Jump to content


Photo

Does the russian OKC (OKS) lenses use F- or T-stops?


  • Please log in to reply
4 replies to this topic

#1 Tomas Stacewicz

Tomas Stacewicz
  • Basic Members
  • PipPip
  • 50 posts
  • Other
  • Gothenburg, Sweden

Posted 15 September 2006 - 06:19 PM

Does the russian made OKC/OKS prime lenses (used together with the Kinor-16 SX-2M) use F- or T-stops?

I have a OKC3-10-1 and on the front of the lens it says 1.8/10 (that is f.1.8) but on aperture ring it has 2.1 as the lowest value. Does the 2.1 signify a T-stop?
  • 0

#2 Thomas Worth

Thomas Worth
  • Basic Members
  • PipPipPipPip
  • 372 posts
  • Director
  • Los Angeles

Posted 15 September 2006 - 09:08 PM

Yes, the Russian lenses are marked in T stops. The 1.8 is the maximum f/stop according to the aperture size / focal length ratio, but the maximum transmission is T2.1. So, use that figure in determining exposure.
  • 0

#3 Tomas Stacewicz

Tomas Stacewicz
  • Basic Members
  • PipPip
  • 50 posts
  • Other
  • Gothenburg, Sweden

Posted 16 September 2006 - 03:18 AM

Thank's
  • 0

#4 Olex Kalynychenko

Olex Kalynychenko
  • Basic Members
  • PipPipPipPip
  • 868 posts
  • Cinematographer
  • Dnepropetrovsk, Ukraine

Posted 16 September 2006 - 10:36 AM

Does the russian made OKC/OKS prime lenses (used together with the Kinor-16 SX-2M) use F- or T-stops?

I have a OKC3-10-1 and on the front of the lens it says 1.8/10 (that is f.1.8) but on aperture ring it has 2.1 as the lowest value. Does the 2.1 signify a T-stop?


A few time ago, i sent answer on sumilar question.
You can check letters about this.

The russian lenses have marks of geometric aperture on front side near full name of lens " OKC-3-10-1 1.8/10 " 10 mm, F1.8, and have marks of T stops on ring of aperture control T2.1.
  • 0

#5 Tomas Stacewicz

Tomas Stacewicz
  • Basic Members
  • PipPip
  • 50 posts
  • Other
  • Gothenburg, Sweden

Posted 16 September 2006 - 11:07 AM

Thank's Olex! I did a search but didn't find any information about this.
  • 0


FJS International, LLC

Aerial Filmworks

Rig Wheels Passport

Wooden Camera

CineLab

rebotnix Technologies

Paralinx LLC

Abel Cine

Broadcast Solutions Inc

Visual Products

Media Blackout - Custom Cables and AKS

New Pro Video - New and Used Equipment

CineTape

Willys Widgets

Glidecam

Ritter Battery

Technodolly

Metropolis Post

Gamma Ray Digital Inc

The Slider

Tai Audio

The Slider

CineLab

Metropolis Post

Glidecam

Media Blackout - Custom Cables and AKS

FJS International, LLC

Broadcast Solutions Inc

CineTape

Willys Widgets

New Pro Video - New and Used Equipment

Rig Wheels Passport

Paralinx LLC

rebotnix Technologies

Aerial Filmworks

Abel Cine

Wooden Camera

Visual Products

Tai Audio

Technodolly

Ritter Battery

Gamma Ray Digital Inc