Konvas Angle of view?

[Adam Paul]

Hi guys,

 

I have a question about angle of view. Is there a

convertion tab to convert Konvas/Kinor angles of view

to Academy? Since Academy is 24x18mm and Konvas/Kinor

is about 22x16mm, there must be a convertion factor.

Specially when using director's viewfinders which only

have Academy, Super 35 etc, but not Kinor/Konvas.

Let's say what's the angle of view of a 18mm Lomo?

What would it be in Cook or Panavision terms when used

on a Arri or Panaflex?

Thanks in advance.

[Thomas Worth]

I have a question about angle of view. Is there a convertion tab to convert Konvas/Kinor angles of view to Academy? Since Academy is 24x18mm and Konvas/Kinor is about 22x16mm, there must be a convertion factor.

As far as I know, the 35mm Academy aperture is 22x16mm. 24x18mm would be closer to full, or "silent" aperture, as anything over 22mm wide would interfere with the soundtrack area. Plus, academy is about 1.38:1, where as full aperture is 1.33:1.

 

22x16mm and 24x18mm are 1.38:1 and 1.33:1, respectively.

[Adam Paul]

Academy is the standard for Hollywood films right? Unless shooting cinemascope of course. So a 18mm Lomo gets you the same angle as a 18mm Zeiss, Cook or Panavision? So I can just use any director's viewfinder to work with Lomo lenses?

Because I was always under the impression the Konvas/Kinor frames were smaller.

Edited March 15, 2006 by Adampaul

[Freya Black]

Academy is the standard for Hollywood films right? Unless shooting cinemascope of course. So a 18mm Lomo gets you the same angle as a 18mm Zeiss, Cook or Panavision? So I can just use any director's viewfinder to work with Lomo lenses?

Because I was always under the impression the Konvas/Kinor frames were smaller.

 

An 18mm lens is always an 18mm lens, whether you put it on an IMAX camera or on a S8 camera. It is still an 18mm lens.

 

I'm not sure what you mean about Konvas frames being smaller. They follow the same standards in the West as far as I know, so they may be Academy or Anamorphic or S35 or whatever. Depends what gate is in the camera.

 

love

 

Freya

[Thomas Worth]

Because I was always under the impression the Konvas/Kinor frames were smaller.

The easy interchangeability between gates and the various gate types for the Konvas may confuse people. For example, I have three gates: academy, 1.66:1 and Super 35 (full aperture). I typically leave the academy one in there.

 

Academy is the standard for Hollywood films right? Unless shooting cinemascope of course.

As far as I know, most films are shot academy, matted 1.85:1. "Scope" films have an aspect ratio of around 2.4:1. Films shot scope, or anamorphic, use the same horizontal film area as academy (22mm), but more vertical area, and the image is, of course, compressed by the lens.

 

Whether you're shooting scope or academy, the width of the camera's gate will probably never exceed 22mm in order to keep the picture off the soundtrack area.

 

So I can just use any director's viewfinder to work with Lomo lenses?

Well, you can't exactly use "any" viewfinder -- the mount on the viewfinder has to match the mount on the lens. Lomo lenses, unless modified, are typically OCT-19 mount. So, your finder will have to have an OCT-19 mount. As long as the mounts are compatible, and the finder has marks on the glass for academy and 1.85:1, you should be fine. As Freya mentioned, an 18mm is an 18mm, whether it's Cooke or Zeiss or Lomo.

[Adam Paul]

Hi guys. I know a 18mm is always a 18mm lens. I meant in terms of angle of view. The angle of view of a 18mm in 16mm film is not the same as in 35mm for example. I wanted to know if the angle of view changed between a Lomo and a Cook when used let?s say on an Arri? I know Lomo can be fitted with PL mounts to be used on an Arri for example.

About the director?s viewfinder, I was talking about the simpler ones like the Mark V where you don?t use your actual lens. If I set it to 18mm and set my shot, will the angle of view match when I look through the 18mm Lomo in a Konvas?

By the way I have never seen a director?s viewfinder for OCT-19.

What I meant about frame being smaller was the ground glass. Isn?t the ground glass smaller in a Konvas than in an Arricam?

[Thomas Worth]

Hi guys. I know a 18mm is always a 18mm lens. I meant in terms of angle of view. The angle of view of a 18mm in 16mm film is not the same as in 35mm for example. I wanted to know if the angle of view changed between a Lomo and a Cook when used let?s say on an Arri?

You just said that you already know an 18mm is an 18mm, so why would you ask if the angle of view is different between a Lomo and a Cooke? Yes, of course it's the same. That's like asking if the 3/8" wrench you bought from Sears will fit the same bolts as is the 3/8" wrench you bought from Home Depot. The only exception to this would be if the lens was specifically designed to give a wider field of view, i.e. a fisheye.

 

The ground glass on the Konvas has marks for academy. Unless it's been custom marked, you probably won't have marks for anything else. Just keep that in mind when you're composing the shot, or get it marked for 1.85:1.

[Adam Paul]

Hey Thomas. Maybe I?m just not being clear here, or I?m just confused, but I will try to explain again. I thought Konvas/Kinor used a different size of film frame, because I have always heard you need to convert them to use normal Kodak 35mm. Then if the frame was smaller, a 18mm would yield a different angle of view in the same way a 18mm yields a different angle of view when used in 16mm (smaller frame) as opposed to 35mm(bigger frame). That was what I was talking about.

To give you a picture of what I mean, let?s say you would manage to install a Lomo Konvas lens and a Cook in a SLR camera . If you take pictures with both, as they are motion picture lenses they wouldn?t cover the still frame, which is 36x24mm. You would end up with a little round image in the middle of the picture right? My question is, would the Lomo circle in the middle be smaller or the same size as the Cook(or Panavision or Zeiss superspeeds for this matter)?

[Mitch Gross]

The images would be the same size. Cooke, Lomo, whatever -- that lens length will deliver the same thing.

 

Don't know who told you Konvas cameras shot a smaller format. It is nonsense. They can shoot, Full silent aperture or something smaller such as Academy. The same can be said for the Arricam and most every other 35mm camera. Perhaps whoever told you this was used to shooting for video transfer using an Arri with a full aperture gate & groundglass, so the standard Academy gate & groundglass on some given Konvas may have yielded a smaller field of coverage. But that is the happenstance of two individual setups, not an issue of the technology.

 

Short answer: The glass is all the same and the formats are all the same. Use a MarkV or similar and select 35mm Academy as your guide. You're good to go.

[Thomas Worth]

I thought Konvas/Kinor used a different size of film frame, because I have always heard you need to convert them to use normal Kodak 35mm.

The conversion you are talking about refers specifically to the Kinor, and it has to do with modifying the registration pins to fit Bell & Howell style (B&H) film perforations (i.e. sprocket holes), as opposed to Kodak Standard (KS). B&H perfs are used on camera stocks, whereas KS perfs are used for print stocks and still photo stocks. The Kinor comes from the factory with KS registration pins, which aren't used here in the states for camera stock. All of this has nothing to do with the size of the image area, and even less to do with the Konvas since a stock Konvas doesn't use registration pins.

 

You would end up with a little round image in the middle of the picture right? My question is, would the Lomo circle in the middle be smaller or the same size as the Cook(or Panavision or Zeiss superspeeds for this matter)?

What you are asking here is how much area the lens "covers." I guess this could technically limit the lens' field of view due to vignetting (dark areas in the corners of the frame), but if you have a 35mm format lens -- that is, a lens that is designed to "cover" 35mm, then you'll be fine. A 35mm format Lomo (not a 35mm Lomo) might not cover the exact same area as a Cooke or Zeiss, but as long as it at least covers 35mm academy (22x16mm), your field of view will be the same with any of these lenses.

[Adam Paul]

What you are asking here is how much area the lens "covers." I guess this could technically limit the lens' field of view due to vignetting (dark areas in the corners of the frame), but if you have a 35mm format lens -- that is, a lens that is designed to "cover" 35mm, then you'll be fine. A 35mm format Lomo (not a 35mm Lomo) might not cover the exact same area as a Cooke or Zeiss, but as long as it at least covers 35mm academy (22x16mm), your field of view will be the same with any of these lenses.

 

I was talking about a Lomo for Konvas or Kinor(motion picture).

 

But thanks for clarifying it all. Now I know where I was confused with the whole different frame size thing. Thanks Thomas.

Thanks also to Mitch and everybody who contributed to the thread and sorry for the big confusion. Mitch said it all for me here:

Short answer: The glass is all the same and the formats are all the same. Use a MarkV or similar and select 35mm Academy as your guide. You're good to go.

 

That was basically the whole reason I started the thread. I was afraid the angles wouldn't match if I used a director's viewfinder.

Thanks everybody.