Sunday, January 20, 2013

Sunshine and Neutral Density Filtration

                                                              ISO 100 F20 SS1/4 18MM

The flow in Sabino Creek has slowed considerably due to some very cold weather here in the Sonoran Desert this past week. With temperatures in the low twenties in the valley it's a safe bet that it was extremely cold at 8000 feet above sea level. When I arrived at Sabino Dam there were still a few places where water was flowing over the top of the dam. Fortunately it was more than enough water for me to use my Neutral Density Filter to see what effects it would have on flowing water.

                                                            ISO100  F 20 SS 0.400000s 18MM

Normally the dam is fairly well shaded but on this visit the entire area was bathed in bright sunshine with the exception of a small portion of the dam.

 This is a shot of the dam from down stream which was taken at F20 18MM. Keep in mind that even though these photos were taken using a tripod the wind was blowing at about 8 or 10 miles per hour and the trees had some pretty good movement which would have some effect on the sharpness at longer shutter speeds.

I plan on taking an early morning trip back to the canyon and photographing the creek at some of the bridges perhaps Monday. I'll have to walk in starting at dawn which at least on the way in means no sun until much later in the A.M. due to the steep canyon walls.  This should give me chance to get a few miles into the canyon and work in the shade at least for a few hours.

I'll also have another chance to keep my eye out for mountain lions and hopefully see some other wildlife as well. With temperatures in the mid to upper 70's this week it should be a fairly pleasant hike and water flow should increase although I'm not certain by how much.

As climate change has already arrived my interest in it's effects on riparian areas has increased considerably. Hundreds of birds that live here or migrate through this area are dependent on a few places that have an adequate supply of water most of the year. Climate change could severely impact the ability of endangered species like the Gray Hawk pictured above which has only about 100 nesting pairs in the state, mostly in southern Arizona along the border with Mexico. Their survival depends on the cottonwoods where they nest along the rivers and streams in the few riparian areas that remain.

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