Hyperfocal or Point in distance

[candleman]

my question is..
how many of you use the Hyperfocal technique, versus using the method of simply focusing on an object of interest in the distance.

from my basic knowlege of the Hyperfocal technique.. this is only useful up to particular print sizes as it allows for an "acceptable" focus.

the "point in the distance" method would generally be easier, BUT throw things in the foreground out of focus more than a hyperfocal focus would... but at least you get all print sizes available.

please correct my understanding if i'm wrong,
but,

which do you use and why?

[Nicole]

I bet I know why you asked this. The Andris Apse interview

I don't get hyperfocal distance. I focus on something in the distance. Simple as that. Sometimes getting too caught up in the technical stuff takes the fun out of it for me.

[candleman]

Originally Posted by Nicole

I bet I know why you asked this. The Andris Apse interview

I don't get hyperfocal distance. I focus on something in the distance. Simple as that. Sometimes getting too caught up in the technical stuff takes the fun out of it for me.

who? i have no idea what you're talking about sorry..

kidding
LOLOL
damn you're good!

[kencaleno]

That's true hyperfocal distanceas per my chart,is accurate until you go bigger than 11"x14", and for any distance over 30 feet(10 meters) just focus on a point 1/3 into the distance-(Lower 1/3 horizontal on imagined rule of trirds matrix)

[OsmosisStudios]

I've only used it a few times: I usually have an object in the foreground that gets focused on and just use a small aperture.

And Ken, print size has nothing to do with focal distance. Focus is focus is focus, regardless of how big you print things.

[kencaleno]

Originally Posted by OsmosisStudios

I've only used it a few times: I usually have an object in the foreground that gets focused on and just use a small aperture.

And Ken, print size has nothing to do with focal distance. Focus is focus is focus, regardless of how big you print things.

Print size has nothing to do with focal distance ,but it does have to do with Hyperfocal distance-when these maths were originally worked out the most common commercial sized print was 11"x 14",and everything was established up to this size-If you search the web you will find a better explanation of this, but it is a fact.Ken- OOOOH!, by the way,Osmosis, I have a favour to ask-I have just finished working on a simplified guide for beginner photographers,who only have an entry-level dslr,and an 18-55 kit lens. I need an unbiased opinion on this,and I know if anyone will try to find fault with anything I write-you will, It's 9 pages long so I will need to e-mail it to you-would you mind? Ken

[kencaleno]

From JimDoty.com

DEPTH OF FIELD
FOR DIGITAL SLRs
Jim Doty, Jr.

This article is essentially the same as one that I wrote for 35mm film cameras. Most digital SLRs have an imaging sensor that is smaller than 35mm film, creating a field of view (FOV) crop (apparent angle of view) that is different when the same lens is used on a 35mm SLR as opposed to a digital SLR. The depth of field and hyperfocal distance is also different when the same lens is used on a digital SLR as compared to a 35mm SLR. The information below will work for all digital SLRs with a FOV crop of 1.5x or 1.6x. The version of this article for full frame digital SLRs, or 35mm film cameras is here .

Since there are several combinations of apertures and shutter speeds that will give the same exposure on film (see the exposure article), how does a photographer choose which combination to use in a given situation? The answer to this question is what gives photographers creative control over their images. It is the specific combination of aperture and shutter speed that a photographer chooses that determines the depth of field in the image, as well as subject motion, if any.

Depth of Field (DOF) is how much of the image from near to far looks sharp. A landscape photo in which everything looks sharp (from the flowers a few inches from the camera lens to the mountains far in the distance) is said to have a lot of DOF. A photo of a field of flowers in which just one flower looks sharp and every thing else is soft and blurry is said to have very little DOF. The wonderful thing about photography is that the photographer gets to choose how much DOF there is in the photo, subject to certain limitations.

Unfortunately, DOF can't be determined by simply looking through the camera lens. Whenever you look through the viewfinder of a single lens reflex camera, you are looking through the lens, BUT you are looking through the lens at its widest aperture. If you take the picture with the camera set at a smaller aperture, the DOF will be different than what you see looking through the lens.

The exception to this is if you have a DOF Preview button on your camera. A "Depth of Field Preview Button" is one of the most valuable features a camera can have. Some inexpensive cameras have DOF Preview, and some expensive ones do not. The next time you purchase a camera body, you should consider getting one that has DOF Preview.

By pushing the DOF Preview button when looking through your camera lens, THE LENS STOPS DOWN TO THE TAKING APERTURE so you can see the final look of your photograph. Because the lens is stopped down when you check DOF, what you see through the viewfinder will look pretty dark. Some photographers put a dark cloth or jacket over their head and the camera when shooting outside in order to see the dark image though the viewfinder a little better. Yes, this looks just like large format photographers under a dark cloth while looking at the ground glass on the back of their camera.

What creates depth of field? A point of light that is properly focused on the digital sensor (or film plane) becomes a point of light on the sensor. If the point of light is not focused on the sensor, it will create a circle on the sensor/film, called a "circle of confusion". The more out of focus the point of light is on the sensor, the bigger the circle of confusion. Most human eyes can't distinguish between a point and a circle that is smaller than 1/100 inch. As long as the circle of confusion on the sensor/film is not enlarged beyond 1/100 inch on the final print, it appears to be in focus. This is what makes DOF possible. An image captured on film or a digital sensor is made up of lots of points of light on the sensor/film. Even though the camera lens is only focused on one plane at a certain distance from the lens, if the other points of light form small enough circles of confusion on sensor/film, they will appear sharp to the human eye when a print is created.

DOF is a function of how much those points of light are magnified or enlarged when the circles of confusion are enlarged on the final print. That is why the same image may appear to have enough depth of field on an 8x10 enlargement but not on a 16x20 enlargement. The more the circles of confusion are magnified, the less depth of field there appears to be in the final print.
Practically speaking, there are three things photographers can do "in the field" to control DOF.

1) With the same lens at the same focused distance, DOF INCREASES WITH SMALLER LENS APERTURES. F/8 has more depth of field than f/4. F/16 has more DOF than f/8.

2) With the same lens and the same aperture, DOF INCREASES AS THE FOCUSED DISTANCE INCREASES. If you are four feet from the subject your lens is focused on, you will have more DOF than if you are 2 feet from the subject your lens is focused on. If you back up to 8 feet from the focused subject, you will have more DOF than if you are 4 feet from the focused subject.

3) With the same focused distance and the same aperture, SHORTER LENS FOCAL LENGTHS HAVE MORE DOF THAN LONGER LENS FOCAL LENGTHS. If you have three lenses (24mm, 50mm, and 100mm), all set at f/8 and all focused on a subject 10 feet away, the 24 mm lens will have the most DOF and the 100 mm lens will have the least. The 50 mm lens will have more than the 100 mm but less than the 24 mm.

If you want to increase DOF, use a small lens aperture, use a wider angle lens, or get farther away from the focused subject, or a combination of all three. To minimize DOF, use a longer focal length lens, use a wider lens aperture, or get closer to your subject, or a combination of all three.

With the exception of close-up or macro photography, you have more depth of field behind the point of focus than in front of the point of focus.

HYPERFOCAL DISTANCE

One very handy way to achieve a lot of depth of field for landscape photos, even if your camera does not have a depth of field preview button, is to use the hyperfocal distance for the lens and aperture in use.

With a given lens and a given aperture, the HYPERFOCAL DISTANCE IS THE FOCUSED DISTANCE THAT WILL KEEP EVERYTHING LOOKING SHARP FROM HALF THE HYPERFOCAL DISTANCE TO INFINITY. It gives you the maximum amount of depth of field you can achieve with that lens at that aperture.

DOF and print size.

DOF also depends on how large a print you make from your original slide or negative. The bigger the print you make, the less DOF you have since you are making the circles of confusion bigger. The DOF scale on many lenses will give you good DOF for enlargements up to 8x12 inches when used on 35mm film cameras of cameras with full frame digital sensors (24 x 36mm). If you want to make bigger enlargements, set your lens for one or two apertures smaller than the lens scale indicates. This will give you some extra depth of field. If the lens scale says you will have adequate DOF at f/8, set the infinity mark opposite f/8 on your depth of field scale just as if you were going to use f/8, BUT turn the aperture ring to f11 if you want a bigger enlargement. The depth of field scales on lenses originally designed for 35mm film cameras are not accurate for use on digital cameras with a 1.5x or 1.6x filed of view crop. (You know from the exposure article at this site that any time you change the lens aperture, you will need to adjust the shutter speed to have the right exposure).

Hyperfocal Formula

You can figure out the depth of field mathematically, design your own depth of field chart, or use the one I provide at this site.

The hyperfocal distance is a mathematical calculation based on the film or digital sensor size, lens focal length, f-stop and desired enlargement size. More information on this formula can be found in Roger Hicks article in SHUTTERBUG, February 1993, pages 42-49. This formula will work with all formats but the values for C change for each format size.

Calculating the Hyperfocal Distance.

For the mathematically inclined the formula is as follows:

HM = ((F*F)/(C*N))/1000
HM*3.2808 = HF

HM = hyperfocal distance in meters
HF = hyperfocal distance in feet
F = focal length of the lens in mm
N = lens aperture
C = circle of confusion on film or sensor in mm.

Use the value given for C for a print of the following sizes:
For an 8x10 print, C = .0189
For an 11x14 print, C = .0137
For an 16x20 print, C = .0094

The values for "C" are calculated for a 15.1mm by 22.7mm digital sensor like the ones used in the Canon 10D, 20D, and Digital Rebel cameras. These cameras have a field of view (FOV) crop of 1.6x. The formula above is close enough to work for any digital camera (including most Nikon D-SLRs) with a 1.5x or 1.6x FOV crop.

For "full frame" digital sensors like those in the Canon 1Ds and 1Ds Mark II, use the 35mm film depth of field formula and the 35mm film hyperfocal distance chart.

Using the Formula

Example: For an 11x14 enlargement (C = .0137), from a photo taken with a 50 mm lens and the aperture set at f/8:

HM = ((50*50)/(0.0137*8))/1000
HM = (2500/0.1096)/1000
HM = 22831/1000 = 22.831 meters

HF = HM*3.2808
HF = 22.831*3.2808 = 74.9 feet



Using the above formula, you can design your own chart

Regards, Ken

[rpcrowe]

That was a comprehensive and excellent explanation of DOF and hyper-focal distance.

There are three general ways that I will focus:

1. Focus on the subject... when the specific subject is the most important portion of the image. This is very important when you are using shallow depth of field to isolate your subject: i.e.: having the foreground and most importantly the background blurred out of focus to either bring attention to your subject or eliminate a busy and/or distracting background. (See image of dragonfly) BTW: often the angle of view or positioning of the subject will help you keep that subject in focus. If I had shot the dragonfly head-on, there is no way that I could have kept the entire insect in focus. This is O.K. when you desire just a head shot but, annoying if you desire to show the entire insect. Using a side view, I did not require as deep a depth of field as I would have head-on.

Additionally, you can often blur annoying foreground distractions such as when you are shooting at a zoo through a mesh cage. Using a longer focal length and a wide f/stop and focusing on the animals eyes will often prevent the mesh from being a distraction. Just make sure that your camera is focusing on the animal, not the mesh. (See image of Cheetah cub). I shot this using Aperture Priority exposure with my 70-200mm f/4L IS lens at f/4. If you look closely, you can see evidence of the out-of-focus mesh on the back wall and on the foreground. This is however, IMO, far less annoying than seeing an in-focus mesh barrier between you and your subject. It can, if you desire, be easily corrected using a photo editing program.

In images of people or animals; the eyes are the most important point of focus. As a quick aside; when shooting individual or team sports - I will most often shoot from a low angle and select the top focus point in my camera. That way, the heads or eyes will be the primary point of auto-focus.

2. Focus for best over all depth of field: I use a relatively small f/stop. However, don't like to shoot below f/11 - or at the absolute minimum f/16; because diffraction will degrade the sharpness of the image.

http://scubageek.com/articles/diffraction.pdf

I will also generally focus 1/3 into the important portion of my image. Depth of field is greater to the rear of the point focused on than it is to the front.

Canon includes an A-DEP mode on their xxD DSLR cameras (I don't know about other models or makers). This is supposed to select a focus point which will give the widest depth of field or keep the major portions of your image in focus. I don't use any of the camera controlled shooting modes because I like to control my own imagery.

3. Finally Using Hyper focal Distance: This is an excellent way to shoot quickly in manual focus. It is especially good for grab shots in the dark - especially outdoors when your autofocus will not work.

Set your manual focus at the hyperfocal distance and you will be in focus from 1/2 that distance to infinity.

Naturally, this requires a lens with a focus scale. Manufacturers, aiming for lower prices, have eliminated focus scales from many autofocus lenses. The Canon 50mm f/1.8 Mark-II is an example. The original Mark-I model had a focus scale but, it was removed from the Mark-II model.

Older manual focus lenses often had a scale which included two sets of f/stops engraved, one set to either side of the focus point. That was a quick and dirty way to determine what your depth of field was. You would be in focus from the f/stop you are using on one side of the focus point to the f/stop engraved on the other side. This was a wonderful way to achieve quick focus in the days before auto-focus cameras.

[kencaleno]

Originally Posted by rpcrowe

That was a comprehensive and excellent explanation of DOF and hyper-focal distance.

There are three general ways that I will focus:

1. Focus on the subject... when the specific subject is the most important portion of the image. This is very important when you are using shallow depth of field to isolate your subject: i.e.: having the foreground and most importantly the background blurred out of focus to either bring attention to your subject or eliminate a busy and/or distracting background. (See image of dragonfly) BTW: often the angle of view or positioning of the subject will help you keep that subject in focus. If I had shot the dragonfly head-on, there is no way that I could have kept the entire insect in focus. This is O.K. when you desire just a head shot but, annoying if you desire to show the entire insect. Using a side view, I did not require as deep a depth of field as I would have head-on.

Additionally, you can often blur annoying foreground distractions such as when you are shooting at a zoo through a mesh cage. Using a longer focal length and a wide f/stop and focusing on the animals eyes will often prevent the mesh from being a distraction. Just make sure that your camera is focusing on the animal, not the mesh. (See image of Cheetah cub). I shot this using Aperture Priority exposure with my 70-200mm f/4L IS lens at f/4. If you look closely, you can see evidence of the out-of-focus mesh on the back wall and on the foreground. This is however, IMO, far less annoying than seeing an in-focus mesh barrier between you and your subject. It can, if you desire, be easily corrected using a photo editing program.

In images of people or animals; the eyes are the most important point of focus. As a quick aside; when shooting individual or team sports - I will most often shoot from a low angle and select the top focus point in my camera. That way, the heads or eyes will be the primary point of auto-focus.

2. Focus for best over all depth of field: I use a relatively small f/stop. However, don't like to shoot below f/11 - or at the absolute minimum f/16; because diffraction will degrade the sharpness of the image.

http://scubageek.com/articles/diffraction.pdf

I will also generally focus 1/3 into the important portion of my image. Depth of field is greater to the rear of the point focused on than it is to the front.

Canon includes an A-DEP mode on their xxD DSLR cameras (I don't know about other models or makers). This is supposed to select a focus point which will give the widest depth of field or keep the major portions of your image in focus. I don't use any of the camera controlled shooting modes because I like to control my own imagery.

3. Finally Using Hyper focal Distance: This is an excellent way to shoot quickly in manual focus. It is especially good for grab shots in the dark - especially outdoors when your autofocus will not work.

Set your manual focus at the hyperfocal distance and you will be in focus from 1/2 that distance to infinity.

Naturally, this requires a lens with a focus scale. Manufacturers, aiming for lower prices, have eliminated focus scales from many autofocus lenses. The Canon 50mm f/1.8 Mark-II is an example. The original Mark-I model had a focus scale but, it was removed from the Mark-II model.

Older manual focus lenses often had a scale which included two sets of f/stops engraved, one set to either side of the focus point. That was a quick and dirty way to determine what your depth of field was. You would be in focus from the f/stop you are using on one side of the focus point to the f/stop engraved on the other side. This was a wonderful way to achieve quick focus in the days before auto-focus cameras.

Two points:

#1. You don't need a lens with a focus scale,because you can estimate distance.


#2. When using older or FX lenses with dof scale with DX cameras, the scale is wrong by 1 stop, so set your infinity mark to the the next larger stop, eg: F8, instead of F11.

Ken

[sybren]

I use both, depending on the situation. Mostly I focus on my subject's eyes, but with landscapes I sometimes use the hyperfocal distance.