maryo Loc: Santa fe

I am confused and maybe someone can explain this to me.
If a lens or camera has f stops listed at F/3.5-6.3 why can I shoot at f /11? What is the difference?
Thanks,
mary

GoofyNewfie Loc: Kansas City

F/3.5-6.3 indicates the maximum apertures (widest) available on the lens, depending on the focal length you select. You still have smaller apertures like f/11, f/16 etc. at your disposal.

maryo Loc: Santa fe

thanks makes sense.

sippyjug104 Loc: Missouri

The f/3.5 - 6.3 refer to the maximum "Openness" of the lens aperture (how wide it opens). The amount of "stop down" such as f/11 is closing the aperture so there is usually a lot of latitude perhaps like f/22 or even more. When you see two numbers listed it refers to a zoom lens. The smaller number is the wide end of the zoom and the larger number is the high end of the zoom (like a 70-200mm zoom lens for example).

The lower the f-stop number the more open the aperture which is commonly referred to as how "fast" a lens is (fast meaning letting in more light).

TriX Loc: Raleigh, NC

The f3.5 - f6.3 you quote is the maximum aperture at various focal lengths with the aperture “wide open”. You may then close the aperture down (either manually or controled by the camera body) to other values (smaller apertures) all the way down to the minimum aperture (highest f stop) on the lens - typically f22 - f32 for 35 mm lenses.

marty wild Loc: England

As a rule of thumb the smaller the F stops the bigger the hole. The big the hole the shallower the back ground is (out of focus) which is called bokeh. Shallow depth of field needs a big hole which means a low F stop. Somethink like F1.8 or F1.4. Low F stop glass is more expensive. In low light photography you need time if you add time to low light you add movement which gives you blurred image. Back to your question F 3.5 -6.3 means the the F stop will change as you zoom in or out. Expensive glass will stop at what you set at when you zoom in or out. When you shoot at F 11 you Need light or exposer time don't get confused with added light. Day light is good enough you can still add fill flash but that's a different question. Hope this helps

maryo Loc: Santa fe

I thought they were saying that 6.3 was as small as you could go. DUH!

RWR Loc: La Mesa, CA

Not so. The smaller the f/stop, the smaller the opening. The smaller the f/ number, the larger the opening.

GoofyNewfie Loc: Kansas City

F/stops are fractions , so f/4 (1/4) is bigger than f/16 (1/16)

amfoto1 Loc: San Jose, Calif. USA

True. But actually it might be more accurate or understandable to think of f-stops as a "ratio"... F = focal length.... So an F-stop is "focal length divided by X". (In fact, many lenses are actually marked with a ratio such as 1:3.5, instead of f/3.5. But when discussing f-stops, we tend to write the latter.)

For example:

A 100mm lens at f/4 will have an opening that's 25mm in diameter (100/4 or 100 ÷ 4). At f/16 the same lens aperture is closed down to give an opening that's 6.25mm in diameter (100/16 or 100 ÷ 16, which will allow less light to pass through).

On a 200mm lens f/4 would make for a 50mm aperture, while f/16 would provide one that's 12.5mm in diameter.

On a 50mm lens f/4 is 12.5mm and f/16 is 3.125mm.

When you think of it as illustrated in the examples above, it might make more sense why the higher the number, the smaller the aperture opening.

F-stops regulate the amount of light that can pass through a lens. Each "full" f-stop smaller reduces the amount of light being allowed to pass through by one half. Full stops are f1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32, etc. (Note that every other smaller f-stop the divisor "doubles".... 1, 2, 4, 8, etc. and 1.4, 2.8, 5.6, 11, etc. This can help when trying to remember the sequence of stops.)

F-stops ALSO control depth of field (which is also effected by focal length & distances). Basically, a larger aperture makes for shallower depth of field (the "plane of apparent sharp focus"), while a smaller aperture increases DoF.

Hope this makes sense... it only took me about 10 years to finally "get it"!

marty wild Loc: England

It looks confusing small F stop number F1.4 is big hole

RWR Loc: La Mesa, CA

Joe Blow

Not to overly quibble, however, ...

Full stops are 1 : 2 : 4 : 8 : 16 : 32. The half stops are 1.4 : 2.8 : 5.6 : 11 : 22. (With each being a fraction) The slope is exponential because it relies upon the area of the aperture, not the diameter. One half of 1 is 1.4, not as often thought, 2.0.

Mechanical cameras were picky when choosing an aperture and only went by full and half stops. Modern digital cameras can choose intervening f-stops.

You probably know this but I wanted to get the "full vs half" right.

TriX Loc: Raleigh, NC

Maybe it’s a matter of semantics, but my understanding (supported by my experience and wiki: https://en.m.wikipedia.org/wiki/F-number) is that what you’re referring to as a half stop is generally considered to be 1 full stop (ie: 1.4>2.0, 2.0>2.8, 2.8>4.0, etc) each stop being equivalent 1/2 (or 2x) the light or 1 EV or 1/2 (or 2x) the shutter speed or 1/2 (or 2x) the ISO for equivalent exposure. Am I misunderstanding you?

From Wiki:

Conventional and calculated f-numbers, full-stop series:

EV. −2 −1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

fstop 0.5 0.7 1.0 1.4 2 2.8 4 5.6 8 11 16 22 32 45 64 90 128 180 256

mborn Loc: Massachusetts

To much information