I've been trying to take some self-portraits, but I often have to struggle with the auto/manual focus. I don't miss by a lot, but I really want sharp focus in the eyes. I'm using a 50mm/1.8 around 2/2.2. What are some good techniques to get the camera properly focused when dealing with narrow DoFs?
Having taken quite a few self portraits lately, I'd recommend the following...
- If you're trying for a shallow DoF to blur out the background, increase your aperture to 2.8-3.2 and move further from your background - it'll be it alot easier to nail the focus on your whole face.
- If you have a face detection in Live Mode, try that.
- Try setting just the center focus point on the camera and line up on that.
- Make a mark where you're going to stand, pick an object you're always going to point your body towards. Pick another object you're going to point your head towards, and then look at the camera. Its probably going to take a few tries, so you want to be as consistent as possible.
Firstly you need a long enough cable release so that you can activate autofocus whilst seated in your final position (focussing on a surrogate object is not accurate enough with this aperture), without having to stretch out an arm as this will make it difficult to remain still.
Using a bit of trial and error you need to select a focus point that will cover your eye (or whatever you want in focus) having the camera display the focus point on the rear LCD image is good for this. Use your reflection in the lens front element to make sure your head is in the same place each time when finding the right AF point to select.
Finally, persevere as this type of shot is very difficult!
As I have had minimal experience with portraiture myself, and only taking photos of subjects while I am behind the camera, you can take this with the appropriate grain of salt. ;) An off the cuff idea, however, might be to print out a sheet of paper with a scale on it. Perhaps just an inch or centimeter scale with fractional divisions (inches) or millimeters. A 2D scale that covers both dimensions of the page would be best. (If you can throw in a light graph across the whole page that matches your inch or cm marks, that would be ideal.)
Hang this paper on a string or attach it to a small stand, about where you want your head to be. Angle it 45 degrees across the plane of focus. Now you have a specific target to set your focus against. Adjust focus, set the correct aperture, and preview your DOF if your camera allows. Try to keep the middle point of your DOF (the focal plane) centered at the center point on your paper scale. Once your camera is set, it should be simple enough to sit down and position your face right next to the paper (without bumping it). I would try to line up your eyes with the center point of the paper. Once you are situated appropriately, take down the paper, and use a wireless remote shutter release to take your shot.
I would try the following...
- Use manual focus
- stand on a mark
- shoot, check focus and reshoot
Also, try a smaller aperture - at f/2 the DOF really is very small indeed (as, I guess, you are finding out).
Try placing some tall object, i.e. a lamp, where you plan on standing/sitting. Then, focus on the object, move to your planned position and take the picture. Be sure to have your eye pretty much exactly where the object was.