Tag Archives: Sharpness

Why is my picture blurry?

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Why is my picture all blurry?

I hear this all the time from both experienced and new photographers.

Well, here’s why.

Focus:

  • You have not focused properly. Solution: select ONE focus point; focus; hold it; and only then shoot.
  • You are using a shallow depth of field. At f/1.4, it is hard to focus.

Subject:

  • Your subject is moving fast. Solution: pan with the subject or increase ISO, open aperture, or shoot the subject at the apex of its jump, say.

Shutter speed:

  • You are using a slow shutter speed (slower than twice the lens length, say, so on a 100mm lens you are using a shutter speed slower than 1/200th second). Solution: open the aperture or increase the ISO).
  • You are using a long lens (say a 300mm lens). On that lens, fast enough shutter speeds are hard to obtain). Solution: Zoom out, increase ISO, open the aperture, or use a tripod.
  • You are not using a tripod when you ought to. Solution? use a tripod!
  • You are using a slow lens. An f/3.5-5.6 consumer lens will never do as well as an f/2.8 pro lens. Solution: need I say?
  • You are using a small aperture, like f/8, when you should be using f/2.8. Solution: open your aperture.

Miscellaneous technique:

  • Your subject is in the dark – where it is muddy and blurry. Solution: Light your subject well.
  • You are not using flash when you should be. Solution: need I say?
  • You are  not using IS/VR. These are great features: stabilized lenses are superb and give you several stops. Solution: get an IS/VR lens.

Equipment:

  • Your camera is faulty – this is very unlikely, but have it checked out.
  • Your lens is faulty – this is also rather very unlikely, but have it checked out.

Clear? (Pun intended). Try all these and you will see your images improve amazingly.  Yes, I know, there are a lot of them. Yes, it’s complicated. But yes… you will take brilliant images once you get all of these right.

Remember these tips:

  • Bright pixels are sharp pixels (that is Willem’s Dictum);
  • Flashed pixels are sharp pixels;
  • VR/IS works;
  • Use one focus spot;
  • Hold the camera right;
  • A tripod is a good thing.

Have fun – a crisp, razor sharp picture really is a joy.

Why is it blurry?

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A question I get a lot from students is “why is this picture I made so blurry?”

We all want super-sharp pictures, and are disappointed when our pictures come out less than perfectly crisp. And then we wonder why.

The bad news: this question can be confusing because first, you need to distinguish between four distinct causes of blurriness. Yes, four: motion blur, focus blur, computer-generated unsharpness and camera-unsharpness. And their sub types: 11 reasons in all.

And then, once you know what caused it, you need to figure out how it came about.

Microphone shot against blurry background, by photographer Michael Willems

Microphone shot against blurry background

The good news: I can almost always tell very easily. And with a bit of training, so can you. And then you can find solutions.

So let’s look at why a picture can be blurry, shall we?

First there is motion blur:

  1. The shutter speed was too slow. This is by far the most common cause I see. Using a 100mm lens at 1/10th of a second is not going to work unless you are very lucky. (A general, very rough, rule of thumb: stay faster than “one divided by your lens length”. So on a 50mm lens, stay faster than 1/50th second. And so on). Solution: turn on more lights, go to a higher ISO (though this has problems too), open your aperture, or use a better lens with a larger aperture. Or use a tripod.
  2. The subject is moving. This is common too. If your subject moves, a tripod will not help! Solution: select a faster shutter speed or try panning with your subject.

Then there are various causes of focus blur:

  1. Simply out of focus, due to focus error. I see this a lot too. Solution: use one focus point, aim that at your subject (the eyes!), focus/lock focus, and shoot without repositioning yourself. Do not let the camera select where to focus.
  2. Out of focus due to very narrow depth of field. This is common with fast lenses. An f/1.8 lens (you need one!) has very selective depth of field, so move even a few millimeters and that eye will be blurry.
  3. Missed focus – due to the subject moving away after you focus. Solution: in these cases use AI Servo/AF-C rather than One Shot/AF-S.

Then there is what I like to call “signal unsharpness” (low signal to noise ratio, for engineers):

  1. The subject is dark. Dark pixels contain the noise and the muddy, unsharp image parts. Solution: light well!
  2. You are using high ISO. This leads to noise. Solution: use as low ISO as you can, use a faster lens, and turn on more lights.
  3. You are using noise reduction, which leads to blurriness. Solution: as above.
  4. You have increased the RAW image’s exposure, which generates extra noise. Solution: try to expose well in the camera and “expose to the right” (see previous posts here: search for them on the blog using the search field above right).

Finally there is camera unsharpness:

  1. Anti-moiré blur. Your camera adds blur to avoid Moiré patterns. Solution: use sharpening.
  2. Your lens is badly adjusted. This happens. Solution: have it fixed, or on professional cameras, do a lens micro adjustment.

I hope the above does two things. First, explain why this is complex, which explains a lot of the confusion (and I hope I removed some of that confusion). Second, help you with strategies to fix the issue.

Tip: Take lessons to learn about this stuff from the pros. Go to your local Henrys, or if you are an emerging pro to www.cameratraining.ca, and explore the possibilities. We make things simple!