mini 35 p+s technik insides?

[Kumar Sharma]

Does any one here know how the mini 35, by P+s tecknik works?? What kind of ground glass technology does it use? has anyone opened one of these? Is it anything special at $10,000. I ordered a mini35 demo dvd but answers none of my questions

cheers guys

[Chris Hurd]

There isn't much of a point to opening one up, as the design is protected by patent. I don't think you'll find anyone here who would be willing to crack one open.

[Filip Kovcin]

i cannot say exacty, but as i remember there were a link to p+s schematics, how it is made and how it works. try to look somewhere inside alternative method. that was pdf file (as i remember) made by p+s technik

another one is to kindly ask that guy who is controling a luggage on airport to put p+s unit inside that a la x-ray scanner, so you can clearly see how it is biuld without destroing it.

but maybe visit to doctor :) who has xray camera unit is better, since you can make a picture of it, he, he... and keep it for future reference :)

if you try that - give us a link to pics. thank you.

filip

[Dennis Hingsberg]

Kumar what exactly are you trying to accomplish? ie. Do you want to build your own adapter or are you just trying to understand the principles behind the adapter and how it works?

If you look in the alternative imaging area of this thread I'm sure you will find answers for both.

http://www.dvinfo.net/conf/forumdisplay.php?f=70

Best way I can explain it though is the image projected from a 35mm lens goes onto a spinning ground glass which then gets reflected through a prism in order to flip the image. The image then lands onto the final screen where the video camera is focused and records the image to the CCD.

A simple and practical hands on experiment: Take a 35mm lens from any SLR camera (Pentax, Canon, Nikon, etc..) and place the back of the lens an inch or so away from a white piece of paper or white wall. What you will see projected (onto the paper or white wall) will be the scene that the lens is facing. mini35 devices simply record that projected image to the CCD of the video camera to get the exact look, depth of field and other lens properties directly to the video.

Spinning glass or sometimes spinning plastic is used for the image to be projected onto so the video camera can record from behind the image. If the glass or plastic is not spinning or vibrating the grain pattern of the plastic or glass will become obvious in the video footage and not look great. Moving the ground glass or plastic enough produces a grain like effect or simulation. A better ground glass generally produces better results.

Because the image comes through a 35mm lens the image is always upside down and needs to be flipped through additional prisms. It can just be filipped in post as well.

www.pixelloft.com has made his on mini35 adapter for HD and achieved very good results. There are MANY others who have also made their own 35mm adapters.

I use the P+S Technik mini35 because it is solid, durable and basically in the end becomes the main support and chassis to the overall camera rig. Other people have build adapters the sag or flop from the front end of their DV cams. For critical and professional camera setups and shoots I can't be farting around with duct tape and plastic boxes, 9 volt batteries, etc.. so I prefer the real thing ; )

[Viktor Bludov]

Thanks for your post, this makes allot of sense!

When I was a kid some of my favorite toys were old soviet photo cameras of my grandfather and dad, as I grew up experimenting with optics.
So the ground glass is what does the trick, and obviously plays a HUGE role on how the picture looks and feels like. any deviation in color, surface type, speed, direction and pattern of the motion will dramatically affect the look.
The depth and the focus could not be applied by the camera lenses any longer since its just making a replication of the illuminated ground glass.


If I understand this correctly this device must also have a "frame" somewhere near the ground glass. it's almost as an open back camera with rolling film in it correct ?

What exactly is follow focus thing ?


Thanks,

Viktor

[Shawn Alyasiri]

I opened mine up this weekend - of course I was curious all along - but I only did it because there was debris on the inside causing blotches on the images. Likewise, I only opened it after talking to the techs at ZGC.

It's a pretty cool instrument indeed. If you open it - be careful, but you'll like what you see.

Thread:

http://www.dvinfo.net/conf/showthread.php?t=52809