# what f stop for a family photo?



## allison_dcp

I'm doing a friends family portraits today, and was wondering if f/2.8 would be to large? I want to acheive the blurred background, but definately do not want to blur any family members....Suggestions? Oh and I'm shooting with a 35mm camera and 50mm lens.


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## Solarflare

One of my failures I had since I got my DSLR was attempting a group shot while I was in aperture priority at f/2.8.

Only ONE person of the group was in focus.

And I "only" have APS-C so I dont have such a small DoF as a full frame.

You may succeed with a small DoF if you manage to line everyone up exactly in the area of the DoF, but in general it wont work.


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## vtf

To shoot a family with 2.8 all body parts must be close to the same focus plane, I doubt you could do that and create a dynamic image. You should shoot at a f6 to 8 to get all family members in the shot and move the family members away from the back ground in order to blur the background. This might help Online Depth of Field Calculator


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## Tee

How many members?  How will you arrange them?


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## Designer

allison_dcp said:


> I'm doing a friends family portraits today, and was wondering if f/2.8 would be to large? I want to acheive the blurred background, but definately do not want to blur any family members....Suggestions? Oh and I'm shooting with a 35mm camera and 50mm lens.



I am wondering why you have seemingly arbitrarily chosen the aperture before doing any testing?  IOW: why not compose the group, and then choose the aperture that will keep everyone in focus?  If the background is some distance behind the group, it ought to be out of focus with even a smaller aperture.  

Do you have a longer lens?  Using a longer lens will help with subject/background differential.


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## simion

If more than 3 people, 2.8 is probably a bad idea.
As *Designer* suggested, if you have a longer lens, try use 150mm if you have enough space.


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## KmH

Designer said:


> allison_dcp said:
> 
> 
> 
> I'm doing a friends family portraits today, and was wondering if f/2.8 would be to large? I want to acheive the blurred background, but definately do not want to blur any family members....Suggestions? Oh and I'm shooting with a 35mm camera and 50mm lens.
> 
> 
> 
> 
> I am wondering why you have seemingly arbitrarily chosen the aperture before doing any testing?
Click to expand...

Because many new to photography don't understand how depth-of-field (DoF) actually works, and wrongly assume lens aperture is the only factor that affects DoF.

The DoF an image has is also dependent on the lens focal length, and the distance to the point of focus. If the background is to be blurred the distance from the point of focus to the background also has to be considered. 

35 mm film is the same as a full frame image sensor, so using a 50 mm prime lens @ f/2.8 the total depth of field at various focus point distances will depend on the size/arrangement of the group. As the point of focus distance increases, so does the DoF:
Point of focus @10 feet - total DoF = *2.06 ft* (0.92 ft in front of, and 1.13 ft behind the point of focus.)
Point of focus @15 feet - total DoF = *4.72 ft* (2 ft in front of, and 2.72 ft behind the point of focus.)
Point of focus @20 feet - total DoF = *8.57 ft* (3.41 ft in front of, and 5.16 ft behind the point of focus.)
Point of focus @25 feet - total DoF = *13.8 ft* (5.1 ft in front of, and 8.6 ft behind the point of focus.)


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## greybeard

Bracket your exposures. f/2.8-f/4-f/5.6-f/8-f/11.  etc.  then choose the best ones.  It's not like you are shoot with a view camera.


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## Theninjaseal

greybeard, it's not as much fun to bracket when you're shooting 35mm and have to pay for each shutter click.

I would suggest metering the shot, then arranging the people, then moving your aperture to the lowest value where everyone's in focus.
Or, you know, you could move into this millennium and go digital


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## allison_dcp

Theninjaseal said:


> greybeard, it's not as much fun to bracket when you're shooting 35mm and have to pay for each shutter click.
> 
> I would suggest metering the shot, then arranging the people, then moving your aperture to the lowest value where everyone's in focus.
> Or, you know, you could *move into this millennium and go digita*l


If youll sell me one for under $200 I sure would


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## SCraig

Theninjaseal said:


> greybeard, it's not as much fun to bracket when you're shooting 35mm and have to pay for each shutter click.


Do you think the term "Bracketing" is something that was developed for digital cameras?  It came into being long before digital cameras simply because with film cameras it was not possible to see the image immediately.  We had depth of field preview on many cameras but that was it.  In many instances the only way to insure that a shot was what you wanted was to shoot at varying settings and then pick the one that worked the best once the film was processed.

I agree with Greybeard, take your best guess at what will work and then bracket the shot using several different apertures.


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## CJThompson

Personally I love to use my Hasselblad with a 150 lens at 5.6 to 8.0 on a tripod. Beautiful for family photos or individuals.


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## Ernicus

There is no reason to bracket aperture.  To me that is silly and a waste of time.  

Keith provided great info above so i won't repeat it, but I will say this.  If you want all of them in focus, then use a dof tool and determine what and where you need to be to get them all in the plane.   Set it to where it is just enough for them only, and leave nice space for your background and you will still have a nice quality blur of background as it will be outside of the plane and not in focus.  

This should take all of 3 minutes, if that, once you are used to calculation dof needs for a shot.

Often I hear people saying and thinking they have to shoot at 1.4 or 2.8 to get a nice blur in the background, and that way of thinking is just wrong, it's a part of the equation...not the formula.


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## TCampbell

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.


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## Derrel

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...)


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## 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.


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## 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.


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## allison_dcp

TCampbell said:


> 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!


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## cgipson1

Derrel said:


> 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?


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## 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.


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