Hello V1 users... I've posted something similar elsewhere in this great site, but was curious what more experienced users of the V1U think of the camera's ability to successfully record controlled environment explosions. The explosions are occurring in a room setup for experiments on the effects of small explosions on people (done on mannequins of course). Since the explosions will create a very bright flash, do you think the V1U's electronics/exposure system can handle it? I'm trying to avoid blowing out the footage completely as the explosion occurs. Previous taping of this work (done by a non-professional camera user) was awful, with the actual explosion blowing out the image for 2-3 seconds. Of course everything was set to "auto".

The other thing I like about the V1U is the HDMI output coupled with soon-to-be-available "portable" recorders. I've narrowed my search down to this camera and the Canon XH A1. I think both cameras are great, but want to maximize for the future as much as possible. Then again, this camera will be used as my entry into the HD world. I'm hopeful I can justify the XDCAM EX when it comes out. Maybe that's another reason to stick with the Sony V1U for now??? Either way, this project is shooting in 10 days, so I've got to move quickly.

Thanks in advance for your input.

Stuart

I know a guy who is now using the HVX200 for recording controlled explosions...Much better than HDV tape - plus being solid state recording
he gets no tape "ripples" the larger explosions might create. And he can shoot at 720 60 fps for true slo-mo.

When I was in the USAF and we wanted footage of explosions, or even things that MIGHT explode (like rocket motors under test), we used high speed film cameras. Too much can happen between one frame and the next of video.

The client knows the cost of a true high speed camera shoot is beyond their budget. Equally important to the explosion is the aftermath and its effect on the dummies (fire, etc...).

BTW, what did you mean by tape ripples? Are you referring to actual disruption on the tape mechanism caused by the shock wave of the explosion?

I have shot a regular fireplace (not even explosions)with my FX1 (HDV) and there were definate "ripples" in the flames. I think it's mpeg compression artifacts. It looks pretty bad. As much as I'm a SONY guy, and love my FX1 and V1 , I think going with the HVX200 makes more sense. Being able to truly slow the footage down also makes great sense for your purposes.

Without knowing the specifics of your shoot, I'd say you need to setup the 'studio' well so that the flames/explosion is highly visible to the camera. You'll need to lock exposure (AE won't be fast enough) - this may take a few test explosions to get right.
Ideally you would use a high speed camera as has already been pointed out, but you have to work with what you've got I guess. If they are happy with 50i or 60i then great.

If the aftermath is very important and the brightness of the scene differs a lot, you may want a second camera locked to a different exposure and maybe even different framing.

As mentioned HDV can suffer from macroblocking which is more evident when there is lots of movement within the frame - fast pans, fog, fire, water ripples and presumably explosions can display this. It may not even be an issue in your case, but then again it might. You could try shooting in DV if it is.

HTH,
Kyle

The client knows the cost of a true high speed camera shoot is beyond their budget. Equally important to the explosion is the aftermath and its effect on the dummies (fire, etc...).

BTW, what did you mean by tape ripples? Are you referring to actual disruption on the tape mechanism caused by the shock wave of the explosion?


Yes, and HDV is Long Group of Pictures MPEG2 recording.
If the explosion is large enough it will vibrate the camera
and could disrupt the recording. Shooting on P2 cards
is more robust.

Hello,

I can tell you that I used an A1-U with great results when recording explosions. I'm guessing that the cameras are similar enough that this should work for you. The only thing I'm not sure about is that the footage I took was outside in bright sunlight.

1. Set the exposure to manual
2. Set the focus to manual
3. You need to protect your camera from both heat, shock and fragmentation
4. #3 really depends on how big the explosive charge is, how big the room is and how far from the explosion your camera will be.

Outside in bright sunlight, I don't think there was much of a difference between the sun and the flash of the explosion so the image wasn't overblown or washed out. However, inside there maybe to much of a difference between a dark room and the flash of the explosion. I had great luck slowing down the video of the explosions, but the other post is correct about missing something that happens in between the 30 fps frame rate.

Just curious, who is your client, if you can tell us? Also, if its a law enforcement agency or government agency, e-mail me and I maybe able to help you a little more than what I can post on a public forum.

Thanks,

Michael
info@mbdigitalworks.com

Thanks for the information Michael. I'm not able to say who the client is, other than it's a major university. It's not related to law enforcement.

Since the client has indicated they understand there will be no frame-by-frame shot of the actual explosion (and they don't want to pay enough to get that), I've narrowed my search down to the V1U and XH A1. Either of these should be a good start for me in the world of HD. I'm not doing broadcast work, so I think I'll be okay. Now the question is which one? Ahhhh... the endless debate!

Stuart

Thanks for the information Michael. I'm not able to say who the client is, other than it's a major university. It's not related to law enforcement.

Since the client has indicated they understand there will be no frame-by-frame shot of the actual explosion (and they don't want to pay enough to get that), I've narrowed my search down to the V1U and XH A1. Either of these should be a good start for me in the world of HD. I'm not doing broadcast work, so I think I'll be okay. Now the question is which one? Ahhhh... the endless debate!

Stuart

Stuart, if you can spend a bit more, and use a dualcore PC and PP2 for editing, get the V1, a Black Magic Intensity card ($250), NEO HD from Cineform ($600) and capture via the HDMI port on the V1. You'll get beautiful uncompressed 1920x1080i output, and record to a HDD you can use immediately. Then you're all set for nice work ahead.

My two bits...

Thanks Stephen. I've thought of that, but it's not portable - yet. I think some in this forum have talked about using the Intensity card with a duo core laptop with an adapter card. Now THAT would be something very interesting and would definitely push me towards the V1U over the XH A1. Do you know if anyone pulled the laptop setup off?

Thanks Stephen. I've thought of that, but it's not portable - yet. I think some in this forum have talked about using the Intensity card with a duo core laptop with an adapter card. Now THAT would be something very interesting and would definitely push me towards the V1U over the XH A1. Do you know if anyone pulled the laptop setup off?

We're working on a very portable solution called the "RIO", but it'll be a bit yet before you can buy one of the little guys. It'll be even easier to use than a laptop, but just as powerful and interface with one.

'Nuf said

I found this device - not cheap... I wonder if this would interface properly with the Intensity card? If so, we'd have a quick and dirty solution until more dedicated devices become available.

http://www.mobl.com/expansion/products/expressbox1/expressbox1_prices.html

I found this device - not cheap... I wonder if this would interface properly with the Intensity card? If so, we'd have a quick and dirty solution until more dedicated devices become available.

http://www.mobl.com/expansion/products/expressbox1/expressbox1_prices.html

Hi Stuart. I think it could possibly work. However, it would be good to check out first and there might be a few caveats. You'd need an inverter for field use and your laptop better be powered by a fast Core2Duo or you might have trouble capturing the HDMI input. Also, you better have a big, fast HDD in that laptop! Even compressed by CF, 1920x1080 sized video takes a lot of space and very quickly at that.

You're right, it would a somewhat expensive stopgap measure (and hassle) and you'd probably be better off to just use CF Prospect and convert the V1's HDV output you recorded to tape, especially if portability is needed. That final workflow result would still be very nice. Though not equal to ingesting and CFing full uncompressed output from the Intensity, Prospect is what you'd probably use to edit the video generated from something like the RIO anyway.

I too have felt the sting of HDV cameras dropping loads of frames when shaked, rattled, or rolled. The most frustrating part about it is that they drop out just before an explosion until just after it. I shoot on Sony HC3Es and they'll foul up if you look at them the wrong way. I'm looking for a way to shoot on them without worry of them cutting out- I'd go P2 right now if it weren't for the H's low cost and small size.

I recently attempted to avoid the problem by recording the cameras onto remote HVR-M10U decks. Unfortunately, do to unforseen circumstances the decks actually took more of a knock than the cameras, so I still don't know if that'd work.

I wonder if anyone has tried the HVR-DR60 for this problem. Its description mentions a 14 second buffer. Does this mean if I was to, theoretically, mount the DR60 in a car, and that car were to, theoretically, roll end over end for 13 seconds, would I still get the shot?

Thanks.

Given the long-GOP dropout potential for loosing half a second's worth of footage I'd be REALLY nervous about using HDV to film something that's a one-shot AND is likely to shake the camera.

You might be okay - but if the compression waves of the explosion shake the camera just a little too much to keep the tape tolerantly tensioned, then you've lost your shot. Even with DV it's bad enough.

I'd DEFINITELY use a solid state camcorder (HVX200) OR use a DTD hard drive - although that brings its own risks (ie. "Whoops! In all the excitement the firewire cable fell out")!

Couple more questions:

Is the HVR-DR60 compatible with Sony cameras with firewire out (HDR-HC3E specifically?)?

I ask because I have a another shoot coming up with a camera in a car and things are going to get really hairy. Hairy enough that I wouldn't put a HVX in the car because odds are the camera isn't going to make it. In fact- I know the camera wouldn't survive. I could however see welding a DR60 into a black box in the trunk and running a firewire cable from an HC3E in the car. Would this work? Would the DR60 record the signal from the HC3E until the camera met its maker or could shock from the car cause it to cut out before and impact (likely to be a big impact)?

Thanks.

Scott, the DR60 works with any 1394 camera outputting DV/HDV. I've now recorded with the Canon A1, H1, and all of the Sony cams. The difference the V1 makes is that it provides display on the camera, as to the status of the drive.

Thanks, Douglas.

Does anyone have any experience with the HVR-DR60 in close proximity to explosions or inside of car in an accident? Specifically, has anyone tested the 3G censors against a 350 mph car wreck? 200 mph?

Also, are there any small, inexpensive, solid state recorders that'll plug into an HC3E?

Thanks.

Um, is ANYTHING tested to survive 350mph?

With both tape and hard drives, you are dealing with moving parts. The low mass and high rigidity of laptop mechanisms helps them a bit against G loads, but nothing that moves is going to be immune to vibration. If you want to increase your likelihood of getting shots with high vibration, you will need to insulate the camera from vibrations. Unfortunately, rubber mounts that reduce vibration to the camera also separate the camera from the vehicle visually. The vehicle will vibrate even if the camera stays still, so your resulting image will be of a vibrating vehicle as the camera moves in relation to it because of the flexible mount. I'm guessing that a mount with a bit of shock dampening material that is overall fairly tightly mounted will be the compromise between protecting the camera and getting the best image.

True, 350 mph is plenty quick. It likely wont be a sudden stop from that speed. More of a violent roll followed by a gentle stop. Ignoring the speed for just a moment, are there ANY HD or HDV cameras in existence built specifically for crashes, explosions, wrecks, or disasters?

True, 350 mph is plenty quick. It likely wont be a sudden stop from that speed. More of a violent roll followed by a gentle stop. Ignoring the speed for just a moment, are there ANY HD or HDV cameras in existence built specifically for crashes, explosions, wrecks, or disasters?Speed an object is travelling isn't really very relevant to whether it'll survive. What is relevant is how quickly that object stops, - essentially how many G is has to undergo in its deceleration to rest. Depends on distance within which it comes to rest. If it's one foot or something thats probably 500g + (sorry tired & can't be bothered to do the maths..).
Sorry if i missed some detail in preceding posts, but AFAIK, no road or race car will go 350mph except a Top Fuel dragster running nitromethane and while those will exceed 300mph fairly easily in 1/4mile (in less than 5 seconds), they pull the chute then.
- Land Speed Record stuff, yes they go plenty faster..

I'm sure there's specialist cameras designed to have a greater probability of surviving very-high G impacts but i don't know of any offhand. Solid-state i would think would be necessary, radio'ing the signal to an external static hard-drive or tape etc. Airplane black boxes (actually orange..) record many flight parameters and are designed to withstand a very rough ride indeed. And generally the key contents does survive, more or less.

The sensors in a DR-60 are designed to calculate if the unit is accelerating in any direction (thats why it takes 3 sensors, in x, y, z axes..) at 1g or 9.81ms-2. If it is, heads get parked.
In a big impact this wouldnt do much good because it won't be decelerating at 1g, it'll be 100's of G (for a few milliseconds..) and any hard-drive will be, almost certainly, toast. Or at least suffer some degree of platter damage.

You can have an object undergo a 500g deceleration to 0mph even when it's going only, say, 30mph.
It's just that the object will be suffering that 500g deceleration for a very very short time indeed. But it's still 500g..

Thanks Stu. I eliminated the hard drive as a possibility myself after reading its manual last night. Sony rates the DR60 for a drop from 100cm (40in). Grossly insufficient for my purposes.

Looking at the Sanyo Xacti. Solid state and cheap.