Jump to content


Photo

Ultra Primes image circle


  • Please log in to reply
12 replies to this topic

#1 Mike Testin

Mike Testin

    New

  • Basic Members
  • Pip
  • 7 posts
  • Cinematographer

Posted 08 April 2009 - 12:48 PM

I have been trying to figure out what the image circle of the Ultra Primes are but can't find it. Can someone tell me what it is in the 20mm-85mm range. I was looking at their (zeiss) technical info but I can figure it out from that.

Thanks,

Mike
  • 0

#2 Mike Testin

Mike Testin

    New

  • Basic Members
  • Pip
  • 7 posts
  • Cinematographer

Posted 08 April 2009 - 01:44 PM

Here is a link to the tech page, but how do figure it out from the degrees listed to a diameter in mm?

http://www.arri.de/c...mes.html#_blank


I have been trying to figure out what the image circle of the Ultra Primes are but can't find it. Can someone tell me what it is in the 20mm-85mm range. I was looking at their (zeiss) technical info but I can figure it out from that.

Thanks,

Mike


  • 0

#3 Tom Jensen

Tom Jensen
  • Basic Members
  • PipPipPipPip
  • 1234 posts
  • Camera Operator
  • Dallas, TX

Posted 08 April 2009 - 02:13 PM

Here is a link to the tech page, but how do figure it out from the degrees listed to a diameter in mm?

http://www.arri.de/c...mes.html#_blank


I'm not sure what you are asking.
  • 0

#4 Mike Testin

Mike Testin

    New

  • Basic Members
  • Pip
  • 7 posts
  • Cinematographer

Posted 08 April 2009 - 08:24 PM

I am just trying to figure out how large of an area these lenses will cover. Lets say I want to use them with the 5k Red in a year, which needs the lenses to cover a 32mm image circle, would these be able to do it without vignetting?
  • 0

#5 Adrian Sierkowski

Adrian Sierkowski
  • Sustaining Members
  • 7116 posts
  • Cinematographer
  • Los Angeles, Ca

Posted 08 April 2009 - 11:15 PM

I wouldn't count on it....
In fact (having read that same thread) I am a bit worried about most PL lenses on the 5K.
Now we know nothing and won't know 100% until we test and get the camera, but when in doubt....
  • 0

#6 Chris Keth

Chris Keth
  • Sustaining Members
  • 4427 posts
  • 1st Assistant Camera
  • Los Angeles

Posted 09 April 2009 - 12:59 AM

I doubt they cover significantly more than an academy frame. Excess coverage is asking for what we call bellows flare in large format photography., where it's more of a problem to watch for. Say, for example you have the sun just out of frame. All that light from the sun is hitting somewhere in the lens cavity of the camera and could possibly reflect onto the film, especially if it's not flocked and baffled well enough.
  • 0

#7 Mike Williamson

Mike Williamson
  • Basic Members
  • PipPipPipPip
  • 534 posts
  • Cinematographer
  • Los Angeles

Posted 09 April 2009 - 03:07 AM

Ultra Primes should cover a 4 perf Super 35 image area which is larger than Academy, but I would be surprised if they cover a "full frame" still camera negative. So if you're talking about the proposed specs for the S35 Epic chip, Ultra Primes should work but it's doubtful they'll cover the full frame chip. You should look into which lens sets have been used for Vistavision and 65mm, as those may be the best bet for motion picture adapted glass that produces a larger image than S35.
  • 0

#8 Mike Testin

Mike Testin

    New

  • Basic Members
  • Pip
  • 7 posts
  • Cinematographer

Posted 09 April 2009 - 03:46 AM

I am just looking at the S35 sized chip (Epic X) which is 30mm x 15mm. I feel like the Ultras should be able to handle that, but who knows. The ANSI S 35 format is about 25mm horizontal, which is covered. What do the numbers in the Ansi s35 column mean (ex. 20mm Ultra is 65.0 degrees)?
  • 0

#9 Leo Anthony Vale

Leo Anthony Vale
  • Basic Members
  • PipPipPipPip
  • 2010 posts
  • Other
  • Pittsburgh PA

Posted 09 April 2009 - 04:56 PM

I am just looking at the S35 sized chip (Epic X) which is 30mm x 15mm. I feel like the Ultras should be able to handle that, but who knows. The ANSI S 35 format is about 25mm horizontal, which is covered. What do the numbers in the Ansi s35 column mean (ex. 20mm Ultra is 65.0 degrees)?


If you don't know trig, do you at least know the basic pythagorian formula: hgt.squared + width.squared = diag.squared? The wording is modified for this case.

Using a cheap calculator I find that the diagonal of 30x15 is 33.54mm.
There seems to be two S35 standards 24mmx18mm which has a diagonal of 30mm & 24.9mm x 18.7mm which has a diagonal of 31mm.

The shorter lenses' circle will be very close to those diagonals, longer lenses circles will be larger.

Why not go with the double 35mm chip, leica RF lens and iscorama attachments, 6K and have digital technirama?
  • 0

#10 John Sprung

John Sprung
  • Sustaining Members
  • 4635 posts
  • Other

Posted 09 April 2009 - 05:47 PM

Here is a link to the tech page, but how do figure it out from the degrees listed to a diameter in mm?


Actually, it can't be done from the info on that page. The angles they give are for 1.33 full silent aperture, not maximum usable diameter. Lenses may cover a bit more than that, especially when stopped down deep. How much more they don't say. You'd have to test.




-- J.S.
  • 0

#11 Mike Testin

Mike Testin

    New

  • Basic Members
  • Pip
  • 7 posts
  • Cinematographer

Posted 09 April 2009 - 11:07 PM

The 32mm image circle number comes from Red themselves. Here is how they list it.

28mm image circle covers 4k
30mm image circle covers 4.5K
32mm image circle covers 5k

The reason I am trying to find this out is because a company I work with is considering a set of Ultras and I know they will be going with the Epic X S35 upgrade when the time comes.
  • 0

#12 John Sprung

John Sprung
  • Sustaining Members
  • 4635 posts
  • Other

Posted 10 April 2009 - 11:57 AM

There seems to be two S35 standards 24mmx18mm which has a diagonal of 30mm & 24.9mm x 18.7mm which has a diagonal of 31mm.


24.9 x 18.7 is the full silent camera aperture, the actual mechanical dimensions of the hole in the plate.

24.0 x 18.0 is the TV transmitted frame, the area that gets scanned in telecine.

21.9 x 16.2 is the safe action area

19.2 x 14.4 is the safe title area

We don't want to see the edges of the aperture plate in the picture. Mechanical registration isn't perfect, so we scan a slightly smaller region in telecine, just to be safe. Old time CRT TV sets overscan to hide the ragged edges of the raster, so we lose a little more on that end, too.

Bottom line, lenses designed for super 35 will cover the full 31mm diagonal. Push it to 32mm, and you'll probably be OK almost all the time. At worst, there'd be a tiny bit of darkening in the corners. Draw your rectangle with the 32mm diagonal, and then draw a 31mm circle centered on it. The part inside the circle will be fine for sure. The corners may be a little dark, especially with wide lenses and shallow stops. To the extent that things are still overscanned, even that goes away as a problem. But with newer display technologies, the massive overscan of the past may also go away. We'd gain the advantage of doing more precise compositions. Unfortunately, nobody's thinking about that, so it'll happen haphazardly if at all.


I did the drawing, let's see if I can upload it:

EpicLens.JPG



Yes, that worked -- it might not look right to you, but it's better if you "Click to view full image" .....

(BTW, that's a 16:9 rectangle.)


-- J.S.
  • 0

#13 Mike Testin

Mike Testin

    New

  • Basic Members
  • Pip
  • 7 posts
  • Cinematographer

Posted 10 April 2009 - 11:36 PM

Thank you John.
  • 0


Paralinx LLC

Aerial Filmworks

Glidecam

Gamma Ray Digital Inc

Tai Audio

CineTape

FJS International, LLC

rebotnix Technologies

Technodolly

Wooden Camera

Visual Products

Broadcast Solutions Inc

Opal

Rig Wheels Passport

Media Blackout - Custom Cables and AKS

Willys Widgets

Abel Cine

Metropolis Post

Ritter Battery

CineLab

The Slider

CineLab

Paralinx LLC

Abel Cine

Visual Products

Media Blackout - Custom Cables and AKS

Ritter Battery

CineTape

rebotnix Technologies

Willys Widgets

Broadcast Solutions Inc

Technodolly

Gamma Ray Digital Inc

Metropolis Post

The Slider

Rig Wheels Passport

FJS International, LLC

Glidecam

Wooden Camera

Aerial Filmworks

Tai Audio

Opal