Jump to content


Photo

Question about Kern Macro Switar 26mm f1.1 RX C-mount Lens for Super 16 use


  • Please log in to reply
8 replies to this topic

#1 Dan Berube

Dan Berube

    New

  • Basic Members
  • Pip
  • 1 posts
  • Producer

Posted 18 March 2012 - 07:59 PM

Hello to all,

I am new to this forum and hoping that my question will be considered for reply by those who are much more knowledgeable than I am at this juncture.

I would like to buy the Kern Macro Switar 26mm f1.1 RX C-mount Lens to use with the Super 16 format.

I have read so many posts discussing the importance of getting a Switar with "preset" and RX to properly cover the Super 16 format.

Could someone please take a moment to educate me and those who may also wish to know? I am happy with being pointed to urls for better learning if that is preferred, but would also love to hear experiences in using Switar lenses with the Super 16 format and to address if "preset" lenses are required, etc.

Again, I value being able to post here and bow profusely to those who are already int he know and would be happy to share their wisdom to a fellow visual storyteller.

Thank you!

Dan
  • 0

#2 Simon Wyss

Simon Wyss
  • Basic Members
  • PipPipPipPip
  • 1411 posts
  • Other
  • Basel, Switzerland

Posted 19 March 2012 - 02:40 AM

So much politeness, awesome!

Confusion about preset and non-preset diaphragm? See, the ones have that lever that allows you to set a stop to the diaphragm ring, the other lever. The older ones don’t have it. There’s no difference to the rest of the lens by this.

If the 26-1.1 Switar is apt to Super-16 I can’t tell.
  • 0

#3 Chris Elardo

Chris Elardo
  • Basic Members
  • PipPip
  • 66 posts
  • Other
  • Arizona

Posted 21 March 2012 - 04:44 PM

The 26mm preset is one of the best lenses for Super16 on a reflex Bolex. The main issue is that the rear element of the lens be large enough for the added width of the frame. Also, lens speed is an issue and generally only lenses that open up to at least 2.0 are safe. Hope this helps-
  • 0

#4 Chris Millar

Chris Millar
  • Basic Members
  • PipPipPipPip
  • 1642 posts
  • Other

Posted 22 March 2012 - 12:32 AM

The more you stop down the more even your coverage will be across the frame... The flip side of this is that the cut off will be a heap steeper (a function of the rear element size and the attendant optics to facilitate it)
  • 0

#5 Steve Mullen

Steve Mullen

    New

  • Basic Members
  • Pip
  • 5 posts
  • Other

Posted 23 March 2012 - 10:00 PM

I have read so many posts discussing the importance of getting a Switar with "preset" and RX to properly cover the Super 16 format.


The difference between RX and nonRX is what is in the gap between the lens back and the film plane. If it is air -- meaning no RefleX prism, use a non-RX lens. This would include the Digital Bolex.

If you have a reflex (later model) Bolex, then you need an RX lens.

Why? Air and glass treat light rays differently and so slightly modify their travel to the film.

So you buy the lens that matches your camera.
  • 0

#6 Chris Millar

Chris Millar
  • Basic Members
  • PipPipPipPip
  • 1642 posts
  • Other

Posted 23 March 2012 - 10:48 PM

If you have a reflex (later model) Bolex, then you need an RX lens.


But not over 50mm - which is why there aren't any switar RX lenses over that focal length ;)

You can also get away with stopping down somewhat if you're in a fix - you'll still get an image either way - its up to you how you define 'acceptably sharp'.
  • 0

#7 Steve Mullen

Steve Mullen

    New

  • Basic Members
  • Pip
  • 5 posts
  • Other

Posted 28 March 2012 - 03:37 AM

But not over 50mm - which is why there aren't any switar RX lenses over that focal length ;)


Thank you for the additional information.
  • 0

#8 steve waschka

steve waschka
  • Basic Members
  • PipPipPip
  • 204 posts
  • Industry Rep
  • Indian Harbour Beach, FL

Posted 29 March 2012 - 07:24 AM

if you want to run and gun with this rig... dont mix and match lens designs. otherwise... read-on:

best investment is a prismatic focuser. sometimes called a critical focuser. little ground glass prism on a magnet with an eyepiece. bolex has one made for them for their gates (2 designes, depends on you body age range). it replaces your pressure plate and allows you to check things like light fall off and focus at the film plane at various focal distances. problem with lenses not desgned for the specific camera body is you can have problems with all of the above. if its not designed for s16. ie its designed for the basic film gauge. it prob wont cover a whole s16 frame. however! and this however comes with its own gambles... if you buy lenses designed for larger film gauges they will obviously cover s16. but then they are not designed for rx. and you will need to buy the appropriate adapter (ie nikon to cmount) yes you can space them off the body with washer shims (sometimes). also some adapters can be rebuilt to accommodate the backspacing difference between rx and cmount. cmount is 17.53mm rx is 20.76. but theres more problems. 1st and its a killer, is most cmount threads arent long enough to handle the amount of spacing youll need. many c mount lenses designed for rx include rear elements that accommodate for the light going through a prism before falling on the film plane. no adapter will ever accommodate for that. and all the backspacing changes your doing will throw off your lenses distance gauge making critical distance measurements impossible. thats where the critical focuser comes in. a couple of the zoom dogleg lenses were designed in there core to fit a variety of camera applications. which means they can be opened, adjusted to hit the film plane at most backspacing distances for 16mm. which ones? well thats the trick. and forget about all the lovely wide angles like 5.5. probably will never be as sharp as should unless used in their designed working environment. bottom line is your doing something bolex did not intend. so it will have compromises. but! tack sharp at the film plane... is tack sharp at the film plane! no matter what the tape, the lens barrel or anything else says. so how you set up your shots has a tremendous amount to do with what you can get away with.
  • 0

#9 Boris Belay

Boris Belay
  • Basic Members
  • PipPipPip
  • 210 posts
  • Other
  • Brussels, Belgium

Posted 23 May 2012 - 07:36 AM

Hello to all,

I am new to this forum and hoping that my question will be considered for reply by those who are much more knowledgeable than I am at this juncture.

I would like to buy the Kern Macro Switar 26mm f1.1 RX C-mount Lens to use with the Super 16 format.

I have read so many posts discussing the importance of getting a Switar with "preset" and RX to properly cover the Super 16 format.

Could someone please take a moment to educate me and those who may also wish to know? I am happy with being pointed to urls for better learning if that is preferred, but would also love to hear experiences in using Switar lenses with the Super 16 format and to address if "preset" lenses are required, etc.

Again, I value being able to post here and bow profusely to those who are already int he know and would be happy to share their wisdom to a fellow visual storyteller.

Thank you!

Dan


So much confusing information guys !

The simple answer is : ALL Macro-Switar 26/1,1 lenses have a preset aperture design AND are RX specified.

And they are great lenses that do cover the Super 16 frame.

Voilà !



  • 0


FJS International, LLC

Wooden Camera

Willys Widgets

Media Blackout - Custom Cables and AKS

CineLab

Paralinx LLC

Metropolis Post

CineTape

The Slider

Rig Wheels Passport

rebotnix Technologies

Abel Cine

Technodolly

Aerial Filmworks

Gamma Ray Digital Inc

Broadcast Solutions Inc

Tai Audio

Ritter Battery

Visual Products

Opal

Glidecam

Abel Cine

Wooden Camera

Aerial Filmworks

The Slider

Glidecam

Willys Widgets

Tai Audio

Ritter Battery

Technodolly

Rig Wheels Passport

FJS International, LLC

Metropolis Post

Visual Products

Broadcast Solutions Inc

Media Blackout - Custom Cables and AKS

rebotnix Technologies

CineTape

Opal

Gamma Ray Digital Inc

CineLab

Paralinx LLC