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  1. #1

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    Stars moving across the sky

    I want to get a shot showing stars streaking across the sky. I would like to do this on Delta 100. Problem is that the reciprocity failure chart only goes to 150 seconds, and I think I would need an exposure longer than this. How would I get the exposure for a shot like this?

    Also, might I need a neutral density filter for this?

  2. #2
    Dan Henderson's Avatar
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    make sure there are no bright lights nearby, close down to f/11 or so, and leave your shutter open for 15, 20, 30, 45 minutes or even longer. Obviously, the longer the shutter is open, the longer the star trails will be. 150 seconds will not be long enough for appreciable movement of the earth to make the star trails.


    web site: Dan Henderson, Photographer.com

    blog: https://danhendersonphotographer.wordpress.com/

    I am not anti-digital. I am pro-film.

  3. #3

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    Are you after comets or the "fixed" stars and star trails? Star trails are caused by Earth's rotation.

    You will not need (or want) a neutral density filter for photographing star trails. I would recommend a fast (i.e. large aperture) normal or wide angle lens and a good tripod. A time or bulb exposure setting for your shutter and a locking cable release are also recommended. Use a fast film, Kodak Tri-X works well, BTW. Fast color films also work well, but if you areshooting color neg, be sure to tell the processing lab that you are shooting star trails.
    Tom Hoskinson
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  4. #4

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    I'm after fixed stars. My assignment is to get motion blur. I though a shot of the stars would be great for motion blur. I need to use a B&W film, which will be souped in 1:1 Kodak D-76.

    Also, why would I use a fast film when my goal is to get motion blur?

  5. #5

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    Shoot a stop or two away from wide open, point the camera up at a relatively light-polution-free night sky, and hold the shutter open for a number of minutes... At least 10 minutes, the longer the better.

    The next few days are going to be great as far as moon illumination.... An LV floating at around -3, so you can catch some scenery while you are at it.

    400 speed Tri-X film might work better... the increased toe speed will give you more stars and the reciprocity will reduce the sky glow (one case where reciprocity failure is a good thing )

    The other day, I took an 8-minute exposure...

  6. #6
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    You may also want to aim the camera at the north star (Polaris) to get the hub of the wheel and wheel effect.

    Below is a photo (and a the link to) of a 2 hour exposure of stars and Old Faithful Geyser that erupted 2 times. The photo was taken on Ektachrome Plus 100 Professional. I had to play all kinds of games and guess for exposure due to the fact that there are lights around Old Faithful all night and I shot the image with a Rodenstock f 6.8 90mm Grandagon N MC on a Linhof Super Technika IV 4 X5. The film was under exposed by about 2 stops and pushed 1.

    Here is the link for any subscribers:

    http://www.apug.org/gallery/showphot...0&ppuser=11550

    Anyone else can check the attachment.

    Rich
    Attached Thumbnails Attached Thumbnails OLDFAITHFUL.jpg  
    Last edited by naturephoto1; 11-03-2006 at 11:42 PM. Click to view previous post history. Reason: Added Camera
    Richard A. Nelridge
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  7. #7
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    If you measured the part of a circle that is drawn out by the stars in Richard's photo, you'd find that they rotate relative to the earth's spin axis (which is pointed at the north star Polaris) at 15 degrees per hour. You'll also see from wirehead's shot that 8 minutes doesn't get you long streaks, about 2 degrees of earth rotation. Find a dark place and use an exposure that gives you the length of streaking that you want. If you have enough time for multiple shots, bracket with the aperture by +/- one stop.

    Lee

  8. #8

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    Quote Originally Posted by reub2000 View Post
    I'm after fixed stars. My assignment is to get motion blur. I though a shot of the stars would be great for motion blur. I need to use a B&W film, which will be souped in 1:1 Kodak D-76.

    Also, why would I use a fast film when my goal is to get motion blur?
    Stars are rather dim light sources. That is why I recommend a fast B&W film like Tri-X and a fast lens. Good advice from Lee BTW to point the camera towards the North Star and leave the shutter open for a long time (several minutes at least, or even an hour).

    I have a North Sky star trail shot that's been published. Shot it with my Hassleblad on Tri-X with the 80mm 2.8 lens wide open for about an hour. I gave the film a 2 stop push in Ilford Microphen. Shows long star trails around Polaris and some Aurora Borealis (lucky shot).

    An alternative is to set up a tripod and photograph car headlights and tail-lights from a bridge or overpass using long exposures on high speed film. You will get lots of motion streaking.
    Tom Hoskinson
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  9. #9
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    Okay, you guys now have me in trouble. It's 2:00 AM EST on Saturday morning (Nov. 4. 2006). I just set the F3 w/Kodak 400TCN up in the freezing backyard on "T" setting. It's been about 4 minutes and counting.

    I'm sitting inside (the good part of this kind of shooting) and counting down the minutes (or hours! :o )

    I sure as heck hope I get something other than a bright haze since we seem to have a nearly full moon tonight!

  10. #10

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    Quote Originally Posted by copake_ham View Post
    Okay, you guys now have me in trouble. It's 2:00 AM EST on Saturday morning (Nov. 4. 2006). I just set the F3 w/Kodak 400TCN up in the freezing backyard on "T" setting. It's been about 4 minutes and counting.

    I'm sitting inside (the good part of this kind of shooting) and counting down the minutes (or hours! :o )

    I sure as heck hope I get something other than a bright haze since we seem to have a nearly full moon tonight!
    Let us know how it turns out, copake!

    On Thursday afternoon Nov. 2, my wife and I attended the Ribbon Cutting ceremony at the newly refurbished Los Angeles Griffith Observatory. The waxing Gibbous Moon was a visual treat in the eastern sky. The Celestron folks had about a dozen of their telescopes set up on the Griffith lawn, pointing at it. I didn't take a camera!

    BTW, the Griffith's new Carl Zeiss Planetarium is spectacular!

    http://www.griffithobs.org/

    http://www.griffithobs.org/
    Tom Hoskinson
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    Everything is analog - even digital :D

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