finding the right focus point

[amayax]

Often on my live viewer screen on my 100D I feel like the focus is right (doing it manual), but then when viewing it on the big screen of my computer, I notice it is just too far back or too close, basically ruining what else could be a good shot.

Now, I want to do more people photography, with a focus good on the eyes. How do you do the focus there? automatic focus or do you have a trick to do it in manual?

 

[photo1x1.com]

I just googled - on page 105 of your manual you find instructions how to select an AF-Point. If I remember right the middle one is the strongest (crossfocus).
When shooting portraits with cameras that have better focus point in the middle, I usually

1. focus (holding down the shutter button slightly)
2. keep the finger on the button to hold the focus
3. reframe to not havy my model in the middle
4. fully release the shutter to take the image

Manual focussing with cameras like that is pretty hard. It is much easier with cameras that have really big sensors (like medium format). So in your case I´d stick with Auto fFocus and select a single AF-Point.

 

[table1349]

The Problem With The Focus-Recompose Method
Photo Technique #006 @Digital Outback Photo

Unless you are shooting at an aperture smaller than f5.6, select the point you want that is closest to the area you want most in focus.

This will answer a lot of your questions about various Canon auto focus capabilities.

 

[Destin]

The first problem is that it sounds like you're using live view and manual focus for people photography.

With modern DSLR cameras your best bet is to look through the viewfinder and use autofocus to choose an appropriate point. Detail on doing so can be found in the previous replies and your manual.

 

[photo1x1.com]

The Problem With The Focus-Recompose Method
Photo Technique #006 @Digital Outback Photo

Unless you are shooting at an aperture smaller than f5.6, select the point you want that is closest to the area you want most in focus.

This will answer a lot of your questions about various Canon auto focus capabilities.

A valid counter-argument. I recommend to the OP to try it. Everybody has his own technique, and cameras are different. Before the introduction of the 5DIII I have had way more out of focus shots due to using other focus points than the middle than I had with the recompose method.

 

[Derrel]

One of the biggest issues is using too wide of a lens aperture at close distances! If you are close enough for the eyes to be a major, large-sized part of a picture, then there needs to be enough depth of field to render them sharply. It's simple: when in-close, stop the lens down to f/5.6 to f/11, somewhere in that region,and magically your photos will have sharp eyes, and probably a sharp nose as well.

Most of the time, beginners misunderstand that at CLOSE distances, smaller apertures, like f/5.6, f/6.3, f/7.1, or f/8, will give great results on a close-in face AND the background will also be adequately out of focus and blurred; shooting at f/1.8 to f/2.8 is not usually a good idea at distances where a face is close-up, and where missed focus will be noticeable or distracting. Again, when you have the camera close enough for the eyes to be a major part of a picture, it makes sense to render them sharply, otherwise the picture will be spoiled, so stop the lens down to an appropriate f/stop for the kind of photo you want to end up with.

When you shoot close-in, and the depth of field band of the lens and f/stop in use is so narrow that focus is critical, the easiest thing to do is to work with a 4 to 5 inch deep DOF band, and that means stopping the lens down a bit. The closer the camera is to the subject, the more error there is in the center-focus-and-recompose method; as distances grow a bit longer, focus and recompose becomes more useful, and less prone to focus errors. One basic issue is shooting close-in, using focus-and-recompose, and then placing the eyes off-center at the top of a tall-framed image: being on a diagonal line from the center of the sensor, the distance to the eyes will be LONGER than the distance from the center of the sensor, and the focus will be off by more than the depth of field band can possibly cover. This is why focusing with an AF square that is closest to the desired focus point works so,so well at close distances!

Try focusing on the ear with the center AF bracket, and then recompose when inside of 10 feet.

 

[photo1x1.com]

I just thought a lot about why focussing and reframing worked for me and why it might not work for others. I guess it has to do with how you move the camera. I tend to rotate the camera body rather than having the center of the rotation in my shoulder or hips. So it would be logical that nothing changes in regard to focussing distance because the focus point rotates along a sphere that is drawn around the center of the camera.

In general I think it has more to do with people moving forward and back while keeping the shutter pressed than with the rotation of the camera.

Here´s a quick drawing.

 

[table1349]

I just thought a lot about why focussing and reframing worked for me and why it might not work for others. I guess it has to do with how you move the camera. I tend to rotate the camera body rather than having the center of the rotation in my shoulder or hips. So it would be logical that nothing changes in regard to focussing distance because the focus point rotates along a sphere that is drawn around the center of the camera.

In general I think it has more to do with people moving forward and back while keeping the shutter pressed than with the rotation of the camera.

Here´s a quick drawing.
View attachment 136866

Perfect example of why focus recompose doesn't work. You are making assumptions based upon a 2d drawing, not a 3D subject. You drawing is showing the point of the shoulder lining up with the eye. Anatomically that is incorrect. Posing wise if the eye and the point of the shoulder are on the same verticle axis then they will not be on the same horizontal axis meaning you will twist you body skightly for framing. With a 3d person it is very hard, without physically measuring, to tell what other parts of the body are the exact same distance from the lens to the eye.

 

[Derrel]

Here is an brief on-line article with a good illustration repre of the basic issue of using center AF point focus-recompose at typical indoor portrait distances, Photo Technique #006 @Digital Outback Photo

 

[table1349]

Here is an brief on-line article with a good illustration repre of the basic issue of using center AF point focus-recompose at typical indoor portrait distances, Photo Technique #006 @Digital Outback Photo

Beat you too it. See post #3.

The B&W photo is a perfect example of parts of the body not being in vertical alignment. His shoulders are behind the level of his eyes.

 

[photo1x1.com]

I just thought a lot about why focussing and reframing worked for me and why it might not work for others. I guess it has to do with how you move the camera. I tend to rotate the camera body rather than having the center of the rotation in my shoulder or hips. So it would be logical that nothing changes in regard to focussing distance because the focus point rotates along a sphere that is drawn around the center of the camera.

In general I think it has more to do with people moving forward and back while keeping the shutter pressed than with the rotation of the camera.

Here´s a quick drawing.
View attachment 136866

Perfect example of why focus recompose doesn't work. You are making assumptions based upon a 2d drawing, not a 3D subject. You drawing is showing the point of the shoulder lining up with the eye. Anatomically that is incorrect. Posing wise if the eye and the point of the shoulder are on the same verticle axis then they will not be on the same horizontal axis meaning you will twist you body skightly for framing. With a 3d person it is very hard, without physically measuring, to tell what other parts of the body are the exact same distance from the lens to the eye.

Thanks gryphonslair99 and Derrel. I reread the text in the Link.
The problem in my assumption isn´t 2d vs 3d because I am not focussing on the shoulder, but on the eye and then I drag down. I don´t worry if the shoulder is in focus or not. The focus point rotates along a 3d sphere, as I wrote.
But the part of the brick wall in the text was what I forgot in my assumptions. That "modern" lenses are created in a way that a plane is in focus rather than a sphere which is quite logical. So this would be the correct model. However, I have to find out why I still got better focus with focus-recompose than with using any other focus point than the center.