Chinese 25mm f1.4 and 35mm f1.7 CCTV Lenses für Micro Four Thirds

    I found these 2 chinese lenses for $18 and $38 and wanted to give them a try.

    • C-Mount 50mm f1.4 covering a 2/3" sensor
    • C-Mount 35mm f1.7 covering a 2/3" sensor
    I'm trying to evaliate their usefulness for FullHD video recording and for 5MPx photography.
    Since they are f1.4 and f1.7, I'm comparing them to a completely unfair competition of modern high end lenses with similar apertures.

    • Panasonic/Leica 25mm f1.4
    • Voightländer 25mm f0.95
    • Voightländer 17.5mm f0.95
    My camera is a Panasonic GH2 (with hacked firmware but that doesn't change the results here).
    EX-Tele mod is not used. Aspect ratio is 16:9 . Thus the crop factor is 1.86 since it's a multi-aspect sensor and no regular  4/3 sensor.

    A normal 4/3 sensor would have 2.0 and a 16mm Blackmagic Pocket Cinema Camera 3.0 .
    These would have less of an issue with the blurry corners of these lenses made for 2/3" or 1"=3/3" sensors. We are using these lenses way outside their intended sensor size.
    • All Photos (Including other apertures. Scaled to FullHD due to Picasa quota.)

    Here are the references:
    Leica 25mm Voightländer 25mm Voightländer 17.5mm
    (All wide open at the fastest aperture)

    Panasonic/Leica 25mm f1.4

    Voightländer 25mm f0.95

    Voightländer 17.5mm f095

    Now the C-Mount 50mm wide open and fully closed.
    I know they are hard to compare since the focal lengthes put the C-Mount lenses at a disadvantage.
    On the other hand trees are known to have tons of detail at any field of view.
    C-Mount 25mm f1.4Add caption

    C-Mount 25mm f1.4 at >f10
    These photos have been scaled down to 1920x1080 FullHD since the lenses are completely unusable beyond that.
    Both lenses are extremely prone to stray light. So don't judge the contrast using these images.
    They must be used with a lens hood (no thread, must be improvised) or french flags.
    The center of the f1.4 image is somewhat usable if moving. Everything outside the center is so blurred that this only works out when it's
    • either a dream sequence or 
    • something in the center of the frame is to be shown in a very shallow depth of field anyway or
    • it's an action cam that's only visible for a short period with the viewer distracted by the action and the lens is at risk of being destroyed.
    Stopped down it gets somewhat better but why would you use this lens stopped down except to get lots of motion blur in an action sequence.

    Now the 35mm f1.7 C-Mount:

    C-Mount 35mm f1.7

    C-Mount 35mm f1.7 at >f10

    Same issues. Just another focal distance.
    These may yield slightly better results on a Blackmagic Pocket Cinema Camera due to the higher crop factor yet they still will be very blury outside the center.

    Both are nice toys where it's not important if they break or not since they cost next to nothing.
    For a few Euro extra you'll get some old Canon FD glass that may have purple fringing and just match the sharpness of these in the center but keep that sharpness into the edges.


    custom XL45 pulley for 8mm D-shaped shaft

    My CNC milling machine has a weak 4th axis.
    I want to attach a larger stepper motor with seriously mor torque.
    However that motor has a D-shaped 8mm shaft while an XL45T10 pulley always has a 6mm shaft.
    I ordered a conventional one, hoping to drill it up but it was stuck in transit (damn Hermes. An envelope would have worked better.).
    So I had to design a custom pulley that could me machined without a rotary axis (less of a top guard) and fits snugly onto an 8mm shaft.

    In fact, I'm 3d printing a first one and plan to do the final one with a full sized top guard on the, thus fixed, 4th axis.


    Email to Makerbot Industries support

    After this hilarious answers from Makerbot Industries to a discussion thread on Google+, I sent the following email to Makerbot Industries....let's see what the answer will be (and open our strategic popcorn reserves).
    The support-Ticket number is #121248.

    Aparently whoever manages your Google+ page is under the impression I would get actual help with any of the following questions:
    (I doubt it.)

    Device: Thing-o-Matic

    Is there any kind of support infrastructure to send in my bot in Europe to get the brownout fuses fixed,
    so the devices doesn't erase it's settings every time is stays connected via USB while powered off?
    (And a way to ship it without the extruder breaking off in transit.)

    Is there any "service kit" or similar to fix the following design failures in your after-sales suport:
    * inadequate mechanical extruder support
     (third mounting hole unused, stepper motor hangs in mid-air. Only supported by 2x M5 bolts through 5mm balsa wood with a 100mm lever for the heavy stepper to break that wood any time the bot is transported and thus shaken or even placed in a not-upright position)
    * Glued together lower parts of the "dinos" not connected strong enough for long-time usage.
    * any way to dismount the extruder for transport despite the next issue named here?
    * missing plugs on the cables to mount any of the alternative tool heads you sold without disassembling the entire machine just to swap between extruder, plastruder MKII or unicorn.
    * missing plug on the interface kit -cable.
    * missing mechanism to tighten the belt (or mount a fresh belt since they come 1-3mm too short to mount by hand and expand to be 1-3mm too long/wavy when in use.)
    * non thermoplastic replacement belts that don't expand and stay flat when heated often for long times
    * metal support tube to support the PTFE being supposed to stay cool yet being directly screwed into the hot-end, thus warming up the filament, causing it to expand and thus jam.
    (Using a dozen heat-spreaders and 2 fans to keep the effect of this design failure to a minimum at the moment. Not exactly pretty. RepMan 3.0 had a PEEK tube years before you started designing the ToM.)
    * The delrin plunger in your 6th generation extruder filament drive mechanism. (high friction, no spring, no lever. Thus shakes loose every 5 minutes and doesn't react in any way to minute changes in filament diameter. Everyone else hat this one sorted out while you where still playing with DC motors.)
    * Any official way to organise the cables in the lower "cable hell" compartment?

    as expected:

    Hi Marcus,

    Thanks for contacting MakerBot Support!

    Unfortunately, no, we do not have any official repair shops in Europe, or even in the USA, which can work on a Thing-O-Matic. We haven't sold this product in over a year, nor have any of our distributors to my knowledge, and there is at this point simply a lack of resources. For the same reasons, there is no available service kit.

    I took a look at your order, and it seems like we've got a record of some support parts being purchased back in June of 2011, but no record of your Thing-O-Matic being purchased through us. If it is the case that you purchased it through us, please provide your original order number so that I can look it up. If it is the case that you purchased it through a distributor, I'd recommend contacting that distributor to see if they have any repair parts available.

    If you have any other questions, feel free to let me know and I'll be happy to help!


    MakerBot Support
    Just as I expected.
    I didn' ask for any kind of repair. There's nothing broken. What's broken is the design itself.

    I ordered via a UK distributer since that meant european consumer protection laws apply. 


    new Zoom H4n camera rig handle

    I'm currently designing a new camera rig.
    Based on the idea of the RotoRig it shall be shoulder rig and travel-jib in one unit.
     However mine shall be CNC made and feature my camera-remote handle and a new version of my Zoom H4n remote control handle.

    So I designed the new handle and prototyped it on a 3D printer during GullaschProgrammierNacht.
    Next step: verify that it fits and CNC machine it in wood.#

    I already designed the other parts for the rig but they are too big to prototype on the crappy ThingOMatic 3d printer. So I'm planning to prototype them in cheap wood and later do them in aluminum.

    Update: Added photos.