Canon EOS Digital Rebel XT Blurry Pictures

Discussion in 'Canon EOS' started by brandy_ferrell, Jan 23, 2011.

  1. Hi! This is actually my first post to this site so I'm not sure I am even posting this in the correct spot, etc. I am hoping that someone can help me with a problem I am having with my Canon EOS Digital Rebel XT. I have had this camera for years and I have taken great pictures over the years. However within the last year or so my pictures have been coming out blurry. I can take several pictures (at a bday party, my kids outside playing, etc.) and some of them will turn out crystal clear while others are blurry. Most of the time it seems to blur my main subject and the background will be in focus. Can anybody tell me what I am doing wrong? The focus is on AF and I typically use the Full Auto setting. Thank you so much for any help! :)
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  2. I believe when you use full auto, the AF system will use all 7 AF points. By doing this, you are allowing the camera to choose what to focus on from those 7 points. If the camera focuses on something other than what your main subject is, then your subject will be blurry. If only one AF point hits your subject, you're giving the camera a 1 in 7 chance of choosing the correct AF point. If it chooses one of the other 6 it results in an out of focus photo. I always choose one AF point myself and I make sure that point is on my main subject when I shoot. This doesn't give the camera a chance to pick an AF point and me hope it picks the right one. I don't think you can choose an AF point in auto mode however, so you may have to venture into the manual modes to gain that control. I think Av is a good place to start. You choose f/stop and ISO and the camera does the rest; its almost like auto, but you're telling the camera what settings you prefer, but in the end its still "point and shoot." There's no adjusting dials between every shot. P mode is even more thoughtless than Av, but I like to have a little control in what the image will look like by controlling depth of field with the aperture settings. Hope this helps.
     
  3. Also, make sure your shutter speed is fast enough. If its too slow it can cause blur from camera shake, but then the whole photo is blurry, even the objects in focus. The rule of thumb to prevent camera shake is to use a shutter speed that is at least the reciprocal of your focal length.
    So for example:
    If your lens is ......, your shutter speed should be..........
    50mm...1/50 sec.
    100mm...1/100 sec.
    400mm...1/400 sec.
     
  4. You need to control the camera, not let it control you. Use center point only, one shot auto-focus, point where you want the sharpest focus to be, hold the shutter in half way, recompose and shoot.
     
  5. Nathan, thank you so much for getting back with me. I am going to play around using the Av mode with some pictures today. I'm not the most camera savvy but you broke that down really well for me and it made sense. Thank you! :) I'm not exactly sure of some of the settings in that mode (like when it ask which AF mode I want; one shot, AI focus or AI servo or which ISO speed I should choose. I also have no idea what the f/stop is but I am going to look through the manual. Again, thank you so much for help!
     
  6. For f/stop, ISO, and shutter speeds, google "photography basics" and a plethera of camera knowledge should come up. Do some research and there should be some good sites that teach what each is, and how it affects a photo, and they should have visuals that will help. In a nutshell, ISO is the sensitivity to light; the higher the ISO, the more sensitive the camera is to light, allowing you to get photos in darker places. The trade off is that the higher the ISO, the worse the image quality. F/stop is the aperture opening in the lens. The lens can open or close to allow more or less light in. This affects yhour plane of focus, or how much of the photo is actually in focus and how much is blurry, but this is where your googling can tell you more specifically how it works. The shutter speed is the length of time the shutter opens to expose the sensor. The faster the speed to more action freezing you'll have, the slower the speed, the more blur. You must understand that the f/stop and shutter speed work hand in hand to create a properly exposed image. I think of it as the f/stop controls "how much" and the shutter speed "how long." You have to let the right amount of light in for the right amount of time to get a photo that looks good. As for AF, here's my rule of thumb; never use al focus; the pro models don't even have this mode b/c it's pointless. One Shot is for still subjects, it focuses and locks. Al servo is for moving subjects, it is continually focusing and refocusing so as a subject moves it maintains correct focus.
     
  7. Nathan, you are awesome. Thank you. You mention the ISO and its sensitivity to light. So if I set the ISO higher (say 800) will it help with the pictures I try and take inside my daughters school. They have fluorescent lights and my pictures always turn our horrible.
    *Oh, and my camera was set on the AI Focus, thank you for explaining the difference in those. In the future I will use the One Shot and the AI Servo modes.
     
  8. EXIF data:
    Focal Length: 28mm
    Aperture: f/4.0
    Exposure Time: 0.017 s (1/60)
    ISO equiv: 400
    1/60 at 28mm should be fast enough to prevent motion blur for this photo.
    The problem is likely with the AF system - in auto it tends to focus on the closest item that's big enough and has enough contrast for the system to get focus lock. That's not what you want. As suggested, take more control.
     
  9. Nathan, I have been playing around with the ISO. Wow, what a world of difference that makes. :) Do you agree with Kerry that I should just keep the focus on the center point?
    * Also, on the White Balance, would I be better off using the AWB or actually changing the settings on that?
     
  10. set on the AI Focus​
    That is surely another contributing factor.
    Pay attention too, to which focus points are "active" (flashing red) and you can see where the camera is focusing, even if you are not controlling it more positively.
     
  11. So if I set the ISO higher (say 800) will it help with the pictures I try and take inside my daughters school​
    Yes. I always use the lowest ISO I can get away with, but getting the shot is the first priority. So if I'm outside and I have a tripod to shoot a landscape, there's no reason to use anything higher than ISO 100, and that setting of ISO 100 will yield the best quality. But if I'm in a dark gym and need to get some action shots, I may be forced to use ISO 1600. The quality won't be as good, but its better than no picture at all or a very dark one where the subject can't be made out.
    Do you agree with Kerry that I should just keep the focus on the center point?​
    This is what I do most of the time. The big thing here is to be sure you hold the shutter button down halfway while you recompose so the AF will remained locked where you set it. If you let up and repush the button, the AF will refocus on whatever is behind that middle point. If I'm using my tripod and have plenty of time, I will usually just select the point that is on my subject so that I don't have to recompose. Also, keep in mind, the center point, recompose, shoot, method will only work with One shot AF. If you are using al servo, the camera will refocus as soon as you take the AF point off your subject.
     
  12. Brandy, couple other things to mention, you can set the cameras White Balance for what kind of light you are shooting under, if you are in manual modes. This will keep your color as true as possible. You can check your manual for what all those little symbols mean. But it is basically Full Sun, Shadow daylight, cloudy day, tungsten lights.AWB means automatc Whilte Balance...etc.
    Hi ISO will allow the camera to take photos easier in dark light, but it will introduce some noise (grain) in higher ISO setting. (Noise is not bad, it is just noise) If pushing the camera to 1600 ISO (Think that is the highest for Rebel XT) you will see some grain or noise in the photos. Consider doing some Black and White shots at 1000-1600 ISO. B&W with a little grain can look pretty cool. Also for low light consider a tripod or mono pod to help keep the camera steady so no camera shake blur as lower light mean the shutter need to be open a little longer to gather light so more susceptible to blur from any movement.
    As you move your ISO up you will find you can drop your F/stop lower allowing you to choose a faster shutter speed. Faster speed means less motion blur in moving subject. Slower shutter speeds and more motion blur.
    Moving the ISO is increasing how sensitive the photo sensor is to light, the shutter does not have to be open so long to gather light, so faster shutter is possible and then less motion blur.
    Also know that lower F/stop narrows your depth of field (area in front and in back of your focal point that will still look sharp and in focus) A lower F/stop (depending how fast your lens is) can have the people you are shooting be perfectly in focus while the back ground a few feet back look soft and blurred (called bokeh) and this will allow your subjects to really pop out from the back ground.
    Higher F/stop widens your depth of field increasing the area in front and in back of your focal point to look sharp and clear, this good for more out door work like taking a photo of a building or many sail boats out on the water or large group shots with many rows of people. Keep in mind as you really move your F/stop beyond 8 or 9 while over all very wide depth of field you will notice you will loose some over all sharpness. You just won't get everything super crisp sharp.
    ISO, F/stop, shutter speed, there is no one perfect setting, these are adjustable so you can set them to what you want to create in your photo. The SLR camera is an artistic tool and these setting are for you to make those photos look exactly like you want
    These are all just some basics and different lens may perform differently at specific settings but pretty much the same basic principles to learn and as you gain experience using them you will just start knowing what you want and can expect from different settings.
    The Digital Rebel XT is a really good camera, I shot with one for a few years and got great results. You can do everything with this Digital SLR.
    Just learn some of these basics and you will really see your photos improve. All the best and welcome to Photo.net. - Mark
     

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