What the heck? - ISO is your friend
Fri, May 29, 2009 First I want to Congrats Miss over at Just Miss for winning the Understanding Exposure book. I used Random.org to pick my winner and it picked comment number 5!! Woo hoo.. Congrats Miss!!
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ISO is the measurement of how sensitive a digital camera's sensor is to light. The speed or light-sensitivity of a digital camera's sensor is rated in ISO numbers -- the lower the number, the slower the response to light. (I took this definition from CNET)
***Shutter Speed will be SS
My personal photography tastes are all about natural light. I am not a fan of using my camera’s flash. I will do whatever I can to avoid using artificial or flash lighting. Now in the winter months this proves to be very difficult as we are stuck in the house because of the weather… BUT..it is now Spring.. (insert doing my stir the pot dance)
Sooo pick up your camera and go outside. Go out at dusk, go out at dawn, just get out and shoot!!
Seriously though, my biggest piece of advice when learning your camera is to practice. You can read every book under the sun, but until you are out there, shooting often, checking the photo data, checking the settings it won’t click. Experiment..and make sure you have fun!
I digress..
Okay, so I want to talk about ISO.
ISO stands for International Standards Organisation and it refers to the industry norm for sensitivity of emulsion based film.
BORING right?
I expected something so flashy for that acronym. Alas, no.
When I talk ISO I always say I am giving the camera a push. When in all reality ISO is amplifying the light that reaches the sensor. It took me forever to really understand the relationship ISO plays in Aperture and SS settings.
Basically by increasing your ISO to a higher number, you can shoot at a SS that wont cause motion blur. For example, if you try to shoot an image with poor light and you do not adjust the ISO, the image will look dark and underexposed. But by increasing the ISO, the light that is available in the will be more apparent in your photos because of the camera's increased sensitivity to light.
When you bumped the ISO in your camera, you’re not actually adding additional light; you are only boosting what it already has. The only way to control real light is to open the aperture or lower the SS. But, what is you run out of options and you still want to try to capture the shot in low light settings? ISO will lend you that extra hand.
Let’s say you are in a room that looks like it has enough light and you are at an f/stop of 4.5 in Aperture priority (your lens is wide open) but your shutter speed selected is too slow to hand hold such as 1/30 or 1/15, try bumping up your ISO.
Using a higher ISO will let you take the shot without using a tripod or adding artificial light (flash). HOWEVER..There is a price to pay with bumping ISO. A high ISO’s give grainier, lesser quality images (also known as noise). Low ISO’s will produce the highest quality, grain free images.
With my old camera body (SONY A100) I could not go above an ISO of 400. My camera would produce extreme grain and ruin the quality of the picture for my personal style. Sometimes grain works, but I usually prefer my images grain free. Now I shoot with the Sony A700 (which I love..cue angels singing.. thank you hubby), and I can push my camera to an ISO of 1600.
Quick recap.. so in addition to playing with the SS and Aperture priority settings, play with the ISO settings.
Ask yourself before taking the shot- 1- Is there enough light? 2- What is the lowest Aperture setting I can push my camera to before my SS goes to slow? 3- Do I want the grain? 4- Do you have a tripod handy? (having a tripod is a great solution to reduce any chance of camera shake which can be helpful if you are looking to achieve a low light shot)
Like I mentioned, if there is enough light, I never want grain. But if the light is limited and I do not have my tripod (it is rare that I have my tripod with me- need to work on that) I will push my ISO as far as I can before I introduce artificial light.
So now, let’s say your child in at his/her school concert** – take your ISO off of auto - this is a GREAT time to play with your ISO skillzzz. Push your Aperture to as low as it will go, (keep it on Aperture priority for now- we will move into Manual shooting shortly) push your ISO up.
First try 200, then 400, then 800 (see how it always doubles). You will see that you can now capture your little one singing without being that parent using a flash. It may work, it may not work with your camera. Like I said, my Sony A100 was terrible past ISO 400, but my A700 handles 1600 like a champ so it opens up more photo opportunities.
<-- This photo was taken in manual with a f/stop of 5.6 (lowest my Aperture would go at a 135mm focal length) and my SS was at a pitful .08 and my ISO was at 100.
The room had poor Tungeton lighting and I cannot hold a camera steady below 1/40 which is why this shot has camera shake.
But notice ..no noise. (click here of the photo to enlarge)
<--This photo was taken in manual with a f/stop of 5.6 (lowest my Aperture would go at a 135mm focal length) and my SS was at 1/40 and my ISO was at 3200.
I went extremely high on my ISO to show you what Noise looks like. You can see the grain of the shot. But by bumping the ISO I was able to get a proper exposure for the shot. (click here or the photo to enlarge)
**I do want to mention here that if your are shooting wide open there is a big risk of missing focus if you do not know your camera's plane of field. This means that if everyone in the about said concert are not sitting or standing in the same plane, some will be sharp and others, well, not so sharp. But we will discuss shooting wide open in another What the Heck? addition.
So, what did we learn today?
I hope something.. I do, because if I confused you, ask away. Or if you know better .. tell me.. All I know is that ISO is a really important aspect of photography. You really need to have a strong understanding of the relationship it plays with Aperture and Shutter Speed if you want to gain more control of your digital camera.
NOW GO SHOOT!!
Reader Comments (9)
I'm learning so much reading up on your posts here. I HOPE I can get a real camera soon. Right now I have a small, digital point and shoot that I have little control over.
So many of my shots have "Noise!"
YAY Miss!!! I'm so jealous ;-) thanks for the info, Kim!!!
Lost...I cant seem to wrap my head around this stuff :( I need to spend some time with a clear head and READ!!
I love What the heck Fridays! Awesome posts, Kim - Look forward to reading more!
you are a good teacher, my friend.
:)
I finally used the ISO feature on my camera about two weeks ago. It opened my eyes, but I need much more practice to really "get it". I think it will take much more practice before I feel like I have a good understanding of the relatedness of ISO, SS, and f/stops.
I would also like to see the images in the post in higher resolution, but they are private on Flickr. I have many of mine that way as well, but I am not sure if you can mark individual pictures as public so blog viewers can see them.
Can't wait for next Friday!
You are like a total photography brainiac! Amazing!
Well done. I'm like you and avoid the flash at all cost. I've relegated my onboard flash to only a supporting role when I want a little fill light on a bright day. Which of course makes the kids ask why I'm using a flash during the midday sun, but I digress.
My Canon does a pretty good job of noise free at high ISO. Looking forward to upgrading though, the new 50D goes even higher.
I've just started experimenting with ISO. Now, I'm trying to use the camera settings to my advantage, with all of the numbers. It's a long learning curve, but well worth it in the end.
I'll have to try some side by side examples as you have done here.
Well done.........................:)