Assignment 06 Depth of Field

Some of the important aspects of still photographic images that we can manipulate in the camera (the old fashioned film pre-photoshop way) are focus, shutter speed, ISO ("film" speed, remember ASA ratings?), and lens aperture or opening size. Let's take a look at the effect of changing the aperture while concurrently changing other settings to produce roughly the same exposure.

The "f" number setting describes the aperture of the lens. It's the ratio of the focal length of the lens to the size of the lens opening. Aperture effects depth of field. Depth of field is the range of distances between which things in the image appear to be in focus. A large aperture (small "f" number) will produce a shallow depth of field. A small aperture (large "f" number) will produce a deep depth of field. You can experience this effect without a camera by simply squinting to read the funny papers when you've left your reading glasses at home on the night stand. For reference, all images here were taken with a Nikon D80, an old manual focus 50mm f1.8 lens, available light (no flash), and a tripod to prevent shake during long shutter speeds. ISO for all shots was 800. The lens was left focused on the cat for all three shots. The only things changed were the aperture and shutter speed. Remember: large opening (small "f" number) + short shutter speed = small opening (big "f" number) + long shutter speed. The key is to keep the same amount of light coming to the sensor (or film).




This first shot was taken at f1.8. Note that the only thing in focus is the cat and imediately adjacent piano keys. Shutter speed was 1/20th of a second.





The second shot was taken at aroung f5.6 or f8 (I didn't write it down, and the camera doesn't record it from a fully manual lens). Shutter speed was 1/3rd of a second. Notice that a few more keys appear to be in focus.





This last shot was at f22 and 5 whole seconds. Notice how all the keys appear to be in pretty good focus. The camera is really squinting here, eh?


You can achieve some similar results even with point and shoot cameras, though you might have to fool the camera by fiddling with some of the auto settings. The main thing is to figure out how to adjust things so that you can control the depth of field. Now get out there and shoot some - digital film is cheap!

fire

Nothing too artsy - simply fire in the chiminea out on the patio. It's so much more soothing in person than as a still image, isn't it?

Fire and Smoke.aGray

fun with mirror images.

simply fire.

Assignment 05 - Fire and Smoke

Oft fire is without smoke.
-Spenser, Edmund The Faerie Queen

Since we are heading into a dreary week weatherwise, lets move inside shortly. The assignment is to capture the essence of fire or smoke. So bring out the welders and embers and find something interesting in the smoke.

More fun with water

I think my neighbors wonder about me popping water balloons on my patio in the dark. Camera on 10 sec exposure and manual focus, then manually pop the flash with one hand and the balloon with the other. The trick here is to pop the balloon and flash at the right time to leave an orb of water. I don't recall which of the colored balloons this was; it certainly wasn't white. I tried twelve times to get this one that almost looks like I wanted. Search the internet for examples of others who've done this much better. Perhaps I'll try again some time.

Assignment 04 - Freeze time

Let's examine the effect of short duration light (flash) on images of objects in motion or transition. If your camera doesn't have a shutter speed or ISO fast enough to capture events that only last 1/25,000 of a second, try shooting in the dark - or almost dark - with a flash (or strobe, or speedlight, or what ever you want to call it). Fun things to shoot can include falling water drops, popping balloons, jumping kids, or whirling dervishes. Use your imagination and have fun. Notice all the words ending in "ing"? That means action. No flash pix of a bowl of fruit on a table.






I'll start, only because I already had these shots on file from some recent fun in my kitchen sink at home. More to come, but for now it's your turn.

I'm reminded of my thoughts on transparency . . . that there is no transparency. Is a window to see through without influence on the view beyond, or is the window itself the view?