Crustal Clear Images - Focusing on families

[Calypso b]

Hello,

I need some advice or someone to point me in the direction of some good resources on focusing. It sounds so simple but I often have difficulty getting crystal clear images. This is especially a problem when i am photographing groups of people. When I am photographing single portraits I focus on the eyes. With groups what if the pose requires each person's eyes to be at different levels? Where should I focus? How can I get crystal clear group photos? Thank-you!

 

[Bitter Jeweler]

Deeper DoF?

 

[MWG]

Deeper DoF?

word

What kind of camera?

 

[Calypso b]

I have a 5d mark ii. I can do a higher f-stop but what about shooting groups- how can I focus on different planes?

 

[tirediron]

Please post 1-2 images which illustrate the problem.

Of course you can only focus on one point, but selecting the right point is critical. Let's assume that you're shooting a group of people ten wide and three deep and you want to use your 50mm prime at f2.8. Where should you focus? Well, using a DoF chart you can see that you have a DoF of a little more than 3' if your subjects are approximately 15' away. The DoF extends from 13' 4" to 17'. Your camera will likely focus on the front row which only gives you (about) 22" behind the point of focus, and the area in front is wasted. Now, if you instead focus on the centre row, then you can used the area that is in focus in front of the point of focus as well as that behind.

Also remember that the farther you are from the subject the greater your DoF, and that the shorter the focal length, the more DoF you will have.

 

[Derrel]

I have a 5d mark ii. I can do a higher f-stop but what about shooting groups- how can I focus on different planes?

You need a large group to be posed all at the SAME distance from the lens in order to get absolutely equal sharpness on all subjects if the depth of field is shallow. How does on achieve that equidistant positioning of all subjects? By using a long strong string fastened to the tripod head,and by arranging the subjects in a slight arc. The people at the edges of the frame must be a bit closer to the camera that you might imagine, in order to get them as sharp as the central people.

 

[KmH]

.... how can I focus on different planes?

You can't.

The camera and lens can only focus in one plane. So, you have to have a good understanding of how DOF works, and use lens focal length, lens aperture, and focal point distance to your advantage.

If you have 3 rows in a group, you focus on the middle row and make sure there is enough total DOF depth that the front and back rows are well within the DOF.

Focus sharpness immediately starts falling off in front of, and behind, the focus point. The rate focus sharpness decreases defines the depth of the DOF. The deeper the DOF the slower the rate of sharpness falloff in front of, and behind, the focus point.

Doing photography well requires a lot more technical knowledge than many appreciate.

 

[flyin-lowe]

Don't take this the wrong way. (there might not be a right way). Isn't that like an almost $3000.00 camera body? Just trying to put 2 &2 together.

 

[Studio7Four]

You need a large group to be posed all at the SAME distance from the lens in order to get absolutely equal sharpness on all subjects if the depth of field is shallow. How does on achieve that equidistant positioning of all subjects? By using a long strong string fastened to the tripod head,and by arranging the subjects in a slight arc. The people at the edges of the frame must be a bit closer to the camera that you might imagine, in order to get them as sharp as the central people.

Sorry, Derrel, but this is incorrect. Lenses are designed around the concept of a focal plane. Equal sharpness will come when all subjects are in the same plane, a plane which is parallel to the camera's image sensor (or film frame, for those who shoot film). Curving the arrangement of the subjects will bring the ones on the end out of the plane of the ones in the middle, so they will not be in the same amount of focus.

Two examples which come to mind which help illustrate this are focus-and-recompose (I've seen plenty of threads on here about that) and tilt-shift lenses. When using focus-and-recompose with a narrow DoF, you often see that the subject is not as sharp as expected. This is because as the camera is turned, so is the focal plane (it stays parallel to the image sensor). So the intended focal point is no longer on that focal plane. Similarly, one use for a tilt-shift lens is to intentionally angle the focal plane so that the portion of an image in focus is counter intuitive. Imagine keeping the optics of a tilt-shift lens horizontal but tilting the camera body. Your focal plane will now be tilted rather than vertical. If you're shooting a field of flowers, this can help get a greater distance (near to far) of the flowers in focus (you lose focus above and below the flowers, but since that's air/obscured ground, you don't see it). If you're shooting a person, you can get only a portion (say, head and torso) in focus while in-camera blurring the lower body.

 

[Hatch1921]

Have a look... will give you a visual to what you are asking...

Online Depth of Field Calculator

Hatch

 

[Calypso b]

Don't take this the wrong way. (there might not be a right way). Isn't that like an almost $3000.00 camera body? Just trying to put 2 &2 together.

Yes, this is a $3000 camera. May I ask what point you are trying to get at?

 

[Derrel]

You need a large group to be posed all at the SAME distance from the lens in order to get absolutely equal sharpness on all subjects if the depth of field is shallow. How does on achieve that equidistant positioning of all subjects? By using a long strong string fastened to the tripod head,and by arranging the subjects in a slight arc. The people at the edges of the frame must be a bit closer to the camera that you might imagine, in order to get them as sharp as the central people.

Sorry, Derrel, but this is incorrect. Lenses are designed around the concept of a focal plane. Equal sharpness will come when all subjects are in the same plane, a plane which is parallel to the camera's image sensor (or film frame, for those who shoot film). Curving the arrangement of the subjects will bring the ones on the end out of the plane of the ones in the middle, so they will not be in the same amount of focus.

Two examples which come to mind which help illustrate this are focus-and-recompose (I've seen plenty of threads on here about that) and tilt-shift lenses. When using focus-and-recompose with a narrow DoF, you often see that the subject is not as sharp as expected. This is because as the camera is turned, so is the focal plane (it stays parallel to the image sensor). So the intended focal point is no longer on that focal plane. Similarly, one use for a tilt-shift lens is to intentionally angle the focal plane so that the portion of an image in focus is counter intuitive. Imagine keeping the optics of a tilt-shift lens horizontal but tilting the camera body. Your focal plane will now be tilted rather than vertical. If you're shooting a field of flowers, this can help get a greater distance (near to far) of the flowers in focus (you lose focus above and below the flowers, but since that's air/obscured ground, you don't see it). If you're shooting a person, you can get only a portion (say, head and torso) in focus while in-camera blurring the lower body.

Sorry Rob, but the concept of focal plane involves subjects located at the same DISTANCE from the focal plane...and the subjects located at the edges of the frame are farther away than subjects located in the center of the lens's area of view. As your own example mentions, focus and recompose shows us that subjects located at the edges of the frame are FARTHER away than objects at the center of the frame. The concept of "stringing out" a group shot, and placing the subjects in a slight arc, is a pretty well-proven professional technique that has been around for over a hundred years. It is based upon the simple fact that, at around 10 feet, with a moderate wide-angle lens, the edges of the field of view will be about 6 inches FARTHER from the film plane than the central portion of the lens; when shooting with large-format cameras, such as 4x5, 5x7,or 8x10, with a wide- to normal angle of view, as were often used in order to include groups, depth of field was often so,so shallow that well-educated, fastidious photographers would "string out" especially demanding group shots. I'm not quite sure why you do not understand how this actually works...you're trying to correct my advice by offering an example that supports my own contention...

Using a focusing string is also a superb way to do self-portraits,reliably, and with super-accurate focusing time after time.

 

[SrBiscuit]

Don't take this the wrong way. (there might not be a right way). Isn't that like an almost $3000.00 camera body? Just trying to put 2 &2 together.

Yes, this is a $3000 camera. May I ask what point you are trying to get at?

i cant speak for flyin-lowe, but i think what he was getting at was that you have a pro camera but may be lacking some of the basic fundamentals of photography. but again...i can't be sure.

 

[AgentDrex]

Well, here's my opinion. There are a thousands and thousands of $20,000 cars driving around at any given point and I would venture to guess less than a quarter of the people who own them can drive professionally. Think about that.

Its an expensive camera, but will teach just as well as a cheap one. Now, if after a year of taking photos everyday, there is no improvement and a waning sense of excitement with photography, then perhaps it WAS a waste of money.

 

[Calypso b]

Don't take this the wrong way. (there might not be a right way). Isn't that like an almost $3000.00 camera body? Just trying to put 2 &2 together.

Yes, this is a $3000 camera. May I ask what point you are trying to get at?

i cant speak for flyin-lowe, but i think what he was getting at was that you have a pro camera but may be lacking some of the basic fundamentals of photography. but again...i can't be sure.

I had a feeling that was what he was alluding to. So because I have a question about focusing on different planes, I am not "qualified" to own a pro camera? Ridiculous to say the least. I owned a rebel xti for 4 years, before that I owned a 35mm Minolta film camera and that is what I learned on in my university photography courses. When I was ready for another camera, I wanted a full frame camera and so I choose the mark ii. Yes I am still learning. I probably always will be. You probably always will be as well. I hardly doubt there is anyone on this planet who knows everything there is to know about photography. The camera that I own is irrelevant. Photography is my passion and I spend some time every day learning about the craft. I don't consider my purchase a waste of money in any sense. I also don't believe that my question demonstrates a lack of knowledge in some of the basics in photography when there are experts on here arguing the answer. Your post was not productive or helpful, just a way to make someone feel bad. There are many people on here who spend there time doing that. My suggestion for you, if you are going to take the time reply to someone's thread, you may as well use your time to be helpful and not catty.