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MusicalPhotog
22-Jul-2019, 12:42
I have a small collection (~18 or so) of LF lenses; many of them convertible. So in experimenting, I discovered that most of my lenses in Copal #1 shutters can be swapped out and 'inter-mingled' with others of different types and manufacturers to yield in-between focal lengths and different effects. (I swear one of my 'crossings' even gave me a Petzval-like swirling background. Unfortunately I have not been able to reproduce it; so I may have been dreaming...)

Has any of you distinguished members tried doing the 'Convertible Cell Shuffle'? Any winning combos you would like to share? (With corresponding images?)

Thanks!

Jim Noel
22-Jul-2019, 13:48
I have a small collection (~18 or so) of LF lenses; many of them convertible. So in experimenting, I discovered that most of my lenses in Copal #1 shutters can be swapped out and 'inter-mingled' with others of different types and manufacturers to yield in-between focal lengths and different effects. (I swear one of my 'crossings' even gave me a Petzval-like swirling background. Unfortunately I have not been able to reproduce it; so I may have been dreaming...)

Has any of you distinguished members tried doing the 'Convertible Cell Shuffle'? Any winning combos you would like to share? (With corresponding images?)

Thanks!

SOunds like a very interesting idea. I may copy it.
Jim

John Layton
22-Jul-2019, 14:16
There was a guy who I remember from a photo trade show years back (I think the 2002 View Camera conference in Albuquerque) who specialized in this sort of element and cell mixing - had it down to an appropriately loose science and it was very fascinating. He also made a business of this which was (I think) located in Chicago. For the life of me I cannot remember his name, nor the name of his business. Anyone?

mdarnton
22-Jul-2019, 14:20
http://www.glennview.com
Is this the person?l

Pere Casals
22-Jul-2019, 15:24
Very interesting !

I'll try it !

MusicalPhotog
22-Jul-2019, 15:57
So far, the lenses I've tried out are:

Symmar Convertible:
150mm f/5.6
180mm f/5.6
210mm f/5.6

Nikkor-W 210mm f/5.6
Nikkor-T 360mm f/8

Fujinon-SF 180mm f/5.6

Since I was just 'goofing around,' I didn't take notes of what went with what. I will need to go back and adopt a more scientific approach, paying particular attention to what's out of focus, as well as what's sharp. I do remember a couple of strange ones, though.... One combo gave me the converted value (I believe it was 370mm from the 210) with a front set. And it looked really sharp. Again, I'll need to sit down and note things like lens combination, bellows draw @ infinity, aperture (relative to available light), and of course any notable effects (such as a swirling background).

BTW: the Nikkor-T really did some interesting things. I'll need to explore this lens more carefully.

More to come, so stay tuned!

Pere Casals
22-Jul-2019, 16:47
notable effects (such as a swirling background).

This is to happen when entrance or exit pupil limits the aperture, it can be seen only in the Out Of Focus, as you stop the swirl disapears because in that case the aperture is not limited by the entrance or exit pupils.

The cells in from a convertible are individually corrected, so the swapping may give a better image than when swapping cells from non convertible lenses, in that case only the full lens is well corrected.