Originally Posted by Ebest Thank you bartron & pathfinder for some VERY useful information! It helped alot. As for you Qarik, you wasted my time and yours posting negativity. Totally not needed.

This stuff is hard to learn in the beginning and your question helped me as I am also new to using studeo flash.

The beauty of studio strobes is that the light output never varies unless you dial it up or down on the strobes themselves. Once you are getting a good exposure the easiest thing is to simply move the lights fore and aft from the subject.

As you move the lights from 2.8 feet to 4 feet, the light will be halved. Move again to 5.6 feet and the light drops by 1/2 again. Move to 8 feet and the light is halved once more. Note that these ratios are the same as the aperture numbers on your camera. Opening your aperture from f5.6 to f4.0 and you double the light your camera will receive. F2.8 doubles it again. ISOs are similar, 100, 200.400, 800 each step reducing the light needed by 1/2.

As I said earlier, shutter speed really does not affect your exposure due to strobes, unless they are just barely brighter than ambient, and usually one plans on the strobe output to be 3-5 stops brighter than ambient, which means ambient has no effect in the mage whatsoever.

I do agree that studio strobes may require slower shutter speeds than battery powered speed light, but it does depend on the brand as well.


The beauty of strobes is that once you know the needed aperture, ,ISO, and shutter speed, it never varies, so you can plug those values in Manual Mode and devote your attention to composition and lighting.

If you move the lights or vary the output, then you must determine your exposure again. You can do this with trial and error, but a good flash meter is much, much faster - One pop and you are ready to rock again.