Review: GL Optics Rehoused Super Speed Sigma 18-35mm and 50-100mm f/1.8

Find out how GL Optics' rehousing of popular Sigma lenses performs in a narrative feature film environment.

Ever since I became aware of GL Optics at NAB this year, I had been wanting to shoot with these lenses. I chose these lenses when directing my second feature film this summer, and we shot 95% of the film just with these two workhorse zooms.

With two lenses, it effectively covers the 18-100mm (minus 36-49mm) range, which provided a reliable foundation for getting coverage and moving quickly through setups.

These lenses favor utility over beauty; the speed of the lens combined with its great zoom range makes it super versatile.

G.L. Optics 18-35mm Super Speed PL Mount Zoom Lens ($3,500)

• Base Lens: Sigma 18-35mm F1.8
• 120 degree/300 degree (add $850) focus rotation
• 95mm front diameter
• Stainless steel PL mount
• 6063 Aluminum Rehoused Lens body
• Collimated/Parfocal
• 0.8 module gears
• New re-designed Lens focus/zoom/ aperture system with a longer rotation
• Weight: 1.5 KG

G.L. Optics 50-100mm Super Speed PL Mount Zoom Lens ($3,850)

• Base Lens: Sigma 50-100mm F1.8
• 120 degree/260 degree (add $1000) focus rotation
• For 300 Degree focus throw option add $1000
• 95mm front diameter
• 6063 Aluminum Rehoused Lens body
• Collimated/Parfocal
• 0.8 module gears
• New re-designed Lens focus/zoom/ aperture system with a longer rotation
• Weight: 2 KG

Image quality and character

Optically, these lenses are what you would expect from high-end still glass from Sigma. Though I find them to be sharp, cold, and fairly clinical, it was an appropriate choice for the incisive feeling I wanted in my film. These lenses favor utility over beauty; the speed of the lens combined with its great zoom range makes it super versatile.

Though it's not going to have the sharpness of a prime, the 50-100mm is the more "beautiful" of the lenses, while the 18-35mm covers your wide/medium range dutifully. The fact that they match perfectly with each other (and play nice with Zeiss and Canon glass as well) is what made them right for my film.

If you're looking to do any zoom shots in low light, these are for you. 

The lenses easily resolve 4K footage and the base optics are advertised with a resolving power of 6-8K.

Here's an example of a wide with the 18-35mm on C300 Mark ii vs RED Dragon. You might not be able to see it through compression, but the lens does extremely well with the sharpness of the RED sensor in wide shots. The C300 is a bit softer, but still holds plenty of detail itself.

Build quality

Overall, these lenses are built like a tank. They feel solid. The rehousing job is excellent, the gears are sturdy, and iris/focus/zoom are butter. I've primarily used still lenses in my work (partly for texture, partly for the weight) and these feel like a really comfortable upgrade.

One of the biggest upgrades to the base lens: both GL Optics lenses are parfocal, meaning they keep focus while zooming. Unfortunately, the pre-production units I used did not have this feature tuned out yet, but I'm told it's present on all production models.

Both GL Optics lenses are parfocal, meaning they keep focus while zooming.

On Shadow of a Gun, we did a fair amount of zooming during shots; the barrel is super smooth. We were able to perform some continuous, Servo-esque slow zooms by hand (with 120° focus rotation). Both lenses are available in 120° focus rotation or 260°/300° for the 50-100mm and 18-35mm, respectively.

More importantly for my purposes—we used four different cameras during our shoot—the PL mount is interchangeable to EF with just a few screws. This allows for relatively quick swapping between cameras.

Usability

These lenses are useful in a number of rough shooting scenarios. The 18-35mm allows you to fit in tight spaces (like car interiors); even on S35 and 50-100mm, it is ripe for mediums and closeups. Though these lenses are much bigger and heavier than their base lenses, the 18-35mm feels very compact. Here's a sample of what we could do in the back of a car at 18mm on a Dragon sensor:

Perhaps the best thing about the lenses is that they are incredibly fast, both with a constant T/2.0 (f/1.8) aperture. If you're looking to do any zoom shots in low light, these are for you. 

While shooting my film, there were situations I knew I could only get once: an improvised moment using non-actors, or filming an event, for example. For this purpose, I could effectively cover a wide master, mediums, and closeups all with the 18-35mm lens (and often did while filming Shadow of a Gun). When combined with a low-light camera like the C300 Mii, this lens was fast enough to capture unlit guerrilla coverage well—even at night.

The verdict

I used to be a "prime or die" kind of person, but after seven years of shooting (and one shoulder surgery later), I value the ability to change my focal length on a whim. Zooming to change focal length saves time on set; I found it especially helpful for getting additional coverage of a scene when time is tight. Both of these GL Optics zooms have singlehandedly convinced me that I should always have some zoom lenses in my kit.

If GL Optics can keep making quality lenses, I'm confident they'll give any manufacturer a run for its money.

Despite the fact that Sigma is making its own rehoused version of many of its popular lenses in the near future, the GL Optics are a solid option for independent filmmakers and cinematographers looking to add a strong base to their kit. As more manufacturers do more rehousing projects (GL's upcoming Zeiss Otus set, for example) there's going to be a lot of new glass options for filmmakers. If GL Optics can keep making quality lenses like these and keep the price down, I'm confident they'll give any manufacturer a run for its money.