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For sale: Crystal Stabilized Stroboscope Lights (for testing movie cameras)


Aapo Lettinen

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Hi you all!

I designed a small led stroboscope light for testing crystal sync accuracy of movie cameras. It is a crystal stabilized strobo, very accurate flashing speed and can be powered with power supplies of from 8 volts to 26 volts (for example with a 9v battery) .

These are supposed to be as affordable as possible so I decided to sell them without case to save about 50% on the assembling costs and because they can normally be used just as is. All the controls are possible to wire to external switches very easily so you can make a housing for it by yourself if needing one ?

They have 4 crystal flashing speeds:  16fps, 18fps, 24fps and 25fps. Duty cycle adjusted for perfect balance between light power and motion blur. There is 2 jumpers and a reset connector on the circuit board to change the speed and one can wire these controls to external switches if needed.

 

Price is 70 euros a piece + shipping costs. PayPal or wire transfer possible. EU VAT purchases possible too if you need one for your company.

I can assemble 10 of these for short notice and more is possible to make with longer lead time.

I am hand assembling these in Finland for them being a relatively rarely asked niche product (if you need 100 or more, I can offer factory assembled ones which are more affordable)

 

Photos!  (final model without finishing touches)

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How these are used then?

Set up the desired flashing speed and shine the light to the movie camera's shutter (either directly or through the viewfinder optics).

Start the camera.  If the camera running speed is exactly the same than the stroboscope light's flashing speed, the shutter seems to stay completely still and you know the crystal sync of the camera is accurate.

If there is difference between the speeds, the shutter seems to move at the rate of the speed difference and to the direction where the speed difference is.

For example, if the camera is running at 25fps and the stroboscope is flashing at 24 fps and the shutter normally rotates clockwise, the shutter seems to be running one revolution a second to the clockwise direction if inspected under the stroboscope light. If the stroboscope is 24.00fps and the camera's real running speed is 23.90fps, the shutter seems to rotate counterclockwise one revolution for every 10 seconds.

Phase difference issues and mechanical friction based issues can be inspected as well. If the camera is perfectly locked in phase and speed, the shutter seems to stay completely still under the stroboscope light or only wander very little back and forth like 1/10th or 1/20th of a revolution depending on the camera model. IF there is phase issues or mechanical issues, the shutter wanders much larger amount, for example half a revolution or full revolution back and forth or more.

 

I will make a video how to use these when getting some of them sold.

The possible profits from these are used for developing new movie camera crystal sync systems

so this is a great opportunity to support the ongoing crystal sync modifications and updates I am working on (Eclair ACL,  CP16R, etc.) ?

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One stroboscope board sold and shipped!

I will make a new batch next week (probably 3 pieces) and can then ship more if needed.

Anyone needing a crystal stroboscope board, PM me or post here ?

Shipping costs are typically about 10 euros if untracked (slower shipping and no paypal buyer protection) and from 25 to 30 euros for tracked packages (buyer protection and tracking available).  If you order more than one board the shipping would be free ?

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Prices changed to USD from now on to ease the paypal payments. No price changes, I just converted them to dollars :) 

Stroboscope board 73 USD 

Tracked shipping usually from 26 to 31 USD depending on location.

Untracked shipping can usually be arranged for about 10usd or so depending on location

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just as a comparison, the "original" stroboscope lights made for testing movie cameras are extremely rare and VERY expensive if one happens to find one on sale. There seems to be one  Cinematography Electronics Stroboscope on eBay... the asking price 1500usd!

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My stroboscope board is designed to be as affordable and easily available as possible so that it is truly possible to quickly get a stroboscope for testing your camera if you need one (73 usd for the board and I have parts for assembling multiple boards quickly if needed, almost always having a board or two readily available for immediate shipping) ?

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I assembled the rest of the boards from the batch today. The next batch will probably be in December2022 earliest or might be delayed even to Autumn2023 if there isn't enough demand for them in the winter.

There is 4 crystal stroboscope boards from this latest batch available at the moment.

When these run out one needs to wait at least half a year before getting more of these, so now is a good time to purchase one if needing them in the near future ?

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