RAW FILE
• not an image file per se (it will require special software to view, though this software is easy to get).
• typically a proprietary format (with the exception of Adobe’s DNG format that isn’t widely used yet).
• at least 8 bits per color – red, green, and blue (12-bits per X,Y location), though most DSLRs record 12-bit color (36-bits per location).
• uncompressed (an 8 megapixel camera will produce a 8 MB Raw file).
• the complete (lossless) data from the camera’s sensor.
• higher in dynamic range (ability to display highlights and shadows).
• lower in contrast (flatter, washed out looking).
• not as sharp.
• not suitable for printing directly from the camera or without post processing.
• read only (all changes are saved in an XMP “sidecar” file or to a JPEG or other image format).
• sometimes admissable in a court as evidence (as opposed to a changeable image format).
• waiting to be processed by your computer.
JPEG FILE
• a standard format readable by any image program on the market or available open source.
• exactly 8-bits per color (12-bits per location).
• compressed (by looking for redundancy in the data like a ZIP file or stripping out what human can’t perceive like a MP3).
• fairly small in file size (an 8 megapixel camera will produce JPEG between 1 and 3 MB’s in size).
• lower in dynamic range.
• higher in contrast.
• sharper.
• immediately suitable for printing, sharing, or posting on the Web.
• not in need of correction most of the time (75% in my experience).
• able to be manipulated, though not without losing data each time an edit is made – even if it’s just to rotate the image (the opposite of lossless).
• processed by your camera.
Exposure Adjustments
Raw files can provide greater exposure adjustments than JPEG files; over 50% more exposure detail (depending on the sensor capabilities). When adjusting exposure in a JPEG file, the highlights and shadows gets clipped resulting in lower details.
When to use Raw or JPEG
There are pros and cons of both Raw and JPEG files and there are actually reasons other than file size why not to use Raw.
Use Raw if:
you need to post process the image the scene contains high contrast the image will be enlarged beyond the camera sensor's resolution the white balance cannot be properly set with the camera you can't decide whether to use Raw or JPEG Use JPEG if:
all the Raw files won't fit in your memory card you don't want to post process the image you want to develop the photos right away before you get to use a computer (some photo finishing labs still do not accept Raw files) you are using continuous shooting mode and want to take as many photos as you can before your camera's buffer is full
RAW + JPEG
Most cameras that support RAW files also support a mode called RAW+JPEG. This mode stores both images into the memory card so you get the best of both worlds. However, it takes longer to store a RAW and JPEG file into a memory card than just one Raw or JPEG file. Whenever you are using continuous shooting mode and need to capture a fast sequence of images, stick with JPEG or RAW.
Written by: Ariff Nasir | Facebook
No comments:
Post a Comment