Beginner question regarding DOF and portraits.

[peter_kim2]

I have a Elan 7e with a 28-105 f/3.5 and will soon be getting a 50

1.8 which I didnt have enough for when I bought my camera. Ive been

wanting to try getting more experience in shooting portraits

something like the upper half or the classic head and sholders shots

and I would love to get the 85 or 100mm usm lenses but they are a

little outta my budget range.

 

 

Anyways long story short. Would my 28-105 be a good 'portrait' type

lens? Using it at the long end means a 4.0 or 4.5 f stop but is this

adequate to throw the background enough out of focus to be pleasing?

I knwo it has to do with the distance of the background to subject,

but my other question was, at what apreture does parts of the

average body go out of focus and the background blurred nicely? I

guess I could use my soon to be aquired 50..then I have all the

fstop choices I want...

 

As an example I really like this person's portraits, simple but yet

so appealing...especially the 1st and 7th pictures.

 

http://www.mysato.com/read_c_portrait.php?id=94&offset=0

[tom_menegatos]

Depth of field is determined by a few different things. The distance between the subject and the lens, the fstop and focal length (although a recent thread seems to indicate it's more of a perceived effect).

 

At the 105mm setting even at f/4.5 with the subject at the minimum focussing distance of the lens and the background a good distance away, you should get pleasing background blur. A teleconverter will also help because it increases the focal length of the lens while keeping the minimum focussing distance the same.

 

with the 50 you should be able to get the effect your looking for in headshots.

 

Since you're shooting wide open you can see the effects of background blur in the viewfinder.

[dennis_pereira]

In the link you supplied, it looks like most were taken with a longer telephoto. The 50 will do a great job of blurring the background at the larger apertures. With a film camera, you will need to be closer to the subject to fill the frame and won't get the same "compressed" look of facial features that the longer lens provides. Here's a shot using a 50mm 1.4 on a 10D. You can get the same perspective but the cropping won't be as tight with 35mm.

http://www.photosig.com/go/photos/view?id=964195

[jimvanson]

I'm going out on a limb with this one...two things Peter; first it ain't the lens, it's how you use the lens. Take a look at <a href="http://www.photo.net/photodb/member-photos?%20include=all&user_id=35846">my stuff</a> most of the shots were taken with a 50mm. And second; I'll swear many of the shots (including the first & the 8th)on the site you listed were taken with glass longer then an 85 or a 100. I'd say at least a 200 f2.8, more likely a 300mm or greater.<p>And my advice to you? Learn to shoot with the lens you have...take thosands of shots with it...then you'll find that it will be easier to get stunning photo's with your dream lens once you get it.

[jespdj]

<p>There are ways to compute the DOF, but the answer is not exact, because it depends on what you'd call "acceptably in focus". Let's try this with the DOF calculator program that you get with Picture Window Pro:

<p>Focal Length: 105mm

<br>F Stop: 4.5

<br>Resolution: 30 lines/mm

<br>Focus At: 400 cm (let's assume your 4 m from your subject)

<p>The results:

<br>Near Focus: 379.87 cm

<br>Far Focus: 422.38 cm

<p>So the depth of the field in focus is about 43 cm. That should be good enough to get the subject in focus and the background blurred.

<p>Someone correct me if I made a mistake in this reasoning...

<p>regards - Jesper

[ken_schroeder]

Would your 28-105 work for portraits? Try it and look at your prints. As far as making the background out of focus, distancing the subject from the background will help.

[craig_bridge]

If you have full control over subject to background distances, you can easily blur the background if you turn off AF. If you focus in front of the subject so that the rear DOF just puts the subject in acceptable focus and there is enough distance between the subject and background, the background will be out of focus.

 

A wide aperture 85mm just makes the range of placements easier, but you can do it with a 105mm at f/5.6.

[ron c sunshine coast,qld,a]

Peter,don't take much notice of the rediculously complicated formulas for DOF!!!Your current understanding of it is essentialy right on-when working at close distances the only variables you have to work with are aperture and(less usefull) how close the background is.<br>Will the 28-105 be good enough?Maybe<br>If you keep the background waaay back you will do 'ok'.But you won't get as good as those picture examples you posted No.s 1 & 7 were taken at about f2'ish.<br>The bad news is there is no cheap alternative in portrait length lenses.I have a nikkor 105/2.5AIS i use on various EOS bodies with a simple adapter but the elan 7e is one of the very few eos models that won't meter right without an electronicly connected lens.You can still do it-but you will have to learn the exposure habits of the camera with a non connected lens,(it'll underexpose 2 stops or somesuch thing).If you do go that route it is easy to buy both nikkor to eos and M42 screw mount to eos adapters on ebay.The only other alternative is to buy a real EF portrait length lens-there are various models in the 85-135mm length

[ron c sunshine coast,qld,a]

Craig's idea is a good one!

[gene_austin]

My 10D just arrived and I tested it out yesterday with my recently purchased Tokina

28-70 2.8. I wanted to check out the location that will be used for outdoor

formals at a wedding I'm shooting in two weeks where the ceremony starts at 6pm.

Due to the anticipated shooting time of 7pm or later, I was concerned about having

enough light to properly expose the background and I also wanted to check DOF with

the new lens/camera combo. Up until now my main lens has been a Tamron 28-

300 4.5 and I needed a faster, sharper glass. I was pleased to see that I can shoot up

until 9pm (w tripod) if need be and still have enough light. However,

in some cases the background blurring at 70mm even at f2.8 was less than I'd

expected. I was wondering if the focal length multiplier effect also impacts DOF, in

other words, is my camera truly reacting as if i were shooting at the effective focal

length of 112mm or at the native 70mm?

[ron c sunshine coast,qld,a]

Gene,because you have to move back further to get the same framing as film,then DOF will indeed increase(unfortunately for you).There are formulas to work out how much but i think i'll leave that to others.

If you want a very rough estimate it is something like losing 2/3,s of a stop,so for the same framing as 35mm, your 10D with lens @f2.8 would have the DOF of an f3.5 lens.That doesn't take into account any extra enlargement effect which could gain a little back

[ken_schroeder]

Let's not forget that having the background unsharp is not the only way to make portraits. In "environmental portaiture" the background (and foreground) are often inportant informational elements. The artistic choice is how much to isolate the subject from the background or include the background. Yes, there are times when shallow depth of field creates a pleasing soft effect. There are also times when one might want to use the camera on tripod and shoot at f16.

 

Those who may have read my earlier resonses realize I am not a zoom person. I would use the lens you have until you can comfortably afford another lens. My personal favorite lens is my old Nikon 85mm f2 AI. I find the 105 a bit long, but I don't do tight portraits. In our age of one lens does all from very wide to very long, I find a single length simple lens refreshing. There are many fine lenses in the 105ish length available. I disagree that all are expensive. The Nikon 100E is an example of a real bargain. It's a first-rate lens available for around $60. It is very lightweight and compact.

 

I think you would find the simplicity of a manual focus one focal length lens conducive to your work.

[yakim_peled1]

My 28-105/3.5-4.5 USM was quite soft when used wide open so I stopped it down to f/8. And there, DOF was too wide for my taste.

 

Remedy #1: Tamron 28-105/2.8 at f/4. Still not enough.

 

Remedy #2: Canon 85/1.8 and 200/2.8 wide open. Will be getting them in about a week. Should be tack sharp wide open and with VERY shallow DOF.

 

Happy shooting ,

Yakim.

[peter_kim2]

Thank you all for your helpful insights. Well I guess I will stick with my 28-105 for now and get the 50mm when I get a chance. But in reading around I have noticed something. Is it true that the dof decreases as the focal length gets longer? so a 50mm at f/4 will have a bigger dof then a 100mm at the same apreture? In spite of the warning above:) I checked out a hyperfocal calculator and the dof for 105mm at f/4 was actually pretty shallow. Soemthing like 2 feet I think.