Why blurry and grainy?

Discussion in 'Canon EOS' started by robert_g.|2, Dec 12, 2009.

  1. I had an interior group shot to take this evening of like 25 people, lined up against the wall. I setup my tripod (on timer) with my Canon T1i (18-55@21mm, Speedlite 430EX II flash) about 20 feet away and took the shot. It was very grainy and blurry.
    Here were my settings:
    Tripod, timer shot, f/4, 1/60, ISO 400, 18-55@21mm, RAW
    For this picture I shot it in the Automatic mode (green box on the dial). The ones shot in Aperture mode were just as lowsy.
    Any ideas why?
    I'll include one person in the group picture so you will see what I'm referring to.
     
  2. Here's part of the picture at 100% zoom...
    00VEzH-200189684.jpg
     
  3. How were you focusing? How deep was the group? Were you 20 feet from the front of the group, or 20 feet from the back of the group?
     
  4. I was using AF and a few of the focus points lit up appropriately. The group was 3 rows and everyone is pretty much blurry.
     
  5. I can only assume you where focusing on someone much closer to the camera. However that much grain at ISO 400 does not seem right. Is this the first time using the lens? As a general rule I would not shoot large groups at F4.
     
  6. The AF was on and there were not many rows of people, plus I was shooting in full automatic mode in this case.
     
  7. Did you have the lens IS on for this shot? When tripod mounting the camera IS is supposed to be turned off. I don't know if that could/would cause this, but it would have some effect. I have forgotten to turn off the IS on my EF-S 55-250 before and it does mess up the shot.
    DS Meador
     
  8. YES, it was turned on. I wonder, could that be it?!
     
  9. No, this has nothing to do with IS being on. Your subjects are clearly not in focus.
    By "Set the Timer" do you mean that you were also one of the 25 people in the photo?
    [[Tripod, timer shot, f/4, 1/60, ISO 400, 18-55@21mm, RAW]]
    As Canon cameras do not allow you to shoot RAW while in Auto mode, I think you're mistaken about your settings.
     
  10. Yes the IS can cause this to happen.
    It is suggested to shut off IS when you are using a tripod.
     
  11. Yes I set the timer then ran to be in the picture. I thought the same thing (about Auto not allowing RAW), but if I preview the picture on my Camera's LCD I clearly see the Green "Auto" Rectangle and RAW as the image type. I find that odd as well. It is definitely a CR2 file as well. (For the pictures that were taken in the other modes these appear correctly, such as P, Av, etc...)
    Is the concensus that it probably was the IS with the tripod?
    I read that some of the newer lenses will turn IS off automatically if it detects a tripod. Is this true of the 18-55mm or 55-250mm lenses? Any place online where I can find this out?
    Thanks!
     
  12. IS won't cause this at 1/60s, whether it's on a tripod or not.
    If the exposure was a few seconds, then IS does need to be turned off since the image will slowly drift if the camera is on a tripod with IS on. Not at 1/60s though and not at any shutter speed if all of the light is being provided by a flash
     
  13. Then what was the problem? The shutter was fast, I used a flash, a tripod, a timer and reasonable ISO. What am I missing exactly? I need to figure it out.
     
  14. At f/4, you're pushing the lens to the limit, on a camera with a lot of megapixels. I'd try stopping it down to f/8 and adding light as needed.
     
  15. You can do a test to determine if it is IS. Duplicate the situation as closely as possible in terms of focal length and exposure on a tripod. Take a picture with and one without IS and compare. Don't trust your camera to automatically turn off IS. In any case I don't believe the 18-55mm lens has this auto tripod detect feature.
    I highly doubt you were pushing the lens at F4. However if you do the IS test above just like the original photo which used a flash, you could do an additional exposure without IS and at F8 to compare.
    How good is your tripod? Some tripods will vibrate when you hit the shutter button. What kind of tripod were you using? Depending on the length of your timer and your tripod the picture might have been blurred by the tripod vibration. Vibration issues can be minimized by not extending the tripod center columb to its maximum height.
    At 21mm / F4 your depth of field at 20 feet is about 10 feet to infinity. With that much depth of field a focus error would have to be completely out to get your results. I wonder if the camera might have focused on you while you were walking toward the group? I would put the lens in manual focus instead of leaving it on automatic. You don't want the focus to change while you are getting into the picture.
     
  16. Is it possible that there wasn't enough light for the auto focus to work?
     
  17. Chromatic aberration, high ISO, out of focus jumps to mind. Also, are you sure you posted a 100% zoom (and not a 400%)? Maybe you can retry this with a different lens in manual (focus, exposure, fixed ISO) mode and compare?
     
  18. With my 50D sometimes the results are like that because of the combination of noise reduction and sharpness settings in DPP.
    My current method is first to dial sharpness back to 0, then experiment with NR (something like Lum 3/20 and Chr 8/20 to start with, using the NR preview to check the result), then set sharpness to the level where the strange noise is acceptable.
    Most of the times this helps. It'll probably help with your T1i because the sensors are comparable.
     
  19. i'm going with IS blur combined with poor DOF due to using f 4.
     
  20. I think it was a combination that caused this. One, the poor on board flash was not strong enough to light the scene properly (one stop under). Two, IS will add just a small amount of blur. Three, since you were in AUTO mode, your camera was in AI servo and when you ran in the frame, the camera picked you up and re-focused on you, changing the field of focus. Four, to have a fighting chance, you should have bumped your ISO up to allow you to use F5.6 to F8. v/r Buffdr
     
  21. The out of focus problem most likely has to do with f/4 aperture. you need to be using something smaller. I used to have an inherent bias towards using large apertures (perhaps because it cost me more money to purchase) and faced this problem multiple times when shooting candid shots of a bunch of people. As the cost of the lens got amortized over time, the bias went away :)
     
  22. Since you were shooting on "Auto", I doubt whether your settings are as reported. Did you get that info from the EXIF data? The grain looks more like ISO 800 at least. I question the choice to zoom out to 21mm, as the lens sees more distortion and chromatic aberration toward the wide end. Plus, you should have been at f/5.6 to f/11 to ensure everyone was in focus. When you set up for a timer shot like this, focus on the middle row (with center-spot focus) and then turn off auto-focus, so the camera doesn't fudge it up, and you'll get consistent, correct focus in between shots. IS should be turned off, since all it can do is interfere and introduce shaking rather than remove it (since a tripod indoors does not shake)
    Can you post the full image? This looks grossly magnified, and I wonder if you didn't cram all 25 people into 10% of the frame. We might just be seeing the detail limitation of your camera sensor.
    One final thing: this has nothing to do with the JPG/RAW issue. Just shoot JPG until you can start getting correct focus and exposure consistently. Only then will you maybe find RAW post processing a useful tool to augment your photography. The trial-and-error learning process moves alot faster in JPG.
     
  23. "Then what was the problem? The shutter was fast, I used a flash, a tripod, a timer and reasonable ISO. What am I missing exactly?"
    Your lens at f4 is not exactly the sharpest. You need to set the camera to 'M' Manual and the f-stop on your lens to around f11, then focus on the group -- then turn-off your auto-focus system . If you use your 'flash' indoors and ISO 400, you should be in the area of 1/10 to 1/15 second shutter speed. And it won't hurt you to bracket a couple of shutter speeds either way if the group shot is important to you.
    [Old 'flash bulbs' were fine for indoor use; the electronic flash units today are designed for fill-flash, but if you practice you can add a lot of light to a scene indoors....that is where the large group would need a slower shutter speed to have a chance for the flash burst to mix with the room light, giving you the best results .]
     
  24. Everyone, THANKS for your input. Very good advice and suggestion. Yes, the crop I posted was at 100%. Pretty crappy huh?
    I will try this in the future:
    1. When using a tripod turn OFF IS for this lens
    2. Turn up the f-stop a bit
    3. NOT shoot in Auto (Av or Manual)
    4. Turn off Auto focus
    5. Shoot in JPEG for now
    Hopefully I'll get a shot I'm proud of in the future. Thanks for your suggestions thus far.
     
  25. Robert:
    When indoors, under low/limited light conditions, use single (ctr) focus point - rather than multiple focus points. Turn IS off and fire away.
     
  26. [[Yes I set the timer then ran to be in the picture]]
    Were you standing behind the camera when you pressed the shutter button to activate the count-down timer?
     
  27. [[ I wonder if the camera might have focused on you while you were walking toward the group?]]
    Steven, I completely missed this part of your comment my first read through, sorry.
    This is exactly what I was (slowly) driving towards. I speak from experience here. I had a rather awkward spot to put a tripod for a family portrait and I did not have my wireless remote. I could not stand behind the camera, only to the side. I thought I was out of the way enough when I pressed the shutter button to start the timer, but as it turns out I was not. The camera grabbed focus on me rather close to the camera instead of on where everyone else was sitting. The resulting picture was out-of-focus.
     
  28. It looks like your autofocus screwed the pooch on that one. Grain, or in this case, noise, will appear more prominent in out of focus mid values. I also see some pretty noticeable color fringing.
     
  29. Robert,
    I was just wondering if the floor you all were set up on was solid, like a concrete floor or was it a bit springy, so that as you ran to get into the picture the solid tripod had no choice but to vibrate along with the floor? Just another thought on your dilemma.
    Dee
     

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