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Leicina Special + Lens + 2X Anamorphic


Carl Looper

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I'm after information on what prime lenses, apart from the one specifically designed for the Leicina Special (the Cinegon), can be used with the Leicina.

 

My understanding is that lenses designated as "Leica M Mount" lenses are compatible. But are there any ambiguities in lens designations (out there in the real world) that might cause confusion when looking for "Leica M Mount" lenses? Or is the designation specific enough to elliminate incompatible lenses?

 

In addition - what other lenses (other than Lecia M Mount lenses) can be used (with or without adaptors)?

 

In particular I'm looking for a suitable prime for the Leicina that can be used in conjunction with an Iscorama Iscomorphot 2X Anamorphic lens.

 

My understanding is that a wide-angle lens (such as the Leicina specific Cinegon) will be too wide for the anomorphic. I've read that lenses around the 40mm mark are about the widest one should go when using the 2X anomorphic.

 

I realise a special mount will be required but I can build that.

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Carl,

 

Can you provide greater specifics re: your 2x anamorphic attachment? The majority tend be 16mm projector optics. My Kowa/Bell Howell 2x has roughly a 58mm rear thread.

 

Here is my sketch of a proposed adapter to mate generic front thread prime lens with 2x front anamorphic adapters, i.e.

http://picasaweb.google.com/nkovats/AnamorphicAdapterProject#5189281243088741858

 

Which was translated into a CAD/CAM prototype by a Prof. Richard Kinch, i.e.

http://www.truetex.com/kovats2.pdf

 

Here is a simple test utilizing a Beaulieu 4008 + C-Mount 8-64mm Angenieux + step up ring + 2x Kowa/Bell Howell anamorphic. The actual 2x anamorphic uncompressed factor in conjunction with the 1.33 S8 aspect ratio resulted in a "Super" widescreen aspect ratio roughly equivalent to 2.66. I forget the focal length cutoff point as reported by my shooter. Note the anamorphic skew, i.e.

http://www.youtube.com/watch?v=ZrvQCV2kfn4

 

I have the 10mm Cinegon. I suspect that it may work and I might be tempted to completed this project + setup but I have once again been seriously distracted by my proposed native spherical 8mm 1:2.4 Cinemascope project. :)

 

Not a heavy anamorphic adapter in sight, no skew, no alignment, nada. However I might change mind again considering how much I admire classic anamorphic originated bokeh.

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I'm after information on what prime lenses, apart from the one specifically designed for the Leicina Special (the Cinegon), can be used with the Leicina.

 

My understanding is that lenses designated as "Leica M Mount" lenses are compatible. But are there any ambiguities in lens designations (out there in the real world) that might cause confusion when looking for "Leica M Mount" lenses? Or is the designation specific enough to elliminate incompatible lenses?

 

In addition - what other lenses (other than Lecia M Mount lenses) can be used (with or without adaptors)?

 

In particular I'm looking for a suitable prime for the Leicina that can be used in conjunction with an Iscorama Iscomorphot 2X Anamorphic lens.

 

My understanding is that a wide-angle lens (such as the Leicina specific Cinegon) will be too wide for the anomorphic. I've read that lenses around the 40mm mark are about the widest one should go when using the 2X anomorphic.

 

I realise a special mount will be required but I can build that.

40mm may be enough for a 35mm frame, but for super 8mm a 10mm anamorphic would be ideal. With a 2x anamorphic, the horizontal field of view is compressed, so a 10mm would yield a 5mm equivalent field of view horizontally. Supposedly, there exists a 10mm anamorphic prime C mount lens. Quite rare I expect, I have never been able to find one, just here about it on chat sites like this one. Let's all petition Vantage films to make a V Lite 16 10mm, both 1.3x and 2x.

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Chris,

 

I believe you are referring to the rare Beaulieu Super 8mm anamorphic c-mount lens with a 10mm prime taking lens which I believe was a Schneider optic possibly Cinegon. The anamorphic front taking lens was an Isco product.

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  • 3 weeks later...

Can you provide greater specifics re: your 2x anamorphic attachment? The majority tend be 16mm projector optics. My Kowa/Bell Howell 2x has roughly a 58mm rear thread.

 

Hi Nicholas - hope you have had a great xmas and happy new year.

 

If you do a search on 'Iscomorphot 2X Anamorphic' you'll find (apart from this discussion!) some pictures on the lens, and what some have done with it. The lens was specifically designed for Super 8 projectors.

 

I've tested it with a Canon EOS - just holding it in front of it's zoom lens, and taking some snaps - and the vignetting is definitely gone at the 55mm focal length. I can probably take it a little wider, but will need to do more exact tests (rather than handheld ones).

 

For the handheld tests I found there was some chromatic distortion towards the edges, but that such was easily correctable. There was also some barrel distortion but likewise easily correctable. Otherwise, and more importantly, the image was very sharp across the entire frame (using the Canon auto focus).

 

Now this is how I'm determining the required lens, assuming 55mm lens on the Canon (which could probably go a little wider)

 

The Canon's sensor size is 22.2 x 14.8 mm

The Leicina "sensor" size is: 5.3467 x 4.01 mm (Super 8 camera frame)

 

The vertical ratio (between sensor sizes) is 3.691 : 1

 

So dividing the focal length of the test lens (55mm) by 3.691, gives a requirement for a Leicina compatible lens of:

 

15mm

 

The angle of view, with the anamorphic lens, would be:

 

V = 2 * atan 2.005 / 15

= 15 degrees

 

H = 2 * atan 5.3467 / 15

= 39 degrees

 

Now 15mm is definitely safe, but I may be able to go a little wider than 15mm because the test camera has a wider aspect than the Super8, ie. some slight vignetting appearing on the test camera may still be out of frame on the Super 8.

 

Carl

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40mm may be enough for a 35mm frame, but for super 8mm a 10mm anamorphic would be ideal. With a 2x anamorphic, the horizontal field of view is compressed, so a 10mm would yield a 5mm equivalent field of view horizontally. Supposedly, there exists a 10mm anamorphic prime C mount lens. Quite rare I expect, I have never been able to find one, just here about it on chat sites like this one. Let's all petition Vantage films to make a V Lite 16 10mm, both 1.3x and 2x.

 

Yes a 10mm c-mount iscorama-cinegon lens does exists, see attached photo

post-29386-0-40791000-1294271307.jpg

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Yes a 10mm c-mount iscorama-cinegon lens does exists, see attached photo

 

Thanks for your posting of your rare anamorphic beast. However this anamorphic produces a 1.5x compression not the 2x factor Carl has calculated above.

 

What is attractive about your setup is that I suspect ISCO internally matched up their anamorphic front end with the 10mm Schneider prime lens elements fairly well. Unlike the adhoc setups we are discussing.

 

Do you have any test footage you can share with this group?

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Thank you Carl. It was lovely and quiet. And yours?

 

Thanks for the calculations. By the way where did you get the S8 frame height? i.e h=5.3467? SMPTE? Such 4 decimal precision. :)

 

By the way did you happen to come across my new project on the "other" forum?

I revived an 8 year old thread and I call it native 8mm spherical Cinemascope. :)

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Thanks for the calculations. By the way where did you get the S8 frame height? i.e h=5.3467? SMPTE? Such 4 decimal precision. :)

 

I just used a nominal vertical height of 4.01 mm (that I picked up from somewhere) and 4:3 aspect

 

4.01 / 3 * 4 = 5.346666666 ...

 

There are conflicting numbers around. Apparently the frame is exactly 4:3. Someone told me off once for suggesting otherwise - but I was using numbers from here (which are probably wrong)

 

http://en.wikipedia.org/wiki/File:8mm_and_super8.png

 

These are probably right:

 

http://www.super8data.com/database/articles_list/super8_fotmat_standards.htm

 

But in the above the specified camera frame isn't 4:3 - it's slightly wider:

 

camera frame width = 5.69 mm

camera frame height = 4.22 mm

 

But anyway, if using the above numbers:

 

14.8 mm (canon sensor height) / 4.22 mmm (Super8 sensor height) = 3.5 (scale factor)

 

55mm (canon lens) / 3.5 (scale factor) = 15.7 mm (required Leicina lens)

 

Carl

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