foto lenses, backfocus

[Manolo S. Navazo]

hi people,

does somebody got an list from all available foto lenses with the backfocus distance?
i mean like all pl-mounts got normaly 52,000mm backfocus distance.
so would be interested to see which distance got fotography-mounts like perhaps nikon, canon, leica and a lot more.

thank you very much, manolo

[Kevin Halverson]

Here is the FFD for a few:

Canon EF 44.0mm
Canon FD 42.0mm
Leica R 47.0mm
Nikon F 46.5mm
Pentax K 45.5mm
Pentax M42 45.5
Olympus OM 46.0mm
Panavision PV 57.15mm

I am sure others can add additional information.

[Sanjin Jukic]

If I understood well that could be this

Camera mounts & registers (http://www.a1.nl/phomepag/markerink/mounts.htm)

or

Camera Mounts Sorted by Register (http://www.graphics.cornell.edu/~westin/misc/mounts-by-register.html)

[Manolo S. Navazo]

hi khmuse,

thanks for your fast response.

the photo-lenses are all lower than the pl-mount with his 52,000mm.

now, i don't understand how somebody could match a photolens to a pl-mount. i'm reffering to those pl-adapters from p+s technik http://www.pstechnik.de/en/downloads/optics_IMS_0708_web.pdf
those adapter mounts are all going outside. so perhaps a leica-r lens never could reach his 47,0mm
it would be impossible to sharpen an 85mm to infinity, would be more like an macro function lens.

perhaps somebody could explain me, or tell me if i'm wrong

thanks manolo

[Manolo S. Navazo]

hey sanjin,

thanks. thats a lot of info.
i like this page

[Kevin Halverson]

hi khmuse,

thanks for your fast response.

the photo-lenses are all lower than the pl-mount with his 52,000mm.

now, i don't understand how somebody could match a photolens to a pl-mount. i'm reffering to those pl-adapters from p+s technik http://www.pstechnik.de/en/downloads/optics_IMS_0708_web.pdf
those adapter mounts are all going outside. so perhaps a leica-r lens never could reach his 47,0mm
it would be impossible to sharpen an 85mm to infinity, would be more like an macro function lens.

perhaps somebody could explain me, or tell me if i'm wrong

thanks manolo

Hello monolo,

If you contemplating a simple adapter to use in front of a PL mount, then yes, there are very few lenses to choose from. The P+S mount system is not applicable as it is intended for their adapter system and its additional length would exclude even more choices. Other mounts, in place of a PL one can allow for both other cine and non cine lenses to be used.

Kevin

[Manolo S. Navazo]

Hello monolo,

If you contemplating a simple adapter to use in front of a PL mount, then yes, there are very few lenses to choose from. The P+S mount system is not applicable as it is intended for their adapter system and its additional length would exclude even more choices. Other mounts, in place of a PL one can allow for both other cine and non cine lenses to be used.

Kevin

don't have understand all, what do you mean with other mounts? you mean perhaps from canon to nikon? or something like that? or you mean some other pl-mount adapters? do you know some others fabricants for some pl-mount adapters?

an other thing i was thinking about, if you addapt a lens to your pl-mount-system/camera. you will also got false lens aperture(f) from your listed marks on optic, right?

but if you perhaps addapt an leica-r lens to your pl-mount, and the adapter truly goes in, to get the place in 47,0mm you will get better lens aperture. (so perhaps one diaphragm more, don't know the calculation). because the lens is now nearer the chip/emulsion, and the light has to pass less way.

-----------------edited version-------------------
i was sleeping one night, and it is bullshit, you don't will get better aperture, because you got same optical film distance like in a photocamera.

[dmartos]

You can find another list of lens mounts and their Flange Focal Distance (FFD) under "lens mount" in Wikipedia. Here's a link: http://en.wikipedia.org/wiki/Lens_mount

Other relevant info when considering using a home made PL - SLR adapter:

1. To use a PL - SLR lens adapter on top of the RED's PL mount without adding any new glass elements we would need to reduce the original distance.

2. Taking a wild guess at the new RED PL mount images, it looks like one can remove the "extension tube piece" and fix the PL mount some 16-18mm closer to the camera using shorter screws. Question is: Can this piece be removed? If yes, how much closer will we get to the camera?

3. Contax P+S lens adapters consists of a modified 7.5mm extension tube fixed onto a tube that ends on an Arri PL lens mount. The complete adapter adds some 26.50mm to the FFD, but the tube can be shortened. Otherwise they can't be too difficult to make using PL mounts from ARRI and thin extension tubes from the original lens manufacturers.

Conclusion: If one can remove the RED's piece behind the PL mount and make thin enough PL - SLR lens mount adapters, one can virtually use any lenses. The fine-tuning can be done easily thanks to the new RED's back focus adjustment technology.

Even better, if this system came directly from RED in the form of pre-calibrated adapters that would allow everyone to use a wider range of lenses and be able to quickly swap different mount types without the need of tools.

[BASSAM MSSALATIE]

take care don't break you camera :nuke:

[Kevin Halverson]

Adding an 'adapter' to a PL mount would only be an applicable approach for the few lens families that have a greater FFD than a PL (like a PV). The better approach is a mount that replaces the PL one that allows for a series of different lens families with the correct FFD for each.

The mount we developed for the Canon FD accomplishes this and we are looking at modifying the design for a number of other lens families. RED is already committed to making a Nikon F mount, we have a Canon FD one now and are looking at a Leica solution too.