Thank you for helping i have a 50mm f/1.4 and thinking of buying 85mm f/1.8 would either of these be good for macro is so would you recommend the 50mm or the 85?
I'd recommend you use the magnification calculator at http://www.mystd.de/album/calculator/
. You'll need the sensor size of your camera, focal length of the lens, extension tube size. Plug those in, hit calculate, and it'll give you the magnification. 1 is 1:1 (or 100%), while >1 is more larger than life, and less than 1 is smaller than life.
Based on the specs of the 50 1.4 and 85 1.8, the 50 1.4 would be better as you get a higher magnification. But it's still not great, only 0.39x or 1:2.6 with 12mm extension tube on FF 35mm sensor. The 50mm Compact Macro is actually cheaper than the 85 1.8, gives you 0.5x out of the box and with 12mm extension tube gives you 0.71x magnification which is getting a lot closer to true macro (1:1).
If you get an extension tube set, you can generally stack then (although you get accompanying light loss from any extension tube), which means you can probably start with just the tube set, use your current 50 1.4, start figuring out best practices and how it works for you (don't forget a reasonably sturdy tripod, mirror lock up, remote shutter release). Once you have the basic technique down, start looking to see if you want to invest in a better lens, or better mounting/tripod system, bellows, etc.