Caldwell Chameleon – Flexible Anamorphic Primes

If you haven’t heard of Caldwell, you’re not alone. Brian Caldwell has been designing specialty optics for decades under different names or for production by other manufacturers. His latest project to be released is called the Chameleons – a flexiable 1.79x squeeze for both Super 35 and Full Frame / Vista Vision formats. We sat down with Brian to get a closer look at what makes these new primes unique.

Matthew Duclos – After performing some preliminary tests with your most recent prototypes, we’re quite excited about the new Chameleon Primes and what they’ll bring to the film-making industry. For our readers who may not be familiar with your history, can you summarize your background in optics for us?

Brian Caldwell- Sure. I got started in optics when I was a kid, due to my interest in astronomy and telescopes.  Later on, I became equally interested in photography and photographic lenses.  After getting a B.S. degree in Physics I was very fortunate to get accepted to the Ph.D. program in Optics at the University of Rochester, where I was able to spend spare time in the optics shop learning to grind, polish and assemble lenses in addition to doing course and thesis work.  After a decade working in industry I started Caldwell Photographic to do lens design consulting and later to develop specialized lenses.  The first lens we did was a 60mm UV-VIS-IR apochromat, manufactured by Coastal Optical in Florida.  Later on, a colleague of mine and I developed a general purpose focal reducer that we called the Speed Booster, which has turned out to be a much bigger success than we ever expected, with more than 100,000 units sold.

Duclos – Right. That would be the Metabones “Speedbooster” that has become a staple in many kits around the globe. In fact, I believe your name is engraved somewhere on every unit if you look close enough. So moving on to your current project… Why anamorphic primes?

Caldwell – We felt that we would be able to fill a valuable niche with consistently-sized and format-flexible anamorphics having classic performance characteristics.  I was also very fortunate in having access to a truly world-class mechanical design team, without which the project would have been impossible.

Duclos – Perhaps the most outstanding question on most peoples mind is why the 1.79x squeeze? Most modern anamoprhics available are a straight 2x squeeze with the exception of Cooke’s new 1.8x Full Frame Anamorphics.

Caldwell – The standard DCI (Digital Cinema Initiatives) Scope format has an aspect ratio of 2.39:1.  Several years ago when we made a commitment to 1.79x many digital cameras had a native sensor aspect ratio of 4:3, or at least had a 4:3 mode.  So, if you do the math, to anamorphically convert 4:3 to 2.39:1 you need a 1.79x squeeze ratio (2.39/(4/3) = 1.79).  Mr. Spock would object and say the true ideal squeeze ratio is 1.7925, but we decided to round it off! 
More recently, FullFrame cameras are being released with a native aspect ratio of ~1.5:1, which would require a ~1.6x squeeze ratio for perfect conversion to 2.39:1.  However, a 1.6x squeeze doesn’t provide the degree of anamorphic artifacts that are often desired, and it turns out that a squeeze ratio midway between 1.6x and 2x is a good compromise.  We were very happy that Cooke made this very argument when they released their 1.8x anamorphics.

Duclos – Besides the uncommon squeeze ratio, what is it about the Chameleon Primes that makes them unique over other options out there?

Caldwell – Several things.  First, the Chameleons are designed to be very flexible in terms of format size and squeeze ratio.  This is done by making the working distance very long, which allows a wide variety of optical modifier groups to be custom designed for the rear of the lens.  The first such rear group will be the expander unit that converts S35+ to FullFrame.  Second, the Chameleons are all very compact and are all series-wise identical in size.  All of the S35+ Chameleons are just 5 ½ inches long, even the 150mm.  The FullFrame Chameleons are only about ¾ “ longer due to the rear optical expander group.  Third, the Chameleons all have the same minimum focus distance of 2.5 feet, even the 150mm for S35+ and 225mm for FullFrame.  This opens up near-macro possibilities for the longer focal lengths, and it also makes focus pulling a bit easier since the distance scales are all identical within a given series (S35+ or FullFrame).  Fourth, although the Chameleons use a very traditional Wallin-style focusing technique dating to the 1950’s, the cylindrical and spherical groups are completely new designs developed from the ground up so that the series matches very well in terms of aberration balance.  Finally, the Chameleons are supplied standard with a single layer coating on the cylindrical elements that results in a blue-colored horizontal flare.  This is indicated by the blue ring on the front of the lens.  Custom versions that provide a more golden-colored flare will also be offered, and the color of the cosmetic ring at the front of the lens will be changed accordingly.

Duclos – This would be the “JJ” look that many cinematographers desire, consciously or otherwise. Traditionally, this sort of flare and character is achieved exclusively with Panavision anamorphics. What focal lengths will you be releasing first?

Caldwell – Two different series are being built, one for Super-35 format and one for FullFrame format.  The S35+ lenses will be 32mm T2, 40mm T2, 50mm T2, 60mm T2, 75mm T2, 100mm T2.6 and 150mm T4.  The FullFrame lenses will be 48mm T3, 60mm T3, 75mm T3, 90mm T3, 112mm T3, 150mm T4 and 225mm T6.  The S35+ lenses from 50mm through 150mm all illuminate Fullframe.  S35+ to FullFrame conversion kits will also be offered.  These kits consist of a rear optical group, new focus and iris rings, and a pair of bolt-on plaques for the front engraved with the focal length.  The 32mm, 50mm and 100mm S35+ lenses will be delivered first by the end of June, along with their FullFrame counterparts 48mm, 75mm and 150mm.  The 40mm, 60mm and 75mm S35+ lenses will be ready by the end of the year, again together with their FullFrame counterparts 60mm, 90mm and 112mm.  Next year we plan to release the 150mm S35+ lens, which can be converted to 225mm FullFrame, and we also hope to have a 25mm lens that converts to 37.5mm.

Duclos – Thanks for geeking out with us, Brian. We can’t wait to get our hands on more focal lengths for additional testing around Cine Gear!

As I mentioned previously, I had a good amount of hands-on time with the new Chameleon Primes leading up to NAB and I’ve very much enjoyed the lenses, especially shooting dramatic narrative pieces, playing with excess light. The look that these lenses provide is truly unique. Here’s a quick rundown of tech specs.


Weightappx. 6lbs.appx. 6lbs. appx. 6lbs. appx. 6lbs. appx. 6lbs. appx. 6lbs. appx. 6lbs.
Front Dia.114mm 114mm 114mm 114mm 114mm 114mm 114mm
Min. Focus2.5’/76.2cm 2.5′ /76.2cm 2.5′ /76.2cm 2.5′ /76.2cm 2.5′ /76.2cm 2.5′ /76.2cm 2.5′ /76.2cm


Length6.4″/16.3cm 6.4″/16.3cm 6.4″/16.3cm 6.4″/16.3cm 6.4″/16.3cm 6.4″/16.3cm 6.4″/16.3cm
Weightappx. 6lbs.appx. 6lbs. appx. 6lbs. appx. 6lbs. appx. 6lbs. appx. 6lbs. appx. 6lbs.
Front Dia.114mm 114mm 114mm 114mm 114mm 114mm 114mm
Min. Focus2.5’/76.2cm 2.5′ /76.2cm 2.5′ /76.2cm 2.5′ /76.2cm 2.5′ /76.2cm 2.5′ /76.2cm 2.5′ /76.2cm

Duclos Lenses will be an authorized dealer for the Caldwell Chameleon Anamorphic Primes as well as the first appointed authorized service facilities for the Chameleons – an aspect that I’m very anxious to bring you more info on in the near future. As usual, drop a comment below or reach out to a Duclos Lenses rep for additional information. You can find Pre-Order details here.

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