Hold them both at arms length from an object. (both at the same distance to an object). The one that give a bigger magnification is the 220mm FL, the smaller magnification is the 650mm FL.

This is also covered in the pro wiki guide... see it here...

cheers,
gs

Can i Use a brand new swiss army knife to cut lenses??

Alex..

You can, but I would not. Many of the tips on my utility knife get broken when cutting the lenses... I woudn't want to risk it on a nice knive. Get a cheap utility knife from the hardware store... it works well... if you really want to be meticulous, you can use a new blade for each cut.

cheers,
gs

edit: sorry, didn't see you were from Venezuela... a Hardware store around here in the US has a number of different items for fixing things around the house... generally they carry the basic homeowners tools for doing basic jobs... you'll likely find a utility knife at the same place you'd find a wood saw, hammer, contruction lumber, etc...

There're 24 hardware stores listed in the yellow pages for Maracaibo

Would microfiber towels be ok to clean the fresnels with? They are not 100% cotton, but they do not scratch clear coat, and they pass the CD test (rub them vigorously against the back of a recordable CD and do not leave scratches) thoughts?

Would an antistatic cleaner work to clean the fresnels and kill two birds with one stone

they probably contain alcohol which could be damaging

so even though the manufacturer and brain child say use the 10% alcohol and water mixture, don't use it, but use the acrillic cleaner from home depot with distilled water? and should i use a cloth to dry the fresnel, or let it the distilled water on the fresnel air dry?

I got some optical eyeclass cleaner with microfiber clothe from costco, will that work?

Drugstore alcohol (isopropanol) is somewhat more of an organic solvent (although miscible in water). What about ethanol, though? General purpose laboratory cleaner and pretty damned safe on plastics. Not the denatured stuff, but the pure stuff. I've read that people use it for cleaning electronics components, so I'm wondering if its acrylic safe.