Questions on exposure for low light photography

[sfhuang]

Hi pros out there,

I have two questions re: exposure for low light photography.

1. I've been playing with the Canon G2, and find that f/5.6 4 secs will generally result in 'realistic' pictures with dark skies and barely visible building edges. Longer exposures tend to give me more lighted skies and generally brighter pictures, but far less realistic. So what is the 'correct' exposure for night scene photography, or is there any such thing as a 'correct exposure' for night scenes at all?

2. How do I know what shutter speed and aperture value to set to get proper exposure for low light scenes on my film SLR? Is it guesswork or is there a technique to getting correctly exposed shots (I believe there is)? Other than using my G2 as a very expensive light meter, what other methods of gauging light can I adopt?

Thanks for any tips and pointers.
sf

 

[sriram]

1. Whatever suits your taste

2. On my old EOS-50E I simply used f/8-f/11 and aperture priority. Every single shot came out perfectly exposed (Provia 100F). Even difficult shots like fireworks. You can have a look at my fireworks shots here :
http://www.rsriram.ws/photo-albums/html/fireworks/new_page_1.htm

I'm sure most newer AE SLRs can handle these situations.

 

[Flare]

Another thing is how well lit the "night scence" is and your personal prefrence... Some people may try a longer exposure to get a more surreal feeling... (images that one's eye will not see naturally) or some other effects...

For film SLR, I guess you can try the same rule and adjust appropriately to the ISO of the film... But then, it also depends on the effect you like... And getting more familiar with the SLR's internal light meter may help in gauaging the exposure it reccomends...

 

[sfhuang]

Thanks guys.

I was talking with a colleague (who's also a photography enthusiast) and he shared with me a technique that he uses for low light scenes. He uses the camera's meter in P mode and then sets it to manual, with adjustments to the metered values (to underexpose or overexpose, depending on the shot). I think I will try this tip out.

But I have another question again ...

What's the difference between shots with similar exposure but with different aperture val/shutter speed combinations? For example, f/2.8 1/125 secs versus f/5.6 1 sec (I'm not sure if these values work out to be the same exposure but I hope you get my point)

thanks again.
sf