Petition-worthy: SpeedBooster PL-MFT mount

M

mcbob

Veteran
OK, sorry to start yet another, but I suppose until we have a dedicated "SpeedBooster" forum....


I haven't seen such a beast announced... yet if the white paper states that DX coverage lenses will be adaptable to MFT, it stands to reason that S35-covering lenses would likewise be adaptable to MFT.

Is there any reason, aside from budget, that you wouldn't want to rent/own a Cooke "14-71 T2.2" or a newer Canon CN-E "10-42 T~1.8" for use with these cameras?

Surely there's enough of a market with AF, GH, and BMCC to make this venture worth their while. For what it's worth, I've sent them an email. With enough interest, maybe something will happen.
 
Maybe instead of a dedicated mount, they could work on a "universal" speed booster base, with interchangeable mount fronts. That way you could buy the $600 base, and add a Nikon, or Canon EF, or PL mount front to it... ?
 
I'm pretty sure they have to have different optical designs for different FFDs. So that probably wouldn't work.
 
S35 PL to m4/3 is only a 1.36:1 reduction in image circle. You would pick up about 1.3 stops of aperture. There is no magic here. You are reducing a larger image circle to a smaller one and concentrating the light gathering power of the lens at a higher density on the smaller area.

Cook did this with their S35 30-60 T3 Varopanchro, producing a 10-30mm S16 T1.6 version. 2:1 reduction in image circle and a 2 stop increase in max aperture.
 
Last edited:
"S35 PL to m4/3 is only a 1.36:1 reduction in image circle. You would pick up about 1.3 stops of aperture. There is no magic here. You are reducing a larger image circle to a smaller one and concentrating the light gathering power of the lens at a higher density on the smaller area."

Well of course it's not actually magic. ;)
 
Adamsenoj said:
I'm pretty sure they have to have different optical designs for different FFDs. So that probably wouldn't work.
Click to expand...
No. FFD is actually just an arbitrary distance somewhere between the imager and optics where each camera manufacturer chose to put the lens-camera split, it doesn't actually have anything to do with the optical characteristics or design (so long as everything fits physically).
 
Actually they said they already have a PL mount in the works.

I inquired a few weeks ago.
 
Kholi said:
Actually they said they already have a PL mount in the works.

I inquired a few weeks ago.
Click to expand...

As I understand it, the concept works with mirrorless mount cameras because we need enough space in the adapter to have the speedbooster glass element. An APS-C EOS camera body, for example, can't have a FF speedbooster for the same reason it can't adapt FD lenses and maintain infinity focus. So, I was about to write a PL mount is less likely because I thought it had less room between the camera and lens than older FF photography mounts. But if they say it is in the works, I guess there IS still enough room. What is the PL mount flange distance again? 50-something mm?

...but that got me thinking. Usually a glass element between the lens and sensor to correct focus is a bad idea, because it will introduce more defects and loss of light, etc. But because the speed booster concept makes up for that, maybe adapters for additional types of lenses are possible? Full frame FD to cropped EOS? I see many possibilities here...
 
PL (on a digital camera) is the original "mirrorless" design. On a film camera, there's a mirror in there, but in the digital cameras it's a straight shot through to the sensor, just like a mirrorless camera. So a PL SpeedBooster would seem to be easily do-able.
 
Barry_Green said:
PL (on a digital camera) is the original "mirrorless" design. On a film camera, there's a mirror in there, but in the digital cameras it's a straight shot through to the sensor, just like a mirrorless camera. So a PL SpeedBooster would seem to be easily do-able.
Click to expand...

I was arguing the other way around- SLRs have the glass further away from the sensor/film to leave enough room for the mirror. Mirror-less mounts don't need as much room since they do away with the mirror and spring mechanism, and are therefore designed to focus on film/sensor that is closer to the glass than a mirrored equivalent. Unless I'm just confusing myself, it would seem to me that this is why mirrorless mounts can adapt more types of lenses (shorter flange distance).
I'm under the impression that PL mounts have shorter distances precisely because they weren't designed for mirrored bodies. Unless I'm completely throwing myself off here.
 
M. Gilden said:
I'm under the impression that PL mounts have shorter distances precisely because they weren't designed for mirrored bodies. Unless I'm completely throwing myself off here.
Click to expand...
The cameras that the PL mount was designed for (Arriflex film cameras) have rotating mirror viewfinder systems, and a healthy flange depth of 52mm.
 
Adapting PL lenses to work on mirrorless -- very easy. And easy to make a SpeedBooster that can accept PL.

Adapting anything to work on PL -- very difficult. A SpeedBooster for a PL-mount camera is highly unlikely. It would, as you say, require an optical element to refocus the image.
 
Barry_Green said:
Adapting PL lenses to work on mirrorless -- very easy. And easy to make a SpeedBooster that can accept PL.

Adapting anything to work on PL -- very difficult. A SpeedBooster for a PL-mount camera is highly unlikely. It would, as you say, require an optical element to refocus the image.
Click to expand...

I think that's sort of what I was getting at, but I'm lost in my own explanation. But I'm picturing using Speedbooster tech to make anything compatible with anything! Might not be practical to produce cost effectively. But so many possibilities!
 
I've mentioned in other posts that we now have Zeiss, Canon and Duclos PL grade lenses available in Nikon and Eos mount, how about just swapping out the lens mount in the CP2s or ordering the Eos mount CE lenses and fitting those to the speedbooster?
 
Chances are, a m43 user delving into PL lens territory may well not own PL lenses; if they had enough money for them, they'd probably have a "better" camera as well.

A Speedboosted PL-MFT mount would give these frugal shooters an ad-hoc S35-sized sensor camera and wider flexibility in renting PL cine lenses as needed, or optimizing less expensive used PL cine zooms for m43 use.
 
Stills lenses full frame must have clearance for the mirror box used in DSLRs

This mean there is a lot of space between the rear element and the sensor.. I am not sure that PLs are retrofocal like this and therefore may not have enought space.. ??

S
 
PLs, in general, have lots and lots of space. They're designed to work on mirror cameras; 35mm movie cameras all have mirrors in them.

There are some PL lenses that don't have as much space, such as the Angenieux Optimo DP series; lenses that were designed specifically for digital cinematography may have optics that protrude further into the mount.
 
You must log in or register to reply here.
Back
Top