Kingmapix Loc: Mesa, Arizona

Another point - focus on the mid-point distance of a group people.
This maximized the chance that all will be in reasonable focus.

jcboy3

You don't mention whether you have a full frame or crop camera, and that's pretty important.

For example, I'll assume you have a crop camera (e.g. Nikon D7100).

Three people sitting in leaves will need at least 6' x 4' of space. You don't want them all lined up, but staggered some. Let's give them each 10 inches, so you need 30 inches (2.5 feet) front to back. Now you can focus on the middle person, so you need 20 inches to the back and 10 inches in front. DOF usually gives more to the back than front. So the key number is 20 inches (1.65 feet). You'll get the front person more in focus that way, as well.

With a 100mm lens, you need to be at a distance of 27 feet to get a 6' x 4' field of view (FOV). At 27 feet, the DOF is 1.3 feet behind the subject at f/2.8. You can move back to about 30 feet to get the desired DOF (increasing the FOV to 6'9" wide), or you can decrease aperture to f/3.6.

For me, if I was interested in narrow DOF, I would shoot at 27 feet with an aperture bracket of +/-2/3EV (in other words, shoot at f/2.8, f/3.6, f/4.5) and then pick the shot I liked.

If your camera will automatically shoot an aperture bracket, then set the bracket to 3 frames/0.7EV, set camera mode to shutter priority, burst mode, exposure compensation to -2/3EV (to avoid overexposure), and adjust shutter speed and ISO to get an aperture of f/3.6 (with shutter speed at least 1/160). And shoot RAW, because the shots will vary by 4/3 EV. Then fire away.

Otherwise, you can set to aperture mode and adjust aperture as you shoot. In that case, lock the camera on a tripod so the framing stays the same as you rotate aperture and press shutter (hard to keep the camera pointed consistently when doing this).

Tracy B. Loc: Indiana

Thanks so much for your answer and taking the time.

redhogbill Loc: antelope, calif

the link that MTshooter posted is also an app, for the iphone it is called "DOFmaster" I have that info with me all the time!! {I can use all the help I can get!!}

dnathan

ALL OF THE INFO IS CORRECT.WANT TO MAKE IT EASY? USE A FIXED FOCUS LENS. EXAMPLE: IF YOU SET YOUR F STOP AT F8, YOU WILL BE IN FOCUS FROM F5.6 TO F11. TRANSLATED: EVERYTHING FROM 5.6 FEET TO 11 FEET WILL BE IN FOCUS. WORKS WITH ANY FIXED FOCUS LENS WITH F STOP MARKINGS ON THE LENS. THE RULE WORKS WITH ZOOMS TOO BUT THE IN-FOCUS RANGE CHANGES AS YOU CHANGE THE FOCAL LENGTH - TOO CONFUSING TO FIGURE ON THE GO. I LEARNED THIS 50 YEARS AGO. WANT TO SHOOT FAST? LEARN TO ESTIMATE DISTANCES & PRE FOCUS AT APPROPRIATE DISTANCE. I SHOT WEDDINGS LIKE THIS FOR 35 YEARS BEFORE AUTO FOCUS & NEVER MISSED A SHOT.

Tracy B. Loc: Indiana

Great tip! THANKS

jcboy3

Would be if it were true. Unfortunately, DOF is not that easy.
If you are in focus from 5.6 to 11 feet at f/8, then (approximately) the DOF is 5.4 feet, the focal length is 32mm, and the distance is 7.4 feet. For full frame, it's approximately valid for a 40mm lens.

A 100mm lens on a crop frame at f/8 has a DOF of 0.27 feet at 5.6 feet, and a DOF of 1.09 feet at 11 feet. Nowhere near the 5.4 feet needed for this "rule".

dnathan

wrong! 3000 wedding shot using this method. never one out of focus. forget the math - real world results rock!!

greg vescuso Loc: Ozark,Mo.

You have gotten a lot of great advice. But I heard somewhere when you buy a new lens try to only us that lens for a year. This may seem extreme but I try to do this to some degree and find I begin knowing what the dof will be for different distance to subject and focal lengths after a few months and don't have to calculate formulas on the fly. It does take time but you will become comfortable with any lens you pull out of your bag in any situation. Hope this helps.

Zone-System-Grandpa Loc: Springfield, Ohio

+++++++++++++++++++++++++++++++++++++

Tracy, your best bet would be to try to arrange your subjects whereby their faces are pretty much the same distance to your camera's lens.. Once that you have made this possible, select a smaller aperture such as f5.6 or f8. Then, if you have post processing capabilities, add a vignette, not only to the edges of the scene, but in a way whereby it trespasses inward into the scene which will result with less background and surrounding areas being noticed. Yet, if I were to be taking the shot, I would be less concerned about some of the surroundings/leaves being in sharp focus, however; if such did bother me, in Lightroom, I would lessen the exposure shown upon the leaves by using a mask, a brush, or both, etc..

Best of luck !!!
~Doug~

Tracy B. Loc: Indiana

jcboy3

With a 100mm lens? Show me.

Tracy B. Loc: Indiana

Here is one of the pictures I took with my 100mm f/2.8 L lens.

Opps. Attachment in next post.

Tracy B. Loc: Indiana

Here is one of the pictures I took with my 100mm f/2.8 L lens.

(Download)

dsmeltz Loc: Philadelphia

Nice composition. To my eye, it appears to be just a tiny bit forward focused. The boy’s pant leg seems sharper than the face. Have you ever had the lens adjusted?