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mattsartin
05-22-2009, 12:58 AM
question number one: how? do you have to havea cable release on bulband just hold it down a long time? can you use a wireless remote? i'm lost and curious. thanks in advance.

Bob
05-22-2009, 02:08 AM
Restate your question - what problem are you trying to solve?

mattsartin
05-22-2009, 02:21 AM
i want to take a picture of star trails and i don't know how

mpphoto12
05-22-2009, 08:12 AM
A cable release on bulb mode for however long. It will be a long time so get an ac adfapter for your camera so it doesnt die during the exposure. Also a good tripod and try not to do it in windy areas.

Ehcalum
05-22-2009, 09:24 AM
There are a couple of ways:


1. As mentioned, a cable release and a boatload of battery juice. A trail will start forming based on thefocal length. A longer focal length will show trails faster than a wide. Generally, the longer the exposuer thelonger and brighter thetrails.


2. Stack images. This is my preferred method.Instead of a single 45 min long expouser, take a series of smaller expousers of the same length and f stop (say2' at F8)and stackthem using Image Stacker or photoshop. If you have an interesting fore ground element, take a singlelonger exposuer, say 5' versus 2and blend that frame into the stack.


Makesure you have something interesting in the foreground. An egg timer helps with timing of expousers. Bring a book, caffinee, and warm clothes. In the northern hemisphere, the sky is better for starts in the dead of winter and not the height of summer. Having the NorthStar will cause full circles of trail and then arcs depending on how far the NS is away from the image.

mattsartin
05-22-2009, 03:07 PM
Thanks! sounds like i should wait awhile since its about to be the summer

Wes
05-22-2009, 09:04 PM
Check out this controler as you can program the number of exposures and the length of each one.


http://www.bhphotovideo.com/c/product/164271-REG/Canon_2477A002_Timer_Remote_Controller_TC_80N3.htm l ("http://www.bhphotovideo.com/c/product/164271-REG/Canon_2477A002_Timer_Remote_Controller_TC_80N3.htm l)

Colin
05-23-2009, 04:55 PM
This is, to date, one of my favorite star trails pictures.


Teton National Park, with a Rebel XT, with my first and only wide angle lens (and still with me today), the 16-35mm f/2.8..


A single exposure with a full battery seemed to work fine. I hung out in the rental car while it was shooting. To the naked eye, there wasn't nearly so much light. I could barely see the mountain range after getting used to the dark for about 20 minutes. I used the cheap canon shutter release.


http://i110.photobucket.com/albums/n87/boujiluge/_MG_7467TetonsStars-Wide-800x1200.jpg



Shooting ModeManual Exposure
Tv( Shutter Speed )993
Av( Aperture Value )2.8
Metering ModeCenter-Weighted Average Metering
ISO Speed100
Lens16.0 - 35.0mm
Focal Length16.0mm

Rodger
05-24-2009, 01:58 AM
That's beautiful Colin!


Time to take some money out of the 70-200 f/2.8envelopeand get a remote shutter! hahah

mpphoto12
05-24-2009, 03:45 PM
do yo have to focus on the North Star first? also i am going on a trip in the open New mexico and was wondering(since it is soooo clear out there due to lack of civilization) if i could get a cable relase for my point and shoot. The G9 that im going to purchase. ??? help becasue i thought that would be amazing.

Jon Ruyle
05-24-2009, 04:36 PM
I don't think the north star is relevant unless you want it in your picture.


I hope you'll post your reslults... I'd be interested to see them.

mpphoto12
05-24-2009, 05:09 PM
haha thanks i can only shoot by my house for now so idk how great they will be lol If ther efis surrounding light like from a town do i need to zoon in more to get rid of it or just stop down to like f/20 for a lonnngggg time lol

btaylor
05-24-2009, 10:33 PM
Stopping down isn't going to remove ambient light from a town/ city etc. That light is still going to filter into the shot and essentially reduce the time you can expose your shot for before everything gets washed out by ambient light. At f/20 you're going to find it difficult to pick up the light from the stars anyway unless you have a high ISO - which is the worst thing you cando for long exposures apart fromleaving the lens cap on.


The major downside of taking night shot near city lights is that you will see a lot less of the stars. Getting out of town makes a huge difference. I live in outback Australia and thestars are amazing if you travel into the middle of nowhere.

Jon Ruyle
05-25-2009, 02:18 AM
I live in outback Australia and thestars are amazing if you travel into the middle of nowhere.


Living there is a fantasy of mine. I envy your starry southern night sky. (I just looked in the mirror and I'm actually green. Hope that clears up before I have to go to work...)

mpphoto12
05-25-2009, 08:53 AM
could one of you maybe post some results? thanks

mpphoto12
05-25-2009, 11:41 PM
http://www.flickr.com/photos/mpphoto12/3564691791/ Jon.... Here are the results of the big dipper i got a picture of tomight





Edit: this one is better but you can look at the others as well http://www.flickr.com/photos/mpphoto12/3564692965/in/photostream/ feedback would be greatly appreciated

Jon Ruyle
05-26-2009, 01:56 PM
Okay, you guys have me hooked. I tried a few star trails last night and they came out okay but with not much aesthetic value. I think I need to try a recognized asterism as mpphoto12 did, or a wide angle with earthbound features included (as Colin did- I like that one).


What focal lengths and exposure times did you guys use? Colin's looks wider, and must have required a longer exposure (and a darker sky, I suspect). Did either of you try subtracting background glow?

Colin
05-26-2009, 03:43 PM
Settings...


Shooting ModeManual Exposure
Tv( Shutter Speed )993 (seconds)
Av( Aperture Value )2.8
Metering ModeCenter-Weighted Average Metering
ISO Speed100
Lens16.0 - 35.0mm
Focal Length16.0mm


It was on a Rebel XT, so 1.6 FOVCF... If I had a full frame body, I think I would have still kept the 16mm (wider), but gone horizontal.


I don't even know how to subtract background glow [:(]