This is one of the first portraits I took using off-camera lighting. It’s shot against a pure white wall and was really a test shot to help me understand the effects of shutter speed & aperture on the photograph. Now, some of you may have not heard the one statement that really helped me understand the flash/ambient relationship;
“Aperture controls flash exposure. Shutter speed controls ambient light exposure.”
Repeat this in your head over & over & over. Take test shots, of anything (I use an Elmo Live!). Keep the shutter speed constant and vary only the aperture & vice versa. Note the effect on the photograph then try it out on a real subject.
Lighting Info:
Canon 580EX at 1/16th +0.3 power, zoom at 35mm, on stand, camera left through shoot-thru umbrella. Triggered by PW Plus II.
’)
Nice pout. That is indeed the mantra you need to work from, but to save future confusion I just have to check – you know that aperture affects ambient and flash, right? Shutter is definitely just ambient (until you crank it up too fast for the flash to register on the sensor) but aperture affects both – to keep the same ambient but affect the flash, you’d have to slow the shutter if you closed the aperture.
I just set up the basics and pop a shot too!
Yeah, slowing the shutter down is the difficult part if you have shaky hands like me.
I think it’s best to just kill the ambient and life is easy!
Here is Owen’s softbox post.
Hi Owen
Yes, I understand that there are multiple variables and I haven’t yet gotten into the situation where I’m slowing the shutter due to a smaller aperture. I do plan to get into that territory soon. I also have plans to mix up some long exposure times with off camera flash.
Now, if we are not worried about ambient and are at our sync speed but want a greater DOF we could just up the power on the lights, or the ISO by the equivalent number of stops, right?
Argh now you’re assuming I know this stuff like the back of my hand, which I blatantly don’t! I just set up the basics, pop a shot, check it, adjust, and roll like that, all the while chatting like I know exactly what I’m doing.
Okay, greater depth of field = more stuff in focus = tighter aperture = less light hitting the sensor = yes, increase the ISO or the flash power if you want the same lit exposure.
But yeah, that’s gonna also shut the ambient down so to keep the ambient the same and just affect the flash, you’d need to compensate with the shutter speed, slowing it down in an inversely proportional fashion.
Oooh, what long words! And I just saw you tweeted my softbox blog post, thanks for that! I posted another yesterday, about shooting some daisies and faffing with gels and white balance for creative effect too, if you’re interested.
Cheers dude!