Wednesday, April 13, 2011

Light outside the camera

Shutter speed, ISO, and F-stop control light in camera, now the rest of the story.  There are more light sources outside the camera than there are purchasers of the Sport Illustrated swim suit issue.  Let's see; turn on or off the light, open/close the blinds, turn on a monitor, light a match, and then a candle, reflection of the sun off tin foil, oh that flash on the camera, car headlights, or a mirror.  All of those are light sources and I have not even scratched the surface.  There has been more written on this than there are sources.  If you think I'm gonna talk about all this junk in detail, then you think I would walk against traffic on the strip in Las Vegas.  Cabbies would kill you in a second.  Well anyway there are a lot of light sources, and a lot has been written about them.  I am going to discuss briefly discuss the reason this is important and then discuss the use of flash.  

Cameras do not see the way we do.  We can see details in the shadows and bright sunlight, but cameras can only see one or the other.    This explains why there are parts of a photograph overexposed and parts underexposed or visa versa.  The picture of the flower below illustrates the point.
There is not a backdrop used in the photograph.  The flower was in bright sunlight, but the background was in shadow.  The camera could not see the shadowed area because the camera was set to see the flower.  If the camera had been set to see the background the detail on the flower would have been overexposed.   The lesson here is that you can't have it both ways.  If you want to shoot both the shadow and the light  then either more light needs to be added to the shadows or the lighted area needs to shaded.  This is the reason so many different light sources are used.  

The most used source of artificial light in photograph is the flash.  It is also the light source I see misused the most.  There are three misuses of the flash I'm going to discuss.

The first problem is understanding the lack of flash power.  I frequently see pics like this: 
The wall is lit, but that is me in the shadows.  There is just not enough light, because the flash is not strong enough.  You would be better off to try a higher ISO and a slower shutter speed.  Unless you find me that ugly and then the photograph would have achieved your goal.  By the way if the flash will not light me then it will not light up an auditorium.  Those graduation pics will light the bald spots on the back of heads, but Johnny or Sue will be in darkness.  Those on board flashes light up from 6 to 12 feet.  That's all folks.  Here is a pic adjusting the ISO, shutter speed, and F-stop.   Sometimes the flash just doesn't cut it.
Here is another problem. 
Yes I have looked better, but that is not the deal here.  It is that blob of light.  All you young ladies taking that pic into the mirror.  Well it has gone to the ugly.  Not as bad as me of course but none the less.  The same thing will happen if you try to shoot through glass.  It will be ugly.  Control your selves do not do it.  If there is glass between you and the subject there will be ugly.  The same thing will happen if there is glass behind the subject.   Again, try turning off the flash and adjusting the ISO, shutter speed and F-stop.

And yet another problem:
Notice the wrinkles in the forehead, the slits where eyes belong, the crinkled nose, the shadow of the leaves on my head.  This happens frequently with the subject looking into the sun.  The photograph is ugly.  Turn the subject so they face away from the sun, or place them in the shade and turn on the flash    
Oh, look how handsome he is now.  Well he isn't looking at the camera, but what do you expect?   So there you have it sometimes in doors you should turn the flash off.  I know everyone and their brother has told you inside use the flash, but try it.  Going outside, hey, try turning the flash on.  Inside flash off, outside flash on.  This isn't always going to work.  Most of the time flash inside will work, and no flash outside will work, but consider the situation.  SO before you shoot think flash on, flash off; flash on, flash off .  thanks Miyagi


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