Schneider/Century achromatic diopter

On my Amphibico Phenom housing I have had issues with trying to squeeze in higher power diopters. +3 is really the limit for a glass diopter and because it is heavy it wants to sag the diopter holder, and there is some interference if you use it with the red filter.

I have noticed that the single glass element diopters have significant spherical aberrations about the perimeters so I start investigating achromatic diopters.

Schneider Optics in Germany has an excellent reputation and they produce an achromatic diopter of +3.5 that is inserted into a 72mm threaded ring that screws onto the front of my Sony FX1.

It must be stated that the lens housing must be modified or you're going to ruin the inside dome port because in stock configuration the +3.5 holder hits the inside of the port and will scratch it to ruination.

Having said that, for macro HD video work, I am extremely pleased with the performance & optical clarity of these dual element, highly corrected glass optics as long as you ar epartially zoomed in. If you are zoomed out, I did notice some distortion, but then the idea of zooming out on macro is sort of an oxymoron.

I had a chance to use this new achromatic diopter several weeks ago in Anilao, Philippines and I got some outrageous macro footage of bobtail squid burying themselves, Coleman shrimp commensal to fire urchins, pygmy seahorses, etc.

I could probably get a +4 to fit by further modifying the glass holder, but it is hard enough to get stable footage zoomed all the way in with a +3.5.

Expect to pay about $400 USD for a Schneider/Century 72mm +3.5 and expect to pay some $ to a machine shop to machine up your holder to clearance it. You'll need a really fine optical component sized 2-pin spanner wrench to unscrew the retention ring too.

Now, if only Sony would come out with a card recording, LANC controlled compact HD cam with a telemacro lens.....