F35 focal reducer/speed booster mod

[Hunter Hampton]

Just an idea here, looking to see if its even possible. Love to hear your collective thoughts:

Idea:

1. Take speed booster for E-mount
2. Remove focal reducer optical block (the part that makes it a "speed booster")
3. Insert "speed booster" block into housing that slides into F35 lens port
4. Gain 1 stop in sensitivity/DOF when used with appropriate lens

Why do this:

1. Would breath even more life into F35 by allowing you effectively "increase" the native ISO to 900 instead of 450 in S-Log gamma. Would really come in handy for low light scenes as you would gain 1x stop.
2. Would allow for very shallow DOF/Easier access to wider angle lenses
3. The f35 has some serious FILM Like mojo, this would allow night scenes to be captured on f35 that are currently not possible

Why this might work:

The optical block in the speed boosters is pretty thin and narrow- It MIGHT be physically possible for it to fit into a housing that slides into the F35 lens port up against the glass filter in the f35 lens port. No permanent camera modification needed.

What are some possible issues to consider:

1. Focal Flange Distance (may not be possible)
2. Would require longer PL lenses or 35mm SLR lenses (in order to shrink down the larger image circle to super 35 and gain the stop)

What do you think? Is this even worth considering? Am I crazy? (YES!)

[Hunter Hampton]

booster-31.jpg
Just remove the glass block pictured: metabones-speed-booster.jpg

[Hunter Hampton]

Insert "speed booster" Block into something like this that fits ID of f35 lens port-> Screen Shot 2014-01-31 at 4.44.57 PM.jpg



Slide small housing into f35 port until it rests against the protective glass here->Screen Shot 2014-01-31 at 4.44.16 PM.jpg

(Its kinda similar to the ALEXA filter module- but with a speed booster )

[jo kami]

This would be a serious game changer if possible! @Barret & Dave , we have faith!

Here are the flange focal distance for E mount and PL. Would the filter near the sensor get in the way?

Sony E-mount

18 mm

Arri PL

52.00 mm

@Hunter, I'm not able to see the attchements, something about it being invalid...

[keithlango]

How many pieces of glass are in the Speedbooster block? The circumference of the glass definitely looks like it could slide into the PL mount opening. I wonder what the FFD of the Speedbooster is.
But I think you're onto something for sure.

EDIT: Thanks, Joe! You posted the answer just as I asked the question. The internet wins!

[Hunter Hampton]

Fixed the attachments- I think FFD would be changed a bit closer but a small part of me believes it just might be within range of what we have to work with in distance.

[Hunter Hampton]

Keith- I believe there are 4 elements but generally how these kind of optics are designed is that they are all individually put into one threaded container- then that single container is screwed into the housing. So I would imagine if you had a speed booster, you could literally screw out that entire block as one piece and screw it into a new piece you made to slip into the f35 (in an ideal world).

[Mitch Gross]

While I was still at AbelCine we did this for a custom solution for a client's Phantom camera. That camera has a lot of open room behind the PL mount so it was feasible, but not cheap. This is not something to be "dropped in" but instead has super-tight tolerances. I haven't looked into the front of the F35 lately but I seem to recall that the camera's flange depth was adjusted by a fairly complex mechanism which was also quite robust. So that would be something that would need to be engineered around.

A project like this would likely cost a good $10K to have someone develop. Of course if that was spread out over half a dozen F35 owners then it's not so bad, but such tasks are not simple to attempt.

[Grug]

I'd say the best bet for this would be to have an e-mount machined into the front plate in the same way that people have done F-mounts (assuming there's enough space to allow it). This would then open up a host of mechanical adapters that could be used.

[Jusgorilla]

Have often wondered about the possibility of a speed booster in a F35. I'll ask Tink (lens and camera engineer that did my PL to Nikon mod) what he thinks, he loves a challenge.
The F35 IR filter might be a bit of a problem, eating valuable distance from the sensor.

But I'd be tickled pink if we could actually do this! extra stop, YES please!