Camera Labs

Dear Photographers,

1. One photographer told me when using Flash TTL Mode, you don’t need to meter. You just estimate/experiment on the ISO, Shutter Speed and Aperture in that area, and snap away. As long as the ISO is between 200 – 800, aperture between 3.5-9 and shutter between 1/20 – 1/80, the exposure of the subject will be ok because the flash TTL mode will expose it correctly. Just experiment with the settings if the picture looks under or over.

Is it true? Iv tried in an indoor wedding and seems to work, but now I asked myself, when actually do you meter when using flash TTL mode?

I know if you’re using the flash as fill flash, you meter the area, and use the flash to light up the subject. Apart from that, if the prime light source is the flash, when do you meter??….

2. I’m using 18-200, and sometimes when I use flash, the subject is still underexpose but the surroundings is exposed nicely, do I move closer, increase flash power or open up my aperture?

I know my questio here is a bit long, but im starting to get confuse here, soo pleeease help me !!!

thank you

Flash in (i)TTL does the metering with an almost invisible preflash. It basically fires off a flash to test, and then calculates the best exposure.

Keep in mind the difference between flash and ambient. You can control ambient lighting with your shutter speed, and flash with your aperture (and flash power setting). ISO affects both.

Try it out, experiment

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I take pictures so quickly, my highschool was "Continuous High".

e-TTL II on canon will operate the flash as fill flash (only) until the EV falls below 13. (in AV, TV and M mode). At nearly 2/3 stop down.

In P mode the story is slightly more complicated. It tries to give you a shutter speed of atleast of 1/60, so your flash may take over even at a much higher EV.

You can not over-ride this if your flash is on TTL.

Read your manual for more details.

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Varun
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i see....that means, to give the pic more ambient ( existing light ) , u probably use slower shutter speed...but to control the output of the flash, u must counter it by using smaller F number i.e F8, F9....

am i right ??

btw, thanks guys for the feedback....

Read in a book -

If source of lighting is almost constant say, in a hall, just just guesstimate the exposure settings and TTL flash will do the rest. If subject is slightly further away, just open up aperture to have more flash output or go nearer.

Metering is when u want to take ambient light into play, such as contrasting subject/situation. U meter the subject, and flash or bounce the darker area...

ok then, i think im beginning to understand now...incase others have more tips or corrections on my explanation above...please do inform me..

thank you !!

You generally do not need to worry about metering if you're using TTL flash, as the camera + flash will work out the exposure for you. Because it's using the camera's exposure metering, the usual caveats apply. In general, if you want to modify the overall brightness of the scene then you change the EV setting. If you want to modify the flash power, modify the FEV.

Good luck and have fun experimenting.

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