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-   -   Experimental film-look-dv-camera (https://www.dvinfo.net/forum/techniques-independent-production/7713-experimental-film-look-dv-camera.html)

Jami Jokinen March 14th, 2003 02:36 AM

Experimental film-look-dv-camera
Check this out. It's complicated to work with, but seems to achieve a nice look...


Charles Papert March 14th, 2003 09:04 AM

Interesting, but this is really just a homebuilt version of the Mini 35. Same idea, lower tech.

Steven-Marc Couchouron March 14th, 2003 12:23 PM

This is something I've been experimenting for a while and which can be done fairly cheaply with an out of usage Kiev medium format camera with a clear matte ground glass as the viewfinder or on the back if you have one of these Hasselblad type cameras with removable back.

As the pictures show very clearly, the problem is that you tend to get vignetting as soon as you go wide and of course you see the grain from the ground glass (along with the hair&dust since it is almost impossible to keep it 100% clean).
With the mini35 the ground glass actually rotates at high speed making the grain and dust in effect (almost) invisible. You also lose more than a stop of light.

But it is very fun to experiment and I recommend it to anyone with one of these cameras lying around. You can get them fairly cheap on ebay, but you also need to find that clear matte ground glass (without the usual fresnel and split focusing aid in the middle).

Rob Lohman March 15th, 2003 08:51 AM

I'm trying to construct a picture in my head of how this rig would
look... but having a hard time. Can anoyne explain to me how
this rig is looking and working?


Mark Austin March 15th, 2003 11:25 AM

Jeez, I have a bunch of that stuff sitting around here. I'd love to see some pictures, or a diagram on this setup too. This would be a great way to make a cheap "film like" rig for certain productions.

John Threat March 16th, 2003 08:02 AM

I would love to see pictures, but it seems like you would be limited to a certain focal length.

The results are really good though!

Of course, you could always overlight a room, zoom in, open wide, and slide on the ND for shallow DOF.

Charles Papert March 16th, 2003 12:35 PM

<<<-- Originally posted by John Threat : Of course, you could always overlight a room, zoom in, open wide, and slide on the ND for shallow DOF. -->>>

Perhaps I am misreading this. If you were shooting wide open, you wouldn't need to add light and then ND down.

You would also never be able to achieve this degree of shallowness with a standard DV lens at the same field of view, or even close to it. I can't recall the magnification characteristics of medium format but it's even greater than the 7x difference between DV and 35mm.

Steven-Marc Couchouron March 16th, 2003 04:14 PM

Sorry, I can't post any pictures right now because I don't have the camera on hand. I'll try to get it back a little later this week.
But it is really very simple. You just stick your camcorder lens as close as possible (depending on minimal focusing distance) to the groud glass, and that's about it. Just make sure that no light filters out between the two.
Basically you're filming what would normally be imprinted on the negative.
It's a little tricky in practice since the image is obviously inverted.
In fact you don't even need a medium format camera (or any camera at all). Just take a lens (from your SLR for example), a piece of fine and clear ground glass and place the two at the correct distance and film the image formed on the ground glass with your camcorder. You then just need to design some kind of box to keep all three elements together at the correct distance one from another, and to keep any light from filtering in or out.

Note however that the result looks a bit strange since the grain from the ground glass isn't "moving" as film grain or video noise would. But it is an interesting look and you can get *extremely* reduced DOF.

Imran Zaidi March 17th, 2003 08:38 AM

Excuse my ignorance... how does one go about getting a piece of 'clear ground glass'? I'm not sure exactly what that is, but I wanna give this a shot with my SLR lenses, since I have a couple of pretty good ones...

Steven-Marc Couchouron March 17th, 2003 08:47 AM

Well, that's the main problem ! ;-)

You can get some from camera shops that handle medium format cameras and accessories but they are expensive. Here are a couple of examples:

(I'm not sure if this one is really without any markings or fresnel)

(This one seems to have a slight fresnel which could cause the sides to appear darker)

The best bet is to ask at a specialized shop or try to have one made to your specifications.

If you just want to try things out you can also build a makeshift ground glass by applying some Scotch tape (the "magic' type) to a clear piece of glass. ;-)

Steven-Marc Couchouron March 17th, 2003 09:41 AM

I need to correct something: the fresnel (which can be noticed on the Kiev ground glass) is actually necessary *NOT* to have dark vignetting at the edges...

Cosmin Rotaru March 19th, 2003 12:52 PM

you can fin your ground glas on a box (the ones with 25 or 50pcs) of CD-Rs. The CDs are place between two "faked" CDs. Offen they are clear but I found some that are like the "ground glas". The good think about thouse "fake" CDs is that they are... round. So you can make something out to rotate the "ground glass"! A small mortor from a toy or something...

where does the fresnel lens goes?

Brandt Wilson March 20th, 2003 03:25 PM

Fresnels, ground glass
I'm curious about the fresnel, too. My understanding is that if the ground glass is in the film plane, then the crisp rectangular image that would be captured by the film would be on the ground glass.

The camera would be focused and fixed on the ground glass image, and all practical focusing would be done with the 35mm/med format lens.

A bit on the glass....

I just spoke with a camera technician who is renowned for his work with ground glass...he was nominated for an Oscar in '97 for his process.

He can brighten a piece of glass between 1-2 stops.

He also says that the #32 glass (ultrafine) will yield about 300dpi. This produces no visible grain in DV, but the contrast is a lot lower. He suggested testing #32 and #16 to see which yielded the best results.

He worked on Top Gun, and they ended up stepping one step back from the ultrafine, as the contrast wasn't where the steadicam operator needed it.

I'm getting a couple scrap pieces from a local camera repair shop. When I have some results, I'll post them. I'm looking at using a K-mount on a small box...my repair resources suggest about 4" long...that's not bad to put on rails in front of a camera.

Steven-Marc Couchouron March 20th, 2003 05:34 PM

Here's a goog link for understanding where the fresnel goes:


I assume the person you're referring to is Bernie O'Doherty at http://www.laserbrighten.com (I've done my homework on this ;-) )

Please let us know of your results! What do the numbers you mention refer to exactly?

Brandt Wilson March 20th, 2003 07:44 PM

Bernie O'doherty, ground glass grades

Yeah, it's Bernie...:) I was just trying to stave off a bunch of emails to the guy...he's swamped with ACL repairs.

Thanks for posting the link...I'll check it out.

As far as the numerical stuff is concerned, apparently the #32 is ultra fine grain, #16 is one step back, then #8 and #4. I'm trying to find out which #'s represent how many dpi.

I found an optical company I that carries 5cm diameter discs that are measured as 240, 400, 600, 800, 1000 and 1500. I'm not sure what that means...I've requested more info. They are at optosigma.com.

I found a company that touts its product as being far superior to intenscreen...go to www.brightscreen.com. Similar product concept, but they claim that they don't suffer from hotspots, falloff problems or manufacturing errors in the optical alignment.

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