Raw vs JPG vs PNG – What’s Best For Me?
As a Photographer, we have quite a few options to what to save our images as. The famous three formats are RAW, JPG, and PNG files. So which image file type is best for me?
What is Raw?
A camera raw image file contains minimally processed data from the image sensor of either a digital camera, image or motion picture film scanner. Raw files are so named because they are not yet processed and therefore are not ready to be printed or edited with a bitmap graphics editor. Normally, the image is processed by a raw converter in a wide-gamut internal colorspace where precise adjustments can be made before conversion to a “positive” file format such as TIFF or JPEG for storage, printing, or further manipulation, which often encodes the image in a device-dependent colorspace. These images are often described as “RAW image files” based on the erroneous belief that they represent a single file format. In fact there are dozens if not hundreds of raw image formats in use by different models of digital equipment (like cameras or film scanners).[1]
Raw image files are sometimes called digital negatives, as they fulfill the same role as negatives in film photography: that is, the negative is not directly usable as an image, but has all of the information needed to create an image. Likewise, the process of converting a raw image file into a viewable format is sometimes called developing a raw image, by analogy with the film development process used to convert photographic film into viewable prints. The selection of the final choice of image rendering is part of the process of white balancing and color grading. – Wikipedia
Advantages
In other words, RAW images are uncompressed version of your images. There’s no compression taking place unlike a JPG image. The biggest advantage of shooting with RAW is the ability to change the White Balance at Post Processing.
Disadvantages
- Being uncompressed and the ability to change white balance doesn’t come cheap. A Raw file is 10-15x bigger than a high-quality saved JPG. But with the price of hard drive space, this should be the least of your worries.
- In order for you to upload online such as your Facebook or Flikr, you will need to convert your file to a compatible format such as JPG. Not a fun task when you are in a hurry or when you’re converting over 300 images.
- Also need to do further conversion before you can use on your normal programs such as Microsoft Word.
My suggestion is to shoot in Raw mode if your camera allows you to. Not only you acquire the highest quality your camera can offer, but it gives you the ability to fix white balance with ease.
If you are in a hurry and just need really quick shots, then I suggest shooting RAW + JPG. Atleast with this option, you get a Raw copy as well. Just incase you do decide to further indulge with post processing.
JPEG – Oldie But Goodie
The JPEG (also saved as .jpg) file format has been around since the dawn of computers. It’s the most used format in photography and computer related images.
JPEG (named after the Joint Photographic Experts Group who created the standard) is a commonly used method of lossy compression for photographic images. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality.
JPEG compression is used in a number of image file formats. JPEG/Exif is the most common image format used by digital cameras and other photographic image capture devices; along with JPEG/JFIF, it is the most common format for storing and transmitting photographic images on the World Wide Web. These format variations are often not distinguished, and are simply called JPEG. – Wikipedia
Advantages
- JPEG files can be saved to much smaller file size allowing faster transaction and online delivery.
- It can be saved at different compression levels (usually from 1 – 12, 12 being the higher quality).
- It’s fully compatible with the majority of computer software. No need for further conversion.
Disadvantages
- Once saved at a higher compression level, there’s no way of getting back the original quality.
- Does not support layers – Only applicable when working with programs such as Adobe Photoshop and Lightroom.
- Does not support transparency. The erased portion of your image will be converted to a solid color upon saving in Photoshop.
PNG – Portable Network Graphics
The motivation for creating the PNG format was in early 1995, after it had come to light that the Lempel-Ziv-Welch (LZW) data compression algorithm—used in the GIF format—had been patented by Unisys. There were also other problems with the GIF format which made a replacement desirable, notably its limitation to 256 colors at a time when computers capable of displaying far more than 256 colors were becoming common. Although GIF allows for animation, it was decided that PNG should be a single-image format. – Wikipedia
Advantages
- Supports 100% transparency. No need to save to a PSD (Photoshop Document) to preserve transparency.
- Supports layers with basic effects and formatting.
- Lossless format. Your images will be kept at its highest quality.
- You can keep saving the exact PNG file and you don’t have to worry about lossing image quality every time.
- Smooth lines on web pages when rendered (as compared to rendering a JPG image).
Disadvantages
- Due to the lossless compression, PNG files are bigger than JPG files.
My suggestion is to only use PNG formats when you’re saving images to a smaller pixel size and want to keep the quality at the optimum level.
Suggestions
I always advice in shooting in RAW for complete control of your post-processing. Make it a habit to shoot in RAW and budget the time to do the image conversion in your post-processing. But if you’re just shooting small things such as for your Ebay auctions, Craigslist ads, etc, then there is no need to shoot in RAW. Simply switch your image quality in your D-SLR to the smallest JPG option available.
