Long exposure problem

Steve M · 22 Jun 2014 at 09:07

Recently bought a D5200 and a 35mm f1.8 lens and took it out last night to get some long exposure shots. I'm having an issue with the images when using bulb mode.

At a glance this one looks ok but when you zoom into the image there are dots all over it..

These dots are not present when using shutter priority on exposures of up to 30 seconds and only appear only on bulb mode on shots of a minute or longer.

This one was a 6 minute exposure, ISO 100, f22

Zoomed in on the water. These dots are all over the image:

Any ideas?

Steve M · 22 Jun 2014 at 09:28

Not reflections of the stars. Completely cloudy, plus the dots are all over the image.

No I didn't. Is it simply noise/hot pixels?

Steve M · 22 Jun 2014 at 09:33

The NR hammers the battery, especially on a 6 minute exposure.

Will try the shot again next week with the NR on.

Steve M · 22 Jun 2014 at 09:38

Wilhelm said:
Even at ISO100 you'll get noise if the exposure is long enough, so it could well be that.

Also, and this may sound silly, but you could check/clean your lens with a blower brush in case it's dust fragments.

The lens and camera are brand new, so both very clean.

I will try again with the NR on. Still learning and this is the first time I've ever taken a shot in bulb mode on a camera.

Anyone have any experience of how effective the NR is in a shot of this kind?