Home · Register · Join Upload & Sell

Moderated by: Fred Miranda
Username  

  New fredmiranda.com Mobile Site
  New Feature: SMS Notification alert
  New Feature: Buy & Sell Watchlist
  

FM Forums | People Photography | Join Upload & Sell

  

Archive 2016 · Focusing on moving subjects

  
 
anais12345
Offline

Upload & Sell: Off
p.1 #1 · p.1 #1 · Focusing on moving subjects


I use the Canon 5d Mark ii, and I've been able to focus well on one subject but am sometimes terrible when it's a moving subject (children) and mother for lifestyle shots. The mother will be in focus and the child will be blurry, or just the fast-moving child will be blurry on her own shot. How do I autofocus so that my subjects are sharp? I like the subject with the bokeh look too, and I don't know if I can achieve that with a moving subject. I also don't understand whether to set my camera to one shot or AI servo, etc. Can someone please help? Actually, the more people the better.


Jul 25, 2016 at 10:02 PM
ucphotog
Offline
• • •
Upload & Sell: Off
p.1 #2 · p.1 #2 · Focusing on moving subjects


A few samples might help, but if I am reading your comments correctly, you probably have several different problems.

1. You may be shooting with too slow a shutter speed. I won't claim to be an expert, but I only shoot children at 1/200th if I am desperately short on light. 1/400th would probably be a minimum if there is light and/or reasonable ISO settings to achieve that. Even faster would be better.

2. If the mother is in focus and the children aren't it could be two things. It could be #1 again, or it could be that your depth of field is too small, which is the same as having your aperture too big.

3. This may or may not apply to you ... I was never all that great at video games because I don't have fast hand-eye coordination. Getting a focus lock on moving children can be tricky and sometimes is a lot like getting "that shot" in a video game.

I don't Canon so I can't give you much help with the settings. Something that tracks objects as they move would be good, but I have no idea what Canon calls it, and I suspect there is more than one variant. Nikon has several.

Good luck! Kids are fun to shoot, but not always easy.

Dave



Jul 25, 2016 at 10:32 PM
friscoron
Offline
• • • • •
Upload & Sell: On
p.1 #3 · p.1 #3 · Focusing on moving subjects



Agree, with Dave. Samples would help, along with what settings you were using.

The autofocus function doesn't necessarily come into play if you're shooting at f/2.8 and one or the other is out of the depth of field. It won't have anything to do what type of auto focus method you're using. Or it could be a slow shutter speed and a moving subject. It could be dozens of things. And every session is different.



Jul 25, 2016 at 10:42 PM
Steve Wylie
Offline
• • •
Upload & Sell: Off
p.1 #4 · p.1 #4 · Focusing on moving subjects


To track focus on a moving subject with a Canon camera, you can set it to AI Servo, but I doubt that that is your problem. I agree with the others that it's probably a combination of too shallow depth of field (solution, use a higher f stop to increase it) and a too slow shutter speed. You say you like bokeh, which typically improves with a wider aperture and shallower depth of field, so there will be some trade-offs between your desire for out of focus backgrounds and the need to keep everyone in focus. In these cases, you can't afford to have a blurry kid, so sacrifice bokeh for depth of field. For the fast-moving child alone, I'd wager that your shutter speed is simply too slow. In these cases, with only one subject, a shallower depth of field (lower f/stop) will automatically give you faster shutter speed (to get the same exposure), and the AI Servo setting should track the child easily.


Jul 26, 2016 at 12:43 AM
schlotz
Offline
• • • • •
Upload & Sell: On
p.1 #5 · p.1 #5 · Focusing on moving subjects


Knowing what lens & body settings you are using would be a big help. Fundamentally photography is an exercise in compromise as Dave, Ron & Steve have pointed out. It starts with light, and if there isn't enough, trade offs immediately commence. You are looking for three aspects (speed, DOF, bokeh) and it's usually one of the three that becomes the compromise. With what has been described my bet is that bokeh will need to be back burnered. BTW: at what mm (lens setting) were you shooting at?

1. Use AI servo and use the single center focal point (note the 5D2 is known for not focusing as well with outer fp's)
2. Go into manual mode. SS=1/400 Ap= f/8 and set the ISO high enough to allow those settings. Note: no mention of distance to subject was provided which is key to understand just how far open the Ap can be to allow a sufficient DOF. Obviously the more the distance the more open the Ap and the lower the ISO can be set depending on the lens mm setting. Get a DOF app and become familiar. ex) 60mm, Ap 5.6, dist to subject 8' will yield a DOF of 1.8' or just under 22" but remember that means when pointed at a subject the perceived in focus range is 11" in front and 11" behind the subject. Moving the Ap to f/8 and the DOF is 31"
3. If the light is low the result of higher ISO's might be poorer quality. Enter the compromise, try shooting at 1/320 or slower knowing motion blur might come into play.

One of the best DOF apps on the iphone is Field Tools



Jul 26, 2016 at 08:31 AM
anais12345
Offline

Upload & Sell: Off
p.1 #6 · p.1 #6 · Focusing on moving subjects


Thanks. What is the one shot setting good for? General use? I'm still trying to figure out how to set shutter speed, I get so confused, so I usually shoot auto or AV so I don't have to worry about shutter speed. Am I wrong in doing that? I want to progress in my photography beyond doing well composed shots in auto and sometimes AV, but as I said, I'm confused about shutter speed, hence blurriness likely.


Jul 27, 2016 at 03:40 PM
CW100
Offline
• • • • •
Upload & Sell: Off
p.1 #7 · p.1 #7 · Focusing on moving subjects


anais12345 wrote:
Thanks. What is the one shot setting good for? General use? I'm still trying to figure out how to set shutter speed, I get so confused, so I usually shoot auto or AV so I don't have to worry about shutter speed. Am I wrong in doing that? I want to progress in my photography beyond doing well composed shots in auto and sometimes AV, but as I said, I'm confused about shutter speed, hence blurriness likely.


yes, that's wrong, Auto and "Av" mode can result in a too slow shutter speed for some action shots. You need to learn how to set the ISO and aperture to get the best or fastest shutter for the appropriate situation. Many sports and action shooters use manual mode where they set the shutter (e.g.1/2000) and set the aperture but using auto ISO















Jul 30, 2016 at 06:21 AM
schlotz
Offline
• • • • •
Upload & Sell: On
p.1 #8 · p.1 #8 · Focusing on moving subjects


Figuring out shutter speed... not certain of your reference. It's used to stop target motion, shorten exposure by limiting light or by slowing it down you allow more light to enter (think of a dark setting where a timed exposure is used e.g. in astrophotography). From the motion equation for example, I shoot professional soccer which is in the evening. I start out able to use SS of 1/2000 Ap 100 & ISO 100 but as the light leaves the Ap has to open up to 2.8, the SS goes down to 1/1250 and the ISO increases 16,000. All of this in order to get a good exposure while attempting to maintain enough speed to stop the action. Best advice is to read the camera's manual in it's entirety (yes it's a bit dry but important). If still a bit foggy, then find a good basic photography book to help solidify the concepts and how they interact. Once you get comfortable with the concepts of shutter speed, aperture and ISO it will become relatively easy to obtain the photos you have described. BTW: One shot mode is good for 'stationary' targets.

Last tip: you can still get a blurry result taking a picture of something that is motionless if the camera was moving when the shutter button was pressed. Learning good holding techniques can allow for good handheld shots at slower shutter speeds e.g. 1/30 or so. Starting out, try to keep the SS closer to 1/200 or more.



Jul 30, 2016 at 07:49 AM





FM Forums | People Photography | Join Upload & Sell

    
 

You are not logged in. Login or Register

Username       Or Reset password



This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.