Red One and Cooke S4 Lenses
Posted 12 May 2011 - 07:07 AM
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.
Posted 13 May 2011 - 05:11 AM
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.
Posted 15 May 2011 - 06:46 PM
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 23 September 2011 - 05:47 PM