Ray diagrams for mirror ray tracing

[RickyWong]

Just a check here...

I'm doing some ray diagram practice for optics and I've hit a road block. Hyperphysics is stating that for a concave mirror o is usually negative due to it measured against the direction of light propagation when applied to the mirror equation (below).

$$\frac{1}{o}$$+$$\frac{1}{i}$$=$$\frac{1}{f}$$

But Hecht, says that if it is a real object to the left of the mirror, it should be positive (which incidentally gives me the correct answer to a question I'm attempting)

Is Hyperphysics wrong? or have I misinterpreted it?

here's the link:
http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/mirray.html#c4

 

[vela]

I agree with you: Hyperphysics is wrong.

 

[RickyWong]

I agree with you: Hyperphysics is wrong.

Thank you.