confused about apertures

[doctorfoz]

looking at buying lenses for a Digital SLR, I see many lenses are described as f1:3-5.6 (or something like that).

does that mean that the entire aperture range for that lens is only between 3 and 5.6? Or am I missing something? :confused:

thanks

foz

[Two-Toe Tom]

no i think that's the maximum aperture, depending on the zoom level.

[Tyger]

looking at buying lenses for a Digital SLR, I see many lenses are described as f1:3-5.6 (or something like that).

does that mean that the entire aperture range for that lens is only between 3 and 5.6? Or am I missing something? :confused:

thanks

foz

Hey Foz,

Here's a good read on understanding camera lenses (http://www.cambridgeincolour.com/tutorials/camera-lenses.htm). Near the bottom it explains all you need to know.

My favourite lens I use is a Canon 100-400mm F4.5-5.6
This mean that at 100mm the lenses maximum aperture available is f4.5, however when fully zoomed to 400mm it would f5.6. The large aperture opening have lower fstop numbers like f1.0 which is considered a very fast lens and enables more light in with a narrow depth of field. Smaller aperture openings let in less light and fstop numbers are higher with a wider depth of field.

What kind of lens are you looking for? What do you plan on shooting?

[doctorfoz]

Thanks Tyger - took a quick look at the article and it looks like exactly what I need (just need a quiet room to read it in so I can digest it properly).

I don't think I shall continue my lens-buying adventure - I'm a danger to myself in all things photographic. I just bought a flash from ebay which claims to be EOS compatible. Only after sending off payment did I find out that not only is it a fairly mediocre flash, but that EOS (film) and EOS (digital) may as well be 2 different brands! There's a good chance that using the flash on my 300d will fry the camera!

but thank you for your help!