star trails...

[justino]

[FONT=Geneva, Verdana, Arial, Helvetica, sans-serif]last night i messed with shooting some star trails, can anybody tell me what the three seperate streaks are in this image? are they airplanes? any suggestions on how to improve this shot?

ISO 400
f/4.0
1 hour exposure (104 - 30 sec exposures)

[/FONT][FONT=Geneva, Verdana, Arial, Helvetica, sans-serif] Thanks for looking!
http://www.justinorourke.com [/FONT]

 

[lostprophet]

my guess is they are planes and there a 5 of them that I can see

 

[flyingseale]

[FONT=Geneva, Verdana, Arial, Helvetica, sans-serif]last night i messed with shooting some star trails, can anybody tell me what the three seperate streaks are in this image? are they airplanes? any suggestions on how to improve this shot?

ISO 400
f/4.0
1 hour exposure (104 - 30 sec exposures)[/FONT]

They're more likely planes than cars
Seriously, if you're on a flight path and they normally fly this direction (left-right instead of up-down) then it's a good bet that they are from planes.
I'm a little confused why you needed to take 104 x 30 second exposures? What camera did you use?
BTW, nice trails. You must be pleased?

 

[abraxas]

Maybe satellites?

 

[justino]

I'm a little confused why you needed to take 104 x 30 second exposures? What camera did you use?

i used a 20d for this shot. the reason i took so many exposures is to keep the noise levels down. the noise would have been pretty bad if i just did 1 hr exposure....plus i wasn't sure how long my battery would last? so i just set the camera in burst mode and locked the remote shutter down and left it sit for a hour to shoot away

 

[lostprophet]

to be honest even with a 1 hour shutter speed if noise reduction was on there wouldn't be any noise BUT it would take 2 hours to take the shot as the camera then has to take a blank shot to cancel out the noise, which has to be the same shutter speed as the original shot

 

[Olympus8MP]

How did you combine the photos? This sounds like a good idea on how to combat the high noise levels found in digital cameras.

 

[justino]

to be honest even with a 1 hour shutter speed if noise reduction was on there wouldn't be any noise BUT it would take 2 hours to take the shot as the camera hen has to take a blank shot to cancel out the noise, which has to be the same shutter speed as the original shot

that's good to know! i haven't attempted night photography before...but i'll probably still do multiple 30 sec exposures and combine them in photoshop. that way i don't have to worry about my battery crapping out on me in the middle of a shot here's a link to a action i used to combine the 104 exposures:

http://www.schursastrophotography.com/software/photoshop/startrails.html

 

[MostlyDigital]

to be honest even with a 1 hour shutter speed if noise reduction was on there wouldn't be any noise BUT it would take 2 hours to take the shot as the camera then has to take a blank shot to cancel out the noise, which has to be the same shutter speed as the original shot

What? I'm sorry I do not understand that? To take an 1 hour exposure, you have to take an additional "blank" shot??

 

[justino]

What? I'm sorry I do not understand that? To take an 1 hour exposure, you have to take an additional "blank" shot??

i believe if you have the in camera noise reduction turned on after you take a shot it will take a blank shot for the same amount of time to try and cancel out the noise in your first shot. i hope that makes sense.

 

[MostlyDigital]

Ohhhhh I get it. Thanks for clearing that up. I dont think my 30d has noise reduction mode anyways.

 

[justino]

no problem. i'm pretty sure the 30d has it b/c the 20d has it. under menu, go to custom functions. in the 20d it's custom function #2, i keep mine off and use noise ninja to remove noise from images that need it.