Can anyone help me with a photography question...

Lately I have been getting into some night photography, trying with my camera to capture shots of stars etc....

But I have been having a problem I can't seem to get past.

In some of my shots, there will be weird trails behind the object ( stars, satellites). Now these are not star trails.... so I'm guessing it has something to do with the atmosphere affecting satellites...

The weird thing is that the trails won't appear on every satellite. When they appear on a few satellites you can see them... they will all be uniform. But on a few photos every satellite will be fine except for one.

Some have really erratic large trails behind them.

So have I caught something weird in them?

My exposure time is always the same 15 seconds. All my other settings are always the same.

Whats up?

Hey Dulcimer.
Is your tripod really really stable? And are you using a cable, or remote release?

also Could you post an example?

I take a lot of night shots too. I should be able to help you with this.

I have been doing it using a self timer. The camera has been steady.

I would post a sample but I have not resized them and I am on dialup now. I was just wondering what causes it.

Thats a toughie without seeing an example.

Most of my issues were with, a cheap tripod..the would slowly droop while the shutter was open..Or the wind..again cheap tripod.. Or, with a vibration set off by me pressing the shutter.

If you get a chance, try posting a sample..

I guess my question would be if movement could disturb only one object in the photo. Would that be possible?

That would seem VERY improbable to me.
Seems that a movement would leave a trail for all objects in the image.
And the trail would have the same pattern for every object.

Although..If some of the objects are dim enough, the movement might only register for brighter objects. depending on your camera settings..

May be iridium satellite flares ?

Satellite flare is the phenomenon caused by the reflective surfaces on satellites (such as antennas or solar panels) reflecting sunlight directly onto the Earth below and appearing as a brief, bright "flare".

en.wikipedia.org...

The link has a photo, which should help you determine if this is the effect you are seeing.

Also has a link for predicting these flares, which could help in ruling them in or out.

Dulcimer, when you get a photo ready to post, it'd be great
if you could post it in the Space forum.
( I'm rarely on BTS, but have great interest in all things Space.)

Again, on the promotions !