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Chasing bees- Part iI

26/8/2014

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Today I’m going to briefly chat about things to consider when buying camcorders for your research. I hope this provides a good start point for anyone wanting to film animals for research. As said in my previous entry, I am assuming that you are not going to use be able to afford very expensive cameras and you are looking to use the sort of equipment found at normal electronic stores.
The main thing to consider when choosing a camcorder is what you are hoping to film, and therefore what you’d want and need your camera to do. Say you want to film elephants from a few metres away- you probably don’t need a fantastic camera, although I’m sure it would help. If you wanted to film those elephants from miles away you may need something a bit better to let you pick out objects at a distance. In my case I needed to identify pollinators and which flowers they visit on lots of fireweed plants in the wild from one or two metres away. This meant I’d need affordable cameras (so I can have a few filming at any one time) with a good enough quality image to identify the species of fast moving bees and clearly show when they are visiting each flower. For this I got a bunch of cameras, but most were a Canon Legira HFR306 or HFR36.

The confusing thing about modern camcorders is that it can be difficult to work out what specifications are needed. Nobody wants to pay for something they don’t need, especially if you are on a limited research budget. Many manufactures make models that differ in only a few characteristics and it’s hard to tell which is good enough. Obviously if the difference between one camcorder model is one has wi-fi and night vision and the other doesn’t it’s easy to say if you need those things. However, as most camera specs are garbled nonsense to a lot of people, I'll do my best to explain what the main specifications mean and what effect they have.

Video quality

The first thing to consider is what video quality the camera can film in. Most cameras say something on the box that looks like ‘[seemingly random number]x[another seemingly random number] HD’ and lots of words like ‘FULL HD’ and ‘REAL HD’- these refer to the video quality the camera can do. Basically ignore FULL and REAL and look at the numbers, which refer to the width and height of the picture in pixels. Many camcorders can go as high as 1920x1080 (Full HD), which is generally pretty good (at time of writing) but you can get higher. Often these numbers are followed by letter either ‘p’ or ‘i’, which refer to how often the camera updates the video image (sometimes called scanning). ‘I’, or ‘interlaced scanning’, means the image is updated in alternating screens. ‘P’, or ‘progressive scanning’, means the image is updated every screen; this is generally better if you are filming fast moving objects and picking finer detail, whereas ‘i’ is fine for slower moving objects but might cause blurriness if used to film something very fast moving (like bee flight). It’s worth noting that most cameras can film in formats that are lower quality then the ones advertised on the box.
Zoom

Most cameras list the number of times it can zoom ‘optically’, with the lens, or ‘digitally’, by zooming into the recorded image. Normally once you enter digital zoom you get a loss in picture quality, though this usually isn’t that bad. If you can’t find how much optical zoom a camera can do, it’s written on the camera at the rim of the lens. 'Optical’ and ‘digital’ stabilisation of video images refers to how the camera compensates for shaking and keeps the image still; this is more important if filming in a windy place or by hand rather than from a tripod. Again ‘optical’ is mechanical stabilisation of the image and ‘digital’ is done by cropping the image a little and compensating for your movement; optical stabilisation is again better.
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A lot of terms listed on the box, most of which mean basically the same thing.
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If you need to know how many times optical zoom you have, look at the camcorder's lens.
Battery

Most cameras come with a small battery relative to those available. If you are going to be filming all day you’ll need a few batteries, so it’s worth checking the cost of spare batteries before you buy a camera. All manufactures make bigger versions of the default battery but there are also second party ones. Often good second party batteries are cheaper and work as well as the manufacturer's, but they sometimes lack Dolby chips, which allow the camera to know how much battery it has. Lacking a Dolby chip can be a pain for two reasons: 1) when you turn on the camera or start recording the camera may claim it can’t talk to the battery and ask if you want to continue (this may stop recording) and 2) you don’t know when the battery is going to die. Issue 1 isn’t a problem if you're not concerned about getting the camera working at the drop of a hat. I set up the cameras on tripods and had them record for hour intervals so it wasn’t an issue that they needed confirmations before they began filming. However, if you are sitting and waiting for an animal to do some momentary action that you need on film this delay could be a problem. Issue 2 is a bit more annoying but if you test how long the camera lasts when filming on the battery and keep track of how long it’s been filming (allowing some room for error) you'll probably be ok.
Words like ‘better’ and ‘worse’ are, of course, relative terms and the less good option may still be good enough depending on what you are doing. For example progressive scanning is better for filming fast moving objects but, depending on what you want to see, interlaced scanning may still be good enough. Similarly you may find that while filming in a high quality format gets a better image you may find lower quality footage is still good enough to make out what you need to see to do your research. On that note I advise where possible doing test runs to check what formats and specs are ok. This could be done on a model similar to those you want to buy (perhaps borrow from a friend or colleague).

I hope that the above has helped you work out what you may need and understand what these different specs mean. As I already said, what you need depends on what you are doing. You’ll have to decide what is good enough. However, I will say that I was able to quite adequately film and identify bees from tripods set up a meter away from fireweed plants filming in a 1920x1080p format, as long as there wasn't a lot of disturbance from the wind. Unless you’re filming something very small from very far away such a format should probably do quite well.

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By Michael Harrap

Michael is an MRes student who studies pollinator foraging behaviours within vertically arranged inflorescences.

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