night photography rule of thumb

[amikhchi]

I am going to be hiking up a mountain overlooking the SF-Valley and I want to take a shot of the *night-valley* I was just wondering before i go up there i was going to practice some night shots of my backyard view. What should my settings be (i know it's different for each shot, but generally). It seems like 10-20 seconds, but as for the f and iso what should those generally be at. I would assume lowest ISO possible to reduce noise, but then wouldn't the picture be too dark? as for the f-stop, i don't really know what that does, but i do know that a lower number blurs out the background more

*i'm new to photography, so i don't know all the terminology and what each setting does*

[chauncey]

You give no indication about what gear you will be using... :confused:

[0o0o0]

Use a tripod... Set the ISO to be the lowest possible. Since you will be on a tripod for long exposure shots, you dont have to worry about under exposed photos from ISO... Use about f11 to capture the whole scene

[amikhchi]

oh, i'm using a canon rebel xs, i don't know which lense i should use:
50mm f/1.8
18-55mm f/3.5-5.6 IS
75-300mm f/4-5.6

those are the lenses i have available, but i don't know which one to use
i have a tripod but it's a cheap target tripod (dunno if that matters)

are HDR images doable w/ nightshots?

[syee99]

oh, i'm using a canon rebel xs, i don't know which lense i should use:
50mm f/1.8
18-55mm f/3.5-5.6 IS
75-300mm f/4-5.6

those are the lenses i have available, but i don't know which one to use
i have a tripod but it's a cheap target tripod (dunno if that matters)

are HDR images doable w/ nightshots?

If I had to guess (and I don't know what kind of pictures you'll be taking), I'd probably go with the widest lens (which is the 18-55)

As long as the tripod is large and sturdy enough to support your camera, you should be OK. Just make sure it's not too windy, and that you at least set it on timer to take the shot rather than press it to take the picture to reduce any shake or possibility of vibration.

[gh patriot]

Mirror lock up would also be advisable in this shooting situation.

[amikhchi]

what exactly is mirror lockup?

I'll try out what you guys were saying, should i shoot in manual mode and set the highest # (which i guess is the smallest) aperture and then just whatever shutter speed necessary, or should i shoot in AV or TV mode?

[syee99]

I'm still a noob, so I shoot in Av mode.
If I'm not mistaken, mirror lockup basically flips up the mirror before the shutter opens and flips the mirror back down after the shutter closes to prevent any movement/vibration in the camera during the time the shutter is open.

The mirror being used for the image you see in your viewfinder.

Pros - correct me if I'm wrong. :)

[gh patriot]

Im no pro but I do use the setting for long exposure shots at night or any long exposure for that mattter. Its a custom function that you must enable. You first get your shot focused and composed, then the first press of the shutter button will lift the mirror out of the way of the sensor and keep it up. Then you will want to wait about 2-5 (approx) seconds to allow all vibrations to dissapate. Then (I use a cable shutter release) the next press of the shutter button will open the curtains and expose the sensor to record the image.

This process reduces vibrations from what is refered to as mirror slap, which is caused from the mirror hitting the foam strip which stops the mirrors travel upward. Someone maybe able to explain this better than me but using the mirror lockup will help make long exposure images sharper by reducing vibration.

[Nacnud]

Either use the self timer or a cable release to fire the shutter. Pushing the shutter button wobbles the camera and blurs the image; a decent tripod blurs the image less, but it still blurs the image.

Take one of those hot-shoe spirit levels as it's almost impossible to tell if the horizon is straight.

Focussing in the dark is a nightmare.
Auto focus can be done using the centre focus point (most sensitive) on a distant light.
Once the camera gets focus, flip the lens to manual focus and recompose.
Don't zoom once you've got focus as this will upset things.
I've found focussing manually really hit-and-miss, especially on lenses with no distance scale. If you have to resort to focussing manually then stop the lens down to f8 to allow for a bit of error instead of leaving the aperture at its widest setting.

Check the composition and exposure by taking test shots at your highest ISO (e.g. 1600 ISO)
This will be VERY noisy but don't worry.
Once it looks about right then turn the dials to add a stop to the exposure and remove a stop from the ISO. e.g. On my camera that is three clicks longer exposure and three clicks less ISO. The changes should balance each other out. Repeat until the ISO gets down to 100 leaving you with with a VERY long exposure.
You can also use this technique to juggle changes in aperture.

If your camera has a longest shutter speed of 30seconds (like both my EOS cameras), then I'm afraid you've got no choice other than to use a cable release and time it manually - take a stopwatch (I use the one built into my mobile phone).

Have a good read over at
http://www.liquidinplastic.com/2008/06/startrails/
http://www.danheller.com/star-trails/

Finally - take a torch and some warm clothing ;)

Have fun !
Duncan

[Nacnud]

Sorry - I forgot to mention.......
Here's some I prepared earlier :D:D:D:D
http://forums.dpreview.com/forums/read.asp?forum=1032&message=30696708