Why target frame rate either 60 or 30, how about 50?

We are making a iOS game, it is an action game so we want to get a higher FPS, but now we can hardly to get 60 fps, to keep the graphics quality, we should can get 50 fps, so here is the question, we can see games with frame rate 30, or 60, but there is no 40, 50 etc. For traditional screen monitor, i know it is because the frame rate of the monitor, but for iPad/iPhone, is it the same? Can i just targeting constant 50 fps? If i do, is there any bad issue will come out? Thanks very much!

iOS devices are always vsynced, so your choices are 30 or 60. (Or 15, but that’s kinda low.)

Application.targetFrameRate = 50;

I dont think this will have an issue… its simply asking the application not to render more than 50 FPS (if it can reach 50 FPS)…

most iOS devices can support max of 60 FPS but it really depends on what you are rendering and running in your game.

==EDIT==
As Eric pointed out… vsync in iOS is always active so we can only target frame rate can only be (15, 30 and 60)

Only downside would be, you will drain the battery of the device faster because you are capping the framerate at a higher value which let’s the device to render more frames in a second which equals more processing power and less battery life.