- Tony Northrup's DSLR Book: How to Create Stunning Digital Photography
- Photography: Digital SLR Crash Course
- DSLR Photography for Beginners: Take 10 times Better Pictures in Just 3 Short Days!
Sharpness and detail are a must if you want your photos to be technically correct. As you well know, or should know anyway, sharpness is influenced by a multitude of factors. Exposure settings, camera stillness and focusing.
It also depends on what you're shooting because you may or may not want everything in the frame to be in focus. In some genres like landscape photography, having everything in the frame nice and sharp from corner to corner is essential.
(Success Tip:Take better photos with this simple deck of cards)
So how do you do that? Aperture is the number one element that dictates depth of field. A wide open aperture will create a very narrow depth of field and it will only allow what's in the foreground to be sharp. A smaller aperture will have an opposite effect, putting everything in focus, regardless of where it is in the frame. With most lenses, the most detail comes out at f/8. This isn't a general rule, so you might want to try different values with each of the lenses you own.
Things are lot easier in with today's cameras than they were 20 years ago when you had to click the ancient depth of field preview button and figure everything out from the viewfinder. There's nothing wrong with this method, and a lot of professionals, including myself still use it. But that's probably because we've gotten used to it for so many years.
The easy way to check that everything is in focus is to use your camera's live view mode. You probably shouldn't trust the camera's LCD for everything, certainly not for exposure and color accuracy, but when it comes to sharpness and focus, it's as good a tool as your computer screen.
With that said, the way to do it is to frame the scene in live view mode, and magnify it to a 100% to inspect the details. Move that square around the frame left to right and from top to bottom to make sure that everything is in focus. If it isn't, it means you have to make some changes and close down your aperture. Just remember one important aspect, closing your aperture all the way down won't make your photos sharper. On the contrary, you'll end up with a lot less detail at f22 than at f8. Also, each lens has its physical limitations that need to be acknowledged before you use it.
Here are a few detailed explanations in this video posted by Professional Photography Tips.