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Izzy Video 139 – How to Focus an HD Camera

Izzy Video 139 - How to Focus an HD Camera

One of the big challenges of working with an HD video camera is ensuring the image is in focus. Unfortunately you can’t just rely on the LCD for this, because the actual resolution of the recorded image is much higher than the resolution of the LCD screen. It’s quite possible that the image on the LCD appears to be in focus when the recorded image is blurry.

Luckily HD video cameras have autofocus. The camera automatically focuses the image, and it usually does an excellent job. However there are times when the autofocus doesn’t work:

  1. When the subject isn’t in the center of the frame. – Sometimes you want the subject of the image to be off to the left or right of the frame. The problem here is that autofocus adjusts according to what it sees in the center of the frame. If the object in the center is closer or further than the main subject, then the camera will adjust the focus for that object, often leaving the main subject blurry.
  2. When somebody or something passes through the frame between the camera and the subject. – I demonstrate this problem in the video, but it’s something that happens a lot. Let’s say you’re at the zoo shooting video of your children with the animals. As people walk through the frame, the camera will autofocus on the people walking by, and then refocus on the children. This gets distracting. It’s a much better image if the people in the foreground remain blurry as they walk through the frame.

In this week’s tutorial I demonstrate several different ways to ensure you have a focused image:

  1. Use autofocus when appropriate.
  2. Use manual focus when appropriate.
  3. Use the ‘focus assist’ function available on many cameras.
  4. Zoom in, focus the image, and then zoom out to frame the image, making sure you don’t adjust the aperture.
  5. Use the “peaking” function available on many new cameras.

Another thing you can do (and I didn’t include this in the video) is use an externally attached monitor with a bigger image. This can help ensure you’re always in focus.

Few things are as frustrating as shooting some great footage and then later when you’re editing it, discovering that it’s out of focus. It’s inconvenient and frustrating, and if you’re doing commercial work, it’s expensive.

I hope this week’s tutorial helps you make sure you get a focused image.

This video is available to members only. If you’d like to see this video in HD resolution, as well as gain access to the large archive of video tutorials, you can learn about an Izzy Video Membership.

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  • http://marketingunscrambled.blogspot.com Dan and Deanna

    Thank you for the work that you do to help others know more about shooting video and making it the best that it can be. If things are not in focus then things will have to be re-done. That does not work very well. Because you give such good information to those that visit your blog. We have added you to our list of blogs that have gotten Best Blog Award and A Lovely Blog Award. If you what to know more visit our blog to see more about it. Have a good day.

    Dan and Deanna “Marketing Unscrambled”

  • http://marketingunscrambled.blogspot.com Dan and Deanna

    Thank you for the work that you do to help others know more about shooting video and making it the best that it can be. If things are not in focus then things will have to be re-done. That does not work very well. Because you give such good information to those that visit your blog. We have added you to our list of blogs that have gotten Best Blog Award and A Lovely Blog Award. If you what to know more visit our blog to see more about it. Have a good day.

    Dan and Deanna “Marketing Unscrambled”

  • james

    Really those tips for focus are very basic. All the info in this six minute video can be presernted in a couple of sentences.

    FYI – when you zoom in and out with a small handicam in indoor lighting you will almost always change the aperture.

  • james

    Really those tips for focus are very basic. All the info in this six minute video can be presernted in a couple of sentences.

    FYI – when you zoom in and out with a small handicam in indoor lighting you will almost always change the aperture.

  • http://www.izzyvideo.com Izzy

    James,

    You’re correct. They are basic because the vast majority of my audience consists of beginner to intermediate video people. While I try to throw in more advanced topics here and there, I need to make sure I’m creating content for my audience.

    And yes, the tips could be summed up in a few sentences, but that would defeat the purpose of the video. I like to show examples and explain things while I’m doing them. This reduces the likelihood for confusion. There’s a lot to be said for seeing concepts in action.

    Your last point is actually wrong if you follow my instructions in the video. You’ll notice that I said to zoom in and then “lock the exposure”. Most consumer video cameras I’ve used have the ability to lock the exposure, and this would prevent the aperture from changing. Of course, if you don’t lock the exposure, then you would be correct.

    Even though the tone of your comment is quite abrupt, I assume that your intent was to be helpful, so I’ll thank you for it.

  • http://www.izzyvideo.com Izzy

    James,

    You’re correct. They are basic because the vast majority of my audience consists of beginner to intermediate video people. While I try to throw in more advanced topics here and there, I need to make sure I’m creating content for my audience.

    And yes, the tips could be summed up in a few sentences, but that would defeat the purpose of the video. I like to show examples and explain things while I’m doing them. This reduces the likelihood for confusion. There’s a lot to be said for seeing concepts in action.

    Your last point is actually wrong if you follow my instructions in the video. You’ll notice that I said to zoom in and then “lock the exposure”. Most consumer video cameras I’ve used have the ability to lock the exposure, and this would prevent the aperture from changing. Of course, if you don’t lock the exposure, then you would be correct.

    Even though the tone of your comment is quite abrupt, I assume that your intent was to be helpful, so I’ll thank you for it.

  • james

    Izzy – I was somewhat surprised at the level yes – it does seem very basic. But given that – setting the exposure the way you describe is bad practice. When you zoom in your maximum aperture is several stops lower than max aperture at the wide angle. I would strongly recommend you set your exposure once you have the framing where you want it.

    Think of a bride in a white dress. You zoom in on her face set the exposure. Zoom out and her dress is blown out.

    Whoops.

    :)

  • james

    Izzy – I was somewhat surprised at the level yes – it does seem very basic. But given that – setting the exposure the way you describe is bad practice. When you zoom in your maximum aperture is several stops lower than max aperture at the wide angle. I would strongly recommend you set your exposure once you have the framing where you want it.

    Think of a bride in a white dress. You zoom in on her face set the exposure. Zoom out and her dress is blown out.

    Whoops.

    :)

  • Michael C.

    Gee, you are both right and wrong. Consumer camcorders, as well as many prosumer camcorders, have variable speed. This means, that at the widest lens the largest aperture can have smaller F-number than at the zoomed in lens. The HV20 Izzy used in his example, has speed F1.8-F3.0. This means that the camera can go as wide open as F1.8 at the wide lens, but only to F3.0 at full zoom. If you lock aperture to F1.8 at full wide and then will start zooming in, the camera will “ramp up” aperture, closing down the iris.

    BUT: this all is true only for the largest aperture. If you don’t want to use the largest possible aperture, then you can simply stay numerically above the slowest speed and avoid the variable region. Say, if you set aperture to F3.0 or a larger number, then the camera will preserve it whatever you do, no ramping.

    Now, where do I get my free membership?

  • Michael C.

    Gee, you are both right and wrong. Consumer camcorders, as well as many prosumer camcorders, have variable speed. This means, that at the widest lens the largest aperture can have smaller F-number than at the zoomed in lens. The HV20 Izzy used in his example, has speed F1.8-F3.0. This means that the camera can go as wide open as F1.8 at the wide lens, but only to F3.0 at full zoom. If you lock aperture to F1.8 at full wide and then will start zooming in, the camera will “ramp up” aperture, closing down the iris.

    BUT: this all is true only for the largest aperture. If you don’t want to use the largest possible aperture, then you can simply stay numerically above the slowest speed and avoid the variable region. Say, if you set aperture to F3.0 or a larger number, then the camera will preserve it whatever you do, no ramping.

    Now, where do I get my free membership?

  • Gregory

    Actually changing your f-stop will never change your focus. It will only change your depth of field. DOF and focus are entirely different things.
    Focus refers to a point on the film plane where all light rays from the subject converge. By zooming in the way you suggest you will always set your lens to that point of convergence (or focus) on your film/sensor plane. If you change your aperture you are merely extended the distance in front of and behind that focus point (i.e. the Depth of Field). The effect is really an optical illusion as these other planes are not truly in focus, they are sharp enough to appear so to the human eye. So technically, a smaller aperture never gives you deeper focus because there can only ever be one point of convergence of the subject, however we say it is deeper focus because our eyes are fooled that those other planes are actually in focus.

    @james: yes, the bride’s dress may be blown out but her face will be properly exposed and 9 out of 10 times that faces are more important that dresses. It all depends on the effect you are going for.

  • Gregory

    Actually changing your f-stop will never change your focus. It will only change your depth of field. DOF and focus are entirely different things.
    Focus refers to a point on the film plane where all light rays from the subject converge. By zooming in the way you suggest you will always set your lens to that point of convergence (or focus) on your film/sensor plane. If you change your aperture you are merely extended the distance in front of and behind that focus point (i.e. the Depth of Field). The effect is really an optical illusion as these other planes are not truly in focus, they are sharp enough to appear so to the human eye. So technically, a smaller aperture never gives you deeper focus because there can only ever be one point of convergence of the subject, however we say it is deeper focus because our eyes are fooled that those other planes are actually in focus.

    @james: yes, the bride’s dress may be blown out but her face will be properly exposed and 9 out of 10 times that faces are more important that dresses. It all depends on the effect you are going for.

  • http://www.jterryvideography.com Jerome T

    Hi Izzy,
    Your videos are great. Two questions. Do you prefer to shot your HV20 in TV mode? Also what was the second camcorder you used towards the end of the tutorial.

    Thanks,
    Jerome

  • http://www.jterryvideography.com Jerome T

    Hi Izzy,
    Your videos are great. Two questions. Do you prefer to shot your HV20 in TV mode? Also what was the second camcorder you used towards the end of the tutorial.

    Thanks,
    Jerome

  • http://www.izzyvideo.com Izzy

    Hi, Jerome!

    Thanks for the kind words. I usually shoot in TV mode with the HV20, but it sort of depends on what I’m trying to do. Sometimes I’ll use the Av mode because I want to control depth of field. But you’re right, usually it’s Tv.

    And the second camera is my Sony PMW-EX1. It’s the camera I use to shoot all the tutorials.

    I hope that helps!

  • http://www.izzyvideo.com Izzy

    Hi, Jerome!

    Thanks for the kind words. I usually shoot in TV mode with the HV20, but it sort of depends on what I’m trying to do. Sometimes I’ll use the Av mode because I want to control depth of field. But you’re right, usually it’s Tv.

    And the second camera is my Sony PMW-EX1. It’s the camera I use to shoot all the tutorials.

    I hope that helps!

  • Jerome T

    Thanks for the info Izzy! Now I have to save some money.

    Jerome

  • Jerome T

    Thanks for the info Izzy! Now I have to save some money.

    Jerome

  • Michael C.

    @Gregory:

    “Actually changing your f-stop will never change your focus.” — who said that it does? But increasing aperture decreases DOF, and vice versa, it is a fact.

    “yes, the bride’s dress may be blown out but her face will be properly exposed and 9 out of 10 times that faces are more important that dresses.” — James is wrong. When you zoom out aperture will not change if it was locked beforehand. When you zoom in aperture may decrease if your lens have variable speed.

  • Michael C.

    @Gregory:

    “Actually changing your f-stop will never change your focus.” — who said that it does? But increasing aperture decreases DOF, and vice versa, it is a fact.

    “yes, the bride’s dress may be blown out but her face will be properly exposed and 9 out of 10 times that faces are more important that dresses.” — James is wrong. When you zoom out aperture will not change if it was locked beforehand. When you zoom in aperture may decrease if your lens have variable speed.

  • Marco

    Hi Izzy, I am from Brazil and I am a new IzzyVideo member. Thank you for you videos. I am leraning a lot! I have a question about focus in a HD camcorder. Can you help me? I have a Sony Z7U HD Camcorder. When I shot one person in a “medium shot” (haf body) I can get e very good a sharp (detailed) focus, but when a I shot a “full shot” (full body) the face of the person get blured. Can you help me with this problem?

    Thank you!

  • Marco

    Hi Izzy, I am from Brazil and I am a new IzzyVideo member. Thank you for you videos. I am leraning a lot! I have a question about focus in a HD camcorder. Can you help me? I have a Sony Z7U HD Camcorder. When I shot one person in a “medium shot” (haf body) I can get e very good a sharp (detailed) focus, but when a I shot a “full shot” (full body) the face of the person get blured. Can you help me with this problem?

    Thank you!