frebe

Hey Oufti, that is really very helpful, thanks! Learning a lot on here 😁

Thanks for your solid input Alfred - helped me to get my brain into gear😂

So I have learned ! - I think I’ve got the hang of it now 😂 Basically, I don’t want to resample until I have to change the image dimensions for printing, so that’s my workflow! 😅

Ok, so I figured I was missing something and found an Affinity video that explains the document resize dialog more clearly. It's actually simpler than the photoshop process but not intuitive if you don't realise that you can change the unit type with resample unchecked (because they are greyed out when default unit size is pixels. So, the process is still 2 step: 1. To increase dpi to 300 - Open document resize dialog, uncheck resample, change dpi to 300, and save. (if you change units to other than pixels, you can see that the dimensions ARE linked to dpi- ie, dimensions get smaller as you increase dpi - hooray! Pixel dimensions don't change (which also confused me- someone could explain it, but I just need a simple workflow!) 2. To change image dimensions (downsize only) - reopen document resize dialog, check resample, change dimensions, save. Or, just export in required dimensions. This is actually an easier workflow! Sorry, if this is simple and obvious! But anyone else who gets confused like me by the different dialog menu might find it useful. Here is the Affinity video: https://www.youtube.com/watch?v=KTmM8hw2r_M

Again, that is correct, but you (meaning me😂) can’t calculate this easily in the Document Resize dialog box. Being able to view the file size in the dialog makes it quick and easy to reduce the dimensions to fit the higher dpi without calculating. File size(bytes) is a product of dpi x dimensions, as I’m sure you know, so file size is a good indicator that you are not adding data. Another option for the Document Resize dialog would be to enable changing the dpi with an option to automatically reduce the dimensions to maintain the same file size, but currently the dialog only allows you to change both separately, they are not linked. I am crap at calculating but if you explain your formula maybe I could do it that way! 😁 (300dpi is specific to print technology. 360dpi is not, so it has to be 300dpi , or occasionally 400 or 600dpi for highly detailed or colour critical images)

Hey Alfred, you are correct. You can’t INCREASE the resolution AND image dimensions of your original file for print production. We only ever reduce dimensions in order to increase dpi as I described. That is why we need to see the file size in the resize dialog to use as a guide to how much or little data we are adding to the file. For basic photos, saved as 72dpi jpegs, the process I have described is how we change the dpi to 300 without resampling too much- You always have to REDUCE the dimensions to increase the dpi. 300dpi is the requirement for high resolution quality printing of photos and raster images. We need to set exact dimensions of the final printed output at 300dpi. if the original photo is too small (ie total bytes) there is nothing we can do with it - it will be pixelated if we enlarge it in the printed output. Photos produced on professional cameras are very high resolution so we can reduce the dpi and the dimensions to suit. But you can never increase dpi AND dimensions without adding more pixels, and thus, distortion and noise, as you say. I hope that makes sense - you are absolutely right - This is actually hard to explain in words😂

I am a print designer too and file size ie. bytes on disk (NOT dimensions) is critical to resizing images for print without resampling too much - which changes the image. The process I use to size an image for print is: - change the dpi to 300 (print optimal) and, in the same step, adjust the image dimensions until file size (bytes, MB etc) is as close as possible to the original file size. If you don't do this you are adding or removing data which you want to avoid. This is why file size is useful in the document resize dialog so that you can make sure you are not adding too much resampled data. - Then you can make your image smaller or crop to requirements. This is always done in a separate step once you have the dpi set with same file size. If you change dimensions and dpi together you have less control over image quality. - It would be really useful if Affinity included the original file size and new file size in the Document resize dialog for print designers! PS If anyone know a better way to to change dpi without resampling too much I'd love to know - this is what I was taught