Thread: DSMC2 Speedboster for everyone!

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  1. #11  
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    Quote Originally Posted by Jacek Zakowicz View Post
    We could convert these to a proper machined parts and add proper lens mounts, we already sell them anyway. If we could get , say 20 Redusers committed I think that would be doable...
    A metal lens mount would for sure be the optimal solution, but it feels very sturdy even with my 820g ZF.2 15mm f/2.8.

    I just printed 10 sets of this, thought maybe some would love the idea of owning a cheap speedbooster now rather tan later.
    A metal lens mount could be added later.

    By following the guide - i estimate that the work you have to do will not take more than an hour tops.
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  2. #12  
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    Quote Originally Posted by Jacek Zakowicz View Post
    We could convert these to a proper machined parts and add proper lens mounts, we already sell them anyway. If we could get , say 20 Redusers committed I think that would be doable...
    If the optical performance holds up I’m in!
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  3. #13  
    Senior Member Minu Park's Avatar
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    Quote Originally Posted by Jacek Zakowicz View Post
    We could convert these to a proper machined parts and add proper lens mounts, we already sell them anyway. If we could get , say 20 Redusers committed I think that would be doable...
    I am one of your dude always +1 here.
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  4. #14  
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    A metal lens mount would for sure be the optimal solution, but it feels very sturdy even with my 820g ZF.2 15mm f/2.8.
    Not even so much strength, but tolerance wise, can a plastic 3d printer even get within .010" ?

    Nick
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  5. #15  
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    Quote Originally Posted by Nick Gardner View Post
    Not even so much strength, but tolerance wise, can a plastic 3d printer even get within .010" ?

    Nick
    Aah, i see.

    The parts were printed with a layer height of 0.007874 inches / 0.2mm.
    I can print with twice the resolution, but it wold take double of the time.

    In the mount i have assembled and use there is a slight variation to either side. But for the max variation we are talking 0.14mm / 0.00551181102 inches.

    I am no optical engineer (I am an engineer though for my day job), but i guess that would be hard to spot in a scene.

    Maybe someone here have the experience with this?
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  6. #16  
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    Have you measured anything? Each layer being theoretically .008" is one thing, whats the margin of error and how many layers?

    Nick
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  7. #17  
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    BTW, not being judgy, mainly just curious. I have a machine shop, and it can be hard to hit tolerances for lens mounts with extremely accurate machine tools, so I wonder how melty plastic works ;-)

    Nick
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  8. #18  
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    Eirik, that's some good work there! I know that 3D printing filaments can be very strong and light, but as for precision, I have no idea. Nick has some good questions.
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  9. #19  
    Senior Member Jacek Zakowicz's Avatar
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    Given that speed booster is essentially a lens, it's performance is affected by the same errors as any lens. Tilt, decentration, backfocus location will all deteriorate the performance to a degree. For 3 micron Helium sensor pixels every bit of performance is needed. Obviously same goes for the lens mount.
    For playing around the plastic 3d printed .2mm precision is fine. For professional gear it is not. Plastic may or may not hold the glass securely and in the same location. Last thing one needs to worry about is the lens falling off or the OLPF dislodging and hitting the sensor cover glass. For back yard testing this is fine. For filming set/location it is liability, even if it holds up well which I think the OP says it does.
    We have three- any more takers?
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  10. #20  
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    Quote Originally Posted by Nick Gardner View Post
    Have you measured anything? Each layer being theoretically .008" is one thing, whats the margin of error and how many layers?

    Nick
    Sorry for the late reply.
    Fully understand your concern.

    Oh, i have spent alot of hours measuring. Both prior to making the parts and after printing the parts.
    The nice thing with FFF-printing (Fused Filament Fabrication) is that even though each layer is a few micro meter off the total steps for the motors will be the same. One layer can be "too high" and the next one will be squeezed a bit more flat.

    Not here to fool anyone, have already stated that a plastic lensmount isnt optimal, but it works.
    As for tolerances, just measured the same spot on all the 10 mounts i have available:
    • 17,21mm
    • 17,17mm
    • 17,22mm
    • 17,22mm
    • 17,25mm
    • 17,27mm
    • 17,17mm
    • 17,28mm
    • 17,27mm
    • 17,20mm

    Hence a variation of 0,11 mm / 0,0043 inches

    The nice thing is that both the speedbooster element can be screwed outwards a tiny bit to nail the infinity focus (If needed) and the sensor itself can be adjusted a tiny bit to get the infinity focus on point.

    My goal for myself was to avoid adjusting anything, and i am getting repeatable prints that hits the mark.
    The way i have been testing is using my ZF.2 85mm @F/1.4, then placing my camera-sensor-mark 2m from a vertical object. Due to the long focus throw in this lens it is very noticeable if anything is off.


    I have to get some better footage for sure, i do understand that people dont want to waste $550.


    For the approach itself - to making this - i used both my vello adapters i had for my A7SII.
    Speedbooster EF adapter depth: 25,9mm
    Regular EF adapter depth: 21,9mm
    There we get the necessary reduction of depth for the Redmount adapter: 25,9 mm - 21,9 mm = 4 mm

    The Canon EF RED-mount i measured to 22,2 mm.
    Hence my target depth for using this speedboster was 22,2 mm - 4 mm = 18,2 mm.
    I do see now that it ended up being 18,34 mm +/- 0,08 mm. Which is corrected by the speedbooster/OLPF holder.

    Hope this makes any sense.
    Last edited by Eirik Fiskkjønli; 08-18-2018 at 01:37 PM. Reason: spelling
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