Downconverting

26th March 2004

I need to downconvert HD to DV on the set; either real time or more probably at night after the day's shooting is done. What's the best way to do this? Are there downconverters that output to a Y/C connector which could go directly to a DV deck? (Don't know yet if I'll be using the Sony or the Varicam.)

Baring that, what the cheapest way to do it? I've done it after the fact and it was rather expensive. I didn't set it up, the producer did so he probably didn't find the best deal around but I don't know.

In that case, we had the Panavision with a downconverter that output component. I had proposed that we rent a DV deck that would accept that, which as I recall was a DSR-45 (but I may not be remembering that the correct model.)

This seemed to me to be the most cost-effective method. Other ideas?

The object, of course, is to produce tapes so for the off-line edit.

Thanks
Blain Brown
DP
LA

>What's the best way to do this? Are there downconverters that output to a >Y/C connector which could go directly to a DV deck? (Don't know yet if >I'll be using the Sony or the Varicam.)

We made Dv copies at night from the F500's downconverter with care to ensure that TC & Audio matched.....

Used a DSR80 as the recorder, and DSR40's in each Avid suite & Logging station

This also gave us a chance to do a front line QC before the actors or set were struck, would have worked better if the night shift actually looked at the images...used to see 1,000+ cookies from porn sites when I looked at the PC in the machine room some mornings...

<sigh>

Theory -VS- Reality

Ta,

Dermot Shane
Vfx guy
Vancouver, Canada & Shanghai, China

>What's the best way to do this? Are there downconverters that output to a >Y/C connector which could go directly to a DV deck?

Hi,

The Miranda Downconverter/HD-SDI Box DVC800 supplies a HD-SDI to Firewire conversion using embedded Audio and VITC for synchron downconversions incl. 3/2 pulldown if necessary even when it is not on the cameras back. If you’re using the rec run TC of the camcorder you can also enable automatic start/stop capturing on your DV device so you can create your downconversions "on the fly" on set.

There should be a similar tool available from Evertz as well, but I haven’t tested it yet.

Yours

+++ Florian Rettich Medientechnik +++

Consider renting a cheap HD deck (HDW-M2000P, 300$/day) and a DVCAM deck with SDI-input.

Matthias Buercher

Blain,

I think I just looked at the answer to your prayers.

Band Pro in Burbank had/has an open house today featuring various pieces of production gear. Of interest to you is a Miranda down-converter and DV encoder that sits on the back of the F900 and replaces the Sony 901 back.

The cool thing about it is that on the back of it was mounted a Sony DSR DU1 mini-DV deck connected by firewire to the Miranda. TC, audio and video all travel to the DSR deck through the firewire cable and the deck starts/stops when the F900 does. If you keep feeding DV tapes to the DSR DU1 during your shoot, at the end of the day you'll have everything you need to go to an off line edit session.

But wait, it gets better. If you connect a palm pilot type PDA to the Miranda you can overlay TC (positioned anywhere you want) and slate info onto the DV signal going to the DSR deck. The Miranda DVC-800 and DSR DU1 are sandwiched between your battery and the end of the 900 and add maybe 4-5 inches overall. The DVC-800 has SDI, HD SDI and a bunch of other ins and outs as well as the firewire connector. There is a model for the Varicam as well, the DVC-820.

Availability may be an issue, but ask at your local rental house and maybe they can hook you up. Oh, and who knows what it may cost to rent.

Hope this helps.

Randy Miller, DP in LA

PS. : All the usual disclaimers, I ain't gettin' no kick backs, but would love to demo it on my next shoot.

>I need to downconvert HD to DV on the set; either real time or more >probably at night after the day's shooting is done

If you are going to work with HDCAM, you can use the deck J3 (it's not very expensive) which has a firewire output

Pol Turrents
Spanish Dp.
www.directordefotografia.com

Just a note on the Miranda. we (Big Zig HD Video) had one back in around May. To put it plainly, it didn't work. About the only thing on it that did work was the HD-SDI output. The firewire did not work and had too many issues to list. Not only that, you need all manner of custom cables to connect all the Firewire and PDA parts to it, which, again don't work, at least not as they should and not with 24p (23.98) with downconversion.

My best suggestion, unless you -REALY- need to downconversions in the field, is to rent a J-3 HD playback deck. They retail for about $20,000 so rental on a daily basis ought to be fairly reasonable. Couple this with a DSR-1500 DVCAM deck and do your transfer via SDI. The J3 can have firewire out, but SDI looks better.

If you -MUST- do conversion in the field you are looking at fairly complex setup. Either drag a F500 with you and pipe your feed through that or you'll need a rack mount unit like an Afterburner so that you will have proper cadence with your 3:2.

Personally, I'd just do it after the fact with the J-3 deck, it's light and small. I think it also give someone(director, editor) a chance to watch the footage as "dailies" and even log time code for editing.

Brett Shapiro

>The J3 can have firewire out, but SDI looks better.

But... if the DVCAM system works with DV compression, at the end it's not the same to transfer by firewire or SDI?

Pol Turrents
Spanish DP

Pol Turrents wrote :

>But... if the DVCAM system works with DV compression, at the end it's >not the same to transfer by firewire or SDI?

Pol

While they are the same, they are not the same.

In Xfer by firewire the images are compressed into Dv codec by the on-board camera converter

In SDI Xfer the images are compressed inside the DSR1500 deck

If there is problems with the Dv codec in the on-board converter then the SDI method and compress inside the deck is a technically identical option that seems to work reliably...so yes they are identical once on tape…

Make sense?

Ta,

Dermot Shane
Vfx guy
Vancouver, Canada & Shanghai, China

Brett Shapiro write :

>Just a note on the Miranda. we (Big Zig HD Video) had one back in >around May. To put it plainly, it didn't work.

True, the DVC-800s were not working earlier in the year and Miranda really blew it to release a product to the market place that was complete unready. But, they work now. Miranda has distributed or made available through their website, updates that one can upload to the Miranda.

Ian Ellis DP
Austin TX
600 op
f900/3 owner
http://www.texashighdef.com/

Brett Shapiro wrote :

>Just a note on the Miranda. we (Big Zig HD Video) had one back in >around May. To put it plainly, it didn't work.

Brett

How valuable is 8 month old information about a product that was brand newin May and had some early software problems ? In this business 8 months on a new product is a lifetime. I am pleased to report that the over 30 that we have seen at Band Pro all work as promised. It is a great product and it has moved downconversion for HD shooting forward in a big leap.

Michael Bravin
Chief Technology Officer
Band Pro Film & Digital

Michael Bravin writes :

>How valuable is 8 month old information about a product that was >brand new in May and had some early software problems ?In this >business 8 months on a new product is a lifetime.

Michael,

I guess you haven't been keeping up with current events on CML-general, where eight months can be a mere blink of an eye. People there are still dissing 45 + year old Angenieux 12-120s while pining for cameras that few of us have ever seen.

>I am pleased to report that the over 30 that we have seen at Band Pro all >work as promised. It is a great product and it has moved >downconversion for HD shooting forward in a big leap.

It is indeed a great leap forward. Maybe someday Sony will build it into the CineAlta.

Brian "satisfied user" Heller
IA 600 DP