Ok, let's plug the desktop screen into your laptop and calibrate that. If it calibrates successfully, we'll at least know that the calibrator is still ok, and works ok with the Mac OS.
Hi Brenda, take a look at the troubleshooting section at the bottom of the Spyder 5 Pro instructions. They're not identical, but should give you some clues to try. Let me know if anything helps.
How long have you had both the calibrator and the laptop?
It doesn't matter. It absolutely does.not.matter. Your master files can be 300, 240, 72, 89, 426, 138265, 9, etc. It's completely irrelevant.
It only matters when sharpening for print, and you'll learn about that in the Sharpening Class.
Excellent.
So yes, do exactly what they say. Give them a Level 11 quality Jpeg file, make sure the resolution is 300ppi, but make NO change to the image size. Send them the full-res file that you camera took.
Oh yeah, very vague. Unfortunately, quite common.
Do you know if the banner is ONLY going to be your photo? Or will it be part of a design of some sort?
Oh boy, these aren't easy.
This is the method you need to use: https://www.damiensymonds.net/preventing-banding-in-backdrops/
Does this look satisfactory?