Please Help...

Hi, i'm relatively new to photography, and i am getting so confused by different things to do with digital photography. Anyway, my lens says on the side of it; 55-200mm, 1:4-5.6 DC
I understand the 55-200mm, but the rest is gobuldi goop...
I know some of this is probably the first things i should have learned but i was given this lens by a friend of my older brother's, so i didn't ask to much at the time... big mistake...
so if anyone has any spare time to enlighten a poor uneducated fool like myself, it would be most apreciated. thanks again

Those numbers represent the maximum aperture.
f/4 at 55mm
f/5.6 at 200mm
It's common for zoom lenses to have larger max. apertures (smaller numbers) at the short end than the long end.
Lenses have the 1: in front of the numbers because the aperture is expressed as a ratio of iris diameter to focal length.

Check this out: http://www.dcresource.​com …d.php?t=8089&pa​ge=1&pp=10

It should explain what all the numbers mean.

richardmincher wrote:
Hi, i'm relatively new to photography, and i am getting so confused by different things to do with digital photography. Anyway, my lens says on the side of it; 55-200mm, 1:4-5.6 DC
I understand the 55-200mm, but the rest is gobuldi goop...
I know some of this is probably the first things i should have learned but i was given this lens by a friend of my older brother's, so i didn't ask to much at the time... big mistake...
so if anyone has any spare time to enlighten a poor uneducated fool like myself, it would be most apreciated. thanks again

Hi Richard, it'll be good if you google "understanding exposure" or "learning apertures". Plenty will probably come up (though I haven't tried it). As for your lens, the maximum aperture at 55mm is f4, and at 200mm the max is f5.6. Your lens is a good consumer grade lens. The DC means it only works on digital bodies like the Rebels, 10D, 20D -- those with the 1.6x crop sensor.

richardmincher wrote:
Anyway, my lens says on the side of it; 55-200mm, 1:4-5.6 DC
I understand the 55-200mm, but the rest is gobuldi goop...

The aperture, i.e. the hole the light goes through (and an image is made of light) is variable on this lens. At 55m it is f4.0 but if you zoom to 200mm it is now operating at f5.6. F4.0 lets in more light and f5.6 less.

You can set the aperture in your camera. My guess is your lens will work best at maybe f8.0. Set it there (read your manual) and see what changing the ISO and the shutter speed does to the images.

You next need to factor in ISO, which is equiv. to film sensitivity, i.e. how much light is needed to expose the film/sensor properly, and shutter speed, i.e. how much time the aperture is open to allow light to the sensor. They each work in tandem Change one and you will impact on the other two.

If you use a fully manual set up for a while you will learn all this stuff easier IMO because you're forced to practice.

A well recommended book is 'Understanding Exposure: How to Shoot Great Photographs with a Film or Digital Camera' by Bryan Peterson; Paperback is £12.90 from Amazon. I just ordered it. Exposure and composition are what photography is all about. If you're a reading type then be worth getting a copy.

wow, thanks so much, i never expected so much response sooo fast. thanks so much for all this Grade A advice... i'll look into that book, definately, sounds excellent, a must have for beginners, and even a Necessity for pros...
thanks so much again.