Home of Professional Cinematography since 1996

Silent Ground Glass

Published : 11th May 2004


I'm shooting a music video next week where the director wants the to use the image from the video tap rather than run film through the camera (nuts as it sounds they principally want the facility to run the camera at non-synch / undercranked speeds to enhance the effect of the mirror shutter visibly rotating).

Some research has proved that an ARRI III is my best bet - apparently more modern cameras won't appreciate being run without film for extended periods of time and they're cheap to rent! - but I need to know if Arri do/did a silent academy ground glass for the ARRI III????

Cross hairs in the middle of the frame will muck up the image.

There's no such thing apparently as a silent ('cross-hairless') ground glass for SR3s otherwise I'd go 16mm. If anyone knows of a custom made silent SR3 (2, 1) ground glass lurking in any UK or European rental house do tell!

Any info or wisdom appreciated at this stage.

Tom Townend,
Cinematographer/London.



>apparently more modern cameras won't appreciate being run without >film for extended periods of time

>Cross hairs in the middle of the frame will muck up the image.


Go for a 435 ( manual shutter would be cheaper ),silent glasses without a centre cross are available

Andy Taylor
Camera Engineer
Arri Media
3 Highbridge
Oxford Road
Uxbridge
UB8 1LX

www.arrimedia.com
www.arri.com



Tom,

Arri make 4-day turnaround for any ground glass :

http://www.arri.com/news/newsletter/articles/0925826714/groundgl.htm

I actually got one two weeks ago in 1 day! It was actually made by Lee Filters in the UK I think.

They charge around £230.00

Oliver Stapleton



Andy Taylor wrote :

>apparently more modern cameras won't appreciate being run without film for extended periods of time

Well...it was someone at Arri media that told me that t'other day

> Go for a 435

But an Arri III is a cheaper rental non? I know that's the producers bag not mine but they're already irate that the directors interpretation of 'shooting on tape' really means 'recording tape off a 35mm film cameras video tap'!

Tom Townend,
Cinematographer/London



>Well...it was someone at Arri media that told me that t'other day


Anyway, the Arri III ground glass holder has those horrible vertical light baffles in it. They'll have to go. Also, as the glass has a curved back surface, you nearly always get some barrel distortion on the video.

Andy Taylor
Camera Engineer
Arri Media



Tom,

How about a "butterfly wooden shutter" on an "varispeed" electric drill in front of your choice of camera ?

Jon Mitchell

Elstree, UK based 1st A.C. / Focus Puller



Andy Taylor wrote :

>Anyway, the Arri III ground glass holder has those horrible vertical light >baffles in it. They'll have to go. Also, as the glass has a curved back >surface, you nearly always get some barrel distortion on the video.

It's THIS kind of sage advice I can never get over the phone.

Does anyone have a link to ARRI's online 'draw your own' ground glass thingy? I can't seem to track it down.

Thanks,

Tom Townend,
Cinematographer/London.



It seems like there would be simpler, potentially less expensive ways to get the "film camera video tap" effect than actually renting a film camera just to use as an optical block for a video camera. Flicker ain't that hard to create nor is low-quality video.

A security camera with fan blades in front of it? How about strobed or pulsed lighting to create or embellish the flicker effect?

Thoughts?

Roderick Stevens
Az. D.P.
www.restevens.com
12on12off



Roderick E. Stevens wrote :

>A security camera with fan blades in front of it?


This would be a great approach, but I guess the best look would be a "open" fan (without grid), but that is a OHS-hazard. You can easily do this in post. I believe QuickTime has the old-video effect where you can set the flicker, but I guess a whole bunch of other programs can do this to.

If you're shooting the whole thing on video anyway, why would you waste money on renting a film-camera for something you can easily solve with video and a bit of creativity or in post....

Cheers

Martin Heffels

Filmmaker/DP/Editor/Filmschool Techie
Sydney, Australia



>they're already irate that the directors interpretation of 'shooting on tape' >really means 'recording tape off a 35mm film cameras video tap'!

Actually, that should be "a single chip, low resolution, industrial quality tap camera that's probably going to get 10-30% of the available light minus whatever the shutter eats" if it's a normal tap setup.

At least the 435 has a barely decent tap and tap optics with (if I remember correctly) Y/C output available. I would also see if the rental house had a 50-50 prism so the tap got more light than usual. The larger, older original 535 had a 50-50 light split position which gave the tap a lot more light.

Bob Kertesz
BlueScreen LLC
http://www.bluescreen.com



Your best bet has to be to use a Panavision Millennium camera.

A little know facility of this camera is that it can be set either for the video and the operator to look at a normal ground glass (like any other camera)or it can be set so that the video looks at an aerial image and gets a totally clean picture clear of ground glass markings and grain while the operator and the focus assistant can also look at a normal ground glass image at the same time.

The whole idea of this facility is so that either a film or a video image can be shot with the same camera. It is made possible by the use of the telescopic extension eye piece that that camera has.

Sincerely

David Samuelson



>apparently more modern cameras won't appreciate being run without >film for extended periods of time??

What about running two mags with dummy-loads? Then you could have your choice of cameras.

Gregg Mc Neill
Camera Assistant
Grand Rapids, Michigan



David Samuelson wrote:

>[...]use a Panavision Millennium camera.

>it can be set so that the video looks at an aerial image and gets a totally >clean picture clear of ground glass markings and grain

Again - something I never knew!

Strangely someone did say to me, "why don't you just remove the ground glass and operate from a monitor", and just as I started to tell them they were being idiotic I wondered if in fact the tap would still see an aerial image...

David, if you could recommend any book with a layman friendly explanation of aerial images I'd be very interested. It's something I know of but don't know about. Aerial images feel a little akin to witchcraft and alchemy.

Tom Townend,
Cinematographer/London.



>Does anyone in the UK have any Reflexed Mitchell cameras with taps?

A lot of Mitchell’s are or can be set up for optical centre (full gate) and lots of odd ground glasses have been made over the years.

I know Panavision had a Mitchell a while back, and Movietech camera rentals had some Mitchell’s I believe.

Mark Weingartner
LA Based