Aperture

[henning_kvaerno]

Hey, I have a Sony DSC-V1 camera and in the instruction manual and

under specifications on the internet it says that the aperture is

from F2.8 - F4.0. I am using this camera for special purposes and am

therefore interested in the smalles possible aperture. When using

this camera in manual mode, I can switch the aperture to F8.0! Why

can I do this? Does the aperture change physically? Is it because I

have a newer edition of the camera? And finally, what does 'aperture

priority mode' really mean? I can change focus, shutter speed and

aperture independently in manual mode...so what is it that I don't

understand? Please help me.

[eduardo2]

F2.8 - F4.0 denotes the maximum aperture of the lens ,F2.8 at "wide" angle and F4.0 at "tele", other apertures are, as you have found out, quite possible.

[henning_kvaerno]

But why are those other apertures possible on a camera which denotes maximum F4.0?

[beauh44]

Aperture priority mode is when you select an aperture and the camera will select the shutter speed to give you correct exposure for that aperture. For example, a smaller aperture (smaller hole for light to pass through) is good for increased depth of field. If you're taking a pic of a landscape and want to get the best DOF, select the smallest aperture you can (which will be a larger f-stop, like f/8) and the camera will figure out the best shutter speed to use for that aperture. Hope this helps.

[skipd]

Henning, it sounds like you don't understand the term "smallest" as it refers to aperture numbers. The smallest NUMBER is the largest aperture opening, and the largest NUMBER is the smallest aperture opening.

 

As has been stated, with the smallest aperture (that is, the smallest opening or the largest number), you will have the maximum depth-of-field and require the longest shutter speed (smallest number - see below).

 

With the largest aperture (largest opening, smallest number), the lens is wide open and gathers the most light. Thus you will use a shorter shutter speed (higher number) and have a minimum depth-of-field.

 

Shutter speeds are typically shown as 60 (or 1/60), meaning 1/60th second exposure time. A higher number such as 250 is actually 1/250th second, a shorter exposure time.

 

It's all potentially very confusing to the novice.

 

You say that you need the smallest possible aperture. If some instruction for a task said that, it means that you need to dial in the highest aperture number. The purpose is probably to gain the maximum depth-of-field which means to have the maximum front-to-back range of your subject in acceptable focus. A wide open lens (largest aperture, smallest number) is often chosen to selectively focus something at a specific distance from the camera.

 

Hope all this helps.

[henning_kvaerno]

Hey again! I totally understand what is smallest (high f-stop) and also about depth of field. But please, I do not need a lecture about what the aperture and shutter speeds do - my question is WHY I can choose a SMALLER aperture, meaning >F4.0, WHEN the instruction manual says that MINIMUM aperture is F4.0!? You see, I am afraid that the camera does some weird calculations to let it seem like less light was allowed in!

[paul -]

Henning, when you use the wide angle, your aperture range is <b>F2.8</b>, F3.2, F3.5, F4.0, F4.5, F5.0, F5.6, F6.3, F7.1, F8.0.<p>When you use the telephoto, your aperture range is <b>F4.0</b>, F4.5, F5.0, F5.6, F6.3, F7.1, F8.0.<p>The aperture can <i>always</i> be set all the way to f8,<br>but f2.8 is available only at the wide setting.<p>When you use telephoto, you cannot get f2.8,<br>as the widest aperture at the telephoto setting is f4.0.<p>Get it?

[henning_kvaerno]

Thank you Paul! Thank you very much! I finally got it! :D

[jbq]

"F4.0" means f/4.0, i.e. 1/4 of f, which is larger than e.g. 1/8 of f (i.e. F8.0).

[andreas_carl]

Sounds like your confusion comes from the manual, it should have said MAXIMUM aperture f2.8~f4.0 (depending on zoom), and MINIMUM aperture f8. A small aperture has a large number, but you knew this, so the manual should not deceive you ;-)