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Photo Technical

The last word in light control: ISO setting – A08

I have covered some very important and essential basic ground in photography, the interplay of the aperture (f-stop) and shutter speed settings.  There is the temptation, even for me, to suggest this is really just cursed technical stuff, but it’s not just that.  These are the technical resources allowing you to be a most creative photographer.  Photography is a product of the Industrial Revolution, now expanding in a Digital Age.  Such a product asks you to use your right and left brain, the whole thing, and also explore the science of art.  O.K., you’re not aiming to be a photo artist, but to improve any capacity; navigation, cooking, all those things we do aboard ship requires both measured and creative thinking.

Sailing with Chris29bw

A particularly noteworthy element of this photograph of a fast-moving boat is that it is framed so there is room in front of the boat, giving viewers a comfortable sense of space.

Having discussed the shutter control, keep in mind, although most times you may want to stop motion, sometimes you don’t.  And in talking about the aperture, you may want great depth of field, sometimes you won’t.  I’ll get into different scenarios and what I think would be the best desired effect, but there remains one more adjustment in controlling light that needs to be covered.  Before that, let’s have one more look at the photograph of the speeding boat published with the last article.  Did you pick up on any key visual elements that improve the picture quality?

The main element in this photograph worth noting is allowing space for the object to move in to.  This is an aesthetic plus that keeps this image from being disturbing.  The boat is quickly moving from the left to the right, so in taking a photograph and making your composition you want to, in effect, leave some open space ahead of the boat for it to move in to.  If you centered the boat in the frame it would be counter-intuitive to your feeling of movement.  This is a rule to follow whether the movement is horizontal (waterskiing, windsurfing, etc.) or vertical (climbing the mast, scuba diving, etc.) or diagonal (possible in para-sailing) were you want to give space for an object to move in to in both directions. The amount of space may even increase incrementally in respect to the speed that is being portrayed.  And don’t forget we can show movement by doing what?  Yes, by controlling the shutter speed setting, and there will be some examples forthcoming.

Now back to the last method, in addition to aperture and shutter settings, by which you can control light for a proper exposure, and this is the ISO setting.  It will help to look back at film to explain this setting.  It used to be you buy film by ISO or film speeds (most commonly) of 100, 200, 400 (etc.), the latter being most sensitive to light.   This meant it was more capable of working for you in darker low light conditions.  But, as with everything in life, this advantage had a disadvantage making lesser speeds more attractive.  Higher speed films (400, 800, 1600, 3200) worked better in getting an image in lower light, but the image suffered from more graininess and noise the higher the speed.  If you were only shooting in brighter daylight conditions you could use slower speed films (100, 50, 25) with far less noise and graininess, and better color saturation.

Digital offers similar settings, again most commonly 100, 200, 400, and as they increase the chip becomes more sensitive to light (and noise and less saturation).  But there are times after exhausting your maximum f/stop and slowest hand hold-able shutter speed you have only one remaining option to capture a low light image, that is your ISO setting.

We discussed how shutter speeds, 1/30, 1/60, 1/125 and f/stops, f/4, f/5.6, f/8 are “full” stops.  If the camera light reading is 1/60 at f/5.6 this = (the same as) 1/125 at f/4 or 1/30 at f/8.  The ISO of 400 is 1 stop greater than 200, which is 1 stop greater than ISO 100, etc.

This means …think with me creatively….if the camera light reading is 1/15 at f/2.8 and are afraid of taking a hand held shot at 1/15 of a second, you can go from ISO 100 to 200 to get an extra stop of light, that means you can raise your shutter speed to 1/30 for a more steady hand held shot.  You now have full control.  Don’t throw me over board!  Permission to come ashore.