what f stop for a family photo?

[timor]

Take Vince advice and go to online DoF calculator. It's easy: for 35mm camera and 50mm lens with circle of confusion equal to 1/30 of mm your DoF at the distance of 10 feet will be around 2 feet. Good for 3 people lined up. The rest you can figur out yourself. If you want realy creamy background use or longer lens (with smaller apperture) or position subject far from background.

 

[Solarflare]

For the record, I just shoot at f/2.8 most likely because thats when my lens gets really sharp. I have no qualms to use f/1.8 though, especially when I am no longer able to shoot at anything near ISO 100.

 

[allison_dcp]

As Keith already pointed out, it completely depends on the distance between the nearest and farthest person in the shot and then you'd need to calculate the depth of field given the focal length & aperture. Few lenses have decent depth of field scales anymore. Some cameras have an aperture preview button which mades the aperture blades extend to the selected f-stop. The image will a bit dimmer (assuming you're selected an f-stop other than wide-open... because at wide-open the blades will stay put.)

My favorite website with a straight-forward look-up tool for DoF is DoFmaster.com. But I'm always quick to point out that a website might not be handy when you're out shooting. They do make downloadable phone apps (when I searched for "depth of field" in the App Store for iPhones there were about 70 apps that matched). Quite a few of these are free and the not free apps are still pretty cheap.

Awesome! thanks I'll have to check that out!

 

[cgipson1]

f/2.8 with many zoom lenses is a risky aperture for a group shot. The DOF is shallow, but also, the lens performance might also be sketchy. One can usually get a somewhat decent background blur at f/4.2 to f/5.6, somewhere in that range, as well as very good to even EXCELLENT optical quality from "most" good lenses. Using a 35mm film camera and a 50mm lens, I'd probably shoot at right about f/5.6 under many conditions, and pay attention. Close attention. I am not a big fan of "Shooting at f/2.8"--which has almost become a silly internet folk myth thanks to YouTube and all these newbs running around making videos and spouting off about "shooting at f/2.8" as if it, the number, automatically "improves" one's photos. No. It's more about skillful lenswork and that means FULLY understanding how lenses work. (I often think to myself, "Yeah, EFF two point eight!" Honestly, f/2.8 ruins more photos than it helps...)

I agree totally! How many times has someone complained about their photo's being blurry... and we find that it is because of that stupid "shoot wide open" mentality... when they lack the knowledge and experience to be able to do that?

 

[unpopular]

F-stops is the factor which the a Lens can mainatain peace within a family during the duration of the exposure. Many people think it stands for "family stop" but really it means "fighting stop". The proper f-stop is a complex calculation, and depends on family size, number of inlaws, age of the family members, etc. While preteens are notorious for increasing f-stop requirements, it is often overlooked that grandparents also push up f-stop requirements as well, until they reach about age 93 and have given up all attempts at being critical and condescending. Teenagers need less f-stop than you'd think, so long as their younger siblings aren't near one another, at which point there is an inverse correlation to age differential.

Fortunately most lenses have a minimum f-stop of around 2.8, which should prevent any ought right physical assault, lenses enjoyed by individuals who take lots of family photos often feature higher f-stop numbers of 4 or even greater. However, it is highly not advised to take family portraits with anything less than 2.8, and serious consequences may result with f-stops less than 1.4.