High speed video at DVinfo.net

Ron Edwards · March 9th, 2011, 04:39 PM

I had a manufacturing company call and ask if I can shoot some good slow motion video of a piece of equipment that they are having problems with. The equipment is running carboard at 800 ft. per minute.

I can overcrank my JVC GY HM700 and shoot 720p set to 60 FPS.

Any idea if this might be a high enough frame rate or will I need to rent a high speed cam .... ie 1000 FPS?

Thanks in Advance
RonE

Bob Richardson · March 9th, 2011, 06:47 PM

You need to find out from the client what the fastest-moving (potentially troublesome) component is within the piece of equipment that they want to record.

For example, if there is a roller that is 6 inches in circumference, and the line is rolling 800ft per minute, that means the roller is turning 4.44 times per second. At 60Fps, you'll capture 13.5 steps of each revolution, probably more than enough to catch a problem.

However, if there is some kind of gear or cog moving faster than that, or a cutting tool that only comes down for a split second and then pops back up rapidly, you may run into trouble. A cutter or press might complete the critical part of its motion cycle in 1/10th of a second, for example, giving you only 6 frames to catch the entire range of motion.

So, the answer is that it is very possible that the HM700 at 60Fps will do what you want, but you'd better communicate further with the client about exactly what it is they want to capture before making that decision. You may also want to simply tell them that you can come out and do an attempt with the standard camera and that if it doesn't work, a high-speed camera (and appropriate flicker-free lighting) will need to be rented at their expense. They'll probably be OK working with you a couple of go-arounds if you lay out the limitations and potential costs for them.

Oren Arieli · March 10th, 2011, 02:28 AM

Not sure that this would work for the purpose, but a variable speed strobe light as the only source might be an interesting option.

Ron Edwards · March 10th, 2011, 09:33 AM

Bob,

Thanks for the reply. Basically I told the customer the same thing over the phone. I will post my findings after the job is finished.

RonE

March 9th, 2011, 04:39 PM	#1
Ron Edwards Regular Crew Join Date: May 2004 Location: Fairview Heights, Illinois Posts: 148	High speed video I had a manufacturing company call and ask if I can shoot some good slow motion video of a piece of equipment that they are having problems with. The equipment is running carboard at 800 ft. per minute. I can overcrank my JVC GY HM700 and shoot 720p set to 60 FPS. Any idea if this might be a high enough frame rate or will I need to rent a high speed cam .... ie 1000 FPS? Thanks in Advance RonE

March 9th, 2011, 06:47 PM	#2
Bob Richardson Regular Crew Join Date: Mar 2009 Location: Portland, OR Posts: 178	Re: High speed video You need to find out from the client what the fastest-moving (potentially troublesome) component is within the piece of equipment that they want to record. For example, if there is a roller that is 6 inches in circumference, and the line is rolling 800ft per minute, that means the roller is turning 4.44 times per second. At 60Fps, you'll capture 13.5 steps of each revolution, probably more than enough to catch a problem. However, if there is some kind of gear or cog moving faster than that, or a cutting tool that only comes down for a split second and then pops back up rapidly, you may run into trouble. A cutter or press might complete the critical part of its motion cycle in 1/10th of a second, for example, giving you only 6 frames to catch the entire range of motion. So, the answer is that it is very possible that the HM700 at 60Fps will do what you want, but you'd better communicate further with the client about exactly what it is they want to capture before making that decision. You may also want to simply tell them that you can come out and do an attempt with the standard camera and that if it doesn't work, a high-speed camera (and appropriate flicker-free lighting) will need to be rented at their expense. They'll probably be OK working with you a couple of go-arounds if you lay out the limitations and potential costs for them.

March 10th, 2011, 02:28 AM	#3
Oren Arieli Major Player Join Date: May 2007 Location: San Jose, California Posts: 919	Re: High speed video Not sure that this would work for the purpose, but a variable speed strobe light as the only source might be an interesting option.

March 10th, 2011, 09:33 AM	#4
Ron Edwards Regular Crew Join Date: May 2004 Location: Fairview Heights, Illinois Posts: 148	Re: High speed video Bob, Thanks for the reply. Basically I told the customer the same thing over the phone. I will post my findings after the job is finished. RonE