Taking portraits

[Toanaldino]

Hi there, I just need some advise. I'm using a Canon 400D + EF 50mm f1.4.

I notice when I take portraits, sometimes a body part out of focus. I know F stopping down sometimes solves the issue to an extend.

Which F stop should I use to make the whole body in focus and yet have bokeh.

 

[SpeedTrap]

It Depends how far you are from your subject and how far your subject is from the packdrop. Start at F8 and play

 

[Garbz]

bokeh is not only a function of aperture but also the ratio of subject to camera and subject to background.

Put a person up against the wall and photograph from across the room and the wall will be sharp at most apertures. Get a macro up close of the eye and the wall even though only a few cm behind and with the same focal length will be a blurry mess. On the same token if you simply move the subject away from the wall you retain the bokeh.

So what you need to do is select an aperture to adequately render your subject in focus and move him/her/it far enough from the background to create a bokeh effect.

 

[Toanaldino]

Thanks for the input guys, I will keep that in mind next time.

 

[Neuner]

When I take portraits and use my 50mm I have it set to f4 and set the subjects about 5-6 feet from the back drop. They are completely in focus and the back drop is slightly blurred. Focus on the eyes.

I've tried 2.8 with close ups and full body and I haven't gotten all of them in focus. If you want more blur, use f4 and bring them out from the back drop more.

 

[JerryPH]

When I take portraits and use my 50mm I have it set to f4 and set the subjects about 5-6 feet from the back drop. They are completely in focus and the back drop is slightly blurred. Focus on the eyes.

I've tried 2.8 with close ups and full body and I haven't gotten all of them in focus. If you want more blur, use f4 and bring them out from the back drop more.

That will not mean very much, as you are missing one very important part of the equation... the distance YOU are from the subject.

If you do not change anything on the camera and keep the subject the same distance from the backdrop, but *you* move further away from the subject, you get increased DOF. If you move closer to your subject, you get a shallower DOF, even if you change nothing on the camera. The reason is the change in ratio between distance from you to the subject and the distance from the subject to the backdrop.

Its all in the ratio of:
- F-stop used
- distance from you to the camera
- the distance of the subject to whatever is behind it that you want to blur (backdrop or whatever).

And more bokeh (background blur) happens when you use a NUMERICALLY SMALLER aperture, not a numerically larger one. F/2.8 will always "blur" more than a F/4 in any given case where all other things are the same, not the other way around as you state.


This is a picture at F/8... note how clear the tree is in the background:

This is a picture at F/1.4 (known as a WIDER aperture). Note the blurred background:

 

[Neuner]

That will not mean very much, as you are missing one verybimportant part of the equation... the distance YOU are from the subject.

You are correct, and what I should have included along with the fact that I'm using a 50mm lens is the distances I provided were for a full body shot. If I do a bust shot or full body of my 3 year old with them 5-6 feet from the back drop I get a lot of background blur.

Sorry I did not include this info.