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-   -   Vibrating 35 mm Adapter, with Auto Focus Feature, for HD Cameras (https://www.dvinfo.net/forum/alternative-imaging-methods/27509-vibrating-35-mm-adapter-auto-focus-feature-hd-cameras.html)

Mike Metken June 13th, 2004 03:39 PM

Vibrating 35 mm Adapter, with Auto Focus Feature, for HD Cameras
 
http://www.adaptronics.com/products/piezoelectric_actuators/amplified_piezo_actuators/APAS.html

I discussed this with an engineer and I made a long post with links that somehow disaappeard. I don't want to go through the details again not knowing if it will be erased or what.

Basically Minolta made the first generation auto focus SLRs. Canon joind the auto focus trend with a second-generation unit. One of the models had a semi-transparrent mirror that did not, or did not have to, go up. I recommended using this model but any auto focus SLR model would do. Other than this model would require the mirror to be up during filming. But you could still autofocus first, lock that focusing and/or auto exposure position, and put the mirror up.

The GG would be high quality Nikon unit without markings, installed at the film plane. The GG would be put in a frame and would be vibrated with two piezo drives, one at each GG side. Couple usable drives are in a link above. They are exteremely efficient.

During experimantation you can use a tone generator fed to audio amplifier and to the drives. One drive would be wired backwards so they both would move in the same direction.

If this post stays, I'll post more details next time.

I said that cheaper piezo elements could be used, and also a used camera body, and that an oscilator and amplifier could be built for about $10, and everything for about $200.

Hope this post does not get erased.

Valeriu Campan June 14th, 2004 01:12 AM

Mike,
Sound like a good idea. Keep us posted. How noisy are the piezo thinghies?

Mike Metken June 14th, 2004 02:21 AM

Valeriu,

I'm not building it, just giving an idea what could be done. Check the link. I think that the frquency they work on is an extremely high sound pitch. You can get these with any frequency and length of stroke. They should not be too noisy, but I have no idea. At such a high frequency sound insulation is extremely efficient. It is hard to isolate low frequency noise. The higher the frequency, the easier is it to damp noise. That is what I was told.

Maybe my original post did not get erased. Maybe I did not post it right. I did not check it after posting.

Mike

Dietmar Zonewicz June 15th, 2004 05:12 AM

I found the description an the graphics how the PRO35 works again - it's an article in german, but the images are the interesting part:

Für den Infos und Beantwortung von Fragen sind diese Foren geeignet:

http://www.pstechnik.de/sheets/downloads/pp-dec12.pdf

dietmar

Les Dit June 15th, 2004 12:39 PM

I've worked with piezo movers before. They sound like buzzers.
-Les

Brett Erskine June 15th, 2004 01:43 PM

P+S Design Diagram
 
Thank you very much Dietmar.

We need this translated. Anyone know German?

Looking at the design we can see they used rubber pulleys instead of gears. Probably for two reasons. 1) they are quieter and 2)Its the simplest setup in order for it to turn all three bearings at the same speed.

I'll have to wait for the translation but it looks like not only does it vibrates the glass but rotates it as well. Simple, well though out design.

Also look at the optics right after the GG. Looks like a achromat plano convex lens. Also you have a clear piece of glass in front of the GG. I did the same thing in my design in order to keep the dust and hairs off the GG. Finally we have a prism system. Havent been able to figure it out completely from the picture.

Can't wait to get it translated.

Brett Erskine June 15th, 2004 04:10 PM

If you dont know German you can always retype the text as you see it and run it thru a German to English translation program. If you dont have the program on your computer you can always get it instantly translated remotely thru web sites that do the translation live online. They arent perfect but you should get a good idea of what its saying.

Dietmar Zonewicz June 16th, 2004 01:17 AM

expecially in things that are so specific like this topic is - these translation apps are very bad.

If this would be some kind of small talk I would try to translate, but my technical english isn't well enough.

But If there is nobody else who can have a try I will do so.

dietmar

Laurence Maher June 16th, 2004 05:33 AM

This is going to sound silly, but I'm not exactly sure just what is up with the whole vibrating adapter discussions. Could someone please tell me what the purpose of a vibrating adapter is and why it is better than say a lens adapter that is not vibrating?

Thanks!

Charles Papert June 16th, 2004 10:33 AM

The oscillation or vibration causes the texture of the ground glass to effectively disappear, otherwise the image looks like it was shot through a screen door (or a lot of dirt on the lens).

Les Dit June 16th, 2004 11:26 AM

To get the DOF, a relay lens or simple lens adapter can't get the desired DOF. You have to intercept the image with an actual image plane, and re-image that. The ground glass does this.
-Les



<<<-- Originally posted by Laurence Maher : This is going to sound silly, but I'm not exactly sure just what is up with the whole vibrating adapter discussions. Could someone please tell me what the purpose of a vibrating adapter is and why it is better than say a lens adapter that is not vibrating?

Thanks! -->>>


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