Focus question

[mamatomaya]

Hi all,
I am doing a photo shoot on Friday for two little ones 1 & 3. I have finally gotten my focus down with using back button and focusing directly on the eyes. I have been happy with the sharp pics that i have gotten recently. My question is when you have two kiddos, do you just focus on one eye and hope for the best for the second person's eyes being in focus. Obviously I will need to use a smaller aperture as well. Will 5.6 do it if they are on the same plane? Just wondered if anyone had any tips for this. I want to do well TIA!

 

[Derrel]

On longer-range shots, such as those that show two kids head to toe, with a short lens like a 50 to 24mm, f/5.6 ought to "pull focus" deep enough to get two kids who are at the same plane, or one right behind the other. TO make doubly sure, an aperture of f/8 would be safer.

If the shots are close-up, like a 2-child bust portrait, where one kid is right behind the other, f/5.6 is probably NOT going to pull the back kid into adequate focus if you are shooting from a close distance and shooting and using the entire picture area.

If the two children are on the same, exact plane, f/5.6 is going to probably be okay as far as getting both in adequately sharp focus on half-body to full-length shots. On closer-in shots, I would not rely on f/5.6, since it might let you down if one kid happens to be a few inches behind or in front of the other kid.

 

[Emilymarie]

great info Derrel

 

[gsgary]

Don't forget about shutter speed if you use a smaller aperture because you could get blur if it is not fast enough

 

[tirediron]

To expand on Derrel's post slightly, I would suggest having a Depth of Field calculator available.

This one

is excellent, and you can find them as applications for almost any smart 'phone, PDA, as stand-alone programs for both Windows and Mac computers, and even good, old-fashioned 'printed on paper'.

When you do the shoot, bring some form of the above for your camera and lens(es) as well as a measuring tape. Pose the children, measure the distance to where you would LIKE to set up, and see if the math works.

Remember that the shorter the focal length of your lens, the greater the DoF at any given aperture (a 28mm lens will have MUCH more DoF at f5.6 than a 200mm lens). Also remember your background. You may need to increase the separation between subject(s) and background if it's one that you want rendered out of focus