Star Trails

[Harmony]

Hi everyone!

I have a question for film users:

I’ve been wanting to try a ‘star trails’ shot for quite a long time, now. My problem? I’m clueless. I’d like the trails to be quite long, and I’d be in a place that wasn’t residential (so no outside light influences… or very minimal, at least).

My camera/equipment is as follows:
Nikon FM2
B&W film @ 400 ASA
28mm (highest: f22)
35-135 mm (highest: f22)

Which lens would work better? How many hours should I keep the shutter open for? Is f22 still too large of an aperture? Any tips? Should I be going for a lower ASA film?

I need TONS of advice, please!

 

[RyanMTaylor]

I don't know anything about the lens side of it because I'm super new but I have read that if you aim your cam at the North Star you will get the stars streaking around the center of them. Something to try maybe.
Good luck on your lens info endeavor.

Hopefully kicking this back up to the top of the threads will help in that.

 

[astrostu]

Take a look at the Astrophotography Part II guide I wrote as an Article of Interest on this site. The guide was written for digital, but almost all the information is still relevant for film.

Edit: To answer your question about aperture more directly, you want to be almost wide open (smallest f/number). Remember that stars are faint, and they will be moving. A smaller aperture will limit the number of stars, but it will also limit the amount of sky glow. Fundamentally, the brightness of the sky due to light pollution will be what limits you in both exposure length and aperture.

 

[Harmony]

That was an amazingly informative link, astrostu. Thank you!

And Ryan, thanks for the idea bout the North Star. That sounds like something interesting to try.

Another question though: let's say I choose f/8 for the aperture. About how long should I leave the shutter open for?

 

[astrostu]

Another question though: let's say I choose f/8 for the aperture. About how long should I leave the shutter open for?

There is really no way to tell you this unless someone is in your area, photographing from the same location you plan on photographing, with the same moon phase out, with the same film.

In other words, the sky brightness is your limiting factor in your exposure length, and the sky brightness depends on city lights and the moon.

 

[Dionysus]

ive been too scared to play with really long exposures since i heard that too long can overheat and fry your sensor..i'm sort of waiting on a definite answer before i try going anywhere past 10 min.

 

[astrostu]

I've exposed more than 45 minutes with my digital rebel and there were no issues. IT was a tad cool out, not cold, so that may have helped, but to be honest I have never heard of people "frying their sensors" except urban myths spread on this forum. If you actually know of someone who has, or know of a reputable article that discusses it, please let me know. Otherwise don't worry.

Oh, and for the original poster, this wouldn't be an issue because you'd be using film.

 

[Harmony]

Great! I'll have to try it sometime on a clear night, then. It won't happen anytime soon... we've had rain for the last two weeks!

 

[zbo2408]

I've exposed more than 45 minutes with my digital rebel and there were no issues.

Sorry for hijacking... but I have been looking at buying a Rebel and all the Rebel's currently for sale by Canon have a maximum exposure time of 30 seconds according to the Canon website....

Am I reading the website wrong ... or what, how could you do a 45 minute exposure? I ask because I'm hoping you are right and you can do 45 minutes b/c I want to do these kinds of shots my self.

 

[Harmony]

As far as I know, Canon Rebels have a bulb feature... basically, the shutter stays open as long as you're pressing the button.

 

[astrostu]

"B" = bulb = expose as long as you want. I was confused about that, too, when I was looking at the Rebel a few years ago, coming from a P&S.

 

[RyanMTaylor]

Yeah, I use my Rebel XS with a shutter release on Bulb and expose for as long as I want.