Smooth Loc: Louisville, KY

I didn't read through all the replies to your question - they were all over the map, mostly correct - Depth of Field is the problem - so someone may have already given my 1-1/2 cents worth below.

A DOF problem can be easily resolved by using an online DOF calculator and table.

http://www.dofmaster.com/doftable.html. (This is one of many.)

Keeping it real simple and using the numbers that you listed, namely, Canon Ti3, aperture set at f/4.5 with a focal length on your lens set at 56 mm and shooting at a distance of 4 feet away from your subjects - neat kids, BTW - I used the above online depth of field calculator.

I plugged in the your 50 mm focal length, Canon Ti and "feet" for measurement, then hit the "calculate button" and perused the DOF table of shooting-distance on the left and f/stop on the top and came up with a DOF of about 4 inches. (You have to subtract the far point from the near point.)

This means that in your entire picture from where you were shooting, and as far as the eye could see, there was only one area that was IN-focus and that area was only 4-inches deep, thick, long or however you want to describe it. Everything else was either somewhat out of focus, like the kid in the background, or completely out of focus, like the far background itself.

Now assuming that both kids heads are about 7-inches in diameter and there was a little space (front to back) of about three inches between them, this adds up to be about 17-inches for the depth (front to back) of your subject.

But the calculator says that only 4 inches of that space will be in focus. The boy in front was in focus simply because that was where you were focusing. Had you had the focus squarely set on the boy to the rear, he would have been in focus and the boy in the foreground would been out of focus.

In order to solve this specific problem, i.e., to lengthen or increase the depth of field, you simply leave all the settings the same except the aperture. "Stop it down" to, say, f/8. The calculator computes the DOF for these settings to be a smidgeon over 2 feet. If you focus on either boy's face, you should get an image with both of them "in focus." But you will have to be "spot-on" as to where you place your focusing square. When shooting living things, I like to focus on their eyes... including race horses running around the track at the Kentucky Derby. (And no, I can't get you any tickets. :-)

There is no magic bullet or "rule of thumb," if you will, that you asked for. As you can see from the DOF calculator, the whole subject can get quite complex. Our eyes and brains - well some brains... mine drags sometimes :-) - do all of this calculating stuff automatically. Unfortunately, no one has invented a camera yet that meets the wonderfulness of an eye/brain combo.

That said, in the future when shooting close-ups of more than once person grouped together from such a short distance of 4-feet, before you hit the shutter button, do a simple pilots check-list to insure that your camera and lens are set at all of the following:
• Mode: Av (Aperture Priority)
• Aperture: f/8
• Lens: 50 mm
• ISO 200
• Focus: Grid or whatever Canon calls its best focus)
• Distance from you to subject: about 4 feet.

You can shoot all you want from 10 am to 2 pm with these settings and get really good images, provided that the subject in-focus. But it's a whole new ballgame if you decide to shoot at a greater distance than four feet and/or at different times of day.

I suggest as many others have: either go online or read a book and bone-up on DOF. There is slight learning curve, but the knowing the subject is necessary if you want to be able to take in-focus shots with good exposures... and to do the nice camera you have justice.

jdcalabr Loc: Orlando, FL

I'm not sure about Canon, but on some Nikons there is a feature that focuses on the closest object in the frame. This is an optional selection. Just check to see if that is the mode you have selected.

jeep_daddy Loc: Prescott AZ

These are also what the camera would choose if it were fully automatic. You may as well put the camera on the green square.

ALYN Loc: Lebanon, Indiana

TOP TRAINER ???? Of what ???
Here is a suggestion: Acquire a book of BASIC informatiom on photography and read it; also read your owner's manual carefully. Maybe your have a Library nearby; go there, have someone there show you the photography section, pick out a simple primer,,,and read it. It is fairly obvious you have little or no knowledge of photography basics. Having a fancy camera does not make you an expert and certainly not a trainer. ALYN
P.S. I have been a photographer for 50-years and I am still learning.

SavvyGal13 Loc: Colorado

The problem with this advice is that at f/11 and his focal length and distance to subject it only nets him 4.41 inches of depth of field!

THIS is what I've been laboring to explain, THIS is why a generic "just stop down the f/stop" sort of advice doesn't work.[/quote]

I get what you're saying and it has been immensely helpful. I've been having trouble getting the bokeh I want in some shots, and while I began to realize focal distance effected my results I haven't been going into a DOF calculator to work things out in detail so that I know how to approach it.

BTW, your posts on this site in general are always helpful. I appreciate them.

jimni2001 Loc: Sierra Vista, Arizona, USA

I think he is a trainer at a spa or gym. He never said anything about being a pro with a camera. Your comment is neither helpful or nice.

rpavich Loc: West Virginia

I thank you VERY MUCH!! :)

NegativeBLUR Loc: Dallas, Tx

I agree....all these variables to a beginner are very daunting. The 5.6 comment I could have been more clear about, true....I was simply trying to explain the larger number the more depth of field. Since the terms "closing down" "opening up" and "smaller" and "larger" aperatures are very confusing when learning (it always sounds backwards as larger number is smaller ap) I was trying to be clear and not confuse. My apologies.

richrunge

Thanks for putting on the calculator that is a big help for someone trying to learn.

Weddingguy Loc: British Columbia - Canada

Well . . . at least one of you came close to the real problem. It is NOT a DOF problem, nor a lens problem. Canon DSLR's have three choices for choosing the focal point. Auto array - all points of focus turned on, letting the camera decide which to use. Center point focus which uses only the center spot, and thirdly your choice of any of the focal spots one at a time. You said that you are using the auto array which automatically focuses on the closest subject. To solve your problem simply turn that off and go to the center spot focusing, or the pick any spot you wish . . . but only one. Center spot focusing is the most effective as all the focal spots other than center favors lines of detail that are perpendicular to the camera in landscape mode..
To use center spot focusing effectively you should use a three step process. 1) Focus by pushing the shutter release button half way . . . 2) While continuing to hold the button half way down, recompose your image as you like . . . 3) Then push the shutter all the way down to capture. You must be sure to not let up on the shutter release button while you recompose or it will refocus elsewhere.

Hope that helps.

overthemoon Loc: Wisconsin

Get the book understanding exposure by Brian Peterson it helps a lot with depth of field

rpavich Loc: West Virginia

Have you read this thread and the OP's first post?

jerryc41 Loc: Catskill Mts of NY

And your little dog is cute.

rpavich Loc: West Virginia

Gracie thanks you!

Luniss-kh Loc: Inverness, Florida

Thanks for the link very informative.