aperature?

Hey i have a quick question
i was wondering what aperature did. I know the lowest aperature the more light you let in, and the higher the less. But other than that, what does it do? can you add any effects to photos changing aperature? I shoot a 400d with a sigma 28-70mm 2.8

Other than controlling the amount of light, aperture also controls Depth of Field.

http://web.canon.jp …ng/enjoydslr/p_​2_006.html
http://web.canon.jp …ng/enjoydslr/p_​2_007.html

IMO, the most important aspect of being able to control the aperture (note spelling) is that it controls the DOF (or range of apparent focus).

Yes, it controls the amount of light reaching the sensor, but that can also be controlled by shutter speed.

EDIT: Knowing what the aperture does and how it can control the look of your images is fundamental to photography. Given the very high ISO values we can use with the new DSLRs, I'd say it's more important than shutter control.

Glenn NK wrote in post #3504519
EDIT: Knowing what the aperture does and how it can control the look of your images is fundamental to photography. Given the very high ISO values we can use with the new DSLRs, I'd say it's more important than shutter control.

I would agree.

There are more questions on POTN about aperture settings, Depth Of Field (DOF), Hyperfocal settings, getting good Boketh and fast glass than there are for shutter speed and ISO settings.

If you have a wander through the All the Best Links sticky at the top of this forum you will find loads of links to more info.

I'd say a good understanding of the Law of Reciprocity is one of the fundamentals. How the relationship between shutter speed and aperture effect our decisions to expose images.


http://en.wikipedia.or​g/wiki/Reciprocity_(ph​otography)

http://www.parkwestcam​eraclub.org/tips/recip​rocity.html

This is a good resource:

http://www.uscoles.com​/fstop.htm

airfrogusmc wrote in post #3506751
http://en.wikipedia.or​g/wiki/Reciprocity_(ph​otography)

The link has a problem. The final ")" is not part of the link, and Wikipedia doesn't know how to deal with it.

SkipD wrote in post #3506809
The link has a problem. The final ")" is not part of the link, and Wikipedia doesn't know how to deal with it.

http://en.wikipedia.or​g …procity_%28phot​ography%29

Do a simple test.

set your camera on a tripod about 5' from your kitchen table
set 3 pop cans on the table about 1' apart in a line on a slight angle off the camera axis
set your center focus point on the middle pop can.
set you f-stop on the smallest number you have ie. 2.8 take a picture.
then without changing focus point change your fstop to a bigger number, do this several times till you get to the highest number your lens has.

now look at your photos and see the difference the f number has on the amount of the picture that's in focus.

for me I can do all the reading I want but doing it sinks in a lot quicker.

Bob

snokid wrote in post #3507864
Do a simple test.

set your camera on a tripod about 5' from your kitchen table
set 3 pop cans on the table about 1' apart in a line on a slight angle off the camera axis
set your center focus point on the middle pop can.
set you f-stop on the smallest number you have ie. 2.8 take a picture.
then without changing focus point change your fstop to a bigger number, do this several times till you get to the highest number your lens has.

now look at your photos and see the difference the f number has on the amount of the picture that's in focus.

for me I can do all the reading I want but doing it sinks in a lot quicker.

Bob

You mean, something like this?

http://web.canon.jp …ng/enjoydslr/p_​2_007.html

Obligatory referral to "Understanding Exposure" by Brian Patterson (I hope that's right).

Best book ever for any new owner of an SLR, digital or otherwise.

Cubix Rube wrote in post #3509218
Obligatory referral to "Understanding Exposure" by Brian Patterson (I hope that's right).

Best book ever for any new owner of an SLR, digital or otherwise.

POTN should get some commission on the number of recommendations of that book I have three of his (Bryan Peterson) and they are all good