Aperture & Family Portrait

I apoligize for the truly an ignorant question I have: Other than playing around for the last year with my Canon 40D,

only now am I going to get serious and develope my portfolio. I have searched and read many forums about Shutter

Speed, Aperture and ISO settings, definitions, ideals etc. BUT putting into practice I have not done much of and I

losing sleep over screwing up my next photography session with out of focus photos...

QUESTION: I have a family of three (mom, dad, and toddler) I am photography outdoors. Some shots taken will not

be perfectly posed together, I'm sure. With portraits, I read to set my f stop to 1.8- 2.8 to get the beautiful focus on

the subject and drown out background. But all examples of this show the subject just being one person. Does a f

2.8 work well for a small group setting such as three? I read forums suggesting the aperture to be set to f8- f11 for

groups to ensure all are in focus. Obviously less of the effect I'm trying to create is applied. I'm just so worried

someone will end up out of focus with the larger aperture. Would you reccomend an ideal aperture that is still

considered "safe"?

You need to experiment with this effect to get it right. Basically you are talking about depth of field and the plane of focus within that depth shifts basically on two parameters, the distance from the subject and the aperture setting. Back when I was taught photography, just a bit before Nelson lost his eye :-) , we would set up various articles along a table and but focussing on the item in the middle distance we would take a series of test shots at different apertures to learn exactly what was in focus at what fstop.

 

Just remember you need to get sharp focus on the eyes for a good portrait, so I am guessing you are going to want to shoot in Aperture Priority and experiment from there. With a digital camera you can see the difference in the shots pretty much instantly, so as you are unsure, try bracketing, i.e. take several shots either closing down or opening up the aperture as you go. My best guess is that you will end up in the F4 to F5.6 range, but give it a try. Or as my old teacher the late great John Taylor would say, if you want to know if it is going to be sharp then suck it and see!

 

Hope this helps

 

Jim

Shayna,

 

Safe probably would be f8 - f11. Ideal would be an aperture where only the people are in focus and everything else is out of focus. What aperture that is depends on the focal length of the lens and camera to subject distance. There is a depth of field calculator on this site somewhere if I recall. The best part about digital is you can look at the photos on the cameras LCD screen and confirm that everyone is in focus. If you camera has a DOF switch you can use that to see whats in focus by looking through the viewfinder.

 

If this is to be a formal family portrait I would highly recommend the use of a tripod if you have one. A remote shutter release would also be useful so you can get out from behind the camera and interact with the family while taking the pictures.

When you're doing a group photo, there is also an issue of camera-to-subject distance. If you shoot from ten feet, depth of field will be greater than if you shoot from five feet with the same aperture. Close-up work at very short distances (inches) results in a depth of field that can be measured in millimeters.<p>

Easy answer: chimp. Take a test shot, preview it on your LCD, and if possible zoom in on your picture to examine sharpness critically. If the face focused on is sharp and the others aren't, you need a smaller aperture, and either a slower shutter speed, a higher ISO, or a supplementary light source like flash.

To to dofmaster.com. Read up on DOF. There is no one safe aperture range, as DOF varies according to focal length, subject distance, and f stop. You could use the smaller apertures as a safety, but you may be wasting an opportunity to throw the background more OOF.

Does your camera have a DOF preview button? Try using that. At least with my film SLR the DOF button on my lenses gives me a fairly good indicator of what the DOF actually is. Chimping should help as well. What sort of lens are you planning on using? Working distance?

 

If you are using a 50mm lens on your 40d for the group shots with a 15ft working range you should be able to get everyone in good focus with an F/4 aperature if the toddler is sitting on one of the parent's lap.

I just did this group shot two weeks ago. It was shot at f7.1 (160/100) and the girls on the edge were a little soft. I focused on the 2nd girl, and she's tack sharp. I think f11 would have got me there.<div></div>

<i> >> I just did this group shot two weeks ago</i>

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"St Pterersburg" ? ;)