Night time exposures...

To conserve battery power - read your manual, and turn off everything except the shutter and diaphragm.

The review screen is VERY power hungry, on any camera. The lit LCDs for your controls are also power hungry. You don't need to see the settings on there provided you know the starting point...just count the clicks for shutter adjustments and then count the clicks for the aperture adjustment. A small torch will allow you to see them if you are not confident.

How many of you DO NOT KNOW which way the control wheel turns to increase your shutter speed?
How many of you DO NOT KNOW which way to turn the control wheel to change the aperture?

You don't need to admit it here! All I am saying is, you should be able to make adjustments without looking, you should habitually count the clicks as you rotate the controls - aperture and shutter. Thats it. That is all you need to do.

Focus - use hyperfocal focussing and everything will be dandy. Don't know what hyperfocal focussing is? Look it up then! Go and find out about it NOW. You will increase your manual focussing speed immeasurably - wide angle lenses? What do you need autofocus for? At f8 everything from about 3 feet to infinity is in focus...
 
Hi Guys, Recently I've tryed for some long exposures (1min+) and have noticed random speckles of colour, not like noise but more like sporadic burnt pixels in either pure red green or blue.
Does anyone know what causes this or how to avoid it??? I'm using Canon 40D and have encountered the problem at a range of different ISO settings. I don't see the problem when shooting less than 1 minute. I would apprieciate any advice you can offer.
Cheers
 
If any of you are on Flickr (or even if you're not), there is a guy on there called AndWhyNot who does some amazing long exposure night time stuff. It's worth a look through his photostream for anybody interested in this kind of thing
 
Robteasdale - it is the long exposure noise. There might be something about it in the manual for your camera. Some bodies have a long exposure mode to tone this down.
 
It is in fact hot pixels. bit of a problem with long exposures on a dSLR. Same with amp glow.

Its due to the sensor warming as it's switched on for such an insanely long period of time.

Have a google of 'Black frame or Dark frame noise reduction' and it will answer all your questions!
 
what do you set for white balance when doing these pitch dark shots?
 
Thanks for your help guys, I've found the "Long-Exposure Noise Reduction" feature but it seems to compromise the overall sharpness of the shot. The 'hot pixels' do seem reduced though, so thanks for your advice.
 
what do you set for white balance when doing these pitch dark shots?
I shoot Raw and then set the WB during processing. I find that better for me as different scenes suit different WB. Remember its very much an artistic interpretation.
 
So I lit a candle in my room but was only able to get a max of 30secs before the display flashed bulb. This was the max time regardless of the iso and fstop settings....how is everyone here getting the longer exposures?

*edit* Just Googling Bulb mode and it seems the way to go??
 
You need to use the 'Bulb' setting and a remote control. Use a watch or timer to monitor how long you leave the shutter open.
 
Using 68lbs example:
1600 iso to 100 iso is 4 stops 1600 - 800 - 400 - 200 - 100
f2.8 to f11 is 4 stops 2.8 - 4 - 5.6 - 8 - 11
Say the shutter speed was 1 second in the original shot you need to increase that by 8 stops: 1 - 2 - 4 - 8 - 15 - 30 - 60 - 120 - 240 secs or 4 minutes.

HTH

I did a roughly calculated 5 min exposure yesterday of a tree outside my bedroom window, which I was happy with, but now I have two more questions:

1) Does the time double per stop? i.e. after 240 it is 480?

2) Does the iso and fstop need to be changed the same number of stops? Chaning the ISO from 1600 to 100 is 4 stops, but going from f3.5 to f20 is lot more. Will this matter, or is it just a simple matter of adding the two sperate stop movements in order to get the total number of stops for the shutter speed?

TIA :)
 
1) Yes

2) Don't understand the question. If you take a test at iso 1600 f/2.8 you will need to change to say iso 100 f/11 for a decent shot. This will result in underexposure of 8 stops. So to compensate you will need to lengthen the shutterspeed by 8 stops. ie: double it 8 times from whatever it was.
 
Thank you.

What I meant by the second question was if I went from 1600 f/2.8 to 100 f/20 would I then have to compensate by more than 8 stops....i..e whatever the total number of stops was? Or is there a golden rule/limit? (Hopefully I haven't confused you more!)
 
From 1600 f/2.8 to 100 f/20 is more than 8 stops... it's 9 + 2/3rds

...which then gets messy for calculating in your head which is why you'd be better off going for f/22 to keep everything in whole stops. Doubling :)
 
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