2 questions for DV Rack users

P

powerdog

Veteran
1. There seems to be a lag when I try to stop recording via the laptop. Regardless of the buttons I press, the timer (in the unscrolled, standard window) keeps running. How do you actually stop it immediately?

2. How does the vectorscope affect how you shoot -- are you using filters, turning off lights that produce color casts....? I use it plenty in FCP, but never thought of it as a shooting tool.
 
powerdog,
I've noticed that myself. I think it's tied to the pre-roll recording setting. By default, the pre-roll time is 5 seconds. You can turn off pre-roll recording.

As for the vectorscope, I have to admit it has limited utility for me as well. I use it to verify that my color balance is close to where I want it. Unfortunately, there's no dials on the cam to make minor adjustments. I suppose it might be more useful if you had a set of those warming cards to tweak the balance. A vectorscope is also useful for detecting 'unsafe' color levels (reds anyone?). I use a vectorscope a lot in my NLE as well.
-Dan
 
Dan, my favorite use of the vectorscope in FCP: when I'm driving home, and I realize I totally forgot to white balance a shot. Then it's my security blanket...fortunately, I've never had colors so "off" that I could fix them later.

So maybe the extra recording is a sort of post-roll?
 
powerdog said:
So maybe the extra recording is a sort of post-roll?
Click to expand...

I just ran a quick test using a clock face. I set a pre-roll buffer of 10 seconds. Looking at the resulting clip, it starts 10 seconds prior to hitting 'record' (as expected) but it stops at the moment I hit 'stop' even though it took another 10 seconds to actually say it had stopped. So it's not a post-roll buffer. More like it's the time it takes for DVrack to flush the pre-roll buffer.

My test was with DVrack in non-slave mode so it was not tied to the DVX record function. I normally use it in this mode so I can change tapes while continuing to record on disk. The above behavior may be different in slave mode. I'll have to try that next.

-Dan
 
So I hit the blue "stop" button, the numbers keep climbing, but my recording actually stopped when I hit the button? I guess it's easy enough to ignore that.
 
That delay-before-finishing also gets longer and longer the more clips you have in your project. When we were doing "Siren" it got to the point where I had dozens, if not a hundred, clips in the project and it could take a good couple of minutes before finishing up. I found that ejecting clips from the project returned it to snappy performance.

So yes, I do expect it's some sort of post-buffer-flushing, temporary-file-management thing that's going on.
 
Barry_Green said:
That delay-before-finishing also gets longer and longer the more clips you have in your project.
Click to expand...
Hmm, that actually sounds like a programming logic problem. Something called an Order-N issue. That means that the time to do something increases linearly with each item/element. Imagine adding a penny to your piggy bank and wanting to know the total. Each time you add one you recount all pennies to get the total. Fast for the first few but each time a penny is added it takes longer and longer to calculate the total.
 
I guess it prevents you from starting a new clip during the finishing process? That could become a minor annoyance.

Barry, what's your thought on the use of the vectorscope during shooting?
 
I don't lean on the vectorscope nearly so much as on the waveform. Vectorscope's great for matching a shot, but unless I'm specifically trying to match a shot I don't usually spend too much time with it.
 
And you would do that matching with, what, gels on your lights?

Also, how do you typically set things up physically? I'm just wondering about the locations of you, camera, and laptop relative to each other. My eyes are over 50, so I can't have that screen too far away and hope to see much.
 
Depends on the crew and the setting. On Siren, Pat was DP/camera op, so we ran the long firewire cable and got DV Rack as far away from the microphones as possible and I obsessed over it while he took care of shooting. On one-man stuff you have to keep it closer, obviously, or you'd drive yourself batty running back and forth... :)

As for matching, it can be done in several ways, including gelling lights, but also through the color temp and chroma phase settings in-camera, or through white-balancing to a complementary color.
 
Oh, yeah. I forgot about manipulation through white balance. It's all I can do to remember to white balance at all -- even when I leave big notes in my Pelican. A mind is a terrible thing to waste. Thanks!
 
One valuable use for the vector scope is checking the lighting on a green/bluescreen. One customer who does a lot of chroma keying says its most useful in this regard in the Line Mode--she scans the line down the screen looking for anywhere that the squiggly line on the vector scope strays too far from the green target. Then using the waveform monitor she's able to isolate problem spots.
 
Hi, Mark...I see you're with the company! Could your respond to the other part of this thread, re the lack of immediate response to the stop button. The numbers keep climbing for a while, but apparently nothing is being recorded at that point. What's causing this?
 
This thread is the first I've heard of this. Never seen it myself in testing. My projects often have dozens of clips, sometimes hundreds, but they tend to be pretty short. I'll need to do some testing with a large number of clips, each at least a few minutes in length.

Those of you who are experiencing this: is it with DV only, HDV only, or both?
 
I've just tried the trial version with my DVX100A, and I noticed that even hitting the stop button several times won't stop the counter right away. From comments here, I guess the only problem is that you can't record another clip until the counting stops.
 
the_other_Mark said:
This thread is the first I've heard of this. Never seen it myself in testing. My projects often have dozens of clips, sometimes hundreds, but they tend to be pretty short. I'll need to do some testing with a large number of clips, each at least a few minutes in length.

Those of you who are experiencing this: is it with DV only, HDV only, or both?
Click to expand...

Mark,
The delay occurs consistently (like every time for me). This is with DV only and with the latest version of DVrack. I don't have the HDV upgrade. I've tried this with a DVX and a Sony with the same results. I'm using DVrack in a 'non-slave' mode so I must manually start and stop the recording. When I click the blue stop button on the DVR, it appears to continue recording although based on the test I talked about earlier in the thread, the actual clip stops at the point I hit stop. The amount of time it takes to 'stop' is directly affected by the pre-roll setting. The test I ran was for only 15 seconds. Hope this helps.
Thanks,
Dan
 
Happened to me a lot, DV only. Of course, we shot something like 300 gigabytes in a couple of weeks so it was a lot of footage, but it was consistent -- the bigger the project grew, the slower the stop response time. Ejecting all the clips returned the project to instantaneous responsiveness.
 
Is it really a "problem", though? If you have to start recording again that soon after stopping, maybe you shouldn't have stopped in the first place. :)
 
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