iMac displays: can a 'modern…' 24" model drive an 'ancient…' 27" screen?

Thanks Den and I'm sorry to seem pedantic but let's remember, this is a very expensive purchase…

That being so, when 'everything including the connections are different…' does that clearly mean the screen connection can't work, or 'merely…' that all the other connections are different?

Thanks and duh!

Technically no, of course a 24" picture magnified to fill a 27" screen would be exactly that and your measure of quality would be irrelevant. In what kind of arithmetic does 24 equal 27?

Please don't patronise people like me with stuff 'If you connect a 27" external display to a 24" iMac…' or suggest that Change your Mac display’s resolution - Apple Support might help in this case.

Sorry to be so blunt, but 'If you use a 27" external display, you get a 27" picture…' is on your hand as childishly, patronisingly obvious as it is irrelevant but on my hand useless; rubbish.

The only point here is 'resolution…' . People with different interests have different ideas of what 'resolution…' means and the worst possible interpretation would be 'If you use a 27" external display, you get a 27" picture…'

You seem not to mind but 'resolution…' might refer to what was specified in a document or to the default, minimum or maximum output of the computer, or to the default, minimum or maximum output of the screen - or, come to that, printer.

If you meant '27" displays are available with maximum resolutions of 1920x1080, 2560x1440, 3840x2160, and 5120x2880, why not say that?

My iMac's 27" display does offer your 2560 x 1440 but not 1920 x 1080, 2560 x 1440, 3840 x 2160. Does that say anything about your assertion?

My iMac's 27" display does offer 1280 X 720, 1600 x 900, 2048 x 1152 and again, what does that say about your assertion?

Did you really not notice, choosing any resolution giving oversized text and objects with coarse detail, and only the amount of workspace typical of a 24" monitor is not an Answer… it's another way of phrasing the Question?

Your supposition that a 27" 1920x1080 display might have a 24" picture magnified to fill a 27" screen would still be a 27" picture – just a lower-quality one than other monitors might have delivered - is also no Answer… merely another way of phrasing the Question?

If you really need it put so simply, will you Post the maximum output 'resolution…' of any 24" iMac?

No, it's you who makes no sense.

Even in proper English, every school-child should understand 'If the physical dimensions of the display are 27", you get an image that is 27" in diagonal size…'

Will you say why it's difficult to accept, that's as irrelevant as it is true?

Will you say whether, on your scale of 24 - 27 - any 24" iMac can put out a picture of the same scale or resolution, and fill a 27" screen?

Do you really need diagrams to show the difference?

Thanks and perhaps I should have put it more simply.

Assuming System Preferences on the latest OS uses the same terminology as my 10.13.6 High Sierra, what Resolution Scales should be available on a late-model 24" iMac?

I'd like to have Posted a screenshot, but the site doesn't want to accept any format I can make.

Will anyone tell me what picture formats this site accepts?

Thanks and I know you're right but no, I'm not looking for any external screen unless there's no other choice.

Thanks and that sounds so reasonable, it might be my best option but unless there's no other choice, I'm not looking for any external screen

Thanks and could you make the technicalities at least as clear as your opinion of the outcome?

You could be wholly correct yet d'you really believe the phrasing you chose was helpful?

Thanks, den.thed

Sadly, I saw nothing in those links, nor their further links, to suggest whether I'd get a 27" picture, or a 24" picture magnified to fill a 27" screen.

Will you clarify?