Astro: Bulb vs. Shutter speed

[Akrnnr]

Okay guys I need help. Usually i can find the answers to stuff like this on elgooG but not this time. I was out taking some astro photos this weekend and couldn't get anything with a set shutter speed. Settings were 18mm/f3.5 iso 3200-6400, 5-25"

I wasn't getting any light (black foreground and a handfull of "stars") so I just kept bumping up my shutter time. I finally got to bulb and guessed around 30sec... overexposed foreground. (But set 25sec had a black foreground) I kept playing with the length on bulb and 10 seconds worked great.. but still a set shutter speed of 10sec didn't work.

Why would a set shutter speed be different than bulb? I would like to be able to use my set shutter speed for stacking and timelapse purposes. Any advice is appreciated (on this or on how to improve this photo).

Here's what I ended up with for the night Nikon d5100 18mm/f3.5 iso6400 ~12"

 

[480sparky]

B (bulb) is usually used for exposures longer than 30 seconds. Not many cameras have settable speeds longer than that.

 

[Akrnnr]

I understand that, but when I set my shutter speed to 10 seconds I got a mostly black image. When I used bulb for the same amount of time I got the photo above.

 

[480sparky]

Post an unedited black image, or at least the exif data for it.

 

[Alexr25]

when I set my shutter speed to 10 seconds I got a mostly black image. When I used bulb for the same amount of time I got the photo above.

Are you sure you set the shutter speed to 10 Sec and not to 1/10 Sec?

 

[Derrel]

when I set my shutter speed to 10 seconds I got a mostly black image. When I used bulb for the same amount of time I got the photo above.

Are you sure you set the shutter speed to 10 Sec and not to 1/10 Sec?

Diz-ACTLY what I was thinking, all the way.

 

[TCampbell]

You should clearly hear the click when the mirror swings up and shutter opens.... Count 10 seconds, and hear another click when the shutter closes and the mirror swings back down.

 

[wfooshee]

The display will use the " mark to show seconds as the shutter speed. 10 is 1/10 second, 10" is 10 seconds.

 

[Dikkie]

Maybe it was the self timer that was set on 10 seconds? Or something else must have been done mistakenly wrong.

Yesterday, I forgot to get off my lens cap for my first night exposure... Hmm, black... need a longer shuttertime then... Hmm, still black those things just happen, probably only to me.
Anyway, did you try turning it off and on again?