Explain aperture to me please?

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With the kit lens attached I can put the camera in Aperture Priority AV and use the wheel to scroll up to F32. Which normally shows the dust on the sensor if taking a picture of blue sky...Im still lost.

xs5875 wrote in post #9046751
With the kit lens attached I can put the camera in Aperture Priority AV and use the wheel to scroll up to F32. Which normally shows the dust on the sensor if taking a picture of blue sky...Im still lost.

???

Sorry, I don't understand your question/issue here!?!

Nor me.

xs5875 wrote in post #9046751
With the kit lens attached I can put the camera in Aperture Priority AV and use the wheel to scroll up to F32. Which normally shows the dust on the sensor if taking a picture of blue sky...Im still lost.

Just because you can do something doesn't mean you should do it. Unless, of course, you want to capture photos of dust, which can be quite artistic and strangely moving at times, expressive of the existential angst created by the clash between the photographer's infinite aspirations and the limitations imposed by diffraction.

xs5875 wrote in post #9046751
With the kit lens attached I can put the camera in Aperture Priority AV and use the wheel to scroll up to F32. Which normally shows the dust on the sensor if taking a picture of blue sky...Im still lost.

xs5875,
Thats because your lens will close the aperture that much. You see sensor dust because at that aperture you have the most DOF (depth of field) which means the most amount of in focus.

Ex. put you 75-300 on your camera and when the zoom is at 300mm you can close down the aperture to f/45

My guess is your seeing the lens state 75-300mm f/4-5.6 and thinking it can only go to 5.6? If so, what this means is when your lens is at 75mm the largest the aperture can go is f/4 and when your lens is at 300mm the largest the aperture can go is f/5.6

I suggest you take a look at this Canon site Enjoy! Digital SLR and on this page Part II Aperture <-- click to see it gives an explanation of how the aperture works

The aperture is how wide the lens opens to let in light.

A f/1,8 50mm lens would have a max aperture of 50/1,8= 27,7mm

The 1,4 version would have a 50/1,4 = 35,7mm wide aperture.

xs5875 wrote in post #9040836
What does it matter what the aperture of your lens is if you can change the aperture via your camera?

Why is the 50mm 1.4 so much more than the 50mm 1.8?

You seriously need to grab a beginners book, and work through it. Tackling all of this with a crash course is the epitome of biting off more than you can chew. Grab the book "Understanding Exposure" that a few people have recommended. It's a great book and you'll learn alot.

I will, however, offer quick summaries to your questions:

1) The aperture is a function of the lens, not the camera. You simply adjust it through the camera, that's all. Hence the range of apertures available to a lens determines the range of values you can set it to on the camera.

2) Read some of the guides on f/stops that have been suggested. Basically, f/1.4 is a larger aperture than f/1.8, which means it can let more light in. That's one reason it's more expensive. Moreover, the f/1.4 version has better build quality and autofocus.

tzalman wrote in post #9049144
Just because you can do something doesn't mean you should do it. Unless, of course, you want to capture photos of dust, which can be quite artistic and strangely moving at times, expressive of the existential angst created by the clash between the photographer's infinite aspirations and the limitations imposed by diffraction.

Wow man - thats deep!

Arguementative or not , you need to read what I wrote and don't put words in my mouth.

Well, strictly for the sake of argument, you understand, that is not true. The sensor - the silicon photoelectric wafer - has only one level of sensitivity (although it does vary according to the wavelength of the light). ISO is a measure of the gain applied to the output from the sensor by the amplifier.

I really enjoy pedanticism.

I think the word is pedantry Elie!

Now who is being pedantic?

http://www.thefreedict​ionary.com/pedanticism