ELAN 7 and 420Ex , low light photography..how?

[quicksilver1]

I have a question about the low light photography.

 

In low light situation, If my flash 420Ex is attached and is ON, when I focus,

are the shutter speed \ exposure already adjusted in (let's say Tv mode).

 

What I have noticed is that it's probably not.

 

In low light the exposure will blink if I increase the shutter speed to say 45.

Shall I still go ahead and click the photograph and exposure will be fine. How

will I know how much the flash will compensate for the low light ? Do I have

the control over it ? How can I calculate such stuff.

 

Thanks,

Rajat

[steve_dunn2]

<p>It would be nice if Canon were to put enough details about their flash system into their manuals that you wouldn't need to ask. But unfortunately that isn't one of Canon's strong points.</p>

 

<p>You need to read <a href="http://photonotes.org/articles/eos-flash/" target="_blank">the EOS flash bible</a>. It answers this question, and many others.</p>

[jim_simon3]

I can't say what the documentation for the Elan nor the 420EX is, and I agree that the answer is well done in the flash bible cited. But the EOS 3 manual does actually tell how this works. You have to read it a few times to sink in. There is a single page with the information and with a chart under flash photography. The chart won't copy for this page but here is the text:

 

"E-TTL Autoflash in Other Shooting Modes

Even in the Tv, Av, and M modes, E-TTL autoflash can be used as easily as without flash.

(1) When you press the shutter button, the shutter speed and aperture

are set by the camera as usual.

(2) When you press the shutter button completely, preflash evaluative

metering based on the aperture setting is used for the flash exposure.

(3) The background exposure is set by the shutter speed and aperture

combination."

 

In human terms it means that the camera in these modes sort of ignores the fact that the flash is on and takes the photo as though no flash so the background is exposed properly for Tv and Av. For M of course the exposure is just what you set. The pre-flash then goes off determines the flash exposure for the near object, and then the picture is taken with the flash.

[KenPapai]

One reason you use a flash is because of the lack of natural or artificial light.

 

Shoot in Manual mode, you have nothing to lose. I have an old 1990 EOS 10S that does great stuff with a 580EX when I shoot the 10S in manual (usually ISO 200 film, 1/90, f/5.6); let the flash then do the thinking for its power output.

 

Using Tv or Av mode indoors, in low light, does not work (unless you are an expert in programming the Speedlite, not the camera). Tv or Av means Flash Fill. Indoors that means a crappy photo when flash on Auto.

[mike butler]

Rajat,

 

You've received some good answers here. But to simplify, in a low light situation you

probably want the flash to be the main source of light. In Tv or Av mode, the camera and

flash want to expose the ambient situation and add flash as fill. To have the flash be the

main source of light, you need to be in manual mode (or program mode, which isn't all

that bad, really, for metering's sake). That's maybe 1/90 or 1/60 at f/4 or so. Season to

taste.

 

I still use a 420ex that I bought with my Elan 7 with a 5D. You can further control the 420

by dialing in minus or plus flash compensation. Practice. Practice.