I am trying to get some night shots of star trails. I am using a tripod, iOS setting of 100, A4 with a bulb setting. All my camera does is Auto focus the lense. The camera will not click. What am I doing wrong.?
Night shots
(11 posts) (8 voices)-
Posted 1 year ago #
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No expert here, but it's unlikely your camera can focus on a star in the night sky. I also suspect an ISO setting of 100 won't work at night either. Turn autofocus off and manually focus and I'd move the ISO up significantly......
The experts here can shoot me down for sure and I'd welcome that....
Posted 1 year ago # -
Establishing the focus is often the trickiest part. Try to locate a bright star or something that is far away in the distance, BUT BRIGHT. Press the shutter until it locks focus. Once you are happy with the focus point, turn off auto focus on the lens. Be careful not to change this locked focus by moving the zoom ring on the lens!
Next comes composition. So you got your tripod and cable release set already and you established your focus point. Now its compo time! Use the widest focal length available and the stars are the main item for this shot. Try to add something in the foreground if you can it really makes a complete image.
To avoid noise, hot pixels and faint star trails, you need to be careful what ISO and Aprature range to use. I have found ISO 200 and an F-stop no larger than 5.6 will often yield good results. Experiment first with 30 second exposures and then bulb. For faster experiments bump up the iso and stop down to F8 and F11 to see the results first. Happy trails! :)
Posted 1 year ago # -
Hi, I hope you have fun trying this. Here is what I do after setting up a composition--can't show you a picture because I don't have an online photo account: set focus to manual, focus as best you can on a bright star as Kanuck has suggested, or on a place you have checked out during the daylight, close to or at infinity. Set camera to an iso 400, f4.5, and bulb to 30 sec (this is what I found out works for a 10-20 mm range lens and on my d700). Assume you have an intervalometer, set it or your camera to a minimum of 100 photos, jpegs. Use startrails.exe (search the web for the free download). You need this number to get a decent trail. Startrails will stack the photos for you, simpler than using layers in photoshop.
Long exposures, like 60 minutes produce too much noise. Make sure you scout the site in the daylight, plan your composition. Take a flashlight, and be careful walking in the dark.
Have fun!
Posted 1 year ago # -
@yetibuddha - welcome to the forum and thanks for nice contribution
@sib - turn off af, use manual
Posted 1 year ago # -
Wow thanks for the input. Enjoy a fantastic 2012
Posted 1 year ago # -
Sib a nice wide lens like in the 10-20mm range Yetibuddha mentioned is ideal too. My 14-24mm does a great job for this kind of shooting. What kind of wide lenses do you have in your arsenal? :)
Posted 1 year ago # -
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A timely thread (almost). I was in the Caribbean this past week and had a few clear nights (most nights the marine layer obscures the stars) and tried this. I shot at ISO 800, and experimented with apertures of f4 to f9 and exposures of 25 to 70 seconds (+/-) using a D90 and a 17-35 (manual focus).
I found I was getting unacceptable levels of noise, mostly in the form of red, blue, and green "spots." Upon closer inspection these appeared to be in the same place in each shot, leading me to believe it's my sensor and not the technique. Anyone experience this?Posted 1 year ago # -
From past experience I always found that ISO 800 was a little bit too high of an ISO value and preferred the 200-400 range and an F-stop of 4 or 5.6. At ISO 800 I would get hot pixels and and other stranger noise factors in the shot.
Posted 1 year ago # -
Like everyone else has said, use manual focus. If your lens has a hard stop at infinity (mostly the older lenses) then focusing is easy- just turn the lens to the end. Most modern lenses can focus past infinity (to compensate for elements shifting slightly due to temperature variations), so you'll need some sort of focusing aid. For wide angles (anything wider than say 20mm equivalent on 35m full frame), you can just focus on something (such as a bright light source) far away using AF or live view if you can.
As far as exposure settings go, a good rule of thumb is about EV -7 in a very dark location, and a higher EV if you are closer to a city, or if the moon is out etc. For reference, EV -7 is 30s f/2.8 at ISO 3200. For a longer exposure which you will need for star trails, you'll need something longer than a few minutes, like 4min f/4 at ISO 800 or 32 min f/5.6 iso 200. Anything significantly longer than 30 minutes, I suggest doing with numerous shorter exposures (30s-2min) and combining them manually with dark frame subtraction. If you want to go that route, you'll need to do some experimentation.
Posted 1 year ago #
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