my lens questions

[etrig]

Sorry to be asking so many dumb questions, but I'm confused as to what the f numbers mean on the lens description, for example : 60-200mm f/4-5.6 does that mean those are the aperture's at full wide angle (f4) and zoom levels. (f5.6) What does fast and slow lens mean. I see a lot of people referring to that.
thanks
trig

[Canuck935]

Sorry to be asking so many dumb questions, but I'm confused as to what the f numbers mean on the lens description, for example : 60-200mm f/4-5.6 does that mean those are the aperture's at full wide angle (f4) and zoom levels. (f5.6) What does fast and slow lens mean. I see a lot of people referring to that.
thanks
trig

Yes that's right f/4.5 is max at the short end and f/5/6 is max at the long end. Faster lenses have smaller f/ numbers. Typically lenses f/2.8 and below are 'fast' lenses.

[another view]

Lower "f" numbers are a wider aperture (opening) and are referred to as faster. f1.4 is faster than f4, etc. This meaning of faster has nothing to do with focusing speed or anything else - only what I just explained.

Note that in some low-light conditions, faster lenses (as in aperture) will focus faster and more consistently than slower lenses just because they let more light in, and therefore let the camera's AF system see a little easier.

[etrig]

Cool thanks guys !! I understand that part... but I've got another one

Using my example (60-200mm f 4--f 5.6 does that mean those are the only apertures you can use? isn't there more settings? ( f-stops? ) or something ?
maybe I should be asking, what are the f-stops? I kinda remember some of this from a high school photo class I took.

trig

[mjs1973]

Trig,

F-stops are refering to the size of the opening in the lenst tha lets the light in. I don't know if F-stop actually stands for something or how they came up with the term.

The numbers on your 60-200mm lens only refer to the maximum aperture available at a given focal length. There is a whole range of smaller f/stops that you can use. You're lens may go as small as f/22 or even smaller. If you set your camera to aperture priority mode, you can choose the f/ stop that you want and the camera will choose the shutter speed for you. I shoot in this mode most of the time as it allows me to choose the depth of feild that I want to my image.

You're lens will stay open to the maximum aperture untill you take the image, or press the depth of field preview button.

[etrig]

I believe I understand now.
I'm trying to educate myself for when I upgrade cameras. I only have a A530 now. I just figured out that the apertures change depending on focal length and was trying to apply that theorie to a slr camera.
thanks bunches!! you people are great!!
trig

[milhouse]

Cool thanks guys !! I understand that part... but I've got another one

Using my example (60-200mm f 4--f 5.6 does that mean those are the only apertures you can use? isn't there more settings? ( f-stops? ) or something ?
maybe I should be asking, what are the f-stops? I kinda remember some of this from a high school photo class I took.

trig

Im not sure if you’re totally clear so I figured I would chime in. The 60-200mm you refer to is the focal length of the lens and that has nothing to do with the apertures (f5.6..), Both zoom and apertures are set individually. For instance when you would zoom in and out 60mm would be the widest view and 200 would more of a close up. The apertures f4 - 5.6 would be set according to light and or how much of the photo you want in focus. For instance if you took a photo of a person outside and you used f4, your subject would be in focus and the background would be blurry unless the background was immediately behind them like a person leaning up against a wall. Another reason to use the widest aperture of f4 would be for low light situations. Now if you had a lot of light and wanted to keep things near and far in focus you would use the other end of the aperture range like 22 or whatever that particular lens goes up to. Other then that your main concern is shutter speed.

[etrig]

Excellent !! you guys have really explained this well.
At least I can browse through the lenses and know what I'm looking at now.
thanks again everyone,I really appreciate the help.
trig

[rzozaya1969]

neat Q... I was going to ask that... thanks for beating me to it