Close-up filters

Hi

I would like to know what the effects are of a close-up filter one the focusing range of a lens.

Naturally it will cut down how close the lens can be to a subject and still acquire focus, but does one loose the ability to then focus on subjects further away from the lens?

If so how drastic is this loss?

Lastly, does close-up filters have a magnifying effect or narrows the field of view of a lens down when used?

Thank you.

Geo

Hi

 

I would like to know what the effects are of a close-up filter one the focusing range of a lens.

Naturally it will cut down how close the lens can be to a subject and still acquire focus, but does one loose the ability to then focus on subjects further away from the lens?

 

If so how drastic is this loss?

 

Lastly, does close-up filters have a magnifying effect or narrows the field of view of a lens down when used?

 

Thank you.

Geo

For a good explanation of this see

http://scubageek.com/articles/wwwdiop.html

and the other articles that explain all you want to know about underwater optics.

In general with a diopter on your lens infinity focus becomes equal to the reciprocal of the strength of the diopter.

Bill

Thank you Bill!