{photography with lei} shutter & ISO speed

Hi friends! How is everyone?  How many of you played around with the aperture settings on your cameras the last 2 weeks?  I'd love to hear about your discoveries and questions, if you have them.:)  You know where to find me!

So this week we are going to discuss shutter speed and ISO.  While aperture controls the AMOUNT of light coming through your lens, shutter speed controls HOW LONG the light coming through the lens gets to hit the sensor (or film) inside the camera.  The amount of time is annotated like a fraction... fractions of a second as a matter of fact.  If you're out shooting a ball game you're going to be shooting with higher shutter speeds than, say, your child taking his first steps.  Because you want to freeze fast action, and in order to do that the shutter has to capture the image quickly.  Most cameras have a pretty broad range of shutter speeds - from as long as a minute to 1/8000 of a second.  Here are a couple of examples of the range of shutter speeds:

{Here my shutter was open for 30 seconds. Because it was open for so long, I was able to actually record the trail of light from the center of the fireworks, and even those that were being fired off from the ground below.}

{Check out this little cutie!  Not the baby, the fly zooming past her right ear!  Lol.  Shutter speed for this was 1/1250.  I didn't NEED for it to be that high... I mean this baby wasn't going anywhere, she was sitting just as still and cute as could be...}

{and a more sensible example... an image that definitely required a higher shutter speed}

So aperture + shutter speed = exposure, right?  Basically.  But we have one more key element to discuss, and that is ISO.  ISO is the light sensitivity of the sensor (or film) inside your camera.  Generally, you're going to set a lower ISO when you have more abundant lighting conditions.  And the lower the ISO, the less sensitive your sensor will be to the amount of light you let in.   Likewise, you would set a higher ISO in less than ideal lighting circumstances.  The higher the ISO,  the more sensitive your sensor will be to the amount of light you let in.  That sensitivity can be seen in the amount of grain you see in the printed picture.

In terms of the numbers your camera offers for ISO settings, doubling or halving the ISO means we have half as much or twice as much light, respectively.

Generally photographers avoid too much grain or "noise" in their images, because it takes away clarity.  But if you are in a low light situation and you intend to freeze action (such as with a nighttime baseball game or something like that) you will have to turn up your ISO.

The ISO offered on a good camera might go up to 6400, and down below 100.  6400 is more for pitch dark conditions, whereas 100 would be used on a bright, bright sunny day.  If I am indoors on a sunny day I might bump my ISO to around 400.

The cheaper cameras' ranges are more narrow and therefore limit what you can photograph in low light situations.  I recently bought a Nikon D700, and one of my first a-ha moments was when I snapped a wonderfully sharp picture of my daughter practicing ballet (grand jetes to be exact) in my living room at 9:00 at night with no lights on.

Here is an example of an image taken at night indoors with little to know lighting, using a very high ISO:

Phew!  Got all that?  Take your time with it.  Read it again and again, and find other info to read as well.  Sometimes it takes more than one kind of explanation to help this stuff make sense (I speak from personal experience!)

Next time we will put all of this together and talk about various manual settings involving all 3 elements.  At once.  You'll do great. :)  In the meantime you guys can focus on your shutter speed by shooting in 'S' mode or TV mode on your cameras.  Similar to what I suggested a couple weeks ago, this will allow you to adjust your shutter speed while your camera takes care of setting the correct aperture for you.

Have fun and good luck!!!