Beginner question - filters

[zendog]

I'm just about to order a filter for a Tamron SP AF 10 - 24mm F/ 3.5 - 4.5 Dill.

Specifically this one http://www.amazon.co.uk/Hoya-Digita...9&sr=8-2&keywords=polarising+filter+77mm+slim

This is my first filter ever!

On the lens box it says "Filter size o77mm". What does the o mean and have I got the right size? I'm thinking there might be different thread pitches or something other than just the 77mm diameter.

Cheers
Steve

 

[JT74]

It's the filter diameter. The lens should have the diameter indicated on the edge.

Edit: This Ø means diameter.

 

[Digitalize]

I means nothing, or it might mean circumference. But you only need to worry about the 77.

 

[zendog]

Thanks - I shall buy with confidence

 

[st599]

I means nothing, or it might mean circumference. But you only need to worry about the 77.

The slashed circle is diameter. It definitely isn't circumference.

 

[AshleyC]

the lens cap also has the size printed on the inside

 

[Digitalize]

The slashed circle is diameter. It definitely isn't circumference.

I knew someone was going to come correct me!