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Thread: Night Vision for focusing?

  1. #1

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    Night Vision for focusing?

    Has anyone tried using night vision to help focus slow lenses in the dark? I've been thinking about getting some sort of pvs14 and trying it out. My main concern is getting magnification to work for critical focus and accounting for whatever ir focus shift/wavelength issues may arise.

  2. #2
    Drew Bedo's Avatar
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    Re: Night Vision for focusing?

    If it is OK to show a light, try a cheap laser pointer aimed back at the camera from the subject.

    The old press cameras often had a light on the Kalart range finder that projected twin beams at the subject; when the beams coincided into one dot, the camera was focused. In rtecient times, folks have used a laser pointer for that too.

    Other options are to pre-measure the composition in daylight and either pre-focus or use hyperfocal settings to get it in.

    The night vision gear uses infra-red wavelengths . ..would that introduce some error? Of course, whether it works or not, it gives you a reason to justify more cool gear regardless.
    Drew Bedo
    www.quietlightphoto.com
    http://www.artsyhome.com/author/drew-bedo




    There are only three types of mounting flanges; too big, too small and wrong thread!

  3. #3

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    Re: Night Vision for focusing?

    A PVS-14 is a light amplification device- it needs no IR, although it's IR sensitive (I suppose a low-powered IR laser at the camera could be used to create an invisible-to-the-naked-eye focus point). The PVS-14 has a resolution of ~64 -72 line pairs/mm and is generally used at infinity focus, so I don't know how well it would close-focus on a GG without some extra work.

  4. #4

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    Re: Night Vision for focusing?

    What Drew said. Get a simple laser pointer and focus the point at the subject.

  5. #5
    (Shrek)
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    Re: Night Vision for focusing?

    I carry dollar store flashlights in my kit at night. I place 2 or 3 in spots that need to be in focus, aimed at the camera, and when I can distinguish the individual LEDs in each flashlight I know that part is in focus. That plus judicious use of streetlights and the moon is usually enough. And if it's not, just twist the camera into a pretzel and say the OOF areas are intentional and artistic.

  6. #6
    Alan Klein's Avatar
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    Re: Night Vision for focusing?

    How about a night rangefinder that works at night. COuld you know where the settings would be for the camera in advance to set once you know the range?
    https://www.nightvisionguys.com/atn-...al-rangefinder

  7. #7
    jp's Avatar
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    Re: Night Vision for focusing?

    I'd also suggest the laser pointer or putting flashlights in the scene for focusing purposes and removing them before the photo... Sometimes a cheap flashlight is a nice effect though...

    https://flic.kr/p/2jfnQtX

    https://flic.kr/p/27PLUj7

    If people are involved, be sure to let them know they are going to be lit with a laser.. Someone might consider it a threat if you surprise them with a red dot and react by defending themself.

  8. #8
    Drew Bedo's Avatar
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    Re: Night Vision for focusing?

    Quote Originally Posted by Jody_S View Post
    I carry dollar store flashlights in my kit at night. I place 2 or 3 in spots that need to be in focus, aimed at the camera, and when I can distinguish the individual LEDs in each flashlight I know that part is in focus. That plus judicious use of streetlights and the moon is usually enough. And if it's not, just twist the camera into a pretzel and say the OOF areas are intentional and artistic.
    I will try out that LED flashlight technique!

    Love the OOF explanation too.

    My fall-back is to just not showanyone the images that don't work!
    Drew Bedo
    www.quietlightphoto.com
    http://www.artsyhome.com/author/drew-bedo




    There are only three types of mounting flanges; too big, too small and wrong thread!

  9. #9

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    Re: Night Vision for focusing?

    Never thought about using a laser pointer. That would totally work. Especially if you can get an assistant to hold it for you.

  10. #10

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    Re: Night Vision for focusing?

    Night vision devices won't give you the critical focus. You have to focus the eyepiece onto a grainy screen then focus the front lens on the image, which might be another ground glass. I love my ATN-Viper, which is about the same thing, but it's grainy screen/fuzzy image isn't going to help focus. I might try it though just to be sure.

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