Jump to content


Photo

Red One and Cooke S4 Lenses


  • Please log in to reply
3 replies to this topic

#1 Jonny Kerr

Jonny Kerr

    New

  • Sustaining Members
  • 9 posts
  • 1st Assistant Camera
  • United Kingdom

Posted 12 May 2011 - 07:07 AM

I'm a 1st AC and I'm looking for advice relating to shooting with Cooke S4 lenses on the Red One camera.

I've been trawling various resources across the web detailing DoF guides and technical specifications for this particular combination of camera and lenses. However, I'm just wondering if there are any Assistants or DoPs out there who may be able to share particular nuggets of knowledge regarding this kit? Are there any specific pitfalls or insider tips concerning Cooke S4s on the Red? How do the S4's hold up when compared to Zeiss ultra or master primes?

Any advice will be gratefully received. Thanks in advance.
  • 0

#2 Markus Rave

Markus Rave
  • Basic Members
  • PipPipPip
  • 103 posts
  • Cinematographer
  • Frankfurt, Germany

Posted 13 May 2011 - 05:11 AM

From the technical point the S4 is just another lens. If you have i-System switched on it will display focus setting, T stop and depth-of-field into the Red´s system. The decision to use either S4 or Zeiss glass is an aesthetic decision and has nothing to do with your technical side of the part. I doubt that many people will be able to distinct the look of an Ultra from an S4. There definetely is one though and you may like one or the other.

What you really should be concerned is that the pin which secures the lens from rotating is smaller than the cutout in the PL mount of the lens. That means if you tighten down the lens will be turned clockwise towards the pin and of course when you hit the other end hard with a motor calibration for instance it surely lacks precision with your witness marks on one of the sides. At least that has happened with my Red when you have strong motors like a Heden. The offset is mostly negligible but it´s there and my 1. AC will not stop complaining about it. But this will happen with any lens out there.

The negative area of the Red´s sensor compared to 35mm is smaller and so there is a difference if you check you FOV with a Mark IV. I helped myself and taped a conversion chart to my Mark IV. But having chosen a lens means your DOF will be the same no matter where you put the lens on.

Shoot safe.
  • 0

#3 Keith Walters

Keith Walters
  • Sustaining Members
  • 2219 posts
  • Other
  • Sydney Australia

Posted 15 May 2011 - 06:46 PM

Another potential problem is that the RED sensor uses microlenses to improve its light sensitivity. With microlenses, an array of microscopic pixel-sized plastic "dewdrops" is used concentrate the incoming photons onto the actual light-sensitive region of each photosite.

The problem is that with ordinary film-type lenses, around the outer edge of the sensor the incoming light tends to strike the microlenses at an angle, which means the microlenses don’t focus it exactly on the light-sensitive region, resulting in a type of “portholing” or “vignetting”.

Lenses designed specifically for microlensed sensors (such as RED’s own lenses) have a “telecentric” design, where the incoming photons tend to strike the image area more or less perpendicularly over the entire image area, avoiding this effect.
This is one reason why cameras such as the Genesis and the Alexa don’t use microlenses, since they are designed to fit as seamlessly as possible into existing rental inventories.

Posted Image
  • 0

#4 Isidro Urquia

Isidro Urquia
  • Basic Members
  • PipPip
  • 11 posts
  • Cinematographer
  • NYC and Dominican Republic

Posted 23 September 2011 - 05:47 PM

Thanks guys for the info. I had a bias toward red lenses but this info will help me to make and inform choice. 1 question, is the vignnietting only noticeable to a discerning DP eye? Or very noticeable. Thanks again. Isidro.
  • 0


Ritter Battery

Opal

Rig Wheels Passport

Technodolly

rebotnix Technologies

FJS International, LLC

CineLab

Paralinx LLC

Willys Widgets

Visual Products

Media Blackout - Custom Cables and AKS

CineTape

Metropolis Post

Abel Cine

Broadcast Solutions Inc

Tai Audio

Wooden Camera

The Slider

Gamma Ray Digital Inc

Glidecam

Aerial Filmworks

The Slider

Abel Cine

Media Blackout - Custom Cables and AKS

Paralinx LLC

Wooden Camera

Metropolis Post

Gamma Ray Digital Inc

Visual Products

rebotnix Technologies

Willys Widgets

Tai Audio

Rig Wheels Passport

Technodolly

CineLab

FJS International, LLC

Ritter Battery

Glidecam

Broadcast Solutions Inc

Opal

CineTape

Aerial Filmworks