Film-Tech Cinema Systems
Film-Tech Forum


Post New Topic  Post A Reply
my profile | my password | register | search | faq & rules | forum home
  next oldest topic   next newest topic
» Film-Tech Forum   » Operations   » Digital Cinema Forum   » SDI cables.

   
Author Topic: SDI cables.
Stephen Furley
Film God

Posts: 3045
From: Coulsdon, Croydon, England
Registered: May 2002


 - posted 08-13-2013 03:58 PM      Profile for Stephen Furley   Email Stephen Furley   Send New Private Message       Edit/Delete Post 
Can SDI cables be used for analogue component and composite video?

 |  IP: Logged

Pete Naples
Phenomenal Film Handler

Posts: 1540
From: Dunfermline, Scotland
Registered: Feb 2001


 - posted 08-13-2013 04:21 PM      Profile for Pete Naples   Email Pete Naples   Send New Private Message       Edit/Delete Post 
Short answer - yes.

 |  IP: Logged

Bruce Hansen
Jedi Master Film Handler

Posts: 847
From: Stone Mountain, GA, USA
Registered: Dec 1999


 - posted 08-13-2013 06:50 PM      Profile for Bruce Hansen   Email Bruce Hansen   Send New Private Message       Edit/Delete Post 
I second that answer, yes you can. SDI cabeling is better at handeling high freqs, and has better shielding than good old RG-59.

 |  IP: Logged

Gialoc Do
Film Handler

Posts: 4
From: Ho Chi Minh / Viet Nam
Registered: Jul 2013


 - posted 08-13-2013 09:03 PM      Profile for Gialoc Do   Author's Homepage     Send New Private Message       Edit/Delete Post 

 |  IP: Logged

Stephen Furley
Film God

Posts: 3045
From: Coulsdon, Croydon, England
Registered: May 2002


 - posted 08-14-2013 04:14 AM      Profile for Stephen Furley   Email Stephen Furley   Send New Private Message       Edit/Delete Post 
Thanks for the replies. Not using SDI at the moment, but almost certainly will need it at some point, so will buy SDI type cable now.

It seems to be either white, or a light blue, similar colour to the aqua sheath on om-3 multi-mode fibre. Is there any difference between the two colours?

 |  IP: Logged

Scott Norwood
Film God

Posts: 7929
From: Boston, MA. USA (1774.21 miles northeast of Dallas)
Registered: Jun 99


 - posted 08-14-2013 12:24 PM      Profile for Scott Norwood   Author's Homepage   Email Scott Norwood   Send New Private Message       Edit/Delete Post 
Purple seems to be common for HD-SDI runs in installations (at least on this side of the pond), but the color of the cable insulation doesn't matter. Belden 1694A comes in a number of colors, as does the Canare equivalent.

Everyone who has posted here probably knows this, but I will mention it anyway: when running cable for component analog video, the cable runs for a given signal all need to be the same length. Same for Y/C (S-video).

Also, for whatever it's worth, SDI cable works fine for AES audio.

 |  IP: Logged

Bruce Hansen
Jedi Master Film Handler

Posts: 847
From: Stone Mountain, GA, USA
Registered: Dec 1999


 - posted 08-14-2013 04:51 PM      Profile for Bruce Hansen   Email Bruce Hansen   Send New Private Message       Edit/Delete Post 
Most cabeling today is avbl in the ten colors of the "color code" (same as resister color code, except that black = 10 in cable color code and 0 in resister color code.

Brown = 1
Red = 2
Orange = 3
Yellow = 4
Green = 5
Blue = 6
Violet = 7
Gray = 8
White = 9
Black = 10

I see a lot of people using 1694A type cable for short runs. This is silly. 1694 is big, stiff, heavy, expensive, and hard to work with. For short runs use 1855A (or Gepco VDM-230). It will transprot HD-SDI up to 200 feet. 1505A (RG-59 size)(or Gepco VPM-2000) is good up to 300 feet. 1694A is good up to 340 feet. DO NOT distort the cable dimentions with tight bends or tight tie raps, or walking on it or running things over it. This can cause the cable at that point to change impeadence, and that will cause problems due to the short wavelengths involved. To be safe, derate the distances a little, that I gave you above.

Just to be clear 1505A is NOT the same thing as the old RG-59 type cable 8241. But 1505A is the same size as RG-59.

 |  IP: Logged

Steve Guttag
We forgot the crackers Gromit!!!

Posts: 11984
From: Annapolis, MD
Registered: Dec 1999


 - posted 08-14-2013 09:54 PM      Profile for Steve Guttag   Email Steve Guttag   Send New Private Message       Edit/Delete Post 
We use 1694A for most all 75-Ohm coax needs (even short runs)...why? Because we are not going to tool up for every cable on the planet. Some of our SDI runs are long, some aren't. We have two spools on hand at all times (Red and Green). The difference in cost of the various types at a 15' run just doesn't justify adding another spool (or 2) of the smaller cable. Whereas it is a "fixed" installation, the size/stiffness just isn't an issue either.

It is all getting to be pretty moot in DCinema though as almost everything is on IMBs which negate the need for SDI in cinema (unless you have broadcast sources like HDCAM...and we do). Conventional analog video is also almost dead.

 |  IP: Logged

Stephen Furley
Film God

Posts: 3045
From: Coulsdon, Croydon, England
Registered: May 2002


 - posted 08-16-2013 02:33 AM      Profile for Stephen Furley   Email Stephen Furley   Send New Private Message       Edit/Delete Post 
Steve,

I've never seen the newer systems with IMBs; I've been out of projection for over three years now. How do the data get into these systems id they don't use SDI? What exactly is a IMB anyway?

 |  IP: Logged

Sam D. Chavez
Film God

Posts: 2053
From: Martinez, CA USA
Registered: Aug 2003


 - posted 08-16-2013 09:41 AM      Profile for Sam D. Chavez   Author's Homepage     Send New Private Message       Edit/Delete Post 
IMB stands for internal media block. This means the encryption/decryption function takes place inside the projector chassis instead of inside the external server. So in this arrangement the server just holds and manages the content and sends the data on Ethernet cables to the IMB.

There are now IMS's on the market; Internal media server or some other similar name. Same functions as IMB but in addition there is storage to hold the "print" is held in the IMS. This allows for lower cost external storage devices to be used so ultimately this will enable lower cost D Cinema.

Problem is, most cinemas have already converted using the technology available at the time.

Maybe next time.

 |  IP: Logged

Brad Miller
Administrator

Posts: 17638
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 08-16-2013 07:40 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
I'm still not sold on the idea of putting the hard drives on the IMB and the placing that in a projector.

 |  IP: Logged

Sam D. Chavez
Film God

Posts: 2053
From: Martinez, CA USA
Registered: Aug 2003


 - posted 08-16-2013 08:28 PM      Profile for Sam D. Chavez   Author's Homepage     Send New Private Message       Edit/Delete Post 
I don't disagree with Brad but it seems to be moving in that direction.

Maybe when there are solid state drives at a lower price point it might not be as much an issue regards heat and vibration.

 |  IP: Logged

Brad Miller
Administrator

Posts: 17638
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 08-16-2013 09:27 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
It will be an issue of storage space though for a long time. It's just not a good idea.

 |  IP: Logged

Steve Guttag
We forgot the crackers Gromit!!!

Posts: 11984
From: Annapolis, MD
Registered: Dec 1999


 - posted 08-17-2013 12:13 AM      Profile for Steve Guttag   Email Steve Guttag   Send New Private Message       Edit/Delete Post 
They also need to get these IMS/IMBs to the point where one can just shut the projector down without having to FIRST shut the server down. At least one brand's IMB system doesn't care if the projector with the IMB is shut off and the server itself is kept running.

 |  IP: Logged



All times are Central (GMT -6:00)  
Post New Topic  Post A Reply Close Topic    Move Topic    Delete Topic    next oldest topic   next newest topic
 - Printer-friendly view of this topic
Hop To:



Powered by Infopop Corporation
UBB.classicTM 6.3.1.2

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.

© 1999-2018 Film-Tech Cinema Systems, LLC. All rights reserved.