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-   -   Really large format SI 2k (http://www.dvinfo.net/forum/silicon-imaging-si-2k/499143-really-large-format-si-2k.html)

Brian Drysdale August 3rd, 2011 01:42 AM

Really large format SI 2k
 
They modified a SI 2k to shoot a 4x5 Ground Glass for the feature film "Bellflower".

Coatwolf

Chris Hurd August 3rd, 2011 01:29 PM

Re: Really large format SI 2K
 
1 Attachment(s)
Thanks for posting this -- I was just about to do it myself, but I couldn't think of a witty title, like "Frankenstein Meets the SI 2K"

Chris Hurd August 3rd, 2011 01:44 PM

Re: Really large format SI 2k
 
See also The Secret Sauce Behind Bellflower, A Buzzy Indie Film? Handmade Cameras | Co. Design

Bob Hart August 4th, 2011 12:00 AM

Re: Really large format SI 2k
 
Looks like the best and biggest AGUS35 in the entire universe.

There is a behind-the-scenes clip of the camera operator sitting in the side window of a moving vehicle, hand operating this rig and holding a laptop at the same time.

Only one word for it from I who loves tripods and safe places - respect.

River Lopez August 4th, 2011 08:10 AM

Re: Really large format SI 2k
 
I'm really interested on how they made the Coatwolf camera. From what I can gather it looks like they created a large format camera and then created a camera with the SI-2K (or the SI-2K Mini) to record the image from the large format camera. But, I also have seen images that look like they filmed straight into the SI-2K without using the large format camera. I can only guess they came up with a way to attach the older lenses directly to the SI-2K unit.
Anyone have more about the camera or how it was built?
I also have yet to see the film Bellflower, so that will be on my list to see...I think it's being released tomorrow.

Brian Drysdale August 4th, 2011 11:38 AM

Re: Really large format SI 2k
 
They basically focused the SI 2K onto the the ground glass and then used large format lenses to form the image on the glass. It's the same system as used on 35mm adapters, except the ground glass screen is larger. From the photograph there seems to be a system of spinning the ground glass, so you don't have a fixed pattern.

You can film the ground glass in a plate stills camera, this is more or less doing the same thing.

River Lopez August 4th, 2011 01:48 PM

Re: Really large format SI 2k
 
You are right. I read this article and there is a spinning glass system in place.
I see there are some youtube vids but, youtube is blocked here at my office. I'll have to check them out at home.
So if I wanted to try something like this I would need to get a 4x5 (broken and cheaply) take off the back and figure out where the focal plane is. Then I'd need to create some kind of spinning glass system on the focal plane.
I would then need to get a digital camera and aim that at the glass focal plane and start to capture my images.
Think that's right or am I just going down the wrong path???

Brian Drysdale August 4th, 2011 03:12 PM

Re: Really large format SI 2k
 
That's basically it.

Jim Michael August 4th, 2011 03:19 PM

Re: Really large format SI 2k
 
4x5 monorail cameras are cheap. Pick up a Sinar or Horseman. Actually, the lenses aren't all that expensive either.

River Lopez August 4th, 2011 08:30 PM

Re: Really large format SI 2k
 
Here is a video Coatwolf model 1 has on their youtube page; ‪Si-2K Portable Camera Rig‬‏ - YouTube
They bleep out the details of the camera but, you get a good look at it and how they set it up.
So, for me it seems like you can get a 4x5 camera kit. If you want to play around without breaking it you can buy a backing for Nikon and Canon cameras.
In the long run I could imagine doing tests and use cheap dv camera on the back until you can either convince silicon images to "loan" you an si-2k mini like they did with Evan or be able to buy your own.
The only thing I can't figure because, I can't see any part of it is the spinning glass and motor. Is it frosted glass, is it clear? Is it an optic or is it just a piece of glass?
I figure that the image only is on a small part of the glass. With it moving I wonder it that give the image a feel of a shutter or is it mainly so, it doesn't look like you projected it on a wall and filmed it?
I find it funny that they have a car battery jumpper cabled to a car cigarette lighter adapter and everything plugged into that.
I see that the films will be close to me in nyc starting tomorrow so, I will have to check it out. Then I probably will look into getting a 4x5 camera on ebay or craigslist, unless someone on here is selling one for research for dirt cheap...

From what I have also read they did do some post to correct the different camera set up. They do say that a lot of dirt does get into the camera they way it's built but, they liked the look and after paying to have the footage cleaned up they went back and put back the original footage (with the dirt) because it added to the film.

Bob Hart August 5th, 2011 04:27 AM

Re: Really large format SI 2k
 
The SI2K also performs quite nicely via a 35mm adaptor, either Letus Extreme/Elite/Ultimate but you have to hack the relay lens arrangement. Between 45mm and 58mm Nikons will do it for you. Dennis Woods of Cinevate built a prototype varifocal relay lens for the SI2K, which he was gracious enough to let me play with out here on one of his Brevis adaptors.

There is a bit of stuff I did with it here :-

http://www.dvinfo.net/forum/silicon-...-use-si2k.html

Bob Hart August 7th, 2011 06:37 AM

Re: Really large format SI 2k
 
River.


I forgot about these two test clips I put up on exposureroom. I later found with the Super16mm sized sensor, that the 45mm Nikon pancake lens I used for relay worked the best for even lighting across the frame but was not as sharp. Dennis Woods' varifocal relay was sharper and lit more evenly.


FURTHUR TEST OF SI2K - LETUS EXTREME AFTER RE-CENTERING By Bob Hart On ExposureRoom

LETUS ON SI2K TEST By Bob Hart On ExposureRoom

Chris Hurd August 7th, 2011 09:23 PM

Re: Really large format SI 2k
 
Photo essy from the New York Times... incl. Coatwolf on Steadicam:

Revved-Up Cinema - Slide Show - NYTimes.com

River Lopez August 8th, 2011 11:32 AM

Re: Really large format SI 2k
 
OK, so I just won a 4x5 camera on ebay. So, how do we purpose I build my camera of mass destruction???
I see that I can get a plate for the back of the camera for attaching a DSLR so, I might play with that first.
I did go out and see Bellflower yesterday I do recommend it to anyone wanting to see a testosterone filled (fueled) movie that isn't an 80's film with Stallone or Schwarzenegger.
In the long run if anyone wants to hook me up with a rep or a connection at Silicon-Images for a SI-2K mini for my camera of destruction then that would be very cool.
I hope to have the camera in about a week.

Bob Hart August 9th, 2011 06:59 AM

Re: Really large format SI 2k
 
River.


A DSLR is already well capable of giving you shallow depths-of-field and other creative options without need to be hanging big heavy stuff off the front of it or hanging it off the back of a heavy rig.

To get the sense of what the "Bellflower" rig would give you, as you already suggest, the small camcorder would be fine.

If you are not going to modify the plate camera with a moving groundglass, the fixed previewing groundglass screen ( which is swapped out for the film pack when the Horsman or Sinar camera is used normally ) needs to be blemish-free and clean.A finer groundglass texture can be had with what is called a Boss screen. It is comprised of two thin glass plates with a thin microcrystalline wax layer in between.

Wax screens were used by earlier builders of fixed home-made groundglass adaptors. I actually made a spinnging wax groundglass for an AUG35 adaptor. It was the absolute best ever but flickered badly.

The finer the groundglass texture, you find the corners of your image become darker. The coarser the groundglass texture, the light transmission through it will be less and the sharpness will fall off.

With a large format groundglass, screen sharpness may likely be the least of your worries


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