In this post I discuss each of the camera formats in Plain English. I also talk about tools used to decode RAW file and some suggested workflows. I hope you find something here that helps you through the labyrinth of confusion. It’s always been my mission to help you get past the technical confusion and move on to creating beautiful imagery. First off, let’s discuss these technologies:
Over simplification follows: In Digital Photography, The light is exposed onto a sensor (often a Bayer Sensor, because of the pattern that the light is captured). This data is then transferred and stored on a Flash card. Perviously, there were 2 options. TIFF (Tagged Image Format) and JPG (Joint Photo graphics Experts Group). More on these in a bit. A third format was introduced, known as RAW. RAW doesn’t process any of the photographs with the camera’s built in settings. Rather the RAW format stores the actual data directly from the Flash card. At this point, you can’t use the RAW data, you have to process it with software such as Photoshop, Lightroom, Aperture or the manufacturer’s software that comes with the camera. Let’s look at the formats in a nutshell.
TIFF: This is an uncompressed file format. It maintains image quality, but because of the size of the file, it takes a long time for the camera to write the data and slows down shooting. Your cards also fill up quickly.
JPG: A compressed file format (Lossy). Because it’s compressed certain detail in the image is lost. Over compressed files will display artifacts (The crunchy look).
- Advantages: Fast, small file size. Ready for use right away. Uses the camera’s enhancement features.
- Disadvantages: Lossy. Inflexible, especially in color casts removal. 8-bit color at maximum.
RAW: Actual sensor data is stored to the card.
- Advantages: 16 bit. Flexibility; you can adjust exposure, color balance and other settings after the fact on your computer. Faster than Tif and smaller file size
- Disadvantages: Larger file than jpg (Although not an issue with fast cards). Needs to be processed before use.
- DNG (Digital Negative) was introduced to avoid the issue of a RAW format becoming obsolete and the photographer being stuck with images that can’t be opened because of changing technologies or manufacturers going out of business. One of the advantages of DNG is that the metadata is wrapped into the same file as the image. This way you don’t lose your settings if the files are seperated. You can covert your files to DNG through free tools, or through Lightroom and Bridge.
Some photographers, mainly event photographers (weddings and sports) who shoot many photos claim advantages of jpg and find speed advantages out of the format.
Personally I shoot almost exclusively in RAW (with the exception of time-lapse) I like the flexibility you get when you are using RAW. In my case I am usually working on a single image at a time and want the best possible quality. I like the fact that I have a 16-bit file. This reduces banding (looks like waves in the image) in areas of gradients. Not really much of an issue until you are making some heavy handed adjustments. If you look at the histogram in an 8-bit file, it falls apart very quickly (noted by the gaps in the histogram, where image data is missing). In contrast, a 16-bit image holds up very well.
My usual workflow is to import the image to Lightroom or Aperture. I do all my overall adjustments here. Color balance and luminosity (Exposure, contrast etc). Sometimes I also create different effects in Lightroom such as split-tone etc. I like the fact the the adjustments are identical to ACR (Photoshop’s Camera RAW) and I can use Bridge for a smooth workflow (see my Lightroom video for more info) and go back and forth as much as I like without losing anything in the hand-off. I can also share presets between lightroom and ACR.
A thing to note about this RAW workflow is that the pixels in the photograph are unchanged at this point. When you make adjustments to the photograph is ACR or LR, you are merely writing to a text file (metadata). This data travels in the form of an XMP file and passes all the adjustment information to the RAW file.
When I’m satisfied with the settings, I then bring the photo into Photoshop. You can place the RAW file as a smart object, or you can import as an 8 or 16bit file.
If you want to do any pixel level work, the file must now be converted into pixels. This is called rasterizing the image. (Right click in the layer panel and choose Rasterize) All the settings are now “baked” into the photograph and you are ready for the next step. Pixel level adjustments include such tools as brushes, clone and patch tools, healing brushes and content aware fill etc, just think retouching or compositing (layer work). You can use many of the filters (as smart filters) without rasterizing the file. When I’m at the retouching and compositing stage, I don’t mind the file being rasterized because I’m finished with all the basic color and tone adjustments.
There is a lot more to be said on this subject. If there are certain areas that are unclear, let me know and I’ll see if I can expand on specific areas, as I have covered a LOT of ground here. Also I have covered it all in my DVD Photoshop for Digital Photographers.
Let me know how this article has helped you.
See you at the CAFE