Need help with focusing issues.

[yakapo]

Canon T4i / 420EX / 18-135mm stm

Newbie here.

I few days ago, I took lots of pictures at a family gathering. Most of the time, I bounced the flash off the ceiling. Most everyone like the pics, but I didn't like them at all. When I took shots at a distance, the faces were out of focus. I usually shoot in aperture priority but... I really didn't want to mess these up so I just shot them in auto. It's possible that the aperture was wide open.

I know the camera has a face detection feature, but I don't like to shoot in the live view. Do you have to manually chose your focus points and put the red dot on an eye every time you shoot people? Is there a camera that has face detection even when shooting from the viewfinder? I'm so frustrated that I'm ready to sell everything. I realize the problem is most likely user error - but I'm frustrated. Maybe I'm asking for the impossible but I want the camera to focus on people's faces.

 

[KmH]

The camera can only focus at 1 distance from the camera, regardless what focus mode you use.
See the Index - page 368 - and all the Focusing sub-section subject pages listed there of your Canon T4i Instruction Manual.

But yes, you need to put the focus point indicator on something at that 1 distance from the camera.
We then rely on the depth-of-field (DoF) to be sufficiently deep to have other peoples faces in acceptably sharp focus. The DoF is distributed both in front of and behind the point of focus (PoF)
DoF gets shallower as PoF distance decreases, and as lens aperture gets larger.
Note - f/3.5 is a larger lens aperture than f/5.6 is.

Understanding Camera Autofocus
Understanding Depth of Field in Photography

 

[yakapo]

The camera can only focus at 1 distance from the camera, regardless what focus mode you use.
See the Index, page 368 and all the Focusing sub-section pages listed there of your Canon T4i Instruction Manual.

But yes, you need to put the focus point indicator on something at that 1 distance from the camera.
We then rely on the depth-of-field (DoF) to be sufficiently deep to have other peoples faces in acceptably sharp focus. The DoF is distributed both in front of and behind the point of focus (PoF)
DoF gets shallower as PoF distance decreases, and as lens aperture gets larger.
Note - f/3.5 is a larger lens aperture than f/5.6 is.

Understanding Camera Autofocus
Understanding Depth of Field in Photography

I believe I understand the basics. (take that statement with a grain of salt)
I understand at f/3.5 (or larger with a faster lens), I can get the blurry background effect. If I could do it again, I would have set the aperture to something smaller. Like I said, I didn't shoot in aperture priority.

I guess my primary question is, can any dslr's detect faces from the viewfinder? I'm guessing the mirrorless cameras with evf's can. Maybe I should purchase one of those. I don't really want to mess with having to make sure the red dot is on someone's face every time.

 

[bratkinson]

Of note is that although you may have set the camera to aperture priority at f3.5, the lens you have quickly moves to a smaller f5.6 as you zoom from 18mm to 135mm. So, without seeing any pictures, I'll also guess that in your 'at a distance' shots, a smaller aperture ratio automatically resulted in slowing down of the shutter speed, perhaps to the point of subject movement causing a blur. Even 'posed' individuals may have a slight movement at 1/60th of a second and slower. In my estimation, that is what is causing the slight out of focus you noticed.

A general 'rule of thumb' is that shutter speed should be at least 1/<focal length> to prevent camera shake from causing blurring. IS on your lens helps in that respect, but does not prevent subject-motion caused blur. In my own experience doing a lot of indoor, low light photography, I can reliably freeze action at shutter speeds of 1/160th and faster. Below that, the 'keeper' rate drops to perhaps 1 in 25 (yes, twenty-five!) at shutter speeds in the 1/10th to 1/20th range. Sometimes I have no choice but to shoot that slow. But when I do so, I take LOTS of shots to get a single keeper! And if there's a group of people, even MORE shots to ensure everyones' eyes are open, they're looking at the camera, etc.

 

[cynicaster]

You're indoors with rather weak ambient light and your camera is set to auto, so I'm guessing your camera--in an attempt to achieve a good exposure--is selecting shutter speeds too slow for hand-held shots, which is causing blurring of the subjects.

If you've got a half decent speedlight bouncing off a ceiling of reasonable height, then you should be able to expose subjects no problem without the slow shutter speeds the camera is picking on your behalf.

I'd recommend you set the camera to M mode, dial in a 1/200 shutter speed, select an aperture between f/5.6 and f/8, set the flash to ETTL, and fire away. This should start getting you some nice sharp subjects, but you might find the backgrounds rather dark. Once you get the hang of exposing the subjects with the flash, then you can start slowing down that shutter to bring in more of the background light.

NOTE--if your flash is struggling, you might want to bump your ISO up to 200 or 400.

 

[waday]

I guess my primary question is, can any dslr's detect faces from the viewfinder? I'm guessing the mirrorless cameras with evf's can. Maybe I should purchase one of those. I don't really want to mess with having to make sure the red dot is on someone's face every time.

Point-and-shoots may have this function. Not sure of any DSLR's having this function? Sounds like you could use a higher-end PowerShot: Canon U.S.A. : Consumer & Home Office : PowerShot G1 X

 

[astroNikon]

My dSLRs have that feature in Live View.
In Live View the mirror is out of the way. I'm going to guess the mirror takes away too much from the image to do any type of face detection.

My $99 Nikon P&S from 2011 has face detection too. But it doesn't have a mirror in front of the sensor nor a ViewFinder.