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Pro35 From P&S Technik


Rich Steel

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Hi Folks,

 

Has any other manufacturer got anything similiar to the Pro35 Unit? It's just that £16K (GBP) is very expensive so thought I'd ask to see if there were other contenders after NAB2004.

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Hi,

 

I thought it was very expensive too, but I didn't see anything at NAB and I spent some time going over what Canon and Fuji were offering. Nice 2.35-to-16x9 convertor for shooting scope on 16:9 HD cameras, but nothing like that.

 

I was going to homebrew (or more probably friendly-local-engineering-firm-brew) one but I can't figure out how to do the relay group.

 

Phil

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Worked on music vid the other day as electrician where the DP used a pd150, a magic arm and a mamayia rz67. fixed the videocamera in position in macro with the magicarm and filmed the groundglass of the mamayia....

None-moving grainstructure yes, but some very intriguing and nice shots though :D

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Hi,

 

The problem isn't so much the electronics as the optics. My (hack, cheap) idea was to salvage the DC servo and bearing assembly as manufactured for a computer's hard disk drive, which provides a low-noise motor and spindle bearing of suitable precision to keep the spinning groundglass in the correct plane. I also looked up a water jet cutting outfit who were capable of taking an optical flat and cutting it to fit the spindle fixings intended to take the hard disk platter. The cut flat could then be frosted by hand in about ten minutes with a handful of carborundum powder and another piece of glass, then bolted into place. This is all zero effort and costs about £150. The hard disk bearing assembly is based on a chunky aluminium casting to which optical components could be mounted. There's some machining to place the PL mount (presumably) in what would be the bottom face of hard disk.

 

The really problematic part is effectively a video-mount macro lens to project the groundglass image correctly into the face of the CCD assembly. I don't know how to do this, but it occurs to me that it might be possible to strip the relay group off the back of a cheap (these aren't the critical bits, as I understand it) existing video lens and end up with something that would do it. I called optical support in London to ask about this, but they didn't know since it's inherently an absurd thing to do, and I haven't done any more thinking on it since.

 

Phil

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Hi,

 

Well yes, but only in the broadest possible strokes, in that it works in broadly the same way they all do.

 

Can't say I'd feel that sanguine about the critical focus abilities of particle board - or a CD spindle motor!

 

Phil

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Can't say I'd feel that sanguine about the critical focus abilities of particle board - or a CD spindle motor!

I agree on the particle board--let's hope it's not too humid the day you build it! But the CD motor spindle motor should spin fast enough that the momentum would make it pretty consistent. Milled in aluminum this should work okay.

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Phil-

 

What's the difficulty in getting a macro/ diopter setup to shoot the GG? I'd have thought this was the easiest bit (good job I'm not building one).

 

Also you're apparently better off with a vibrating ground glass to avoid visible artefacts closer to the centre of the disk. (I think Anne Summers has something you could use...)

 

Cheers

Dan

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Hi,

 

I don't want to end up with something that has to strap on the front of an existing video lens. Add the device itself and the PL-mount prime and you're suddenly using an exceedingly huge setup. Actually I'd be more likely to make something to take 35mm stills lenses as they're cheaply available, but it'd be nice to be able to use anamorphic primes.

 

Until I can find an optics expert to confirm or deny my suspicious about disassembling the relay group off the back of an existing video lens, the whole thing's more or less stalled.

 

Phil

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