What is the 35mm equivalent for the Zeiss CP.2 Superspeed Lens on the Dragon?

[Lee M]

I was told that I am not getting true 35mm focal length while using a 35mm Zeiss CP2 superspeed lens on my Dragon and the shot should appear wider than it actually is. Still new to how all this stuff works but does anyone know which focal length lens in the CP2 series would give me an equivalent of 35mm?

 

[David Mullen ASC]

Focal lengths don't change -- it would be a "true" 35mm whether you mounted it on a Super-8 camera or an IMAX camera. It's an inherent physical dimension of the lens independent on whatever camera it is mounted to.

What changes is the field of view, plus whether the lens is designed to cover the sensor area without vignetting. So what are you actually asking? Do you want to compare the view of a 35mm lens on a Super-35 sensor (24mm wide) versus a Full-Frame 35mm sensor (36mm wide) versus the area being recorded by the Dragon (30.7mm wide for 6K, 25.58mm wide for 5K, etc.)? When you ask about "equivalence" are you referring to the equivalent view of a 35mm prime on a FF35 sensor?

Between the 6K Dragon sensor width of 30.7mm and the 36mm width of a FF35 sensor, there is a 1.1726X difference, which works out to needing to use a 30mm lens on a 6K Dragon to match the horizontal view of a 35mm lens on a FF35 camera. Conversely, the 35mm lens on the 6K Dragon would have the same horizontal view as a 41mm lens on a FF35 camera.

 

[Lee M]

I am pretty new to all of this so am still learning all the terminology. I want to get a perspective close to the human eye.

 

[Oron Cohen]

I am pretty new to all of this so am still learning all the terminology. I want to get a perspective close to the human eye.

First it will be good if you share in which resolution are you shooting on Dragon?

Basically a 35mm focal length lens is considered the "normal" (closest to human eye if you wish) lens on a super35 sensor size, so if you shoot Dragon @5K you will make the field of view of your 35mm CP2 lens to be normal.

However, if you're shooting on 6K resolution to get a "normal" lens field of you, you probably want to use a 28mm CP2.

You can read all about this stuff on RED website and a gazillion of reduser posts and youtube videos online, start here: http://www.red.com/tools/crop-factor

Having said all of that, I have to say I have a mixed feeling about what is really close to the human eye on super35 size sensor, I would say anything from 28mm to 50mm would be fairly close.

 

[Lee M]

I am shooting 6k widescreen. So would the crop factor be 1.33 then? Meaning I should get as close to 26mm as possible? I have started reading more about crop factor but still learning. Would it be better to use a 35mm lens that would get 35mm without cropping?

 

[David Mullen ASC]

Would it be better to use a 35mm lens that would get 35mm without cropping?

It's not the lens that does the cropping... there is no 35mm lens made where the view is not affected by the sensor area used for the image.

 

[Mark Andersen]

What lens is "normal" is kinda a matter of opinion. In Cinema many feel that a 35mm lens is kind of "normal" or feels the most non-optical (is that a term?) where it doesn't feel wide or telephoto, but just feels real or natural. In 35mm still photography its probably closer to a 45mm lens, When shooting with a Hasselblad the 80 was considered a "normal" lens. But human eyes are different and are both wide in field of view but magnify at the same time. I once tested the focal length of my eyes (comparing their magnification to a lens) and found that they were around 82mm, but maybe everybody is a bit different just like the way everybody sees color a bit differently.

David, I'm realizing as I read this that this is your page and I should ask questions only (I did have a small question in there) sorry if I've hijacked it to some degree.

 

[Satsuki Murashige]

I am shooting 6k widescreen. So would the crop factor be 1.33 then? Meaning I should get as close to 26mm as possible? I have started reading more about crop factor but still learning. Would it be better to use a 35mm lens that would get 35mm without cropping?

I think you are way over-thinking this. Just put a 35mm lens on the camera and get acclimated to the field-of-view. Shoot with it for awhile. Then if you find that the 35mm is too wide/tight for your taste, step down to 24/25/28mm or up to 40/45/50mm. The important thing is how the lens works for your style of shooting, not whether it fits some arbitrary definition of a 'normal human perspective.' There is no universal standard for such a thing - ask Gordon Willis, and he would probably say a 40mm spherical on Academy 35mm is normal for him; ask Wes Anderson, and he would say 40mm anamorphic on 35mm. The latter lens/format has nearly twice the field-of-view of the former. So who is correct? Well, they both are...

More examples - Yasujiro Ozu (50mm spherical on Academy 35), David Fincher (27mm spherical on Super 35 2.40 - cropped in for post-stabilization), Roger Deakins (32mm spherical on Super 35 (2.40/1.85). You see, it's all in the eye of the beholder.