which lens is sharper on super 16mm

[Julian Fletcher]

There have been similar questions around using lenses designed for 35mm on the Super 16mm system before, and apologies if my specific question has been asked before.

 

However, assume we have two 50mm lenses – one designed for 35mm system and one designed for the Super 16mm system. Both cover the super 16mm frame size, but they each designed for their dedicated systems.

 

As the Super 16mm version is designed to provide a sharp image on a smaller sized area, will the image be inherently sharper than the image provided by the 35mm version? So in practice, if the two different lenses are PL mount and can be mounted on say an SR3, will the dedicated super 16mm version produce a sharper image than the 35mm version? I am intrigued to know your thoughts!!

 

Cheers

Julian

[Jay Young]

I thought a 50 is a 50 is a 50.

[Stuart Brereton]

The s16 version would theoretically be sharper, as it was designed for that format, but when using the 35mm version, you'd only be utilizing the center portion of the lens, which is where it is sharpest. So, depending on the individual lenses being tested, you may find the differences are only noticeable on a lens projector.

[Simon Wyss]

We must not compare apples to oranges.

 

A 50 mm lens for 35-mm. film cameras can be a Tessar variant or a more complex system while a 50 mm lens for the 16-mm. film format as a double-normal focal length is a tele lens. Generally, really only in the broadest general sense, longer focal length lenses are of simpler design.

 

Now come the exceptions. Many a 50 mm lens for the 16 film format is a Double-Gauss system of six elements or more. The Kern-Paillard Switar 50 mm, f/1.4 is a six-element design, similar to the the Switar 25 mm, f/1.4. The Wollensak 6 inch telephoto for 16 mm film consists of two doublets. The 16-mm film Kern-Paillard Yvar 25mm, 75 mm, 100 mm, and 150 mm are all triplets.

 

Zeiss, Kinoptik, Panavision, Leitz, Cooke, Kilfitt, and other lenses of 50 mm focal length vary the more the younger they are. Up to the 70s six elements were rather standard. The early and the later Kern Switar 50 for 24 × 36 still photography have seven and eight elements respectively.

 

A well mounted and well used triplet gives better technical sharpness than a not perfectly mounted and or focused six-element lens. One chapter of the story bears the title Macro. Standard lenses are made for the object distance range from infinity down to about four or three feet. They cannot keep up with macro lenses specially designed for short distances. The other way round, macro lenses perform mostly only moderately on longer distances.

 

I am a huge fan of small, compact, and lightweight triplets. Only very few film stocks have enough resolving power to capture all the detail the lenses deliver, especially in the 16-mm. film format. Expensive lenses are an overkill. They are actually, in my humble opinion, only justified when a wide opening is needed, from f/2 to f/1. As long as one has enough light for, say f/2.8 through f/11, triplets and Tessar designs do the job alright. So, instead of the Switar 50-1.4 I mostly use a Cinor Berthiot or a Xenon by Schneider. With 35-mm. shoots my favourite 50 is the Angénieux 50-1.8 (S1).

[Dom Jaeger]

I thought a 50 is a 50 is a 50.

Only in terms of their field of view, and only if a lens is designed to cover the format. So two lenses, one made for Super 16mm and the other for Super 35, will have the same fields of view when mounted on a S16 camera. But mount them on a 35mm camera and one lens will be like looking through a tunnel, with a small circle of image in the middle of a black field.

 

One of the first design parameters a lens maker needs to take into account is the size of the image circle, what format the lens needs to cover. This will dictate what angular field of view a particular focal length needs to transmit, which in turn dictates the type of design. So a 50mm designed for standard 8 will be a very different type of lens from a 50mm designed for VistaVision, for example.

 

With PL lenses, most lens manufacturers never bothered to make anything longer than 25mm, since longer focal lengths could be found among lenses designed for 35mm, and the expanded image circle design didn't impact overly negatively on the image quality.

With wider focal lengths however, there is a definite advantage in only needing to cover a smaller frame, and smaller, faster, sharper lenses can be made.

 

As Stuart mentioned, it depends on the lens, but in theory 16mm lenses should be computed to resolve finer detail. But the centre of 35mm lenses is where they are sharpest. Zeiss did make a separate 50mm for S16, which projects a little sharper than the one made for 35mm, but whether it's noticeable in most real world applications is another thing.