EL-Nikkor 40mm?? how is it? for what is it?

Can i substitute my focotar 40mm by one of these???

Thanks

Dear ruilourosa,

I use mine for what I would call really big enlargements. The highest magnification (I hope that is the right term) I've attempted was a 35mm negative enlarged a bit over 38 times and cropped to an 16 x20 sheet of paper. It worked quite well.

Neal Wydra