File Formats, Left Brain Thinking!

 

When it comes to exporting/saving images you have some options on which file format to use. The 5 most common image file types are RAW, JPEG, PSD, PNG & TIFF. You probably have heard of most of the file types but this week I’d like to elaborate on their differences and when each is best used.

 

  • RAW: These files are what you get straight out of the camera when shooting in RAW format. They contain the unprocessed data captured by your cameras digital sensor. Each camera manufacturer has it’s own RAW file type. Canon has CR2, Nikon has NEF, Sony has ARW and there are many many more. Adobe is attempting to standardize RAW files into their version called DNG. These files are typically processed in software like Lightroom and then need to be converted to one of the last three types in this blog to be viewed by others.
    • RAW files are ideal when…..
      • Shooting in camera. These files can later be processed non-destructively in Lightroom or Camera Raw.
    • Don’t use RAW files when…..
      • You are ready to print or upload your images to the web. They will need to be converted to a different file type first.
  • JPEG or JPG: This is probably the most widely used image file type. JPEG stands for Joint Photographic Experts Group who are the people who developed the format. This is the default option for most cameras. Most cameras offer an option to shoot both RAW and JPEG, RAW alone or JPEG alone. JPEG files are compressed into smaller sizes for easy sharing in email and on the web. JPEG’s can be shared right after you take them out of the camera. They can also be further processed but this becomes somewhat destructive as the camera has already compressed the file removing large bits of data that you can no longer manipulate. In working with JPEG’s you are stuck with the compressed image the camera made for you.
    • JPEG files are ideal when…..
      • You want to share processed RAW images to the web.
      • You want to quickly get previews of images to someone.
      • You want a good quality image with a smaller file size.
    • Don’t use JPEG files when…..
      • You want to preserve the layers you have created with Photoshop for later editing.
      • You need to display an image that has transparency. JPEG’s require a solid background color. By default most software will display transparent pixels as white.
  • PSD: Photoshop has its own file type for saving images while preserving layers and adjustments you have made. These files can become really large depending on how much work you have done to your image in Photoshop. This file type keeps your image fully editable when opening it back up in Photoshop. However, it will need to be converted to a different file type once you decide to share it. Some labs will accept PSD files for printing but most will ask for an alternative file type.
    • PSD files are ideal when…..
      • You are editing an image.
      • You want to save an image with all of its layers, transparencies and adjustments for future adjustments.
      • Creating multiple adjustments in layers that can be turned on/off for comparison.
    • Don’t use PSD files when…..
      • You are ready to print or upload your images to the web. Note: Some labs will accept PSD files for print.

 

  • PNG: It stands for Portable Network Graphics. For me this is classified as a fancy JPEG. Similar to JPEG, these files are web friendly and easily recognized across most software. The upside is the ability to preserve transparency when displaying images on a webpage. They also have greater color depth for more vibrant images. However, with more info you take up more space. PNG files will be larger than JPEGs and should only be used when you need to display transparency.
    • PNG files are ideal when…..
      • You want to display transparency in an image on the web.
    • Don’t use PNG files when…..
      • You don’t have any transparency. This should be the case with your photos 99% of the time unless you are doing some fancy stuff.

 

  • TIFF: It stands for Tagged-Image File Format. I would classify this as a step up from a PNG. They share a lot of the same qualities but they really shine for print. TIFFs are compatible with most software but not as universally accepted as JPEGs & PNGs. One of the major benefits over PNG is the ability to preserve transparency including alpha channels. Alpha channels are the amount of transparency for a specific image. The downside to this file type is the size. Preserving the highest quality and data comes at a cost in hard drive space.
    • TIFF files are ideal when…..
      • You want to save the best quality, layers and details in your images.
      • You want to print super high quality photos.
    • Don’t use TIFF files when…..
      • You are uploading images to the web.
Now that you are an expert on file types be sure to choose wisely to optimize space on your hard drive and the viewing pleasure of your audience. My suggestion, start with RAW in camera. Process the RAW file and convert images for web sharing into JPEGs and images for high quality prints into TIFFs. PNGs should only be used for graphics or when you need to display some transparency in an image on the web.
-Jack

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