Which aperture or auto-focus mode is good for group shots?

[UltraLuxe]

What aperture or auto-focus mode is good for group shots of 4 to 5 people, or even 2 or 3 people?

I was shooting at f1.8 on a 50mm lens on a DX camera, and only the 1 or 2 people that was in the center was in focus, while the people on the outer edges were blurry.
I forgot which auto-focus mode I was using.

Also it's really hard to tell if the pictures are sharp, or not, since I can't see what the result of the aperture size will be through the viewfinder, or the super tiny LCD screen.
I wouldn't even notice that some of the subjects are out of focus at all, until I load the pictures into Adobe Lightroom.

Here are examples, from some family photos.

 

[480sparky]

You're lacking a small enough aperture to generate the depth-of-field required.

 

[Designer]

Hey, welcome!

Actually, you can figure the DOF before you even take the shot. That way, you can position your subjects in such a manner that they will be more in focus.

Shooting at f 1.8 is a sure way to have such a shallow DOF that almost nothing but one person's eyes or nose will be in focus, while everything else is not.

So in case you don't have a speedlight, start saving up for one, because you need to get more light on these people and that will also help you use a smaller aperture, keeping everyone in focus (and well lighted too).

 

[pgriz]

Your lens was doing what it was designed to do at the aperture you selected. As Sparky noted, to get enough depth of field, you need to adjust the aperture to get you the depth-of-field required. Since DOF is also linked to focal length and distance, you decide how far your group has to be from the camera (say 10 ft), then you decide what DOF you need (say about 4 ft front to back). With a 50mm lens on a DX body, you'll need to reduce your aperture to f/8 to get the required DOF. Now this is 3 stops darker than if you're wide open, so either you need to get more light (as with a flash), or use a higher ISO (if you shot at 100 ISO originally, you'll probably now need ISO 800).

Use the DOF calculator to find out which aperture gives you the right amount of DOF: Hyperfocal Distance and Depth of Field Calculator - DOFMaster

 

[UltraLuxe]

Your lens was doing what it was designed to do at the aperture you selected. As Sparky noted, to get enough depth of field, you need to adjust the aperture to get you the depth-of-field required. Since DOF is also linked to focal length and distance, you decide how far your group has to be from the camera (say 10 ft), then you decide what DOF you need (say about 4 ft front to back). With a 50mm lens on a DX body, you'll need to reduce your aperture to f/8 to get the required DOF. Now this is 3 stops darker than if you're wide open, so either you need to get more light (as with a flash), or use a higher ISO (if you shot at 100 ISO originally, you'll probably now need ISO 800).

Use the DOF calculator to find out which aperture gives you the right amount of DOF: Hyperfocal Distance and Depth of Field Calculator - DOFMaster

Thanks for the DOF Calculator.
It looks like it will be a big help, until I could become more familiar with it.

 

[UltraLuxe]

Hey, welcome!

Actually, you can figure the DOF before you even take the shot. That way, you can position your subjects in such a manner that they will be more in focus.

Shooting at f 1.8 is a sure way to have such a shallow DOF that almost nothing but one person's eyes or nose will be in focus, while everything else is not.

So in case you don't have a speedlight, start saving up for one, because you need to get more light on these people and that will also help you use a smaller aperture, keeping everyone in focus (and well lighted too).

Thanks,
I'm actually saving up for a speedlight, with a softbox on a monopod.

 

[pgriz]

@ ultraluxe: You don't need to memorize all the options. Figure out how you usually like to shoot groups (focal length, distance), and then figure out how much aperture you need to get the right depth of field. If you're working with a prime (fixed focal length) lens, then it's easy. It's slightly more complicated with a zoom lens. But the reality is that we don't usually shoot all over the place - there are generally certain distances and focal lengths we tend to use, and THOSE are the ones you should figure out the key setting for.