Stars moving across the sky

Discussion in 'Exposure Discussion' started by reub2000, Nov 3, 2006.

  1. reub2000

    reub2000 Member

    Messages:
    646
    Joined:
    May 23, 2006
    Location:
    Evanston, IL
    Shooter:
    35mm
    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. Dan Henderson

    Dan Henderson Member

    Messages:
    1,888
    Joined:
    Feb 6, 2005
    Location:
    Blue Ridge,
    Shooter:
    4x5 Format
    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.
     
  3. Tom Hoskinson

    Tom Hoskinson Member

    Messages:
    3,879
    Joined:
    Mar 7, 2004
    Location:
    Southern Cal
    Shooter:
    Multi Format
    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.
     
  4. reub2000

    reub2000 Member

    Messages:
    646
    Joined:
    May 23, 2006
    Location:
    Evanston, IL
    Shooter:
    35mm
    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. wirehead

    wirehead Member

    Messages:
    169
    Joined:
    Apr 13, 2006
    Shooter:
    Medium Format
    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 :smile: )

    The other day, I took an 8-minute exposure...
     
  6. naturephoto1

    naturephoto1 Subscriber

    Messages:
    1,819
    Joined:
    Mar 26, 2006
    Location:
    Breinigsvill
    Shooter:
    Multi Format
    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/showphoto.php?photo=14274&cat=500&ppuser=11550

    Anyone else can check the attachment.

    Rich
     

    Attached Files:

    Last edited by a moderator: Nov 4, 2006
  7. Lee L

    Lee L Member

    Messages:
    3,247
    Joined:
    Nov 17, 2004
    Shooter:
    Multi Format
    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. Tom Hoskinson

    Tom Hoskinson Member

    Messages:
    3,879
    Joined:
    Mar 7, 2004
    Location:
    Southern Cal
    Shooter:
    Multi Format
    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.
     
  9. copake_ham

    copake_ham Inactive

    Messages:
    4,090
    Joined:
    Jan 26, 2006
    Location:
    NYC or Copak
    Shooter:
    35mm
    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! :surprised: )

    I sure as heck hope I get something other than a bright haze since we seem to have a nearly full moon tonight! :confused:
     
  10. Tom Hoskinson

    Tom Hoskinson Member

    Messages:
    3,879
    Joined:
    Mar 7, 2004
    Location:
    Southern Cal
    Shooter:
    Multi Format
    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/
     
  11. Helen B

    Helen B Member

    Messages:
    1,557
    Joined:
    Jul 1, 2004
    Location:
    Hell's Kitch
    Shooter:
    Multi Format
    It's not my normal thing, but sometimes I just can't resist it...

    Here's a shot taken in Sullivan County, New York last Christmas. The distant glow is from a neighbor's house. To the best of my memory it was around twenty-five or thirty minutes at f/5.6 on Fuji Pro 160S with a 105 mm Nikkor-W lens on 4x5. The finer star trails are lost on the web reproduction, as is the flashing of the plane's lights just above the tree line on the left (though the continuous red line of its port nav light is just visible). The 105 doesn't cover 4x5 very well at f/5.6, but it was the widest I had with me.

    Best,
    Helen
    PS You probably know this, but you must focus on infinity to the best of your ability. Because a star is a point source, any spreading of the light, even by a small amount, is a bad thing.
     
    Last edited by a moderator: Nov 4, 2006
  12. Lee L

    Lee L Member

    Messages:
    3,247
    Joined:
    Nov 17, 2004
    Shooter:
    Multi Format
    If you are willing to stand and watch for the entire exposure, you can use the "hat trick" used for long shutter speeds in the early days, covering the lens with a black cup or putting a paddle covered with black felt or velvet in front of the lens whenever a plane comes through your field of view. (I know Helen knows this, but I thought it might be a useful idea to mention for beginners.)

    I've seen star trail photos taken with the lens covered/uncovered in a pattern that spells out callsigns or other words in Morse code dots and dashes. That one's for copake_ham. :smile:

    The full moon will introduce serious sky fog from scattering in the atmosphere. It's much better to do star trails near the new moon.

    Akira Fuji, a frequent contributor to Sky&Telescope magazine, uses Softar filters to make his brighter stars "bloom", and his medium format photos more closely approach the impression of relative brightness received by the naked eye.

    Lee
     
  13. Donald Miller

    Donald Miller Member

    Messages:
    6,242
    Joined:
    Dec 21, 2002
    Shooter:
    Large Format
    Very nice shot Helen.
     
  14. Sponsored Ad
  15. Donald Miller

    Donald Miller Member

    Messages:
    6,242
    Joined:
    Dec 21, 2002
    Shooter:
    Large Format
    I made some star trail photographs back in the 80's on Fujichrome 50 and 100 and Kodachrome 25 and 64. So high speed films are not necessary, at least in my experience.
     
  16. NikoSperi

    NikoSperi Member

    Messages:
    576
    Joined:
    Mar 2, 2004
    Location:
    Italy
    Shooter:
    Multi Format
    Star trails in B&W

    I've done a few, including a couple with FP4 which I believe suffers even more from reciprocity failure. In effect, reciprocity failure can actually help you by combating the background sky glow from light polution. The stars themselves are actually quite bright. However, for the person trying this tonight under a full moon: forget it. You need a dark sky.
    A stop or two from full open is good, f/11 is probably too closed and you will lose most of the fainter stars.
    Another tip is a red filter can actually help reduce the light polution from artificial illumination, seeing you're using B&W film.

    Also, as Helen has said, focus is not as obvious as it seems at first. If you are using 35mm lenses, know that they usually focus quite a bit beyond infinity, and you won't see a darn difference in the view finder unless you have some serious magnification. (Tip: Google for "Hartman Mask" to construct a quick and dirty focusing aid)

    Final piece of advice: tripping the shutter, and then going inside to wait out the two hour exposure usually ends up with you waking up on the couch... around 10 AM. Shutter still open of course.

    Murphy's corollary to the above tip: Any cloudless clear night will immediately turn into a biblical deluge and/or hurricane Katrina the second you fall asleep.

    Murphy's second corollary to the first corollary: if nothing else screws up, you haven't yet discovered what refraction does with dew.

    Argh... have fun! You'll rip your hair out.
     

    Attached Files:

  17. vet173

    vet173 Member

    Messages:
    1,212
    Joined:
    Mar 29, 2005
    Location:
    Seattle
    Shooter:
    8x10 Format
    You said you had an F-3? I know when I was shooting sunrise at Mt Ranier, without the motor drive to provide power, the camera shut itself down due to cold. Temp goes down current draw goes up, camera will shutdown to protect circut. If it does you will be given only default shutter speed ( 1/90 ?)
     
  18. titrisol

    titrisol Member

    Messages:
    1,671
    Joined:
    Aug 2, 2004
    Location:
    Rotterdam
    Shooter:
    Multi Format
    About 1 h should give you the effect you want.
    Good luck!!

    But for motion blur, I think that "tracking" is simpler and works best.
    Have someone running in your yard and "follow" them with the camera, then shoot at 1/30 or 1/15 without stopping the follow trough motion.
    It works fine with cars as well.
     
  19. Lee L

    Lee L Member

    Messages:
    3,247
    Joined:
    Nov 17, 2004
    Shooter:
    Multi Format
    Which reminds me of another standard caution for this kind of work. If you have an LED (or other light generating) meter readout in your SLR finder, be sure either to disable it or test for leakage onto the film during long exposures. I have one body with an electronic shutter in which I have to remove the battery before time exposures to avoid a red LED bleeding onto the film. Fortunately that body still has mechanical B and 1/100 sec shutter speeds with the battery removed.

    Lee
     
  20. Jim Jones

    Jim Jones Subscriber

    Messages:
    2,428
    Joined:
    Jan 16, 2006
    Location:
    Rural NW MO
    Shooter:
    Multi Format
    Don't worry about reciprocity failure. As the image of the star moves, it exposes the film for a small fraction of a second. Reciprocity failure actually helps darken the background sky. Star trails are best done away from urban lights on a moonless night. Otherwise, exposure is limited by the brightness of the sky. Here in a rural area with dark skies I got several hour star trails on Kodak Tech Pan film exposed beteween f/5.6 and f/8 and developed in Dektol for a few minutes.
     
  21. reub2000

    reub2000 Member

    Messages:
    646
    Joined:
    May 23, 2006
    Location:
    Evanston, IL
    Shooter:
    35mm
    Not really possible here. To the south the sky has a nice red glow. Light pollution for Chicago.
     
  22. copake_ham

    copake_ham Inactive

    Messages:
    4,090
    Joined:
    Jan 26, 2006
    Location:
    NYC or Copak
    Shooter:
    35mm
    The best nights for shooting star trails up in Copake are in the dead of winter (crystal clear skies when it's not snowing!).

    Any thoughts on how long to put the camera out to become "acclimated" to the cold before opening the shutter? And is there a risk of the shutter freezing in the open position if it's too cold? (i.e. is there a "too cold").

    I "played" around with star (and moon) shots this past weekend with the F3HP - little "rusty" using the "T" position so blew a few shots. Still have half a roll to go.

    I want to try doing more of this - as winter sets in so advice on camera-care under those adverse conditions is welcome.
     
  23. naturephoto1

    naturephoto1 Subscriber

    Messages:
    1,819
    Joined:
    Mar 26, 2006
    Location:
    Breinigsvill
    Shooter:
    Multi Format
    Hi George,

    Best to let the camera acclimatize probably for a few hours before shooting if cold. But afterward return the camera to case or plastic bag and let re-aclimatize to indoor temperatures for many hours before taking it out in the warmth.

    It is also best to use a mechanical camera with a mirror lock up if it is an SLR. Or a camera that has a B setting that will not rely on battery power. Otherwise, the mirror may swing down when/if the camera battery fails.

    You can take photos if the moon is out but, it is best to wait until it sets. If you go back and see the photo that I posted of Old Faithful, the moon was almost full but it set at about 1:00 AM. That is why the image was taken between about 1:00 and 3:00 AM and I was able to record the image without any spill from the moon. Also, in this case, as mentioned the Geyser erupted 2X but I had to play games for exposure due to the lights around Old Faithful that run up into the trees.

    Good luck however and stay warm.

    Rich
     
  24. Lee L

    Lee L Member

    Messages:
    3,247
    Joined:
    Nov 17, 2004
    Shooter:
    Multi Format
    I can't give you a lot of advice about freezing shutters and mirror boxes. I've shot with my SLRs in -13F all day long without any problems, so they're not susceptible under normal circumstances. I did once work on a job with a Hassy that shifted to about 1 second on the 1/15 setting in -20 weather at sunset.

    Frost and dew are another concern. There are strings of resistors or insulated resistant wire that are used to warm telescope optics to just above ambient temps, and so above dewpoint. These go by various names like dew-tape or dew-chaser. They come in sizes to fit common telescopes and can be run off batteries or AC mains, with the attendant higher drain you'd expect from a resistive load. A deep cycle or a UPS lead acid battery come in handy here. I have a dew-tape that is long enough to wrap around the body and lens of a 35mm camera, so I use that on wet or frosty nights. There are plans online that you should be able to google, and being a ham, you should have no trouble putting one together. Some people use gutter heating tape cut to shorter lengths. This could also help keep batteries warm and mechanics working, but I prefer to work with mechanical cameras for this kind of work. Lately I've been using rangefinders with hot shoe finders for wide field astrophotography, which works very well. You can actually compose on the night sky through a decent hot shoe finder like the Cosinas and other good makes. That's tough to do even with most "bright screen" SLRs.

    Another good idea for dew prevention is the longest, "tightest" lens hood you can find, but those become less effective at preventing dew as your angle of view gets wider. On a telescope the long lens hood is called a dew shield.

    Rich's advice on a good plastic bag or case as you take the camera inside is a very good suggestion. Under severe circumstances you could get condensation on camera internals bringing a very cold camera inside to warm and humid conditions.

    Lee
     
  25. Jim Jones

    Jim Jones Subscriber

    Messages:
    2,428
    Joined:
    Jan 16, 2006
    Location:
    Rural NW MO
    Shooter:
    Multi Format
    To eliminate dew on the lens, I fabricated a large lens hood from a rectangular tin can and installed resistors dissipating one or two watts of power beneath the lens. Others say air from a small fan also works.

    I've never taken precautions when taking a camera from warm rooms into intense cold. Like Lee says, when bringing them back indoors, they should be protected from humidity until they are near room temperature.

    Considering the current prices of older high quality all mechanical cameras, buying one just for cold weather photography and long night-time exposures seems reasonable.
     
  26. reub2000

    reub2000 Member

    Messages:
    646
    Joined:
    May 23, 2006
    Location:
    Evanston, IL
    Shooter:
    35mm
    Seems like a good idea. Especially since my ELAN 7 uses power to keep the shutter open on a bulb exposure.