Star trails

mentos_007 · Sep 4, 2004

Hi! I hope you'll help me. I'm fascinated by some shots of star trails and... I wanna have my own

Unfortunately my digi cam allows me to take only 2 sec. exposure so it fails in this case. But I heard about program called Image Stacker. Did anyone of you use it? I visited it's website, but I want to have a real, non-commercial review from you mates.

The second thought is my Zenith. It has b-setting and it's smallest apperture is f/22. How shoul I set those parameters in night so that I won't overexpose the film (and what iso)? I live in a non light polluted area so light from buildings won't disturb.

malachite · Sep 4, 2004

For some serious star trail action use slide film. In a non light poluted place, open that lense up to like f/4 or f5.6 With 100ISO film you can go for hours. If you're gonna do an all-nighter with one frame, I'd go f/8. Focal length plays a bit of a roll too. Stick with 'normal' to slightly 'wide angle' for the most prominent trails. And stick to the week of a new moon for exposures going into the hours for the 'completely around' effect.

photobug · Sep 4, 2004

Go with small aperture & a wide angle if you have one. Lock the shutter open (cable release very useful here) and don't jiggle the tripod.

Point North or South to get circular paths, East or West for straight ones. In between gives angled tracks.

Use iso 100 film. Reciprocity may cause color shifts no matter what you do.

Have fun & don't forget to share.

malachite · Sep 4, 2004

Go with small aperture & a wide angle if you have one.

Hahaha! Guess we read different books :wink:

I've gotten good results both ways but lean towards the middle ground.........

Sk8man · Sep 4, 2004

guys, there's one problem. our camera can give us a maximum shutter time of 2 seconds and in order to capture the stars we need a little longer than that.

i know that a closed aperture and a long time exposure will do the trick but we have no ability for the long time.

photobug · Sep 4, 2004

Oops! Hate them brain cramps! I meant large aperture, not small. Good Catch Mal, thanks!

If you can't do long exposures you're pretty much stuck doing the 8 bazillion shots and stacking them as layers in Photoshop thing. Never tried it, but I've seen examples of the results and it does work.

Corry · Sep 5, 2004

So...you can do exposures that are hours long and it won't make the entire picture look like daylight???

mentos_007 · Sep 5, 2004

Sk8man said:
guys, there's one problem. our camera can give us a maximum shutter time of 2 seconds and in order to capture the stars we need a little longer than that.

i know that a closed aperture and a long time exposure will do the trick but we have no ability for the long time.

but I'll be using Zenith

it has b-mode

Our digi isn't good for that

mentos_007 · Sep 5, 2004

I herad that I could open the apperture at f3.2 for example, and set exposure speed on... let's say... 30 minutes on iso 100 and I won't overexpose it... Is that true?

Digital Matt · Sep 5, 2004

As long as there is no light pollution, I doubt your going to over expose anything in the dead of night. The longer you expose, the longer the trails.

mentos_007 · Sep 5, 2004

ok I'll try... and one more question: is there any difference in b&w film and color one in night shots of star trails? Night sky will be black or dark blue?

malachite · Sep 5, 2004

It's all about the moon. The night shots you see where the sky is blue is during the week of a full moon. 2 days before, the day of, and 2 days after. Those are about the only days you're going to get a blue sky and/or make the sky look blue.

With half a moon or less, you'll be hard pressed to to get any color but black out of the sky. I've got a shot over in the time exposure thread in themes that was taken during a half moon. 40 minutes @ f/5.6 and I could have gone twice as long for more star trail action without making the rock any more exposed than it already is.

You also get different effects with daylight film compared to tungsten film as well. Daylight film will turn the sky really blue with moon light but if there's not enough moonlight, reciprocity will take over and make the sky either green, brown, or some other puke like yellowish goo, it ain't pretty. Tungsten on the other hand will give you the closest thing to "what you see is what you get" to a certain extent.

I could go on for hours (as if you couldn't tell) as there are so many variables that can only be truely learned by going out and doing it yourself. Everytime I got out I learn one more 'trick of the trade'. The learning so far has never stopped. My suggestion, start out with you've gathered so far, scan and post a few and we can all compare notes. :wink: