Aperture values on my camera

[Goldcoin79]

On my camera which is a canon sx30 is bridge camera when setting the aperture f number you cannot set it any higher than f8. A friend of mine that is much more experienced in photography than me said that all cameras should be able to be adjusted to f22.

When I asked him about what the values mean that are printed on the lens he said that the f number values written on a lens are the lowest f numbers that can be set (or widest aperture) but you should be able to go upto f22 as this is the smallest apeture that you can set.

Does any one know any reason why I can not set the f number higher than f8. What my friend tells me makes sense to me but if any one can shed any more light on this i will be greatful, as I am confused and wondering if I should be able to set my apeture upto f22 or not.

James

 

[tirediron]

My guess is that your friend may not be as experienced as you or he/she seems to think. Many bridge and P&S cameras have a very limited range of selectable aperture values.

 

[cgipson1]

Point and shoots are much more limited than DSLR's are in many ways. One of those ways is in the number of available apertures. With the small sensors that most point and shoots have, that F8 will give you all of the DOF you will ever need! The main issue with the small sensors is the using the widest aperture available, you often still have too much DOF for a soft, blurry (bokeh) background.

This is a list of available F-stops for that camera:

Maximum Aperture
f/2.7 (W) - f/5.8 (T)

- The following f/numbers are available in Av or M:

W: f/2.7, 3.2, 3.5, 4.0, 4.5, 5.0, 5.6, 6.3, 7.1, 8.0

T: f/5.8, 6.3, 7.1, 8.0

Canon U.S.A. : Support & Drivers : PowerShot SX30 IS

 

[Big Mike]

That's right. Most P&S/Bridge (whatever you want to call it) cameras have a rather limited range when it comes to aperture.

Most lenses that are compatible with SLR cameras do have a larger range of aperture values and can 'stop down' to F22 or smaller.

So no, you probably shouldn't be able to set such a small aperture on your camera.

 

[SCraig]

I'd recommend looking in your owner's manual. The aperture values should be listed in the specifications.


Edit .. Sorry, I just saw that Charlie had posted them.

 

[Helen B]

There's a reason that camera lenses for small sensor cameras do not stop down as much as those for larger sensors: diffraction. In very simple terms this softens the image overall: the higher the f-number (smaller the aperture) the more the effect of diffraction. When viewing, the image from a small sensor needs to be enlarged more than the image from a large sensor, so the softness from diffraction becomes more obvious. (I've tried to keep that very brief. Ask if you want it explaining in more detail.) It may also be a practical thing - the aperture gets very small physically, so precision becomes an issue.

Although there are some lenses for 'full-frame' SLRs that can be set at f/45, there are also some that don't go beyond f/11 or f/16 - so even high quality lenses for SLRs may not go to f/22, mainly because of diffraction.

 

[KmH]

The limitation is essentially because of an optical effect known as 'diffraction'. http://en.wikipedia.org/wiki/Diffraction

The very small size of a lens opening at f/22 is determined in large part by the very small size of the image sensor in your camera. The smaller the image sensor, the smaller the image circle that gets projected onto the image sensor.

Diffraction would be so severe anything approaching a reasonable degree of focus sharpness could not be achieved.

The smaller the image sensor, the more sensors that can be made on a single wafer of silicon, and the cheaper each sensor is to make. Which has a lot to do with how much your camera cost.

 

[Goldcoin79]

Thank you all for your valuable information, I new there had to be an explanation.

 

[o hey tyler]

[IMAGE REMOVED]

Does posting image files that are not yours apply to non-photographed images...? Not trying to be a dingus, but it is strange to see a mod post an image directly that they didn't make themselves. As I understand it, the image is from: Buying a camera: everything you need to know | The Verge

Hopefully your response will clear up any future confusion. Thanks Keith!

 

[table1349]

 

[mjhoward]

[IMAGE REMOVED]

Does posting image files that are not yours apply to non-photographed images...? Not trying to be a dingus, but it is strange to see a mod post an image directly that they didn't make themselves. As I understand it, the image is from: Buying a camera: everything you need to know | The Verge

Hopefully your response will clear up any future confusion. Thanks Keith!

Double standard - Wikipedia, the free encyclopedia

 

[KmH]

Charts and graphs, among other things, cannot be copyrighted. www.copyright.gov

 

[o hey tyler]

Charts and graphs, among other things, cannot be copyrighted. www.copyright.gov

It might be nice to link to a source. Someone took time and effort making that chart after all, much like anything copyrightable.

 

[amolitor]

Charts and graphs, among other things, cannot be copyrighted. www.copyright.gov

With all due respect, this appears to be simplified to the point of being completely wrong. Going to the link and actually reading the law is interesting:

"“Pictorial, graphic, and sculptural works” include two-dimensional and three- dimensional works of fine, graphic, and applied art, photographs, prints and art reproductions, maps, globes, charts, diagrams, models, and technical drawings, including architectural plans. Such works shall include works of artistic craftsmanship insofar as their form but not their mechanical or utilitarian as- pects are concerned; the design of a useful article, as defined in this section, shall be considered a pictorial, graphic, or sculptural work only if, and only to the extent that, such design incorporates pictorial, graphic, or sculptural features that can be identified separately from, and are capable of existing independently of, the utilitarian aspects of the article. "

(emphasis mine)

seems to be the definition in play here, and these this category certainly can be copyrighted. It looks to *me* like you cannot copyright the technical content of a chart, but the artistic elements of it most certainly are. Just lifting the image of a chart wholesale certainly copies the data, but also the artistic elements, if any.

It looks pretty clear to me that if you'd made your own chart from the same data, you'd be in the clear, but since you didn't, you're not.

Of course, expecting rules to be uniformly enforced in some internet forum is absurd and silly. I'm pretty sure nobody's going to give a damn if someone copies a trivial little chart like that.

 

[table1349]

Infographics can be copyrighted. Copyrightability of Charts, Tables, and Graphs | Copyright Office, MPublishing | MLibrary

Do we have here in question a chart or an infographic? :study: