Jump to content


Photo

Konvas 2m shutter angle


  • Please log in to reply
11 replies to this topic

#1 Thomas Beetz

Thomas Beetz

    New

  • Basic Members
  • Pip
  • 6 posts
  • Cinematographer

Posted 25 January 2009 - 09:03 AM

Hi,
I was wondering whether anyone has used the Konvas 2m with different shutter angles.

I have read about shutters made from cds, done by a film technician. It sounds very interesting, as it seems to reduce noise. Has anyone heard about this?

I want to make different shutters in various angles, i.e. 45, 90, 180, 280, 320 degrees to use them creatively on an upcoming short film. Is it difficult to change the shutter on the Konvas or can it be done relatively quickly?

Any input or shared experience in this matter would be much appreciated.

Regards Thomas
  • 0

#2 James Steven Beverly

James Steven Beverly
  • Basic Members
  • PipPipPipPip
  • 4199 posts
  • Director
  • El Paso, Texas

Posted 26 January 2009 - 01:13 AM

Man, I don't know how you can really do that, the mirror is the shutter and you have to take off the front of the camera to change it out which means once you pull the front and install the modified shutter, you have to re-calibrate everything. That's a HUGE pain in the ass to do if you have multiple shutters to change out during filming especially for a short. Is there any scenes where the shutter really needs to be changed? I mean can't you do something just as artistic without changing the shutter angle? BTW "noise" is a digital term, in film the KINDA equivalent would be "grain" There are a LOT of factors that will increase or decrease grain, Do a search and learn, it is fascinating. B)
  • 0

#3 Olex Kalynychenko

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

Posted 26 January 2009 - 06:21 AM

Hi,
I was wondering whether anyone has used the Konvas 2m with different shutter angles.

I have read about shutters made from cds, done by a film technician. It sounds very interesting, as it seems to reduce noise. Has anyone heard about this?

I want to make different shutters in various angles, i.e. 45, 90, 180, 280, 320 degrees to use them creatively on an upcoming short film. Is it difficult to change the shutter on the Konvas or can it be done relatively quickly?

Any input or shared experience in this matter would be much appreciated.

Regards Thomas


Any cine camera, and Konvas cameras, this is high precision system of mechanical and optical parts.
Konvas camera have shutter mirror disk with 150 degree. ( angle of shutter disk open ).
The working of shutter disk synchronize with all transport mechanism of camera and claw mechanism.
The claw mechanism have two main points : " the point of begin of moving of film " and " finish point of film moving".
That's why, If you wish change of angle of shutter disk, you must take into account of all technical sides of this idea.
Theoretically, you can use of shutter disk with less angle of opening without problem. ( less of 150 degree ).
The shutter disk with more wide angle of openning - do not possible, because, the film will exposing at time of moving of film at film gate.
and , you wil have degraded picture on film.

That's why, theoretically, you can setup of shutter disk with angle ( angle od shutter disk open ) less of 150 degree. ( 45, 90 ).

From practical side, you will have problem to realize of this idea.
The variable angle of shutter disk do not possible,
because, you must have two shutter disks, one - mirror 150 degree, second - black disk.
This is disks must set on one axis and black disk must be mobile.
The similar design have 16 mm Kinor-16 SX-1M, 35 mm cameras Rodina and other.
But, the design of Konvas camera do not possiblity to install of additional mobile black disk with system of control.

Other idea, to setup additional black disk under of main mirror disk.
yes, theoretically, this possible.
But, the black disk must have small thickness, will need setup of fucusing screen on other positon and will need re-adjust of all optical system of body of camera.
From other side, will need re-balancing of shutter disk axis, because, the additional part will destroy of balancing.
And you received camera with fixed shutter disk.
If you will need re-adjust of angle of shutter disk, you will need do of all procedure of adjusting of optical system of camera.
This is do not good.

Possible, to have of a few bodies of Konvas cameras with different angles of shutter disk can be better from financial side.

You can see, this is complex procedure.
That's why, if you wish have camera with variable angle of shitted disk, you need choose of cine camera with variable angle of shutter disk, like Rodina and similar.
  • 0

#4 Daniel Porto

Daniel Porto
  • Basic Members
  • PipPipPip
  • 201 posts
  • Student

Posted 26 January 2009 - 06:48 AM

Any cine camera, and Konvas cameras, this is high precision system of mechanical and optical parts.
Konvas camera have shutter mirror disk with 150 degree. ( angle of shutter disk open ).
The working of shutter disk synchronize with all transport mechanism of camera and claw mechanism.
The claw mechanism have two main points : " the point of begin of moving of film " and " finish point of film moving".
That's why, If you wish change of angle of shutter disk, you must take into account of all technical sides of this idea.
Theoretically, you can use of shutter disk with less angle of opening without problem. ( less of 150 degree ).
The shutter disk with more wide angle of openning - do not possible, because, the film will exposing at time of moving of film at film gate.
and , you wil have degraded picture on film.

That's why, theoretically, you can setup of shutter disk with angle ( angle od shutter disk open ) less of 150 degree. ( 45, 90 ).

From practical side, you will have problem to realize of this idea.
The variable angle of shutter disk do not possible,
because, you must have two shutter disks, one - mirror 150 degree, second - black disk.
This is disks must set on one axis and black disk must be mobile.
The similar design have 16 mm Kinor-16 SX-1M, 35 mm cameras Rodina and other.
But, the design of Konvas camera do not possiblity to install of additional mobile black disk with system of control.

Other idea, to setup additional black disk under of main mirror disk.
yes, theoretically, this possible.
But, the black disk must have small thickness, will need setup of fucusing screen on other positon and will need re-adjust of all optical system of body of camera.
From other side, will need re-balancing of shutter disk axis, because, the additional part will destroy of balancing.
And you received camera with fixed shutter disk.
If you will need re-adjust of angle of shutter disk, you will need do of all procedure of adjusting of optical system of camera.
This is do not good.

Possible, to have of a few bodies of Konvas cameras with different angles of shutter disk can be better from financial side.

You can see, this is complex procedure.
That's why, if you wish have camera with variable angle of shitted disk, you need choose of cine camera with variable angle of shutter disk, like Rodina and similar.


I thought that the shutter angle was 180. But I must be wrong
  • 0

#5 Thomas Beetz

Thomas Beetz

    New

  • Basic Members
  • Pip
  • 6 posts
  • Cinematographer

Posted 26 January 2009 - 07:22 AM

Thanks for your replies. You have been very helpful. I did not realize that you have to calibrate the entire camera mechanism. It s definitely not worth it.
I ll come up with different ways to achieve the desired effects.
  • 0

#6 Thomas Beetz

Thomas Beetz

    New

  • Basic Members
  • Pip
  • 6 posts
  • Cinematographer

Posted 26 January 2009 - 07:25 AM

Thanks for your replies. You have been very helpful. I did not realize that you have to calibrate the entire camera mechanism. It s definitely not worth it.
I ll come up with different ways to achieve the desired effects.
  • 0

#7 James Steven Beverly

James Steven Beverly
  • Basic Members
  • PipPipPipPip
  • 4199 posts
  • Director
  • El Paso, Texas

Posted 26 January 2009 - 10:57 PM

I thought that the shutter angle was 180. But I must be wrong


Don't feel bad so did I, and I'm suppose to know a lot about these cameras. :D
  • 0

#8 Olex Kalynychenko

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

Posted 27 January 2009 - 04:46 AM

I thought that the shutter angle was 180. But I must be wrong


The 180 degree of shutter disk do not possible at Konvas, because, we will open of film gate at time of moving of film at 15 degree of phase of begin and 15 degree of phase of end of film move.

Yes, possible, what the diffuse image ( 30 degree of rotation of mechanism ) will have small part from full image ( 150 degree of rotation of mechanism ).

But, i do not know of factory made shutter disk with 180 degree for Konvas.

Any case, if the anybody have information about shutter disk upgrade of Konvas camera, i will be glad to study of this upgrade detailed.
  • 0

#9 James Steven Beverly

James Steven Beverly
  • Basic Members
  • PipPipPipPip
  • 4199 posts
  • Director
  • El Paso, Texas

Posted 27 January 2009 - 11:19 PM

No one is doubting you Olex, I'm just a little ashamed I didn't know that about the Konvas, I SHOULD have known it, that's all.
  • 0

#10 John Sprung

John Sprung
  • Sustaining Members
  • 4635 posts
  • Other

Posted 02 February 2009 - 06:35 PM

Konvas has a fixed shutter. There are other cameras with varible shutters, such as Arriflex 2-CV, some of the Mitchells and Eclairs. On those, it's quite easy to change the angle.

All film cameras require time to pull the film down. That limits the largest shutter angle you can have. On practical production cameras, none go significantly farther than 185 degrees. With digital cameras, for the first time, we can experiment with large shutter angles, within a fraction of a degree of the full 360.




-- J.S.
  • 0

#11 Olex Kalynychenko

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

Posted 03 February 2009 - 05:25 AM

Konvas has a fixed shutter. There are other cameras with varible shutters, such as Arriflex 2-CV, some of the Mitchells and Eclairs. On those, it's quite easy to change the angle.

All film cameras require time to pull the film down. That limits the largest shutter angle you can have. On practical production cameras, none go significantly farther than 185 degrees. With digital cameras, for the first time, we can experiment with large shutter angles, within a fraction of a degree of the full 360.

-- J.S.

I think, the full 360 dergee of shutter disk do not possible for digital cine ( video ) camera.
The any electronics system with CCD sensor need time for pixel inquiry of CCD censor.
Yes, of course, this can be very short time, depend from power of microporcessor,
but, this will like cine camera with very high speed of shooting and very small angle of shutter disk.
The high speed of shooting canbe show like frequency of inquiry of CCD censor, the angle of view will like of time of pixel inquiry of CCD censor.

Yes,of course, the time to pull the film down depend from mechanical characteristics of claw mechanism and have physical limit.
The time of pixel inquiry of CCD censor have electronic limit and will diminish with evolution of microprocessors and technology of production of electronic components.
  • 0

#12 John Sprung

John Sprung
  • Sustaining Members
  • 4635 posts
  • Other

Posted 03 February 2009 - 07:51 PM

The large shutter angles and operation without a mechanical shutter are possible on CCD's by making a chip with two complete images worth of charge wells. One is the photosensitive part that captures the picture. The other, right next to it, is under a metal cover to protect it from light. The whole exposed frame is shifted very very quickly from the active area to the covered storage area. Thereafter, the camera has a whole frame's worth of time to read it out before the next image shifts down. The shift happens in microseconds, or in terms of shutter angle, less than a degree. In effect, the CCD, like film, also does a "pulldown". ;-)





-- J.S.
  • 0


Abel Cine

Broadcast Solutions Inc

CineTape

CineLab

Metropolis Post

Technodolly

Opal

Tai Audio

FJS International, LLC

Visual Products

Aerial Filmworks

Wooden Camera

Willys Widgets

Glidecam

Media Blackout - Custom Cables and AKS

The Slider

Ritter Battery

rebotnix Technologies

Rig Wheels Passport

Gamma Ray Digital Inc

Paralinx LLC

Gamma Ray Digital Inc

Glidecam

Paralinx LLC

The Slider

Rig Wheels Passport

Ritter Battery

Willys Widgets

CineTape

Wooden Camera

Visual Products

Aerial Filmworks

Broadcast Solutions Inc

Technodolly

Tai Audio

Metropolis Post

Media Blackout - Custom Cables and AKS

Abel Cine

CineLab

rebotnix Technologies

FJS International, LLC

Opal