Just ignore that this is being posted on Sunday and pretend it's Friday. 🙂
Last week we talked about aperture right? Now the third part of understanding how to shoot manually is ISO. Next week we'll talk about how they all work together to get the proper exposure. But for now I think it's best to keep it simple and just go one step at at time like I have with the past two posts. Oh and what the letter ISO stands for I'm not sure. I'll have to drag out one of my photography books and get back to you on that.
Long, long ago (about 9 or 10 years ago) you chose your ISO when you chose your film. Film has an ISO rating. Basically that meant how sensitive to light the film was. The lower the ISO number, say 100 or 200, the more light you would need. The higher ISO rated films like 400 and 800 were more sensitive to light and better to use in lower light situations. The downside to that was (and still is depending on your camera) the graininess or noise that the higher ISO films gave. Now sometimes this can be a good thing if you are going for an artistic type photo and the graininess adds to the effect. I've seen some very powerful photos taken using a higher ISO. The noise just added to the emotion of the photo.
Now, I have to put out a disclaimer here. You need to play around with your camera and see how it handles the digital noise of a higher ISO. Print the photos and see how they look. I know that my first digital SLR, the original digital rebel, didn't handle the noise well at all above 400 ISO so I almost never changed it from 200. There are times when it's worth it to use a higher ISO like when you are just trying to capture a memory. It's most likely going in an album or your scrapbooks and 15 – 30 years from now your family isn't going to care that the photo was grainy, but that they have the memory.
Now I'm fortunate enough to have a Canon 5D that I love and can shoot up to 1600 ISO and get good results. I don't worry if I need to increase the ISO from the normal 100 or 200 I shoot portraits with to an ISO of 800. I probably wouldn't shoot any portrait sessions with the 1600 ISO, but I have been so thankful I had the option when wanting to get some shots that I knew I wouldn't get at 200 without a tri-pod. For example on the last photos in this post, I shot them as the last moments of the sunset were dissappearing. No tri-pod. I used a 1600 ISO so I could handhold it. Dragging the tripod out just wasn't an option. I had one printed and couldn't have been more pleased.
Honestly I'm so glad that the digital revolution found its way to me where cameras are concerned. Now it's so easy to change the ISO depending on the situation. So let me show you the difference when you change your ISO and how it can change your photos.
These were taken of my dog. She doesn't have a choice but I do have to chase her around quite a bit and I think she stays a bit more still than my DS these days.
The lighting situation was the same in all of them and I didn't change the shutter speed or aperture. I used a shutter speed of 1/250 and an aperture of f/2.8 with my 85mm lens. The first photo I used ISO 100 and as you can see it came out very underexposed, meaning too dark. The second one was taken with an ISO of 200. It's better, but still a bit too dark. The third one was taken with 400 ISO and to me it's about the best exposure. Nothing is too bright or too dark. And the last one was taken using and ISO of 800 and it's a bit too bright. Remember I changed nothing but the ISO. If I had taken a shot using an ISO of 1000 or 1600 it would have been way too bright or overexposed.
I hope ISO is a little less confusing now. Next week we'll explore how shutter speed, aperture and ISO all work together to give us the proper exposure.