Im sure you are just like me and like to believe that it couldnt possibly be our fault that at photo comes out blurry, only sadly most of the time it isnt true. I was surprised at how often a blurry photo is caused by me not picking the right settings for the situation.
The following is some reasons why we might not be nailing our focus.
1. Shutter SpeedOur shutter speed is simply to slow. We want to make sure our shutter speed is at least two times the length of the lens that we are using. This will help minimize the blur caused by camera shake. For example if you are using the popular 50mm (which I used for all the samples posted in this lesson) we would want to keep our SS at a minimum of 160.
Sometimes if we are shooting a subject that is fast (bird in flight, toddler, and sports activity) we will get motion blur, to combat this we simply need to pick a faster shutter speed.
Toddlers and young children I try to keep my shutter speed over 1/250 of a second.
For Sports where I want to freeze the action I bump up my shutter speed to 1/500 of a second or even 1/1000 of second.
The only time we really dont need to worry about our SS is if we are using a tripod and the self timer or wireless trigger. Remember to turn of the IS for your lens and you should have no issue with camera shake at all (None moving subject).
Below is an example of how shutter speed can affect your focus. The first image was shot hand held at 1/800 of a second, the second was also hand held but this time the SS was .5 of a second. As you can see the camera shake was more noticeable in the second image.
http://i20.photobucket.com/albums/b220/ToadMum/7961fbc9.jpghttp://i20.photobucket.com/albums/b220/ToadMum/3542523c.jpg2. ApertureWhen we pick to narrow of a depth of field we are upping our chances for focus issues. Every lens has a sweet spot which is usually two stops higher than the widest opening. Test out your lenses to find out your happy place (ok stop laughing). Lots of people fall into the trap of shooting at the widest aperture their lenses will allow, thats great and is totally up to you just make sure if you are going to shot wide open you know how to handle it. The most common mistake in shooting wide open is being too close to your subject, step back!
Below is an example of how the aperture setting can affect your focus. The first image was shot with an aperture of f/1.8 the widest aperture my little 50 mm will allow. The second was shot at f/8.0. In the first image you can actually see how narrow my depth of field was.
http://i20.photobucket.com/albums/b220/ToadMum/9ad94e06.jpghttp://i20.photobucket.com/albums/b220/ToadMum/e16ce9a9.jpg3. Focal PointsPicking the wrong focal point will also throw off your focus, so keep an eye on those little red dots. Actually grab your manual right now and find out how to turn your camera to single point focus, you will thank me for this later, I promise. With single point focus, you select where the focal point will be not the camera. See that little red dot light up when you push the shutter button down half way? That is where your focus is going to fall. Make sure you aim that little dot right where you want it. If you want to change your composition of your shot, then change your focal point accordingly and re-focus.
Below is an example showing how selecting the wrong focal point (or leaving your camera on auto) can affect your focus. The fist image I allowed the camera to pick the focal point and it chose the blade of grass in front of the domino. In the second image I selected center red dot and placed it just over one of the dots on the domino.
http://i20.photobucket.com/albums/b220/ToadMum/84d6ff96.jpghttp://i20.photobucket.com/albums/b220/ToadMum/8e469688.jpgThere are a couple of other things to consider when working on nailing focus:
Focus Modes:One shot: Suited for still subjects, when you press the shutter button half way the camera will focus only once. Use this when you wish to try focusing and recomposing as well.
Al Servo: Suited for moving subject when the focusing distance keeps changing (them quick little toddlers come to mind). When you press the shutter button halfway, the camera will continually focus on the subject. Also great for sports.
Al Focus: Suited for still subjects which MAY start moving. When you press the shutter button halfway, the camera will focus only once unless the subject starts to move. Then it will automatically start using Al Serve mode.
Back Button Focusing (BBF)Back button focusing is like the secret no one in high school would tell you about. Instead of pressing the shutter button half way down, you can assign your auto focus to a different button on the back of your camera. Some people (myself included) find this method helps with focusing tremendously. Check your manual for how to set this feature on your camera and play around with it see if its for you. There are also many, many tutorials on this subject on YouTube.
I find that using BBF is beneficial when shooting fast moving subjects (like them kids again) I set the auto focus mode to Al Serveo and hold my BBF button down and follow my subject until I am ready to take the picture. You are less likely to lose focus this way over trying to use one shot mode and taking your chances on catching your subject at the exact right time.
Other Misc. InfoYou can get a photo in focus with any camera but you cant get every photo in focus with every camera. Are you lost? Let me explain
. Some cameras have higher ISO capabilities than others and if you want to be able to control your shutter speed and aperture, you know from week 3s lesson that we will have to factor in our ISO settings.
Im sure everyone has a different opinion on the topic of lenses, but I am of the opinion that some lenses are just better than others when it comes to focusing. Some are sharper and some are quicker to find focus. Youll need to research to make your decision on which lenses to purchase based on your needs. Dont forget some lenses have IS (Image Stabilizer) build in to minimize camera shake.
Sometimes it will come down to just not having enough light to get your settings where you need them to be. Artificial lighting can be very helpful tool in this instance. Whether it be an external flash you bounce of the ceiling or a set of studio lights. The choice is yours as to whether you want to spend any money on artificial lighting to help you nail your focus.
Sometimes your camera has a hard time locking focus when there just isnt enough contrast. Just try to take a picture of a solid white subject, like an egg on a white background. Youll have a nearly impossible time. This normally isnt an issue when shooting people, just focused on their eyes. If there isnt enough contrast in our desired frame, its time to use Manual focus and trust your good old eyeballs.
Alternatively, if someone is wearing a high contrasting shirt, your focus might fall off their eyeball and onto the pattern instead of where you want it. Ask your subjects not to wear bold patterns close to the face or try if placed in that situation, switch to manual focus.
So now your most likely asking how do I know if my focus fell in the wrong place? the LCD screen on your camera is usually too small to see if your focus is off, so you can either wait till you get home to check or use the little magnifying glass button on your camera to zoom in and check.
DistanceMake sure you are not too close to your subject; your lens may have a hard time focusing where you want it. Take a step or two back and refocus. Its easier to crop a well focused image that try and sharpen a mess.
Sun/LightIf you are shooting into the sun, you may have a hard time getting your lens to focus as well. If this is the case, then you may have to switch to manual focus to get your camera to allow you to take the photo. The same problem may occur when you are dealing with a great deal of reflection coming onto you lens. It may be reflection from some water or window but whatever it is that is causing it, you will need to either move away or try that manual focus again.
HomeworkFor your homework/assignment, you might have to dig out your trusty camera manual (sorry).
#1 - Set up a stationary item and take a picture letting your camera pick the focal points.
#2 - using the same settings take the same picture but select a single focal point placed over what you think is the most important part of the image.
#3 - same picture again but this time drop your F/stop as wide open as it will go, adjust your settings to allow for correct exposure. make sure to also keep your SS above 200 (so you might have to adjust your ISO as well.
#4 - once again take the same picture up with a smaller aperture (larger f stop number), adjust your settings as before.
Now upload the images and take a look at your sharpness, what do you notice?
To find the previous weeks lessons:
Lesson 1:
http://www.uglyhedgehog.com/t-41242-1.htmlLesson 2:
http://www.uglyhedgehog.com/t-42355-1.htmlLesson 3:
http://www.uglyhedgehog.com/t-44193-1.htmlLesson 4:
http://www.uglyhedgehog.com/t-45521-1.html