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David Baron

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Posts posted by David Baron

  1. Always be aware that many compressions really do a number to the shadows. If you under expose on certain cameras that use a lower bit-rate you might get smearing in the shadows (not the case on the f7, but this almost killed me on a movi shot using a GH4).

     

    I would always rather have to pull down the shadows in post than risk loosing detail in the shadows of an under-exposed image. Light the faces 1-2stops under anticipating the grade but no more than that. This will help highlights or hard hits of lights from being over.

  2. Thank you so much Charlie for the very thourough response! This has definatly gotten me on the right track with this motor. I have been on-set the last few weeks and haven't had a chance to take a look at this untill now.

     

    The phase shift attachemnt on my motor will have to stay on - I removed the caseing as suggested and the output shaft on the motor has been replaced by the long plastic accessory seen in the photo. On the output side of the attachment is the ball-like clutch connection but on the input side to the accessory is a gear that connects directly to the motor. The original output shaft was not included with the motor.

    post-67054-0-06032000-1422545671_thumb.jpg

    post-67054-0-03624300-1422545683_thumb.jpg

     

    I removed the phase shift accessory by removing the caseing and then removeing the 3 screws seen in the second photo above.

     

    It appears that the gear ratio of the accessory is VERY slightly less than 1:1. It took me some time to notice this because it is so slight but the attachment appears to slow down the output of the motor slightly.

     

    My best guess would be that it takes the framerate from 24fps to 23.976 for recording NTSC systems?

     

    As for the power supply unit - Charlie, do you have any idea how they manage to go from a 1phase 120v source to 3phase 42v? Also - inside the motor, I see 4 wires going into the windings but industial 3-phase motors only have 3 wires plus chassy ground - is this motor not a regular 'Delta' or 'Wye' three phase motor?

     

    I am pretty sure I could create a powersupply/controller for this motor that chops a 42VDC supply at 60hz (120deg out of phase with each other) and provide the required 8VDC to the auto-clapstick and camera controls.

     

    Thanks again! This has been a very good first experience on cinematography.com!!

     

     

  3. This is an optional motor that plugs into the mains through a transformer. I have also used the variable and constant speed motors for this camera. My motors run at the original 8volts although i think many have been modified to work on 12v.

  4. Hello!

     

    I have been trying to outfit my Arriflex 16MB with a sync motor for music videos or similar (knowing how loud my camera is). I purchased a 60hz - 42v sync motor without its transformer for a reasonably low price on ebay. I shouldn't have any trouble building my own transformer but the connector on the motor is a little confusing to me.

     

    Does anybody know what the pins are on these 60hz - 42v motors? I assume there is a ground, pilot tone, +/- 42v, maybe a secondary at 8vdc for the torque motor on the SB model?

     

    Any help would be appreciated!!

    post-67054-0-13734900-1421720454_thumb.jpg

    post-67054-0-18582300-1421720462_thumb.jpg

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