lens help please

im new to photography and im using my friends rebel xt, ive been reading tutorials and this and that for a couple weeks one thing im havent touched on much is lens and what i have read has me lost, basically i have 2 lens to work with one is efs 18-55 the other is 75-300 , i have no idea what either means, im bout to go play with them, but if any one can give me a quick run down on what each would be for, or if anyone can link me to a good lens tutorial i would apreciate it greatly

The smaller the number the larger the angle or bigger the field of view will be. The larger the number the more magnification. On Canon site the have a FOV tool that will help you see what i mean it part of the lens 101.

Don't try to use either of them in low light settings, because they won't perform well. Stopping the kit lens down to f/8 when using the AV setting usually gives best results.

thanx parker im on that canon lens page now, that should help me alot

liza wrote in post #2344442
Don't try to use either of them in low light settings, because they won't perform well. Stopping the kit lens down to f/8 when using the AV setting usually gives best results.

yeah i noticed that, i thought it was because i just dont know what im doing yet(which is still pry true also), what would be a good lens for low light settings

The Tamron 28-75 f/2.8 and the Sigma 70-200 f/2.8 are both good examples.

There's a forum dedicated just for EOS lenses on this board.. There are FAQ's and lots of other good info:

https://photography-on-the.net/forum/forumdis​play.php?f=33

thanx you guys.

what lenses are good for low light?

would a sigma 28-300 be good for low light?

No. But that's not a problem, as you can always switch lenses on a DSLR.

If you look at the aperture (the /4-5.6 etc.) part after the focal length, it will tell you whether the camera is good for low light, i.e. if it has a large aperture (low number).

The aperture basically tells you how 'large' the hole is that lets the light in ... if the 'light hole' is twice as big, the shutter only has to stay open half as long. Aperture is measured in full stops, where one full stop equals twice the amount of light. Full stops are multiples of the square root of 2 (physically, a hole has 2 dimensions) and run: 1.0 ... 1.4 ... 2.0 ... 2.8 ... 4.0 ... 5.6 ... 8.0 ... 11.0 ... 16.0 (and so on)

So a 28/2.8 lens will let in twice as much light as a 28/4.0 lens and 4 times as much as a 28/5.6 lens.

Normally, fast prime lenses (i.e. non-zoom lenses) like the 75$ Canon 50/1.8 or the 350$ Canon 50/1.4 are good low light lenses.

Generally, zoom lenses are only good for low light, if they are quite expensive (the mentioned /2.8 zooms - mind you ... NOT /2.8-4.0 etc ). 'Hyperzooms' (that have a 10x zoom range) are never good for low light. For example, your Sigma 28-300 most likely is the Sigma 28-300/3.5-5.6 lens that has an aperture of 3.5 at its wide end and an aperture of 5.6 on its long end. While f/3.5 is not that much slower than f/2.8, it is only usable in low light with good results if it also yields sharp images at this aperture ... which cheaper lenses normally do not do.

So if you have to stop your lens down to f/5.6 (or even f/8 ) to get sharp images, it will be a lot slower than the Canon 50/1.8 or the 200$ Canon 35/2.0 (if you need a wider image) that give really sharp images when used at f/2.5 or f/2.8.