Star trails - confused

[TCav]

Originally Posted by MartinSykes

... I saw some tests with a dslr with a laser pointer attached which suggested the mirror slap was a pretty small effect and on a long exposure any shake from the slap should be lost I think. ...

That depends on the camera, the tripod, and the length of the exposure.

[TCav]

Distortion would be tough to see without any straight lines for reference, and I don't think it's the distortion that's giving me a headache when I look at your photo. But otherwise, I like it.

[MartinSykes]

Originally Posted by TCav

Distortion would be tough to see without any straight lines for reference, and I don't think it's the distortion that's giving me a headache when I look at your photo. But otherwise, I like it.

You can't really see the distortion I'm talking about in the posted shot but at 100% it looks like the trails on the right don't curve the way I'd expect - they sort of curve away from the centre instead of around it. I'll wait and see when I get better weather and some longer trails.

I know what you mean about the headache. Best I can describe it is that it looks like the stars are sharp and out of focus at the same time. I think maybe the gap in the middle where I dropped the frames with airplane has given it a sort of double-vision except that due to the rotation the offset is in a different direction across the picture so it messes with your head

[Ozzie_Traveller]

G'day Martin

Originally Posted by MartinSykes

OK, I think I've got it. Unfortunately within 5 miniutes of me starting, a beautiful still clear night had clouded over and half way through a low flying plane went through the middle.

Welcome to the club !!! - happens to the best of us

Originally Posted by MartinSykes

..... I think it's showing some promise

Yes - I'd agree with that too
I have dozens of startrails 'qwikkies' like yours - I don't keep 'em for too long as another better one soon comes along. But it's surprising how often 'something; comes along to muck it up

Just to put you in the mood, here's a recent one of mine ~ in outback Australia, 150km [100 miles] from nearest town, campfire on the banks of a small creek > hell of a life but somebody's gotta do it ...

Pentax w- Sigma 18-125mm at 18mm, f5,6 x 30sec x 100 images at ISO-1000 Exposure started about 45 mins after sunset

Regards, Phil

[MartinSykes]

Looks nice there Phil Funny that we're on opposite sides of the planet and both have what looks like a eucalyptus pride-of-place. Weather has turned for the worse here now so won't have another chance for a few days at least but will definitely be giving it another try.