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aerial image telecine


Rolando Fernandez

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i have chosen to go a different way. As i had an editor that was pretty useless cos it gave a very dark and rubbish image, i decided to recycle it's transport mechanism to do a slow frame by frame capture.

I had a broken DVD player that was dismantled and is now acting as my chassis. I'm using it's power supply as it had +2, +3 ,+5 and +12 v outputs. 2v go to the motor via a switch. 5v go (via a 1.2 ohm resistor) to a 3w Lumiled that is used to light the film ( i used an old camera translucent lens cap as a diffuser and it works quite well)

For 9 euros i bought a used low gear dc motor and it is attached to the take up reel. The sprocket is still used but no power is applied, i only use it as a trigger via a microswitch that is connected to a left button in an old mouse.

At the moment i'm using a 55mm pentax slr lens inverted as a close up lens. I put my Canon xl1 in front of this lens and i have a nice magnified view of the film. Only trouble is to align perfectly the cam with the lens to avoid vignetting. As soon as i have more cash i'm going to get a Canon compact digicam (no mechanical shutter) that can be remotely operated via software and save automatically images on hard drive. It should manage to keep up with speed as at the moment it's about 1fps.I'll probably get a proper close up lens as well like the Raynox 250 or similar. For the moment i'm experimenting with the XL1.. i still have to get synch right with the microswitch , for some reason it doesn't click always at the right moment so i have a lot of jitter because every frame is captured at slightly different moments... but i think that moving around the switch a bit should solve the problem .. i just need more time.

Here are some pics:

keep in mind that this is still very experimental and most important very cheap: i tried to recycle as much as possible and at the moment it has cost me around 15 euros (motor and LED)...

 

Front view of the assembly (if you dare call that an assembly)

Front view of assembly

 

 

DC Motor with switch connected to take up reel:

DC motor

 

 

Lighting and lens. The wooden block supporting the lens is now much shorter so i can put the Canon XL1 right up against the lens:

 

Lighting and close up lens

 

 

I don't have any clips or frames at the moment to show cos i forgot them in my pc at home, and the clips were too jittery anyway. I'll post updates a.s.a.p

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Hi, very interesting setup, for the frame jitter problem I will replace the slow gear motor by a stepper

pulse controlled motor , that way your micro switch will be always in sinc with the capture time.

 

Also you can use the stepper motor pulses as your trigger signal for the software.

 

very nice!

Edited by Rolando Fernandez
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Hi, very interesting setup, for the frame jitter problem I will replace the slow gear motor by a stepper

pulse controlled motor , that way your micro switch will be always in sinc with the capture time.

 

Using a stepper motor would complicate things a lot. You have to consider that using the take up reel as the main transport, the speed changes from the beginning of the reel compared to the end of reel (film is moving slower at the start 'cos radius is lower and it's moving faster towards end of reel), so for example 10 impulses to the motor could correspond to an exact frame in the first feet of film, but would not be correct for the last feet of film, so i would need a 'sensor' anyway to know when the frame is correctly positioned.

If i can't get the microswitch to work properly i was thinking of using a fotosensor that commands a relay to give the mouse click. With a bit of tuning the fotosensor should recognize film perforations; this way i can get rid of the sprocket all together leaving only 2 rollers to physically touch the film.

Now i'm leaving the office and it's back to home to fiddle with the switch a bit..

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Your right about the linear speed change.

 

Well I did't mean to move the film by the take-up reel , the stepper is for moving some sprocket gear that

a single pulse will position the individual frames in front of the lens.

 

Now that I see more clearly the photos it looks like you don't use a frame guide or sprocket gear?

 

Do the film is in constant movement or for some fraction of a second it stay still?

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Now that I see more clearly the photos it looks like you don't use a frame guide or sprocket gear?

Do the film is in constant movement or for some fraction of a second it stay still?

 

No, i don't have a film guide at the moment. I guess that's the main problem. The microswitch gives some resistance on the sprocket teeth and this does make the film move a little when it is released. I guess i need to put some tension on the film between the sprocket and the lens so it keeps more still. Yesterday i changed a bit the position of the microswitch and things are a bit better, but still each frame is captured in a different instant.

Here is footage filmed on minidv as the film is moving. You can hear the clicks of the microswitch:

 

Footage filmed from XL1

 

 

And here is the resulting clip captured to PC:

Captured footage

 

It's a bit orange cos i was using Wittner100D film and forgot to remove daylight filter.....

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Ok, remove the take-up reel an let the film drop in a bucket (use gravity) then use a sprocket gear to pull the film in an intermitent movement and place a frame holder to prevent vibrations an bending of the film.

 

Remember cameras and projector always use intermiten movement no matter the speed.

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After working with diferent way to DIY telecine I found this to be of a very decent quality results.

 

http://super8todv.free.fr/

 

pardon my french.

 

A some time ago, the russian skilled craftsman upgraded of standard Super 8/ norma8 cine projector RUS on device for telecine.

The projector had DC, variable speed motor ( original ), crystal sync speed controller ( new ) and take away of shutter disk and replace of bulb on low power light screen.

RUS prodector have contacts and give of pulse of every frame and this pulses can be use for outside synchronization.

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Ok, remove the take-up reel an let the film drop in a bucket (use gravity) then use a sprocket gear to pull the film in an intermitent movement and place a frame holder to prevent vibrations an bending of the film.

 

Remember cameras and projector always use intermiten movement no matter the speed.

 

i'll first try to put in some kind of gate for the film. I can see the film moving around a bit when it advances so i need to keep it still and put some tension on it.

If this fails, i'll have to change completely setup and go to intermittent mode... at this point i guess i'll be better off using a real projector ....

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