Close up filters. Need help

looking for 55mm close up filters for my Leica 50mm f/2, can do 2:1 or 1:1 macro shot. looked at B&H, they have several 55mm Close-up filters available.

what confused me is the how to determine I need +1, +2, +3 or any combination of them.

B&H's description didn't help me, see below:

• The maximum magnification achieved with these attachments will depend on the focal length of your lens as well as the actual close focusing capability of that particular lens

• A +1 close-up lens will allow you to focus your lens somewhat closer than it already does; A +2 close-up lens will allow you to focus closer than the +1; A +3 lens will allow you to focus even closer than a +2

• A +1 combined with a +2 will equal a +3, while a +2 combined with a +3 will equal a +5, and so on
... ...


anybody can give me a clear idea how to calculate what combination I need based on lens focal length? is there any formula available? i.e. 50mm lens need +3 can do 1:1, 35mm lens need +4 can do 2:1, etc?

scroll down a little, you'll see a section on close up lenses:
http://photonius.wikis​paces.com/Close-up+%26+Macro

I know there are a lot of cheap knockoffs, I would avoid those. I have a Canon 500d which works great. The Canon 250D also has a excellent reviews and would be appropriate for a 50mm.

WOW! Thank you so much, melvinudawl

On a 50 mm you need about a +20. Basically, you need a close-up lens the same power as your prime lens to get 1:1. Close-up lenses are measured in diopters, which = 1000/focal length.

i did realize that after reading melvinudawl's URL. dream broken.

buy a second hand macro is the way to go i guess

Single-element close up filters are inferior to the double-element close up filters offered by Canon.

But close up filters were designed for cameras that have permanently mounted lenses, and there is some degradation to IQ caused by the filter. For cameras with interchangeable lenses, it is better to use extension tubes.