Need Help- Rebel Long Exposures - DPChallenge Forums

01/01/2006 08:49:47 PM · #1

For the first time I am trying out "bulb" exposures on my Rebel XT. My first attempts tonight of the bay at night were not good. I seemed to have gotten some
shake" in the photo, but that wasn't the only issues. How does one get those clear crisp blue night sky pictures with stars et al.
Any Pointers?
--jrjr

art-inept

Olympus C-5060WZ

Canon EF 35mm f/2.0

01/01/2006 08:51:11 PM · #2

i dunno about the stars and clear skies, but as for the camera shake, make sure the camera is in mirror lock up mode

rex

Canon PowerShot SD780

01/01/2006 08:52:30 PM · #3

I assume you were on a tripod? How was the wind? You also have to remember the earth moves so if it is a loooooong exposure then you will get star trails.

elsapo

Canon EOS-5D Mark II

Canon EF 50mm f1.2L

01/01/2006 08:55:11 PM · #4

for this photo,

i set up the tripod and set the camera on timer, that way you wont move the camera while clicking the shutter. a 30 second exsposure is enough to get stars, if I want star trails then I set it to bulb. (a good buy is a remote)

01/01/2006 09:02:08 PM · #5

I did use tripod. I did not mirror lock. I tried 2 minute, 3 minute and four minute exp. w/ 400 iso. I do have a remote which I will use next time.

01/01/2006 09:03:12 PM · #6

elsapo-
how much ambient light was there when you took that photo?

Prof_Fate

01/01/2006 09:29:06 PM · #7

Upping the ISO will increase noise, and noise is more prominent in dark areas (like night shots). Increaseing ISO is done to reduce the shutter speed - since this is not a factor, shoot at ISO 100.

I don't ahve the exact specs, but mirror lockup reduces the shake for exposures of 15sec to a minute - longer exposures it does not matter. On my 300 with the hack, the delay from mirro going up to the shutter releaseing is adjustable - i have not practiced enough to know haw much of a difference this makes. i am at 1.5 secs...my exposures have been below 25 secs at up to f10, no moon and well after sunset. I use a wired remote (off ebay, $10)

Make sure the gound is not shaking - a bridge is a bad place for long exposures, as are boardwalks, decks - anything that can move at all - your walking away from the camera can shake it.

Also, Shoot in RAW - you will likely want to WB a night shot, and this also gives you two stops of leeway for exposure.

A shot from last tuesday:
30 secs, iso 100, F5.6. WB adjusted, sharpened.

Message edited by author 2006-01-01 21:31:04.