

Batch conversion of RAWs to JPEGs makes this relatively simple, or you can set up your camera to record RAW + JPEG. (So the camera saves both the RAW and JPEG version of each shot).

Given that you will probably want to resize a JPEG file anyway earlier emailing or uploading it, having to convert from a RAW file does not crusade much of an inconvenience.

In Windows, RAW files do not ordinarily show up every bit thumbnails, whereas JPEG files do. This can exist an inconvenience if you utilise Windows Explorer to view / manage your photos at all. This can be fixed past installing a RAW codec pack eastward.g. Microsoft Camera Codec Pack or FastPictureViewer Codec Pack. Mac users don’t need to download anything – OSX supports RAW files natively.

Whether you desire to shoot RAW or JPEG is really up to yous (and whether your camera supports saving as RAW). If you lot are spending money on a photographic camera considering it offers good image quality, then I would actually recommend shooting RAW and so you lot can brand the most of that image quality.

It likewise makes nigh sense to use RAW if y’all are shooting under many different types of lighting and don’t want to (or don’t remember) to change the white balance setting. Y’all can just set the correct white balance when performing the RAW conversion.

On the other hand, if you shoot continuous bursts of shots (e.chiliad. Sports photography), so y’all may be better served sticking to JPEG. The smaller file size of JPEG means it takes longer for your photographic camera’s buffer to fill up, and yous can fit more images on 1 memory carte du jour.

Source: https://www.discoverdigitalphotography.com/2012/what-is-raw-image-format/