Hyperfocal distance and wedding photography

This question is specific for Bob Atkins, and anyone else who has

more technical knoledge for obtaining "sharp" images. I just

finished reading Mr. Atkins articles on HFD (<a

href="http://www.bobatkins.com/photography/technical/doftable.html">ar

ticle</a> and I'm still wondering how concerned should a wedding

photographer be about this issue? With spot meters and flash meters

so common, don't these little devices make HFD a non-issue for

obtaining the sharpest image possible?

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Also, what is "circle of confusion" and why is it measured in microns?

Your flash will stop motion blur, but you can still worry about what's going to be in focus in your image. That's what the HFD is about.

 

The circle of confusion is the allowed "blur distance", or a kind of resolution, on the negative, once you've defined your print size and viewing distance. Has to do with how much fuzziness is allowed on the negative before you can actually see it on the print from whereever you decide the viewing distance is.

 

It's measured in microns because, it's, well, small. You could always convert it into a dpi value, I suppose.

I would suggest you get a basic book on photography,or study the online info here at photo.net.Hyperfocal distances relate to optics and have nothing to do with light meters or wedding photography specifically.Wedding photographers will commonly "rack focus" to maximize the available DOF for a given F stop,but since infinity isnt always (or often) included,this isnt HFD."Circles of confusion" are discs of light on the image,formed by the lens from points of light in the subject.The smaller these discs are in the image the sharper it appears.When these reach a size that they can be seen as discs,and not points,the image is considered to be unsharp.

What some photographers do, as I do, is to "Zone Focus". At weddings, some planning

may be used before a shot is taken. The camera is focused at a distance of, say 5 ft in

order to give the photographer a usable "zone" in which to take a quick picture. Naturally,

the photographer may have to move closer to be at this 5 ft distance, but this can be

accomplished without thinking while the photographer concentrates on the scene and

expressions of the people.

 

If the photographer uses alot of flash power, he can rely upon this method. Alot of flash

power is 50-200ws or more. This is not a method for a user of small hotshoe flash

equipment when the film is ASA 100.

 

"Circle of Confusion" is the output of the lens. The lens makes dots, like you see in

newspaper photos. The photographic picture is really thousands and millions of dots.

 

The reason they call it "Confusion" is because when these dots are focused on the paper,

there is an image to look at. When these dots are not focused, there is "Confusion" in the

viewer's mind as to what the image is. This "Confusion" is the blurred image.

 

The reason that the image becomes "blurred" is because the dots become larger as they

become "out of focus". When they become larger, they overlap more. When they overlap

more, the effect is smoothness or bluriness.

 

To have a "depth of field", the dots must have a range of smallness. At some point, when

the lens is focused, the dots become too large to look "in focus" and at this point is the

limit of the "depth of field".

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The lens on the left has been set on f22 and focused to infinity. Everything is in "acceptable" focus from 18 feet to infinity. On the lens on the right, the infinity mark has been moved above the 22 on the right and and 9 feet falls above the 22 on the left. Everything is in acceptable focus from 9 feet to infinity. The hyperfocal distance is 18 and falls at 18 on the lens pointer. If you know how to use the distance scales, you don´t have to go squinting through the viewfinder in dim light trying to focus or you can use it as a check. On the lens on the right, at f16, everything is in acceptable focus from 10 feet to 50 feet, read above the 16s on both the left and right side of the lens.

I don't think that you should concern yourself with this issue when

photographing a wedding unless you are using a manual focused lens and

must shoot fast at times and have as much dof as possible. The point is to

make sure the bride, goom and standups are perfectly focused and a dof

preview gets this done if need be. SInce many are now shooting auto focused

cameras, hfd has become an unknown practice by many. Practice on a roll

out shooting street scenes and become knowledgeable before possibly

applying it for a wedding.

Circle of confusion represents the largest circles formed by a lens of points that are not in focus that appear to be in focus at a agiven maginfication.

Another little thing to remember is this: If you cannot be perfectly in focus, try to be

focused on something alittle bit in front of your subject. So, if the subject is exactly 7 feet

away, be focused at 6.8 feet. You will attain more overall "in focus" look for your

subject.

 

In otherwords, if you can't be perfect, focus on something alittle short of the subject. If it

is the Bride running out of the church, you could focus on her bouquet. Sure, it would be

great to focus on her eyes, but if you know you can't do this due to the speed and

movement issues, focus alittle closer than her eyes as an alternative.

Thanks everyone for your wonderful responses...

 

Timber, you said "Alot of flash power is 50-200ws or more." This might be getting off of the subject, but I'm wondering how big of a mono-light should I used for formal portraits? Many wedding books I read are using several 1K or better. Is there a rule of thumb for how many watts I should choose for a mono light that I use to flash sync for formal portraits? So I have the choice between a 400W, 800W, 1200W or more.... I'm not sure which one I need.

Steven, there are people that do their formal portraits in a studio before the

wedding, so if asking about flash power you can obviously see that it can be

different for a studio than if shot at the church. What you want to know is the

power of the light at various distances when used on full power and what the

the diffusion subtracts, and where that puts you for an aperture. Also realize

that you get a softer light which is more wrap around when it is close and

diffused.

 

I have to date not seen one photographer that used monolights at a wedding.

This does not mean that it is not used, but that there are other ways to go. The

best I've seen yet is where the photographer (using mf with a flash on it) had

two assistants off to the side holding adjustable light poles with flashes at the

top with slaves and battery pack powered. He directed them to be out of line

of sight but as close as possible. This worked really nice and obviously

spread a wide flash of light.

I need a battery powered unit for formal portraits in church and outdoors. (portability) The Hensel set up looks nice, and has a lot of output. I won't have any assistants for either of the two weddings this spring, so i will use a stand and a PocketWizard to flash sync with my camera. I am undecided, but I will also use a softbox or a reflector for the lighting. So the wattage of light I use idealy works the same indoors and out. So I also need to choose which power of lighting will work best.

 

Thanks all for your input!

IF you're going to be using a softbox for group formals, you'll need more power than if you will be using the heads without modifiers. Also, if you don't have assistants, working with multiple lights (more than one off camera flash) or stands with reflectors is going to eat up too much time--time one normally doesn't have at a wedding. Softboxes and reflectors outdoors without assistants are iffy because of the wind. Any breeze and your expensive flash gets knocked over. I happen to use a Norman 200B both indoors and outdoors, sometimes bare head and sometimes with an umbrella (inside). Sometimes I use the wide angle diffused dome head. Using 400 speed film, it has more than enough power to light groups (bare head) and full length individual or small group shots with an umbrella at f stops like f8. It has almost too much power for outdoors. If you need more power, there are units that run on battery power up to 400 or 800 watt seconds--like Lumedyne, Norman, and Quantum. Monolights tend to be top heavy and are more prone to tip-over. You should check out another thread in the Lighting Forum about flash at weddings, where lots of different flashes are discussed.

Steven:

 

Some of these "lighting up the church at the altar" are discussed here:

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=007a4u

 

I give about 3 ways to approach the matter using umbrella, bounce light, big packs, etc.

 

What you should start with is assembling a few Norman 200b units. You can use them

indoors or out. I like Norman 200b more than Lumedyne, and you can search for Norman

200b on photo.net to find my opinions on them in comparison. Try "Norman 200b

Lumedyne timber" in www.google.com for starters.

 

If you had 2-4 of these, you would be very well off. You can simply bounce them off of

light discs or white flats such as foam core in the church. Of course, they have a Norman

softbox that is 19" round that looks good. You need solutions that can be set-up FAST. I

just purchased another Norman 200b for $135 on the auctions. It is practically new. I

own 7 of them now.

 

What you want is to proceduce a f8 at the altar for any picture. Sure an f6.3 will work fine.

But let's target for high quality. Having said this, a 200ws Norman can give a f11 at 11'.

If you use a Lumedyne Normal reflector and throw away the Norman reflector, you will get

another 1/2 f stop of power. So, if you used 2 Norman 200bs at high power, you would

get f11 + f11 = f16. F16 is more than you need. But you will want softness. So, when

you direct the light into a white umbrella or softbox, you lose 2 f stops. Now that pretty

big f16 becomes an f8. So, using 2 Norman 200b's into an umbrella we have an f8 if the

lights are 11' from the person.

 

Now, if you want to use a floor pack, you should go to the reference above. However, I say

to use alot of power to achieve more perfection. You could do less and do it well with a

1200ws pack from Speedotron. It doesn't matter whether it is a Blackline or Brownline for

your purposes. This extra power, 1200ws, will allow you to do groups at a fair distance.

I have seen such packs go for about $250 on auctions. I bought one for $175 in near new

condition.

 

The pack is also great because it may have 250 watt modeling lights. This helps you see

to focus!

 

So, the ideal to me, is to have both a few Norman 200b's and at least 1 floor pack. Mono

lights are optional. I have monolights, too. But they are $800 apiece! For now, i think

you should go for the 1200ws pack in a Speedotron. If you wind up with a 2400ws pack

like a 2401 Speedotron which is many years old for $400, fine. The idea here is that you

have some serious power available, but not spend $2,000 to get it.

 

You need power to use bounce light and umbrellas and softboxes to get that f8. Nobody

will get angry if you don't. It is not a requirement in wedding photography!

 

And pick up a nice Minolta flashmeter, too.

Search on www.google.com for "lightingatthealtar" No spaces. Just copy it.

Search for:

 

"Norman 200b photo.net"

 

You will receive about 60 places to look.