last updated: 16th March 2017 - Day 178 & day 181 Acoustic Apogee Detector

Safety First

Search

Site Index

Tutorials

Articles

Rocket Gallery

Labs

Where To Buy

10 Challenges

Links

Blog

Glossary

Contact Us

About


Construction - Basic

Body

Ring Fins

Flat Fins

Nozzle

Nosecone

Construction - Advanced

Robinson Coupling

Splicing Bottles #1

Splicing Bottles AS#5

Reinforcing Bottles

Side Deploy #1

Side Deploy #2

Mk3 Staging Mechanism

Multi-stage Parachutes

Fairings

Construction - Launchers

Gardena Launcher

Clark Cable-tie

Medium Launcher

Cluster Launcher

Launch Abort Valve

Quick Launcher

How It Works

Drop Away Boosters

Katz Stager Mk2.

Katz Stager Mk3.

DetMech

Dark Shadow Deployment

Articles

Recovery Guide

Parachutes

How Much Water?

Flying Higher

Flying Straight

Building a Launcher

Using Scuba Tanks

Nozzles

Video Taping Tips

MD-80 clone

Making Panoramas

Procedures

Burst Testing

Filling

Launching

Recovery

Flight Computer

Servo Timer II

V1.6

V1.5

V1.4

V1.3, V1.3.1, V1.3.2

V1.2

Deploy Timer 1.1

Project Builds

The Shadow

Shadow II

Inverter

Polaron G2

Dark Shadow

L1ght Shadow

Flight Log Updates

#181 - Acoustic Apogee 2

#180 - Light Shadow

#179 - Stratologger

#178 - Acoustic Apogee 1

#177 - Reefing Chutes

#176 - 10 Years

#175 - NSWRA Events

#174 - Mullaley Launch

#173 - Oobleck Rocket

#172 - Coming Soon

#171 - Measuring Altitude

#170 - How Much Water?

#169 - Windy

#168 - Casual Flights 2

#167 - Casual Flights

#166 - Dark Shadow II

#165 - Liquid Density 2

#164 - Liquid Density 1

#163 - Channel 7 News

#162 - Axion and Polaron

#161 - Fog and Boom

#160 - Chasing Rockets

#159 - Measurement

#158 - Dark Shadow

#157 - Polaron G2

#156 - Foam Flights

#155 - Down The Barrel

#154 - Revisits

#153 - ClearCam

#152 - Mullaley, Axion G2

#151 - Competition Day

#150 - Rocket Salvos

#149 - Glide Fins

#148 - Too Windy

#147 - Descent Rates

#146 - G2 Launcher

#145 - Harness

#144 - Water vs Foam

#143 - Whalan Reserve

#142 - Doonside

#141 - Windy

#1 to #140 (Updates)

 

TIPS FOR PRODUCING WATER ROCKET VIDEOS
Filming water rockets can be useful for sharing your greatest achievements in your favourite hobby, as well as providing a valuable analysis tool for improving your rockets.

These tips are not supposed to be a comprehensive list of steps in creating perfect videos. Rather it is a collection of techniques we have found useful in the course of filming some 350+ water rocket launches with a standard digital video (DV) camera.

Filming

  • Bring a spare fully charged battery and at least one spare video tape. If you forgot batteries, try to conserve power by switching off the fold out screen and using the view finder. If you forgot a spare tape and you only have a few minutes left, you can switch to Long Play to get a few more minutes.
  • Set your camera to fixed focus – This allows you to use your zoom without the camera having to hunt for focus while looking at a blue sky. Most camera’s auto-focus is based on the camera detecting high contrast lines in the image and then focusing the lens system until they are sharp. In the absence of high contrast lines (blue sky) focus can be a real problem. To prepare do the following:
    a) Set your camera to focus lock (read your camera manual how to do this)
    b) Zoom in on an object perhaps 100 meters away
    c) Manually adjust the focus so the image looks sharp (using the large foldout screen is easier than the viewfinder)
    d) Zoom back out and the camera is ready to shoot. The image will still mostly be in focus unless you are too close to the subject.

    When the rocket is flying, you can zoom in and know that the rocket will be roughly in good focus, even if it moves in and out of frame.
  • Use the zoom only when the rocket is descending under parachute. It is very difficult to track the rocket in the ascent stage while zoomed in.
  • Start recording at least 20 seconds before the launch so you can hear the count down, and observe any conditions around the rocket should you need to later analyse what happened. The video can always be edited later.
  • After you press record, purposefully move your shutter finger/thumb away from the record button and rest it somewhere on the camera. This will prevent you from accidentally pressing “stop record” when the rocket launches. This is quite common problem if you often use a still camera where you need to press the shutter button during launch. We have been caught out by this a number of times until we started practicing this technique.
  • Point the camera such the rocket is in the bottom third of the screen so that you can maximise the amount of the launch you will see. If it is a fast launch there will be a certain amount of lag between when the rocket takes off and you react to track it.
  • Don’t use the viewfinder or the foldout screen to aim the camera after launch. We generally hold the camera at arms length sighting down the top of the camera just pointing our arm at the rocket as it flies. Since the camera is zoomed out it has a reasonable field of view and almost always catches the rocket. If you are looking through the viewfinder or at the screen, and the rocket moves out of frame it is very difficult to find it again specially at distance. As you hunt around with the camera and look back and forth between the screen and where the rocket is in the sky can make for very shaky video that generally does a good job at filming only sky.

    When the rocket starts falling under parachute you can try to use the foldout screen to track it and only then zoom in, but use the zoom sparingly. Zoom out before the rocket hits the ground so you can see the ground coming in the scene.
  • Continue filming for a few seconds after the rocket lands as some cameras may roll the tape back a little when you stop recording. Keep filming especially if the rocket crashes into something, and try to get peoples reactions. Again editing software will be able to remove any excessively long scenes.
  • Try to have the sun at your back. You may need to have a guess at which way the rocket will go so that it doesn’t go between you and the sun.
  • Stand back between 5-15 meters from the launch pad. Too close and the scene will be a blur, and you will get wet. The lens is also likely to get water droplets on it. Stand too far and little detail will be visible on the rocket. Having said that, if you are doing multiple launches on the day, you can try some long distance shots for variety. If the rocket is predictable where it will land try to go to that general location. (usually downwind from the launch pad) You may get a really good shot as it descends on top of you or near you.
  • If you also have a digital still camera you can often use its movie capture capability to shoot reasonable video. These are best set up on a tripod closer to the rocket for launch detail, as the video quality tends to be worse than a normal DV camera.
  • Make sure that the person launching the rocket waits until you are ready, as you may need to set your manual focus first.
  • Try to capture other scenes other than just the launch. Setting up the rocket, filling it with water, folding parachutes etc. always makes the video more interesting.
  • Think about who the video is for - most likely friends and other water rocket enthusiasts. As a water rocket enthusiast you should know what you would want to see in other peoples videos – and film those things.

Inflight Filming

This topic is an evolving topic in water rockets as technology becomes cheaper and smaller it is allowing people to place cameras onboard rockets without too much worry about braking them and loosing too much altitude due to the weight.

  • Cameras come in two flavours: those that record footage on board; and those that transmit it. Storing on board typically means you are free from interference and the whole set up is simple. If you loose the rocket you also loose the footage. With transmitted video you can get a live view on the ground and if you loose your rocket you at least have the footage. With transmitted video you also essentially have unlimited amount of recording time whereas on board video can be limited. Resolution and amount of available memory drives the price up.
  • When you place your camera on the rocket try to place it such that it will give you a good view of the ground. When you point the camera sideways, try to angle it down slightly so that most of the frame is taken up by the ground. This is where most of the interesting things are and if the rocket tips over backwards you are still likely to see some of the ground.
  • Attach your parachute in such a way that it still allows the camera to point at the ground while it is descending.
  • The other standard angle is pointing the camera almost straight down so you can see the rocket body and fins. This has the problem of having to place the camera in the air stream and adding more drag. You can use a small mirror to point at the ground while keeping your camera vertical.
  • Try to film sideways on rockets with very little spin, and downwards if they spin a lot.
  • Be prepared that on every launch there is a possibility that the camera will be smashed into a million little pieces if the recovery system fails.

Editing

These are some suggestions for editing videos associated with water rockets regardless of what editing program you use.

  • Make sure you have plenty of hard drive space to do your editing before you begin.
  • Always add some kind of title screen including date. You can do this as a standalone screen or as an overlay on the video.
  • It is always good to provide enough information for people to know what is going on. You will find this useful weeks and years later when you are reviewing the footage and want to know the rockets parameters.
  • You can also measure the total flight time in your video editor as you can step from the very first frame of launch to the first contact with the power lines … err I mean ground.
  • When including text, make sure you leave it on long enough for people to read. A simple way to know is preview it on screen and see if you had enough time to read it – adjust accordingly. Don’t leave it on too long though, the really slow readers can always replay the video if they need to.
  • Think about safe areas on screen. When video is displayed back on a TV a certain amount of the frame is not shown (known as over-scan). Don’t put text in that portion of the frame.
  • Allow at least 5 seconds of video in a scene before the action happens so people can get oriented as to what they are watching. Also allow a few seconds at the end of the scene.
  • Try to use minimal transition effects from scene to scene. Only use an effect if it adds to the movie, not because the software has it.
  • As water rockets are fast moving objects, slow motion of the scene is always interesting. Always add the realtime footage first followed by the slow motion (does not have to be from the same angle). Only include the most interesting part of scene in the slow motion. How slow motion is set up depends on your editing software.

Sound

It is a good idea to add music to your video as it helps to link the entire movie together. (A good source of music is: http://ccmixter.org/ )

  • Try to pick a sound track that goes with the movie. Often just playing the sound on a CD player while watching the images will give you a good idea if it works with it or not.
  • Before you start editing the video lay down your sound track as you can match the scene events with events in the music. You can easily align the launch with a prominent transition in the music. This adds to the mood and continuity of the video.
  • If the video turns out to be shorter than the song, you can always fade the music out before the end.
  • Instrumental music is almost always a better choice over vocals as it allows people to concentrate on the vision rather than concentrate on the lyrics.
  • After you finish editing the video portions you need to edit the sound that was recorded while filming the video. Generally you can use the volume envelope to cut out most of the background noise and only leave the count down, launch noise, crashes, screams and any clear commentary. When that is done you may add any narration that you want to record with the video.
  • You can then adjust the music volume envelope to make the narration to be heard clearer.
  • Be ruthless with cutting things out, and keep only the very best bits of video. It is always better to keep the audience wanting more than having them be bored.

Slow Motion

Some new digital cameras allow you to film at up to 60 frames per second which is useful for slow motion scenes. See if your camera has this setting. Often the trade-off is a smaller video frame such as 320 x 240. But for close up work this can be very useful especially for static fire tests to see what is going on.

You can still achieve reasonable slow motion even if you do not have a high speed camera. Read your editing software manual on how to achieve slow motion. Experiment with the different settings for frame interpolation and setting different rates.

Lighting

Make sure your scenes are always well lit. Filming in low light tends to give more grainy images and auto-focus can be a problem.

Whether filming static tests or real launches, make sure any artificial light sources are protected from the water spray. Don’t worry about the sun, the sun can protect itself from any water splashes.

Filming a static test from multiple angles is great for later analysis. Always make sure that the scene is well illuminated for all the camera angles, and that there aren’t items in the background that will interfere with the subject matter.

If you can help it, keep the background dark and dull.

Editing Software

Most editing software available today is good enough to create very good movies. The one you choose will depend on your budget, or what came with your camera. We use Sony Vegas + DVD to edit our movies. It is very easy to use and has some powerful features.

One tool that we find useful is VirtualDub – a freeware tool that can easily and quickly process videos. We use it to produce a series of still images from the 60fps video sequences, and then import those into Vegas. We also use it to enhance the video with its built in filters.

Hardware

We use a small run-of-the-mill DV camera (JVC GR-D73A). Almost any medium range will do though.

We also use a Cannon Powershot A540 still camera as well as an Olympus digital camera for stills. The Cannon can shoot decent video with sound and it offers the 60fps option but at only 320 x 240 resolution. Otherwise it can film at 640 x 480 at standard frame rates.

There are now affordable high frame rate cameras on the market such as the Casio Exilim FC100. Other than being able to film in HD it can also record at 210, 420 and 1000fps at smaller resolutions.

For in-flight videos we use either a small inexpensive US$20 digital camera (JB1) that records up to 30 seconds of 320 x 240 video at around 15 frames per second. It has 8Mb of onboard storage. This camera is now outdated and no longer sold. It runs from a single AAA battery. Alternatively we also use the more recent FlyCamOne V2 camera which will record for up to 30 minutes of 640 x 480 video.

A recent addition to our camera line up has been the small Mini DV MD80 camera that records 640x480 video onto micro SD card.  

See Also

Dean Wheeler's video tips : http://www.et.byu.edu:8080/~wheeler/benchtop/videotips.php

Thanks Gene for suggesting this topic to be added.

 Back to top



Copyright © 2006-2017 Air Command Water Rockets

Total page hits since 1 Aug 2006:

George Katz - Google Plus