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  1. #1

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    weird lens rendering, nighttime

    Hey all, I've been doing a few tests with a couple lenses: Micro Nikkor 55mm f/2.8 AIS and Micro Nikkor 60mm f/2.8 AF. I did a couple night shots tonight and came back with two different renderings of light. The 55mm made the lights into this circular shape, while the 60mm made them into a hex type shape. I'm not sure if this is normal for AIS lenses? If anybody could chime in it'd be great, as I'm pretty confused right now.

    55mm -

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    60mm -

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  2. #2
    Sirius Glass's Avatar
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    It is called flare and the shape is often from the lens iris.
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  3. #3

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    Both exposures were 15 seconds in the same position, I thought it was strange how one was different than the other. I thought it might be because the 55mm is an older model. Thanks though.

  4. #4
    jp498's Avatar
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    The lens or filter was also slightly dirty or foggy. The shape of the iris determines the number of points of the star as well.

  5. #5
    Chris Lange's Avatar
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    also rounded aperture blades will deliver softer points, straight blades will define them more sharply.
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  6. #6

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    That's not weird. That's diffraction on very overexposed lights. The overexposure was necessary to expose deeper into the night scene.

    When I built a homebuilt reflector I used a 4 vane spider because with a 4 vane spider you get only 4 diffraction spikes but with a 3 vane spider you get 6 spikes. Such is one effect of diffraction.
    Last edited by pen s; 11-29-2013 at 08:15 PM. Click to view previous post history.

  7. #7

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    Chris, I looked at the blades on the 55mm and they're much rounder than the other lens, which is straighter. I've just never seen a lens render the light like that before.

  8. #8

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    Quote Originally Posted by Noah B View Post
    I've just never seen a lens render the light like that before.
    I think you might not have noticed this effect as much because the lights were not overexposed as much as they were in these photos.

    One more thought. Try taking the same photos but with the lenses wide open. That should not show the spikes.
    By the way, your 60mm lens has a 7 blade aperture, correct?
    Last edited by pen s; 11-29-2013 at 08:29 PM. Click to view previous post history.

  9. #9
    Mustafa Umut Sarac's Avatar
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    One of the strangest lens effect I have ever seen, I dont even want to write about colors. But may be reason for that stars are the modern optics of the street lights. They can be very angular diamond cut like shapes on the light source. If your light source was clean and point light source diffracted like this , this a bad japanese lens. In real optics , point light sources must appear as point images otherwise its a very bad optics. Look for point spread function. Nikon have the worst optics I have ever seen or used.

  10. #10
    AstroZon's Avatar
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    Just curious, but were you shooting through a window? A lot of solar films will cause starlighting.

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