Advice Please, How to use my Imac retina, 4k, 21,5 (late 2015) as monitor for my Macbook pro 15" (late 2015)

[UncleM]

Hi Guys

I recently receive a iMac 21,5 Retina 4k, late 2015 (Monterey) and a Macbook pro 15" retina,(Quad-Core Intel Core i7, 16 GB memory) late 2015 from my dad, (he upgraded to the new Mac's)

I cannot see or find any advice on if its possible to use the iMac as a second monitor. Can I use a Mini display port male to male cable, or a HDMI ame to a mini display port male cable?

Will one of these cable do the trick? The iMac is running Monterey and the Macbook pro still on Catelina.

I can duplicate my macbook onto the imac, but I would like to have it as a second monitor.

I can add as well,I don't need the sound to work. I want the Imac to display remote connection pages while I'm busy with spreadsheets on the macbook, or maybe have 2 financial systems connected, (like SAP on the iMac and Oracle on the macbook pro)

Thank you for any advice

kind regards

 

[arw]

There is no cable based solution. Older iMacs once supported Target Display Mode.
The only cable based solution I can think of, is to completely strip the iMac of its motherboard etc and connect the panel to a driver board which then has an HDMI/DP input. Quite brutal for a device from 2015.

EDIT: ignore the info below, AirPlay to Mac is only "Available on MacBook Pro (2018 and later), MacBook Air (2018 and later), iMac (2019 and later), iMac Pro (2017), Mac mini (2020 and later), Mac Pro (2019)".

AirPlay to Mac should be configurable to behave like a separate external display for your MacBook. But the image data is compressed and can therefore display artifacts/lag when content is changing rapidly. Although for your use case it should be perfectly fine.
From the Monterey feature list:

AirPlay content to your Mac​

Use AirPlay to send content to your Mac from an iPhone, iPad, or even another Mac. View videos, edit Keynote presentations, and hear music on your Mac as it’s being played from your other device. Your Mac works with any Apple device, and it’s even easier to connect if the devices share the same Apple ID.

MacRumors: Newer Macs Can Use Another Mac as an External Display on macOS Monterey

 

[UncleM]

Hi, thank you. the 2015 imac is in prestine condition, maybe I will look at a monitor to get the split view.

Any recommendation for a screen please, also in the 22" range that give brilliant colors? I dont have space for a 32"

kind regards

 

[UncleM]

Hi

Can you please recommend one of these?

Dell SE2222H 22" Full HD 1920 x 1080 LED Monitor / Vivid viewing / Supports VGA/HDMI (the cheaper of the 2)

Dell 24" Monitor - SE2422H 24 5ms (gtg), VA (Vertical Alignment), Full HD (1920 x 1080), 60 Hz (VGA) / 75 Hz (HDMI), Monitor Connectivity: VGA, HDMI 1.4, AMD FreeSync

thanks

​

 

[arw]

Sorry, I can't recommend a specific monitor but just two things to consider:
- Are you sure you want to go back to Full HD when you are used to 4K on your iMac and to your MacBooks Retina display?
- In case of a 4K display, make sure you use a Thunderbolt 2 to DisplayPort connection as HDMI on your MacBook is limited to 30 Hz (instead of 60).