My 500D always uses 1600 ISO?

[Ballistica]

Ive got two questions so if anyone can help me out that would be great.

Im fairly new with SLR photography (got my first one, a EOS 500D a few months ago), and Ive been taking photos for a while but ive noticed a trend.

I usually leave my ISO settings at Auto (Im still learning how to use all that) and thats fine for now but Ive noticed that it seems to always take them at ISO 1600, even during quite bright sunlight. This annoys me because it introduces noise that I obviously dont want. I tried to beat this by manually setting an ISO of 100 or 200 but as I expected my photos appear under-exposed. I usually use Av mode and set an aperture at f3.5 and still get the same result. The only way to get a properly exposed shot is to reduce the shutter speed right down to the point where it introduces camera shake in the photos. Could anyone suggest whats going on?

Second question is relating to the IS on the lens, now im sure its great and all but I cant see how it actually makes a difference. One friend told me to go full zoom on my lens (18-55 IS) and turn the IS switch on and off and observe the difference but Ive done this and compared the results and there doesn't seem to be any difference at all (of course I hadn't set the shutter speed too fast or else it wouldnt make a difference).

Anyway, I realise this is quite a bit of reading and its turned into an essay of sorts but if anyone is kind enough to offer advice it'll be greatly appreciated.

[inkista]

Originally Posted by Ballistica

... I usually use Av mode and set an aperture at f3.5 and still get the same result. The only way to get a properly exposed shot is to reduce the shutter speed right down to the point where it introduces camera shake in the photos. Could anyone suggest whats going on?

Assuming you're using the 18-55 kit lens, my guess would be that you're zooming in after you set the aperture. At the 55mm end of the lens, your maximum aperture is f/5.6. But in bright sunlight, you shouldn't be having this problem, unless you've got a dark filter on the front, like a circular polarizer, or you're using a very very fast shutter speed.

Maybe some examples with EXIF information to help us figure out what's going on? A lot of times people swear they know what they set the camera to, and it turns out the EXIF tells a very different story.

Second question is relating to the IS on the lens, now im sure its great and all but I cant see how it actually makes a difference.

You may not have set the shutter speed slow enough to see it. With shutter speeds below your handholding threshold (for me, that would be around 1/30s), it becomes pretty evident. Try shooting shots with a 1/8s or 1/10s shutter speed with and without the IS.

[Ballistica]

Here's a quick picture I just took to show you. (Just changed the batteries on my TV remote).

ISO 1600
44mm Focal Length
f5.0
1/13sec



I think you are right about zooming after ive set aperture, I forgot that it changes. Could my problem also be that im not using the flash when I should be? Im still getting used to when and when not to use it.

[sybren]

You use your flash when you want to use flash ;-)

Your exposure looks correct. How much light was there? Try shooting something outside in broad daylight, so that we know a bit more about the lighting conditions.

[gturner]

I strongly suggest you read and spend time understanding this:

Learning about Exposure – The Exposure Triangle

once you understand WHY and HOW the camera tries to automate the exposure, you will find life much easier

I would take the ISO off auto to force you into using aperture and shutter speed

[inkista]

Ballistica--that actually looks like the camera's doing the right thing to me--shooting indoors without a flash is a "low light" situation for cameras, even though it's not for our eyes. Even if you had wider apertures available, you'd still likely need iso 800 or iso 1600 to get a shutter speed fast enough to eliminate camera shake blur.

What I was more concerned about was your saying that the camera was forcing you to iso 1600 even in bright sunlight. If you were outdoors in bright sunlight, there's no way that the camera should be pushing the iso that high.

[Ballistica]

Thanks to everyone who helped. Im going to spend some time trying to undertstand how the manual exposure settings on my camera work and hopefully will return here with some decent photo's sometime!

Ill post some mid-day outdoors photo's just to conclude that its me not the camera.

[Ballistica]

ISO 125
55mm
f/5.6
1/80 sec

So is this normal? I mainly thought that the camera could be better in low light, im guessing a better lens is the way to go?

Again thanks to everyone and sorry I wasted your time.

[inkista]

No, no. It's never a waste of time helping someone to figure stuff out. And yes, it's normal. Cameras and sensors need more light to see by than our eyes do.

It's not so much getting a better lens, as it is getting a lens that works better in low light. A lens with a wider maximum aperture can be opened up to a wider aperture setting and can let in more light. The most-recommended "training wheels" lens for lower light conditions would be the EF 50mm f/1.8 II. It's about $100 new, and the low-low price makes it one of the best bang-for-the-buck lenses in the Canon lineup.

It's optically probably sharper than your 18-55. And its maximum aperture is f/1.8.

To get you a feel for what this means, f/2 is three stops wider than f/5.6 (what your 18-55 does at 55mm). Three stops is 2³ or eight times more light. It's the difference between using iso 200 and iso 1600, or the difference between a shutter speed of 1/200s or 1/25s.

That doesn't mean you'll be able to shoot in the dark with the 50/1.8. But it will be better at low-light performance than your 18-55. It does have some restrictions, though. It's a prime lens, which means it doesn't zoom--any "zooming" has to be done by you moving your butt. Secondly, the wider apertures will also vastly reduce your depth of field--so accurately focusing the lens will be come much more critical. And the lens is at its sharpest at f/4-f/5.6. So while you can shoot with it wide open to get more light, you may not always want to. It's also not great for macro photography all on its own.

[Ballistica]

Ahhhhh, I see. Thanks very much for the advice. I might have to go get one of these lenses!