Manual mode with auto-ISO

It actually works fairly well... I spent a week at AirVenture learning about new airplanes, light sport aircraft, and doing a lot of photography.  I took over 3400 photos, and have to now sort them.

I ended up using the manual mode of the camera with auto-iso in raw mode the last day I was there.  I did most of my ground to air shooting that day.  While you have to be careful to watch the exposure in case you over expose (my usual problem) having the Canon 7D handle the ISO worked surprising well. 

And the reason?  When you take photos of aircraft, you want to have the shutter speed slow enough so that the prop is not stopped still. That gives you a sense of motion.  For a slight blur, you can go as high as 1/800 of a second. I tend to shoot someplace around 1/400 of a second.  A tripod works well, or an image-stabilized lens. Since I have never been very good at panning with a tripod, I use the 100-400 IS lens from Canon. I suppose a gimble head would work well.

If you want to have the full arc of the prop, you need to drop down to 1/80 or less when the engine is at full RPM. Needless to say, 1/80 is very slow for a 400 mm lens. The P-51 shot was taken at 300 mm, 1/80 second, f.16, iso 100.  Handheld but braced.

If you want to practice this, see if you can attend a seminar by one of the professionals. I went to listen to Paul Bowen, a very entertaining and enlightening speaker.

telephotos and fog

You'll find multiple articles saying that given a set of criteria, telephoto lenses do not compress objects, that they react the same as wide-angle lenses.  And that is true.

However, one of the ways I think about lenses is that the view-angle is narrower for a telephoto lens than for a wide angle lens.  For a 250 mm lens (as was used for the photo of the bridge), the angle is fairly small.  People interpret the size based of an object partially based on how much of the image the object takes up.

Normally, a 55 mm lens (for 35mm film cameras) is around what the eye sees.  When we look at an image taken with a 250 mm lens, the difference in how much an object takes up changes.  Because we know how big the bridge is, we interpret the pelicans as proportionally larger when in fact they are just closer.

The one thing that cannot be changed is atmospheric changes due to distance.  A 250 mm lens will still have as much atmosphere (fog in this case) between it and the bridge as a 55 mm lens.  That helps provide context to the sizes, making us know that the pelicans are much closer to us than the bridge.  It's also one of the reasons that photos of the astronauts in space look so strange, we lose some context.

All of this is good to know, but the real goal is to take good photos. Just as a warning, although the Canon 7d allows you to manually set the aperture and shutter speed while it handles the ISO (in auto mode) for perfect exposure, it won't let you under or over-expose it by using the dial.  It will let you bracket though.

8 fps

These three images are taken from a sequence I took with the new Canon 7D.  There are 7 totals images, all taken within 1 second showing the redtail hawk launching off of the lamp post.

One of the problems I had with my old camera (a Canon Digital Rebel XT) was getting exposure right.  You could tell the camera to be in all-manual mode, shutter preferred mode, or aperture preferred mode.  The ISO was only set by hand.

On occasion I wanted an additional auto-adjustment.  The Canon 7D also has an auto ISO adjustment which is very close.  I set the shutter speed and aperture, and the camera figures out the ISO needed to get the shot.  Given the wide range of ISO (100- 6400) that allows for a very broad range of exposure. This particular series was ISO 640, which would be very noisy on the Rebel XT but quite reasonable here.

Especially if you use a technique I read about (sorry, I can't remember where) where you stack multiple layers of images and average across the layers.  I haven't had a chance to play with this yet, but it looks really intriguing.

Patient subjects

 It's good to have a patient subject, and thankfully my cat is a fairly patient subject. This image was taken about 6 inches from her nose, taken with a 28-105 mm lens at about 65 mm, with 34 mm of extension tubes on the front.

The exposure was f.25 (yes, 25) at 1/80 second.  There were two flashes, one on camera and one off camera.  There is no cropping of this image, so the actual image is 5100 x 3400 pixels. It was taken with the Canon 7d.

I was basically playing around with one of their toys for macro photography, and noticed that she was resting peacefully on a lap, so I brought the camera in close.  I was able to shoot some of her eye, but it was this nose that caught my interest.  Her fur is black, white and orange, and there is just a touch of orange in this shot.

I had to hand-focus it because of the extension tubes, but the small f stop helped keep everything in focus. Even with that, her cheek was out of focus.  If I had focused a little further back, I probably could have helped. Of course, all of this was shot on a tripod, something I need to carry around much more often.

Right now I am wondering what this would look like at 3 feet across.  Sometimes I like to take the context out of the image, and I like this image because it provides just enough context.