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BUILDING MY OWN PRE-FLASHER


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#1 Matt Pacini

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Posted 15 September 2005 - 12:57 PM

I am (along with my nephew with a huge brain) am building a pre-flashing unit inside my CP-16R/A.

Just wondering if anyone here has made their own, and if there's any advice you would give?
Looks like I'll have the ability to control the intensity of light, as well as the ability to control the color temperature, by either:
A. Separate RGB controls.
B. A simple filter slot, perhaps even one that will take the CP-16 filter holders, which I already have right there inside the camera.

Which would you do?
Probably going to use LED lighting, to get around how tungsten bulbs go orange over time, etc.

I've never done flashing before, so obviously I'm going to have to shoot mondo tests, but perhaps some of the more experienced people here can give me some advice & pitfalls about that.

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#2 John Pytlak RIP

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Posted 15 September 2005 - 01:28 PM

For in-camera flashers, getting a UNIFORM flash is usually the biggest challenge. Obviously the flash must be uniform across the entire frame, but if it varies from frame to frame, you could see it as flicker.

Give some thought to a flashing device that puts light on each frame by using a beamsplitter.

If you decide to use LED's, match their colors to the film's spectral sensitivity peaks:

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#3 David Mullen ASC

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Posted 16 September 2005 - 12:53 AM

The Panaflasher is a pretty simple device. Brightness of the light flashing the film is controlled by having one slotted disk (sort of pie slice openings) rotate over another set of slots. So as you rotate the disk, more or less light gets through without altering color temperature (the light bulb is a little warmer than 3200K, so there's a pale blue screw-on filter over the light and other filters can be added to color the flash.)

The main thing is that the Panaflasher uses some sort of built-in Minolta light meter parts so that you can measure the EV value of the flash and adjust to the level you want consistently.
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#4 Matt Pacini

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Posted 16 September 2005 - 12:55 PM

Thanks David, that's extremely helpful!
We were discussing whether or not to go with an electronic, or physical solution to the intensity function, & I'm going to stick with whatever is proven to work.
Thanks!

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