Understanding Digital Images

If you’ve ever wondered what the difference is between a TIFF and PSD file, what 16-bit means or which color mode is best for printing images, then this is the photography class for you.

Before looking at the Photoshop interface and main features and controls, it’s important to understand each of these concepts and how they affect your images. Understanding all of this may seem overwhelming at first, but in this photography class Karl explains each concept clearly.

Here he provides detailed explanations of different file types, resolution, bit depth, color profiles and color modes, outlining all you need to know about digital images.

In this photography class we cover the following:

  • Image file formats: Types of digital files


  • Pixels & resolution
  • Bit depth
  • Colour space & colour profiles
  • The difference between RGB and CMYK
  • Recommended colour modes for printed images
  • Resizing images

If you have any questions about this course please post in the comments section below ?


  1. Nigel

    Karl, I’ve often seen you “Neutralise” the colours in an image in Phocus by clicking on a feature and then clicking on a certain area of the subject. What exactly is this? Is it just ‘White Balancing”? Can you tell me what it is you are clicking on etc so I can figure out how to do this in Capture One.

  2. Hi Karl, many thanks for your insight! In order to get the best quality, can I shoot in TIF format instead of RAW? Or is it best to always shoot in RAW and then convert to TIF? (If RAW is the best way to go, what software should I use to convert RAW files to TIF files?) Thank you so much!

    1. Hi Nic, always shoot in RAW and then convert to either Tif or PSD in 16bit. You can use various software for handling the RAW files depending on whether you want to shoot tethered or not and which camera you are using. For example a good tethering/RAW software is Capture One but you can also use Lightroom to shoot tethered and handle RAW. Photoshop can also handle most RAW files and you process them in Photoshop Camera Raw and then can export them as 16bit PSDs to continue working on them in PS. You can (if necessary) convert them to a smart object and leave them as RAW files while you work on them in PS (we have a class on that somewhere) but I find this a bit unnecessary.

    1. First props to how you explain things…i am learning a ton. One thing i need clarifying on is when i first put a raw file in PS…do i go ahead and put it in PSD..and 16 bit for editing, then begin my editing? Thank you

      1. Hi, yes once you have made your adjustments to your raw file then export the RAW file as a PSD or Tiff in 16bit and then open in PS.

  3. Hi Karl,

    What should the width and height of a picture be for screen and printing or does it depend on how you cropped it?

    1. Hi Maryke, it depends on the size of the screen print you are having made. For the very biggest prints for your wall then of course you want to provide the printer with the full resolution file or even consider increasing the resolution of the image by using Topaz Gigapixel or Photoshop’s Super Resolution feature, this is only necessary with exceptionally large prints (a few meters across) but can help with moderate size prints too.

  4. Hi Karl,

    I’m used to working with raw files in Lightroom, but am now keen in getting started with Photoshop. Just get into terms on how that will affect my workflow, what is the main advantage on working with tiff vs raw in photoshop?


    1. Hi Paulo, you can actually work with RAW files with Camera RAW in PS too. And it is also possible to continue to work with the file as a ‘Smart Object’ which basically means the layer will link back to the RAW file if you need to update something. However this process (we have a class on it) is somewhat convoluted and once you done you main RAW adjustments in Camera RAW or LR it’s usually easier to convert it to a PSD or Tiff in 16bit and then you have almost as much information as a RAW file anyway but with an easier way to control lots of layers and speed up the workflow. I’d suggest you follow the process in my course first and then when you’re familiar with Photoshop then look into ‘Smart Objects’.

  5. Hi Karl, I have always wondered why all my photos look different in terms of color in different devices. It’s like after I edit a specific photo on my laptop and I send it to someone else and if they are seeing that same photo on an iphone then the colors seem more raw/less bright. The colors aren’t bright at all when compared with the same image on a samsung phone. Right now I just checked by uploading a photo in photoshop and the default color profile setting is on sRGB IEC61996-2.1. Could it be possible that the reason for which different devices show different color be due to that fact that I haven’t set my color profile to Adobe RGB(1998)?. To be honest I never really knew about the color profiles up until this moment. Thanks a lot for your tutorials. It’s really helping me a lot to progress my knowledge in photography as well as in post production.

    1. Hi Niks, that will be part of the reason but the most common reason is simply that all devices/screens yield different results, viewing conditions, ambient brightness, time of day, type of screen etc. The best we can ever do is use proper calibrated screens and good colour management procedures and then hope that everyone else’s screens aren’t too far from the industry benchmark. I spend a huge amount of time using all the correct procedures and then shiver sometimes when I see someone viewing my website on a phone with the brightness on zero!

  6. Hi Karl! I have a MacBook Pro. What’s the proper Color Calibration for my screen? how would I know what’s good and what’s not?

    1. Hi Malex, there can unfortunately never be a proper calibration on that type of screen simply because they are not capable of producing all of the colours accurately because of the type of display technology they use. That being said they are still very good for laptop screens and if you use a calibrator such as an Xrite then you will benefit but for absolute colour critical work you would need to consider buying a second screen that you can plug into your macbook which can be properly calibrated.

Leave a Comment