Is there a site that explains how to set the right f/stop for certain conditions?

[ziggie216]

Perfer something that explains in simple terms. 90% of the time I'm using Aperture priority and hope that I can learn from it before messing with the shutter speed. The pictures looks great on the LCD screen, but by the time I'm looking at it on my computer, I find it really disapointing. The background was too blurry, I should have lower the f/stop for more light, etc.. I understand what it does, but I'm always guessing if should I have the aperture larger or smaller.

[Ade H]

There's the DoF Master (http://www.dofmaster.com/dofjs.html) website, which provides a DoF calculator. That can be useful on occasions for experimenting with some rough examples or working out a specific solution to a specific scenario.

I can't think of any other useful resources that can guide your f-number selection. Practice makes perfect, as the saying goes, or closer to perfect at least.

[DAMphyne]

ziggie,
Unknown to you, you can't really learn aperture without also learning shutter speed.
By changing your f-stop in A, your shutter also changes to compensate to keep the same exposure.
You do use aperture to control DOF(blurry background), but that is also affected by other parameters.
Find what speed you can "hand-hold" and get a nice sharp photo, do that by adjusting the f-stop.
This forum may be your best choice when trying to understand how this stuff works.

[tonylong]

Here's a quick place to start: "Ben's Newbie Guide":

http://photography-on-the.net/forum/showthread.php?t=414088

Then, I'd suggest "Understanding Exposure" by Bryan Peterson as an easy read that will help you to grasp the "whole picture". As David suggests, there is no "pat formula" but more a grasping of how the several elements that combine exposure, subject and whole composition.

So, you could ask "What's the best aperture for sports?" and the "correct" answer would be "it depends" -- on things like lighting (especially) and then what the subject is and what is the intent of the composition.

See what I'm getting at?

[Sorarse]

Unfortuantely there is no easy answer to tell you what the correct f stop for any given situation, because there is no such thing. Present a photo opportunity to 2 or more photographers, and it will be a mighty big coincidence if they all choose to use the same aperture for their photo.

Each will select what he feels will give him either the depth of field he requires to achieve the result he wants, of they will choose an aperture which gives them the shutter speed they need to achieve a particular result.

If you are not sure, why not take several photos of the same scene, at differing f stops, and then decide which gives you the result you are looking for. By experimanting like this, you will get a better feel for what the numbers on your dial actually mean in real terms.

[braidkid]

I also recommend the book "Understanding Exposure". I think it will answer a lot of your questions.

To give a brief and general answer to your question here.....There are mostly two types of photos, "story telling" and "singular theme".

"Story telling" photos are as they sound, they try to convey a story such as a landscape. They usually have large depth of field and are sharp throughout the frame. You typically use a higher F stop (f16 or greater) for these types of photos.

"Singular theme" photos are anything that you want your subject to stand out. Portraits are a good example. You typically want your depth of field to be short, hence using a lower F stop (f5.6 or less).

The sweet spot of most lenses (sharpest point) is anywhere between f8 and f11. When the entire frame is in same plane of field and you're not concerned with isolating your subject, use this range.

Hope that helps. It's explained more in the book.

[HuskyKMA]

+1 for Understanding Exposure by Bryan Peterson (here (http://www.amazon.com/Understanding-Exposure-Photographs-Digital-Updated/dp/0817463003/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1227326301&sr=8-1))