Shutter speeds outside

Yesterday I went out to experiment more with shutter speeds, shooting down by the river, and I found that I needed to change the ISO to get better results.  I wanted to shoot the water flowing over some rocks.  I found that I had a reasonable result with the shutter speed at 1/1500th - but there was a big difference between the results before and after changing the ISO.

first try, shutter speed 1/500th, ISO 100

This was of course too dark.  So I changed the ISO to 800.

2nd try, shutter speed 1/500th, ISO 800

Better, but still a bit dim.  So the ISO went to 1600.

3rd try, shutter speed 1/500th, ISO 1600

That gave me an image true to the early evening light at the time.

I did go on to increase the shutter speed to 1,000 and 2,000, but that is another story.

Changing the ISO

Today I decided to follow the advice of some literature I've been reading and changed my ISO back to 100, instead of keeping it up higher, (800 and even 1600, because of photographing birds).  I wasn't really happy with the exposure on my images, so I shot the whole session today with ISO 100.  I was very happy with the results, the shots don't seem so harsh.  I've been shooting early in the morning when it's still cool, but the sun is still very bright and harsh as it usually is in the Aussie summer, and often I am aiming at the sky.  I am however mostly walking in shady areas.  So I never really was sure about the exposure.  I stayed with Aperture Priority and shade or cloudy for the white balance, but taking into account that I am often shooting up to the sky, I have found the ISO 100 has given me much better results.  I especially noticed it with the koala - yes, it's still in the same tree, still way up but in a different branch so I was able to get more open shots of it.  He noticed me and kept his eye on me the whole time, even when I tried to change position.  They can suffer harassment from some people and from dogs.  A kind person had left a plastic ice cream container of water at the bottom of the tree for him - they don't usually drink water but in heatwaves such as we have now they will gladly do so.

Koala  optical zoom ©Christine Linton

Technical details: Aperture Priority, F/2.8, shutter speed 1/10, ISO 100, AF 23 area, white balance - cloudy.

Koala optical zoomed x24
Technical details: Aperture Priority, F/2.8, shutter speed 1/4, ISO 100, AF 1 area, white balance - cloudy
I was focusing on his eyes here, but being far apart, I went for the closest one (his right one).
©Christine Linton