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


Dan Berube

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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

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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.

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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-

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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.

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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'.

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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.

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  • 1 month later...

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 !

 

 

 

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