iMac or MBA for show on large screen

[dbolt]

I'm concerned about the quality of high resolution photos displayed on a fairly large screen (~12 x 24').  For small screens and small rooms, I show P2E slideshows with a Macbook Air with a maximum display of 1440 x 900 px.  My wife has an iMac with maximum display of 3200 x 1800 px.  I've been told the projector in the auditorium will display up to 2K, but not 4K.  I also have the option of plugging my slideshow on a thumb drive directly into the digital projector.  The downsize of the later solution is their flaky handheld remote and/or remote operator (I don't want to shout, "Next" for each slide).  Testing on site is possible, but not convenient.  My question has to do with quality of my images on the screen.  Which approach should I use for the presentation?  I'd also be interested in your reasoning for your recommendation, eg. what are the important factors affecting quality of photos projected on a large screen, how much deterioration in image quality occurs when images in P2E have a much larger pixel dimension than the digital projector used for the presentation, etc.

[davegee]

Depending on your graphics card, your MBA "might" support the hd resolution of the projector but the mba screen would be disabled. You can only check it by trying it out.

If you connect the output of the mba to a hd monitor it would give a good indication of what is possible. Most pc laptops that I have had are capable of outputting at a higher resolution than their display resolution.

You would need to be able to patch the output with a lead with a HDMI connector on the remote end.

One of the Mac users here might offer more advice along these lines.

DG

P.S. Your images only need to be the same resolution as your output device i.e. The projector plus any allowances for zooming etc but you should pay little or no penalty if they are bigger other than putting unnecessary strain on the processor.

[dbolt]

Good to know, Dave.  Thanks.  The facility does supply a HDMI cable at speakers stand.

I generally keep the MBA screen set to on during a presentation.  Maybe I should try with it set to off and see if the image quality is better.  About all having the MBA screen on does for me is to remind me how poorly the digital projector and the MBA agree in color management.  When I can create  profile for the the MBA using the specific digital projector, color differences are generally acceptably close.  Not so much without an ICC for the specific projector.  Not sure If I'll have time and the opportunity to profile the projector for the presentation in question.  My images all have sRGB color profile embedded.   Setting the projector to sRGS usually projects an acceptable image, especially if one doesn't compare it to the image on the MAB, which is calibrated.