April 25, 2014
Recently I purchased a Canon 70D DSLR that has advanced HD video capability and improved auto focus, especially on moving objects. I went with Canon as I already have a Canon 5D DSLR and I am familiar with their operation. The 5D is a full-frame 12.8megapixel sensor, still image camera. In contrast, the 70D is a cropped-frame 22.2 megapixel sensor camera for stills or video. In video mode it shoots using only a small portionof the sensor.
Because of the cropped-frame sensor it has a 1.6x telephoto effect. (One multiplies the cropped sensor focal length by this factor to get the equivalent focal length on a full-frame sensor.) That is troubling for model railroad photography where we usually want wide angles and not telephotos. However, for other photography the increased telephoto might be useful. The 70D is available with a 18mm-135mm zoom. At 18mm the lens is equivalent to a 29mm lens for a full frame 35mm sensor. That is sufficient for model railroad shots. I am not sure how the cropped sensor compares to standard video camera optics.
In addition, the cropped-sensor grants increased depth of field due to the effective smaller apertures at any given f stop compared to full-frame sensors. For most videographers this is a drawback as they like shallow depth of field to achieve the so-called bokeh. But in model railroad photography we usually want increased depth of field to simulate the hyper focal range of prototype rail photography where everything is in focus.
My initial tests with the 70D are promising. See the video here. I used the 70D mounted on a Kamerar 23 inch slider, Manfroto Ball Head and a heavy duty Manfroto tripod. I do not own a fluid damped video head. In addition to the layout lights, I used a 700W 3200K tungsten bulb for extra illumination. Most of the shots were at about f7 and ISO1200. You need a lot of light to shoot at these small f stops with video as your shutter speed should be less than the 1/(2x frame rate).
I used iMovie to make the video. It allows for some limited color and exposure correction. I have a copy of Adobe Premiere Elements, but I have not tried it yet. The current iMovie version is fairly easy to use. There is still a lot to learn, but it will be fun doing so.
If you are a still photographer, like I was, and are getting into video, you may find this book by Richard Harrington very helpful. He takes you through the whole process from equipment selction to editing software. Very much recommended.