FM Lens

• Focuser by Valdas Misevicius
• Single Focus : Variable Diopter
• Mount: 72 MM

The Focus Module - popularly known as FM lens - was the first variable-strength diopter to come out on the market to solve the issue of double focusing with projection lenses. I've written enough about variable-strength diopters, so I won't dwell on its workings. The name, Focus Module, is pretty straightforward about the product's goal. This was the second anamorphic-related product released by Anamorphic Shop.

Released in late 2014, it was the first taste of single focus with beloved projection lenses such as the Kowa B&H, Schneider Cinelux and Isco Blue Star. Since the FM was the first one to hit the market, I believe users were more lenient with it.

The FM Lens is massive. The casing weighs 850g and measures 15cm from top to bottom, focused to infinity. It grows additional 2.7cm at close focus. Focus goes from infinity down to 65cm in just over 180 degrees of throw. Front thread is 105mm (male) and rear thread is 72mm, with a custom step-down ring for the Schneider Cinelux. If using another anamorphic than the Cinelux, you won't have rear threads. In order to use the front threads, unscrew the front lip and install your 105mm filter backwards on it.

The back clamp is also a lens collar and has a slot for a 1/4" screw for lens support. The front part of the lens rotates and moves with focusing, which makes it hard to use another lens support than at the back. The rotation is also challenging for variable NDs and polarizers. This is a setup that REQUIRES rails. You can't just hang the FM in front of your taking lens and go out to shoot.

In order to get it working, focus your anamorphic to infinity and place it inside the Focus Module. This is also the time when you align the lens and lock it into place internally. The FM can take multiple anamorphics but might need additional accessories to hold them in place like the FM Collar 24, since the inner diameter of the tube is 71mm. It all has to fit under 89mm length, which is why the Schneider Cinelux is the ideal candidate (71mm diameter and 89mm length).

Anamorphic Shop's youtube channel has a video on how to fit the Cinelux in there. It's a straightforward process that is also explained on their product page.

I didn't expect it to be super sharp, and I was mistaken. I was able to get pretty decent results down to f/1.4, but the sharpest images come from f/2.8 and upwards.

The large front element doesn't worry me since the FM is capable of very decent close focusing, dismissing the need for extra diopters.

The FM is neutral on the flares, introducing no other reflections or colors to the anamorphic's original flare.

For 2.4:1 shooting, you can go as wide as 50mm, since the 40mm pancake already introduces intense vignetting. As for 3.56:1, 85mm is the way to go. Test ahead, because vignetting creeps in slightly as you focus closer. It's not a lot, but definitely some.

The biggest challenge with shooting the FM is its weight. Support at the back of the lens, and by a single screw, isn't a well thought out solution. It causes the lens to rotate ever so slightly if you're not careful when moving. I was able to jury rig mine with 1/4" screws, nuts and spacers, but I heard of users building big rigs just to be able to work properly with it. The focus throw is also very long, which works with the thick focus gear that came with it, but wouldn't work with a normal gear.

The results aren't unpleasing, though. Single focus solutions have a spell that always blows me away when I use them. The FM is no exception. My confession is that support and weight sucks, but having the anamorphic always aligned, just sliding in and out as I swapped taking lenses was a more than pleasant experience.

The main issue, in terms of performance, is that you can get a bloom/glow kind of thing when using fast apertures with the FM, like what you see in the low-light tests. I am OK with that - I usually add that in post to most of my footage - but it's something that, as I just said, I'd rather add in post than in camera.