Shooting wide open

[elordi]

My question is about shooting wide open, when I shoot portraits with my 50mm 1.8 wide open or even at 2 or 3 I am only getting one eye or parts of the face in focus and the rest are very soft. Why? How do people shoot wide open like that and still get good sharp portraits with the entire face in focus, mine are always only parts never the entire face. I dont feel like it is the shutter speed I usually keep it above 125, so what am I doing wrong? Help?

[Digidave]

This is where Depth-of-Field(DoF) comes in. At wide apertures(smaller f/number) you have a very small DoF. You need to stop down your aperture to f/5.6 at the very least. It does depend on how close you are to the subject also.

Here is a self-portrait I took a few years back. The lens was about 4 to 5 feet away. Taken at f/4 with my 50mm f/1.4 lens. Notice the diamond stud is out of focus.



Here is a D0F calculator

http://www.dofmaster.com/dofjs.html

[elordi]

Thank you for your reply I appreciate it, and I am still a little lost. I understand DOF and what you said totally makes sense I dont shoot usually below f/5.6 but I have heard many who do shoot wide open with their 50mm or the 85mm, am I just mistaken and they want their photos soft?

[dakwegmo]

Depth of field is also determined by distance to the subject. If you're using a 50 mm at f/1.8 on a crop sensor body, your depth of field at 5 feet is going to be about 6cm (less than 2.5"). Take two steps back, so you're 10 feet away and your depth of field increases to about 24cm (or nearly 10"). So it is possible to get the whole face sharp at f/1.8 you just have to be further away.

Here's a great calculator to help you see how aperture, focal length, and distance from subject affect your depth of field: Online Depth of Field Calculator

[Elmo]

A face totally in focus when shot wide open is not true only an illusion. note the image above you likely would not have noticed the studs being out of focus if not pointed out.

Generally the eyes should be tack sharp everything else can fade away

[SusanH1970]

It took me a long time to finally understand DOF (using the calculator posted above). What an "a-ha" moment when I finally figured it out! It is more difficult to get both eyes in focus if they're not on the same plane, though. When I get the 85mm 1.8 I suppose it'll be that much more of a learning curve for me, since I'm so used to using my 50mm.

Here's a shot from when I finally figured it out. 50mm, f/1.8, ISO 100, 1/320.