Confused about flash photography

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Berto

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i am an absolute flash amateur and basically have just put the flash on the camera and fired of a shot before! so go easy on me.


i have read the posts on here and different online help articles but i am lost

what i want to know.
how do i light up a moving car successfully?
in the past i would hit lucky and get a shot of the car well lit and using continuous shooting i would get a handful of photos that are just black! :bang:

has everyone who uses a flash at night have this problem? :thinking: can you over come it?

what way should i set up the flash and camera?
 
If you are continuous shooting you are always going to get frames that are black!

1DmkIIn is how many frames/sec?

The Canon Speedlite 580EX II Flash is rated for approximately 100 to 700 shots from new AA-size alkaline batteries which deliver a fast recycling time of approximately 0.1to 6 seconds.

So you have a camera firing at several frames/sec and a flash that is only capable of firing every 0.1 to 6 seconds. The 0.1 sec will be for a flash fired at minimum power with a relatively close subject. Your car will be a distance from you so your flash will more likely be at full power. i.e. your recycle times will be closer to 6 sec than 0.1

So that's why you are getting black frames, the two are working at completely different time scales. Chances are you are getting flash on the first frame and not a lot after.

Time to get the manual out and go and read up on high speed synch. :)
 
The high speed sync mode on the 580 will help to a small extent but it's mainly designed to enable you as a photographer to shoot at shutter speeds greater than the maximum shutter speed to flash gun sync. Unfortunately when using high speed sync your flash is firing in high speed pulses at reduced power so you will struggle to get the power you need. and it will drain the batteries even quicker too.
 
Berto said:
i am an absolute flash amateur and basically have just put the flash on the camera and fired of a shot before! so go easy on me.


i have read the posts on here and different online help articles but i am lost

what i want to know.
how do i light up a moving car successfully?
in the past i would hit lucky and get a shot of the car well lit and using continuous shooting i would get a handful of photos that are just black! :bang:

has everyone who uses a flash at night have this problem? :thinking: can you over come it?

what way should i set up the flash and camera?
Click to expand...

the images are black because flash does not get sufficient time to recharge between shots.

you can try reducing flash output. put it on manual power. try continuous shooting. see if the flash can keep up with your camera. it depends on camera's shutter frequency, aperture, shutter speed, ISO, flash batteries, and flash power setting.

try finding a flash power value that gives you several identically lit continuously shot images. after that bump up ISO, if necessary, to get the exposure right.

this may or may not work depending on your gear.

hope this helps.
cheers!
 
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