My r8 won’t take a picture

[Asher5]

Mf light in view finder is blinking and won’t let me take a picture 

[Waddizzle]

I assume that you mean “MF” is flashing?  Those two letters usually stand for “Manual Focus.”

Blinking and Flashing icons in the viewfinder is how the camera calls for help.  I would guess that the camera needs/wants you to change the setting of the “MF” switch on the lens or camera body.

[EDIT] Having the camera/lens set for manual focus should not prevent the camera from taking a photo.  Being too close to a subject, or insufficient light may prevent the camera from taking a photo.

[Asher5]

I have it turned on to Manual Focus but it still won’t take a picture 

[Waddizzle]

We do not know and cannot see what you are doing.  Help someone to help you.

What are you trying to photograph?  Will [it] take a photo with the top dial set to Green [A+]?