Hi all, I'm looking for an external monitor for my 15inch mbpr (late 2013) specs - i7, 16gb ram and 512ssd.

My preference is somewhere between 24-27inch monitor which I will mainly use for photo/video editing. Can sifus here recommend me a good monitor to pair with my mbpr?

Secondly, I have a concern if I connect the monitor directly, will it cause any performance drop like lagging issue etc?

i have one of these in my office
https://pcmonitors.info/reviews/dell-up2716d/

Did u pair it with a mbpr?

nope, with Mac Pro

For photo and video editing, I would recommend at least a 27" monitor that has higher resolution than HD, a 4K monitor if you can afford otherwise then another lower spec model. It has to have an IPS panel with a high Adobe RGB % rate for the monitor.

Personally, I also prefer if it didn't have a glossy screen so I would choose a matte screen.

Dell Ultrasharp Monitors are a good choice
http://www.dell.com/il/en/p/dell-up2716d-m...d?flyingspaghettimonster=PD_Family

This article might help you as well.
http://www.144hzmonitors.com/best-photo-editing-monitor/