do i need a sync box to keep an arri alexa TC jammed for a couple of hours?

[dominiquegreffard]

hi guys,

so from what i understand the built in TC generator holds well for a couple of hours right? and what happens if you turn off the camera for a battery change or a media change? will i have to re-jam like i have to do with the red?

i am basically asking if i should need a sync box to prevent me from having to rejam frequently during the day?

thanks!

[RPSharman]

What I have learned from reading posts on this board about the exact subject (a really good idea to do a quick search)...

The Alexa contains a clock made by Ambient, and therefore holds time code as well as a Lockit box.  Once the Alexa is jammed (you can do this from a Denecke slate or TC box, Lockit box, recorder, whatever), there is an internal battery which holds the time during battery changes.  This should certainly be good for 6 hours.

It has been written that you should re-jam after frame rate changes.

So the answer is... You don't need to attach a sync box to the Alexa, but you will need some method of jamming it with time code in the morning and at lunch and after frame-rate changes.

[Richard Lightstone, CAS]

I have a "first person" perspective, after just completing a pilot with 3 Arri Alexas. My crew jammed them via a Denecke Time Code slate in the morning and after lunch. Contrary to what Robert wrote, they do not have to be jammed after a "frame rate" change, but he is correct that the Arri uses an Ambient TC clock.

The Alexa will maintain time code after a battery change, but it is recommended that you re-jam the camera if it has been powered down for over ten minutes or more.

The menu is really easy to navigate and here is the step by step external jamming procedure with thanks to Robert Kennedy of Coffey Sound:

Jamming TC into an Arri Alexa:

[list type=decimal]

[*]power on alexa

[*]go to timecode page by pressing TC button

[*]go into options and change the mode to "Ext Jam" using rotating push dial

[*]connect TC source

[*]press info button to go to info page, wait for it to say "system good"

[*]go back to timecode page and change to INT TC

[*]remove timecode source

[*]press TC button and compare to slate (if jammed properly it will be ~1 frame off)

[RPSharman]

Contrary to what Robert wrote, they do not have to be jammed after a "frame rate" change.

Good to know.  Previous reports were that this was required.

[dominiquegreffard]

hey thanks guys!

i m gonna do just that. i m filming for the first time with the thing and i m glad that you guys came in and helped me in this gentle matter,

i m gonna let you know how its went but it makes all a lot of sense and since i use a 744t recorder with a ambient tc generator i m pretty sure it s gonna be just fine,

cheers!

Dominique

[Jim Gilchrist]

Good to know.  Previous reports were that this was required.

I saw this behavior by the camera with an earlier version of the camera firmware but it might well have also been due to camera department error. It was the first time with the camera for all involved and a number of months ago.

Best regards,

Jim

[larry long]

I'm working on a pilot for ABC now using these cameras, I'm using Denecke SBt's. The problems we've encountered are when the cameras are rebooted they must be rejammed (not battery changes) and transfer requires a 10 sec preroll before slating (not going to happen). I am using a 10 sec pre roll on the Deva, like that fuckin' matters, apparently roll sound is the new last looks. Plus this director would lose his freaking mind if he had to wait 10 seconds for camera pre roll. So the tranfer guys sent us notes that we are making their jobs HARD, really? You think making films is easy? How's that leather chair? is the temp good for you? can I get you some coffee? I will as soon as I get a decent turn around and some dry socks....

anywho that's my 2 cents,

LL

[studiomprd]

while I might question it,  I would certainly allow the camera department and post to sort out their own pre-roll situation!

[Philip Perkins]

I'm working on a pilot for ABC now using these cameras, I'm using Denecke SBt's. The problems we've encountered are when the cameras are rebooted they must be rejammed (not battery changes) and transfer requires a 10 sec preroll before slating (not going to happen). I am using a 10 sec pre roll on the Deva, like that fuckin' matters, apparently roll sound is the new last looks. Plus this director would lose his freaking mind if he had to wait 10 seconds for camera pre roll. So the tranfer guys sent us notes that we are making their jobs HARD, really? You think making films is easy? How's that leather chair? is the temp good for you? can I get you some coffee? I will as soon as I get a decent turn around and some dry socks....

anywho that's my 2 cents,

LL

Down with all that.  They need to fix their system.  No one has asked me for a 10 sec preroll on Alexa yet.  We didn't end up with 10 sec of preroll back in the 1/4" Nagra TC days, fer Chrissake....

Mostly the Alexa is great for TC.  You had better at least check that it is still on the same TC as you jammed if they either reboot the camera or change the frame rate to something off-speed and then back to sound speed.  Sometimes it's fine, sometimes it's not.  Fortunately it's easy to just look at the display on the side of the camera.  In my experience, if the Alexa blows its jam, it goes all the way back to counting from 00:00:00:00, so it is is easy to see that you aren't jam synced anymore.

phil p

[soundbeing]

Now working on my 3rd show with Alexa.  First show went perfect with morning and lunch TC jam.  Second show had problems with TC consistency(we ended up slapping syncboxes on the cams).  Current show with current Alexa firmware has B cam working perfectly with 6 hour jams but A cam spitting TC out every so often  requiring numerous re-jams.

We give cam dept sync boxes and let them deal with camera issues.  We have our hands full without babysitting camera idiosyncrasies.  They keep trying to give the boxes back so they won't have to be responsible for them but we are holding strong  to the logic that if the camera dept needs sync boxes they have to keep track of them but can turn them back in at end of day.

Life is Good.

[larry long]

Yeah I really haven't gotten any flack, the DIT is a good guy and he is taking the heat as he should. I provide them a crossjammed box and they can deal with it!

Life is good. #hi5

[RPSharman]

Yes Yes Yes!  Give the camera department the sync box and be done.  My show has elected to rent sync boxes from the camera house and not from me, which makes this even easier.

I leave the boxes with camera THE ENTIRE TIME!  My guys go to the camera in morning, swap the batteries in the sync box, jam the TC, return at lunch to jam TC and that is it.

We ought not be responsible for anything else other than delivering TC to the lockit boxes.

Robert

[bmjord]

Jamming TC into an Arri Alexa:

• power on alexa
• go to timecode page by pressing TC button
• go into options and change the mode to "Ext Jam" using rotating push dial
• connect TC source
• press info button to go to info page, wait for it to say "system good"
• go back to timecode page and change to INT TC
• remove timecode source
• press TC button and compare to slate (if jammed properly it will be ~1 frame off)

Why will there be a ~1 frame difference on the Alexa display? 

[Michael P Clark]

We have seen 1-2 second offset from the camera display.

[Marc Wielage]

Yeah, we saw the same thing a week ago on the shoot I did. There's internal processing in the camera that results in a slight 1 or 2-frame offset -- no biggie. As long as it's consistent, post can deal with that.

The problems we've encountered are when the cameras are rebooted they must be rejammed (not battery changes) and transfer requires a 10 sec preroll before slating (not going to happen).

That's pretty weird. Is this a file-based show? If it is' date=' they don't need any pre-roll at all as long as the slate is captured. I bet somewhere they're going to HDCam-SR, and those machines need a minimum of 5 seconds pre-roll to lock. The typical trick in post is, we'd ask for 10 seconds of pre-roll, hoping to get at leat 5 or 6 seconds. Without it, the take gets captured [i']without a clap, which drives the editor and assistant editor crazy.

The camera crew is reluctant to roll early because they're worried about a roll-out on a card or a tape (whatever they're capturing on). This is no different than film shoots in that respect. In the 1990s, I've handed a bottle of Scotch to the 1st AC and said, "for the love of god, please give us another 5 seconds of pre-roll," and sometimes that works.

--Marc W.

[Michael P Clark]

You guys must have eyes like a hawk to visually see 1 frame off between your slates and the TC display of the camera. Are you sure you're not noticing the seconds instead of the frames?

[Wyatt Tuzo]

No news here. On a show with the Alexa right now...same 1-2 sec offset on the display. Love how quiet it is though! TC stability seems great too. I'm just jamming it in the morning and after lunch -with no complaints.

-Wyatt

[RPSharman]

Yeah, we saw the same thing a week ago on the shoot I did. There's internal processing in the camera that results in a slight 1 or 2-frame offset -- no biggie. As long as it's consistent, post can deal with that.

That's pretty weird. Is this a file-based show? If it is, they don't need any pre-roll at all as long as the slate is captured. I bet somewhere they're going to HDCam-SR, and those machines need a minimum of 5 seconds pre-roll to lock. The typical trick in post is, we'd ask for 10 seconds of pre-roll, hoping to get at leat 5 or 6 seconds. Without it, the take gets captured without a clap, which drives the editor and assistant editor crazy.

The camera crew is reluctant to roll early because they're worried about a roll-out on a card or a tape (whatever they're capturing on). This is no different than film shoots in that respect. In the 1990s, I've handed a bottle of Scotch to the 1st AC and said, "for the love of god, please give us another 5 seconds of pre-roll," and sometimes that works.

--Marc W.

Marc,

On a file-based camera, can't they attach some sort of "slug" or 10 seconds of video black on the beginning on the file in the NLE system in order to have the pre-roll for their tape transfer?

Our show is using SSR decks (Genesis file-based), but is being totally handled by editorial.  They are laying off to D5 for a camera master.

Robert

[Marc Wielage]

On a file-based camera, can't they attach some sort of "slug" or 10 seconds of video black on the beginning on the file in the NLE system in order to have the pre-roll for their tape transfer?

They should if it's a time-line based system. But everything's different depending on what system they use. If it were up to me, I'd build the whole project in a timeline, based on a one-hour reel for dailies, then lay it off on an HD videotape as backup. I believe this is one of the options available on the MTI Dailies system, as well as Bones Dailies.

Our show is using SSR decks (Genesis file-based), but is being totally handled by editorial. They are laying off to D5 for a camera master.

Yeah, I'm hearing that a bunch of shows here in LA have switched from HDCam-SR to D5, simply because Sony's tape plant was badly damaged in the tsunami, and SR tape stock is very difficult to find right now.

--Marc W.

[soundbeing]

Thought a follow-up post on my third Alexa shoot might be in order.  We are running 3 Alexas.  #3 is steadycam and is jammed each time they build it so no problems there.  Our A cam was TC intermittent.  It jammed and all works fine until the camera suddenly spits the TC out and syncs itself to some other planet in the solar system.  We have numerous memos from editorial at this point.  This camera sometimes goes into error mode upon rolling and requires re-boots.  May be a camera problem or a camera assistant problem.  Our B cam has not had many problems.

Production has now requested we mount a clockit on all cameras.  Now everything is TC stable on A cam, but B cam has rejected the external TC a few times.  At this point A cam has clockit mounted and B cam only uses clockit only to jam but not mounted.

M.Weber

[Glen Trew]

You guys must have eyes like a hawk to visually see 1 frame off between your slates and the TC display of the camera. Are you sure you're not noticing the seconds instead of the frames?

I imagine the "1 to 2 frame offset" was observed in post, not by holding a slate next to camera display.

gt

[Richard Lightstone, CAS]

The instructions from Robert Kennedy has a typo. The display screen on the Alexa will be about one second off from your slate. However  the internal TC on the Alexa will be correct.

[soundbeing]

Here is a follow-up to my follow-up.  Arria Alexa is becoming a problem without dedicated clock-it boxes.

Here is a note sent out by our telecine lab regarding timecode issues in Alexa;

  Hello All,  Well, as was the case yesterday with multiple camera rolls having mismatched CAMERA to AUDIO TC, there were several again today....I will now be noting this daily on the reports when it occurs.   The following is listed on todays' daily report:    CR A49-53: Scenes 39,44-46 have several takes with mismatched timecodes between CAMERA and AUDIO. Slate and AUDIO TC  match and are correct.

  Camera MUST be monitored and jammed ( and as frequently as the other equipment) in order for a consistent match between AUDIO and CAMERA codes.  SG

  We are asking to have clock-it boxes attached to all cameras, at all times.

M. Weber

[Philip Perkins]

Here is a follow-up to my follow-up.  Arria Alexa is becoming a problem without dedicated clock-it boxes.

Here is a note sent out by our telecine lab regarding timecode issues in Alexa;

  Hello All,  Well, as was the case yesterday with multiple camera rolls having mismatched CAMERA to AUDIO TC, there were several again today....I will now be noting this daily on the reports when it occurs.   The following is listed on todays' daily report:    CR A49-53: Scenes 39,44-46 have several takes with mismatched timecodes between CAMERA and AUDIO. Slate and AUDIO TC  match and are correct.

  Camera MUST be monitored and jammed ( and as frequently as the other equipment) in order for a consistent match between AUDIO and CAMERA codes.  SG

  We are asking to have clock-it boxes attached to all cameras, at all times.

M. Weber

Weird. That camera needs to visit the Arri mothership....  I have seen some "spontaneous TC dumps" w/ Alexa but not this frequent, and never to some oddball TC value--the dumps I've seen always reset the camera back to 00:00:00:00.

phil p

[Jan McL]

Managed to get on the distro list for discrepancy reports these last 3 pilot weeks.

The Alexas performed well and held sync after jamming in the morning and after lunch (Lockits on the cameras were banned at the request of the DP), except after a frame rate change, after which they required a re-jam that sometimes did not happen, thus, the several "synced to time code" notes from the transfer house.

On a show like the one we just wrapped that incorporates many frame rate changes a day, I will recommend that if it gets picked up, some kind of time code feed device be attached to the camera. TV is just too crazy chaotic and communication too sparse to achieve perfect time code on the camera. Hell, the 2nd AC's could hardly manage to get the slates on "tape".

-- Jan