Video Tips #1

There is a learning curve to shooting good video for medical education purposes.

I’ll share with you the things I’ve learned over the years, but I certainly don’t claim to be an expert. Further, what has worked well for me won’t necessarily work as well for you.

The Camera

I’ve used a variety of cameras over the years, ranging from relatively inexpensive camcorders at 320 x 240 (in the early days), through 640 x 480 higher resolution, to Digital Video (DV) and High Definition (HD). All of them have produced usable video, but I think that the higher resolution is better for teaching purposes.

Until recently, I tended to favor fewer pixels and lower resolution, primarily because download speeds in the past were relatively slow.  I needed to keep my file size small. The main issue for me: was the resolution good enough to show what I was trying to show.

Now, most people using my videos are accessing my websites through some form of broadband, and even those accessing the site by smart phone still have relatively high download speeds.

Small file size just isn’t as important as it used to be.

So now, I much prefer higher resolution videos because they are easier to teach from. Whether you are blowing them up on a screen, or an individual student is watching them on an individual laptop, higher resolution is better than lower resolution.

Those who want to spend a lot of money on commercial grade cameras can find many that will work well. But as long as you are working in high resolution (HD or DV), I personally don’t think it matters that you have three CCDs (image sensors) in the camera, rather than one CCD. What is much more important is what you do with the camera…how you use what you’ve got.

Tripod

Always use a tripod.

Rarely, when I’ve been trying to capture action-based activities in an OSCE, I’ve used a hand-held device, but even then, I’ve braced it on a door frame or table to stabilize it.

Few things are more distracting to the viewer than having a shaky image. It detracts from the learning experience.

Lighting

The biggest mistake I’ve made over the years has been using too much light during video shoots.

I grew up with 35 mm film cameras, where generally more light meant better, crisper pictures. I became a master of 3-point lighting (main light (“key light”) at an angle, lesser “fill” light from the other side, and “back light” to brighten the background.

Lighting for digital video is different, a fact that took me a while to figure out.

The digital (non-film) sensors on contemporary video cameras do an excellent job at working in pretty low light conditions. They are very sensitive. But that same sensitivity can be a handicap if there is too much light. The sensors get overwhelmed and the image is degraded by glares.

Here is an example of one of my first videos showing a vaginal delivery. There are a number of things wrong with this…image in too tight, lack of a tripod, etc.  But the main problem is that the image has too much light. I had the two overhead lights pointing directly at the perineum, to insure plenty of light – a mistake I wouldn’t make today. I didn’t need all that light and it ended up making for bad video.

Watch a brief clip of the bad video here.

In contrast, I shot video on another delivery a number of years later. I had learned to use indirect, soft lighting, and not to point spot lights at the objects I was filming. In this case, I had the overhead spotlights off, and just two lights on tripods, pointing into the corner of the ceiling of the delivery room, to spread a diffuse, indirect light bouncing off the walls. The results are much better, the skin tones more natural, and I’ve avoided shadows without flattening out the image too much. This is a much better video to teach students from.

Watch a brief clip of the good video here.

Tight Shot

A tight shot means the important structure you’re shooting fills the screen.

This is most helpful when filming fine surgical manipulations, or suturing. It is among the most useful of video shots for medical education. Using this technique, I was able to visually take the student inside the vagina to see exactly how a Pap smear is obtained. This is a better view than the student would get if he/she were standing right behind me, looking over my shoulder.

But as useful as these shots are, they can be difficult to obtain. Part of the problem is getting just the right amount of light into the tight spot. Another problem is keeping your hands and instruments out of the way so they don’t block the camera. In the Pap smear video, I had to manipulate the Pap broom and brush at an angle. It was hard to do this in a way that didn’t make things look awkward on camera.

Another problem with tight shots is that if you use them exclusively, the educational value goes down. You need the wider angle, open shots to establish perspective, orient the viewer to where you are, and show the gross movements of a particular technique before going to the tight shot that reveals the tiny details.

Notes from a Medical Educator