Multi point focussing

Hi
Sorry if this is such a stupid question, but i am trying to take pictures where the "focus" is on everything in the shot. I have looked in the instruction book on the various focusing formats but cannot find the answer. I only seem to be able to focus on something in the foreground, or the background, but not on both.
Im sure its something easy, but would really appreciate any help
Thanks

You're searching on "focusing" and that's not what you want... What you need/want to understand is "Depth of Field'... and HyperFocus distances...

Here is an excellent video on depth of field - Photography Online - https://www.youtube.com/watch?v=abzjSaID6Ec

As Fred mentioned, what you need is to learn about depth of field. Your aperture controls the depth of field. Other things that factor into depth of field are the focal length used as well as how close you are to your subject.

I really like this app called Simple DoF (a paid app) because of how it illustrates the differences. Let's say you are using a D7200 with a 70-200mm f/4 lens. First you choose the body. Then you choose your focal length (I chose 150mm here). When you change the aperture (in this case f/4 and f/10 are shown), you will see the depth of field range change. This particular example is with you standing 35 feet from your subject.

The first diagram shows the area that will be in reasonably sharp focus is 2'7.46" in total (two feet 7.46") when focusing 1/3 of the way into your subject. The only difference compared with the second diagram is switching to f/10. Now the entire area that will be in reasonably sharp focus is a larger distance of 6'7.87" (six feet 7.87").

When you focus and want the greatest amount of depth of field, choose a smaller aperture (higher number f/stop) and focus about 1/3 of the way into your subject.

The closer you are to your subject, the shallower your depth of field will become. So the values posted below are specifically when you are standing 35 feet from your subject with this particular body and focal lengths. Yet if you slap on a 35mm lens, those values will change drastically simply because wider angle focal lengths have a great amount of depth of field compared to longer lenses.

Hi everyone. Thanks for your kind replies. I did consider depth of field and changing the aperture. I did try doing that, but the room was dimly lit, so when i upped the aperture from 2.4 to something like 8, it came out totally dark. I appreciate that i can change the speed and ISO, so adjusted accordingley, but had to endure a lot of noise. I was only doing practice shots, so the results weren't important. However it did make me wonder, how i would achieve satisfactory results in that situation. I presume the answer would be to add lighting.

The extra info from Hark and Peter is fantastic and much appreciated.
However is there a way of changing the focus from just one point? I have tried putting it to 9 and 21 points, yet it still only focusses (spelling?) On one thing in both the viewfinder and the results.

Thanks again for your help

The camera can only focus at one distance at a time...

Roscoe

There are so many variables that work into this equation.

For starters, the size of the sensor in your particular camera affects depth of field greatly. The smaller the sensor generally, the larger your DOF can be. Check what you can achieve with a cellphone camera or even an old compact pocket size camera from 10 years ago. If this is the sort of camera you are accustomed to, picking up a camera with a larger sensor can be a learning experience just for that. Then you factor in the aperture (f-stop). Here a smaller aperture opening (which is actually a bigger number in f-stop) increases the depth of field. Taken to the extreme, a pinhole camera uses the tiniest of holes possible and does not need an actual glass lens to focus because that tiny aperture gives near infinite focus. But it takes a long time to expose a photo that way.

It has been mentioned, but there is a way to address this problem with software. If you can use a tripod to keep camera still and not moving between shots, and nothing moves in the room, you can take a series of photos all with the same exposure settings and manually adjusting the focus point at regular distance from front to rear in the room. Then software or a filter in Photoshop can perform a "focus stack" (I think sometimes called a depth-merge) by combining the focused parts of each photo into a single image. I wish I could guide beyond that but I have not really needed to try doing that yet.

Change the Focus mode to Single point... Then when you 1/2 press the shutter, it will focus on that point.... Using the round cog wheel, you can move the little red square (focus point) anywhere within the screen... 1/2 press the shutter, and it will then re-focus on that new position...