Failed Star Trail

[delphicwhisky]

Hello people

Recently I read a little article on star trails and was just wowed by the great effects you can get when shooting one so I decided to get my self a tripod and a wireless shutter release button to try it out for my self.

Well, I tried it last night and the results were horrific.

1st attempt: Exposure at about 25 minutes in bulb mode at F4 and kit lens at 24mm with ISO at 800.
Result: TOTAL BLOWOUT! It was all white.

Tried bringing ISO down to 100 then.

2nd attempt: Exposure at about 20 minutes in bulb mode at F11 ISO 100
Result: Almost entirely white with a single dark star trail barely visible

3rd attempt: Exposure at about 18 minutes in bulb mode at F20 ISO 100
Result: Reasonably darker image with 2-3 horrible star trails.

What am I doing wrong?

Most people recommend shooting hundreds of images at 30 second exposure each but I can just not find a way to make my camera do that on my own.

Any help with this would be highly appreciated.

Thank you.

[delphicwhisky]

Sorry, forgot to add the camera is a Nikon D3000.

Thanks.

[Nicole]

Depending on where you're trying to take those shots, it might just be that there's too much ambient light (either from the surrounding area or even from a full moon). It kind of sounds like you might need to find a spot that suffers from less light pollution. This might be helpful to you: Visual Astronomy: Find a Dark Sky Site Near You

[OsmosisStudios]

I was shooting downtown the other day with similar settings and was getting UNDERexposed shots. You've got far too much ambient.

[delphicwhisky]

Thank you for your responses. I am located in the UK and can not find a link to darker skies in the link posted above

Could you please tell me how I could make my camera take multiple photos automatically; all with say 30 second exposures? e.g. 100 images at 30 seconds each.

Thank you.

[scootermcq]

You can use an interval remote

Remote Control Shutter Timer for Nikon D3000 Camera # on eBay.ca (item 120705868342 end time 01-May-11 05:22:01 EDT)

[navcom]

Another thing you can do is close down that aperture. F/4 is wide open. Try something around f/11-13. That will dramatically cut down on the light and might help get your exposure better.

But no matter what, if you have too much ambient light, it will always overpower the stars.

Here's one of my favorites. Notice how there almost appears to be a sunrise coming from the lower left. I live quite a ways from town and that was a lone porch light on someone's house about 1/2 a mile down the road. If one little light can do that, imagine what a whole neighborhood or city can do...

[ElCapitan]

Originally Posted by delphicwhisky

Could you please tell me how I could make my camera take multiple photos automatically; all with say 30 second exposures? e.g. 100 images at 30 seconds each.

Thank you.

If you don't want to buy an intervalometer, you cant set your camera to continuous shooting, set the camera to manual with a shutter time of 30 sec, and then lock the shutter release cable.

A tip to find out what ISO and aperture you are going to need is by taking a test shot. Pick something like 4 seconds (which is 3 stops down from 30 sec), the aperture you want to use (the aperture may be lower since you aren't doing a really long exposure), and then bump the ISO pretty high and test away. Take a few shots adjusting the ISO to where the stars are pretty visible in your shot, but you aren't getting excess light from anything else. When you find the right ISO, set the shutter speed to 30 seconds again and then lower your ISO by 3 stops. This will give you the exact same exposure as your test shots, but will allow you start capturing the movement of the stars.

If you are on PC, there is at least one program out there that will merge all the photos. If you are on Mac, there is an action you can get that does a really good job as well.