Star trails using red filter with hp5

[tim k]

One of the things on my bucket list is to get a decent looking star trail shot.

I've been working on this for several years. Its usually a once a year (at best) chance to get out with no moon, and no city lights. Needless to say my progress has been slow, and my results less than exciting.

Here is the shot I am envisioning. At the racetrack in Death Valley. Having one of the sliding rocks coming at you, pretty much in your face, slightly side lit, with a heavy full circle of stars in the background.

I have two or three ideas about getting there at twilight, and starting the exposure and just letting it run. But thats a bit of a guessing game as to when to start. And there is the artificial light idea on the rocks.

So here is my question. Has anybody tried doing a double exposure. First the foreground and sky, with a red filter, late evening while there is still enough blue sky so that the filter would keep the sky dark, so there would be some contrast between the sky and stars. Then later after it gets dark, burn the stars in over the filtered blue sky.

Anybody think that would work.
Thanks

 

[dehk]

Sounded like a good idea, probably lots of tweaking. Do it!

 

[holmburgers]

You mean like this?

http://apod.nasa.gov/apod/ap070508.html

 

[hpulley]

That nice APOD photo is not star trails though. They used a drive to track the stars and then digitally combined the images rather than attempt a double exposure.

I'd be afraid to remove a screw-in type filter without moving the camera. A Lee or Cokin system might let you remove it more easily? Or a very heavy tripod might help.

 

[holmburgers]

Good call, but the sliding rock... heck of a coincidence.

 

[Jeff Bannow]

Interesting shot.

I have nothing useful to add, except that I too am curious about this idea.

 

[Kevin Kehler]

There was an issue of Black and White Photography a while back (I'm not near my house so I can't tell you which one) where a guy takes shots in the desert at night. They tended to have a lot of foreground detail as well as star trails. If I remember correctly, he used winter nights so he could get longer exposures, calculated when the moon was either not in his shot (behind the camera) or when it would rise after his shot was concluded and used a compensation developer to eek more detail out of the foreground. I remember the article because he mentioned going to sleep in a tent with no flashlight (no flare) and having to set an alarm to get up prior to the sky brightening because of sunrise. IIRC, it was 7-8 hour exposures.

 

[tim k]

I picture the rock something like this http://apod.nasa.gov/apod/ap020410.html

And the stars more like this http://www.google.com/imgres?imgurl...a=X&ei=TfFBTdzPKo3SsAPf89HoCg&ved=0CCQQ9QEwAw

 

[tim k]

Kevin, I've done a bit of testing with moon lite for the foreground, and had some success. But the day I will be there, the moon will be somewhere else.

 

[tim k]

Hpully, I think I could just hold the filter for the first exposure.

 

[tim k]

You mean like this?

http://apod.nasa.gov/apod/ap070508.html

Thats an interesting shot, and while interesting in its own right. I hope to get my shot on one sheet of film. Without the help of electricity.

 

[Kevin Kehler]

Because I am somewhat obsessive when curious, I dug through back issues and found the magazine issue I referenced. Chris Conrad is the name of the photographer, using 4x5 FP4+ or HP5+ in HC-110 and I quote:

"Pre-exposing the scene to build some shadow detail, he uses a combination of polariser and red filters - also adding split neutral density filters - to hold density down in the sky portion of the negative during his first exposure. After darkness falls, he opens the shutter again to catch the star and moon trails, often leaving it open for up to eight hours"

Something like this

 

[tim k]

Kevin,
Thanks for your efforts. Thats exactly what I was thinking about doing. So much for my original idea. I'm not sure I'm smart enough to start stacking filters, but perhaps I need to do some experimenting before the trip.

I googled Chris Conrad and came up with his website http://www.chrisconradphotography.com/ he has some great stuff on his site, but not a lot of insight on the process.