I own a macbook pro 17" late 2011 which has a 1920×1200 display with a pixel density of 132 ppi. Yesterday I tried hooking up the display to an Apple Thunderbolt Display, and to my great disappointment a window, when split across the two screens, was larger in the external Apple display than on the internal screen, due to the difference in the pixel density. I own a 24" HD display, and there I also notice the same issue.
I've spent some time researching, and I haven't been able to identify a potential candidate screen that has a display with comparable pixel density, and finally, size.
I see that some have suggested (in other questions) to lower the resolution on the internal screen, but that is, in my opinion, defeating the purpose of purchasing such a laptop and I would never consider such an idea.
Who can suggest displays, by any manufacturer, make and model, that are a good match as an external display for my MBP? The only condition I pose is that the display's resolution should be greater than the Macbook Pro's internal display resolution, as I see no advantage in using a second smaller screen.
Best Answer
Unfortunately I think you're out of luck. The LCD panels that get put into computer displays are made by a relatively small number of companies. For various reasons (but primarily economies of scale) the manufacturers have settled onto a relatively small number of different panel sizes and resolutions (particularly at large resolutions), so it's pretty tough, if not impossible, to match pixel densities across different displays.
For resolutions higher than your MBP (1920x1200), there are really only two options on the market today:
Even if you go for a resolution around the same size as your MBP (1920x1200 or x1080), you can't get a similar density, as that resolution is typically only used in 21" - 24" external displays, resulting in PPI between 94 and 105.
The one device out there that does have a PPI close to your MBP is the non-retina iPad, which is pretty close to 132 PPI, but obviously you're giving up size and resolution there.
The next likely bump in resolution for desktop displays is probably going to be 3840x2160, which is 147 PPI in a 30" display, so still not that close.
You may find this page on Wikipedia informative.