infra red filter, what size and what brand?

[Kho King]

I am thinking of getting an infra red filter, but I am totally blur and new in this. So, need some advice:

1. what brand to buy?
2. what size available? My lenses are 77mm and 72mm and 52mm...
3. are there any variant? different model? different intensity? which one should I get?
4. What's the price that we are talking here?
5. which shop to buy from in Singapore?

thanks.

 

[RossChang]

I'll probably be getting a Hoya R72, 77mm thread somewhere around this week... wanna buy together to get more discount?...

you could probably ask around for what variants in the IR/UV sub-forum