Screw In Close Up Lenses... Thoughts?

Thanks to you Gentlemen for your practical comments. I've learnt that there is a law of diminishing returns - so typical when adding reciprocal values (resistors-in-parallel, vaguely remembered) and I've learned that a spade can be called a shovel if used as such ;-).

I regularly use a screw-on attachment on my 100/2.8 macro. With that and a 12mm tube I find I can work in the magnification range I like ie a bit either side of 1:1 but more towards the 2:1 area.

The reason for using the "filter" is that it's easy to remove if needs be, even with the macro flash attached, whereas changing a tube is a right PITA.

I have the good quality Canon version, it does look soft through the viewfinder but at f16 the results are just fine.

I am glad you put filter in commas Bob becuase it is not a filter but a lens ... not sure if this is a shovel or spade description but a lens adjusts the focus and a filter adjusts the colour

That's true, they are different as are shovels and spades :)

It's pretty common to call them filters I think, not right but common none the less. So I put 2 bob each way by quoting the word.