02. Understanding digital Images

Throughout this chapter you will fully understand the different types of image files, Karl explains what each type is and when each image type is best used including PSB, PSD, JPEG, TIFF And RAW. Plus he’ll explain in more detail about Resolution, Bit Depth, Color Profiles and Color Modes.


  1. Like to know how we can convert on 16 bit files if we have 8-bit raw files using Photoshop/Lightroom. Is there such option available in PS/LR and whats the drawback if we do so? Will there be any degradation of quality when we convert 8-bit file to 16-bit file in Photoshop/LR while we edit? If we are doing composite using the mix of 8 bit and 16-bit files, will there be a seamless merging of end result or we see some differential artifacts in the end result.

    1. Hi Melvin, my first question is why aren’t you able to generate 16bit files out of the raw software in the first place? My normal process is to grade the RAW file in Phocus or LR and then export the RAW file as a 16bit tiff and then I start any necessary photoshop work. If you only have 8bit images then you will still be better to convert them to 16bit before you start photoshop work.

      1. Hi Karl, I get the same, I shoot with a Canon 70D and my raw file is only 8 bit, is that something to do with the camera that we are shooting with? is there a setting that we can change on the camera? How important is to get to 16 bit instead of 8, is the quality of the image really compromised?. Thanks
        Very happy I joined the course btw, it’s great!

        1. Hi Leonor, you would have to check in your camera menu settings, it might be able to achieve 12bit but that would be in the settings. If it only shoots in 8bit convert the image to 16bit when you export the digital file and before you do any post production/retouching work, it will help you with hight quality during the post production stage.

  2. Hi Karl
    Just to say I think these tutorials are brilliant. I have been on various workshops over the years and have mostly switched off after a few minutes of techi stuff! But for me this is at the right pace and it’s sinking in! Well don’t test me on it!
    So well done.
    I have most of your dvd’s which I purchased several years ago and they were brilliant, but now having access to them on your tutorial site is so valuable to

  3. Hi Karl I have most of your DVD’s too you have made an photographer out of me tho the years. Justr an Question as I have moved to light room as photoshop bridge is not to good. well that what I think lol. I use lightroom but do I loss info from moreing from lightroom to photoshop then move back to light room. or is there and eazy way.

    2ed Question is is there a way to do 3D gray scale relief for carving with photoshop its for a friend to see if we can and how we find more info on.

  4. Hi Karl,
    This bits of information has really helped me to have an extensive knowledge on my images.
    One of the challenges I had with my images was that,prior to this tutorial, I discovered that I usually have a lots of changes in colour spacing which usually affect my images ezpecially when clients view my images through their phones.
    After I followed this wonderful tutorial, I discovered I have not been applying any of the information I got from this tutorial.
    Many Thanks
    Oluwatobiloba Amusan

  5. Hi, Karl,

    What are your thoughts of using AI/neural network upscaling where there’s not enough image data to hit the resolution mark or for extra sharpness? These sorts of upscalers don’t just use bicubic upsampling or sharpening like Photoshop would, but actually analyze the image data and retain sharp details and lines upon upscale – basically a much better job than Photoshop could do. I always turn to them for lower-res assets at work.
    I was wondering if you ever used anything like this and what your thoughts are, if any.

    1. Hi Rimantas, I’d only read an article about this I think on the BBC technology page a few weeks ago and whilst the results were impressive they were still plenty of artefacts and problems with the upscaled images. Also the examples shown were of images taken from very very low resolution so it would be interesting to see what it could do with say a regular 12 or 18mp image. I’ll be honest with you though it doesn’t appear that this solution will oust the capabilities of say a 100mp Hasselblad as the data is not there then it’s just a computer/AI making a guess, which is never as good as having all the facts in the first place.

      1. Thanks for the reply, Karl. I was wondering that because not all of us have access to 100+ Mpix Hassies and maybe a 30Mpix image could be upscaled to push it juuust a hair towards an acceprable print in certain scenarios.
        While there definitely are artifacts typical with upscaling, I’ve at least come to rely on such upscalers to keep the lines sharp, something PS does not yet do well, even with the latest upscaler of theirs. Though I’m sure you won’t need anything like that with your files! 🙂

  6. in this video, you explained how CMYK is simply there so you can look at what the printed result will be. You mentioned that you shoot in RGB and edit in RGB and sent it to the print lab and the lab will convert the image from RGB to CMYK……my question is (please keep in mind yesterday was the 1st day I have ever even OPENED photoshop!)… Does converting from RGB to CMYK, have a significant visual difference? I guess I’m wondering if after I edit, and before I print, if I should convert to CMYK myself to see any differences? I hope that question made sense (it did in my head, but not sure how to convey what I’m thinking) 🙂 thanks!!!

    1. Hi Ashley, yes converting from RGB to CMYK in photoshop will result in noticeable differences but these are usually only perceptual in relation to lithographic printing on printing presses and the simulations in photoshop are designed for that purpose to simulate for designers what will happen in say a brochure. However in photographic lab inkjet or RA4 process printing things are somewhat different as the type of inks used are much more vibrant and often instead of a 4 ink process they use a 6 and sometimes 9 ink process, resulting in images far more vivid than those of a litho process. It is also worth mentioning that the choice of paper from a photolab has a large influence on the final appearance, contrast and vibrance. My suggestion is not to convert to CMYK, use a calibrated high quality monitor and find a professional lab that you can trust and run tests on various stocks of paper to establish what suits best the type of work you hope to produce. All the best Karl.

  7. Hi Karl, to what color space would you suggest setting the camera to, sRGB or Adobe RGB? What is the difference?

    1. Hi Giovanni, I’d go with Adobe RGB as it is a large color space and then continue to work on the image in Photoshop in Adobe RGB and then convert to SRGB if you are sending the image to the web or digital media/video etc. For print with good labs you can leave the image in Adobe RGB and let the labs RIP convert the image. If you are shooting for magazine then the final conversion will be to CMYK and this is better from Adobe RGB too.

  8. Hi Karl, at last I understand pixels and resolution, the difference and most importantly, how to use them for different purposes. You explain them so well. Thanks a mil…!!!


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