580EX ETTL vs. Manual: Fill Flash Intensity Question

I decided to try manual settings for casual photography and quickly found the approach almost unusable.

When I set my exposure for the background, even a 1/128 intensity resulted in blown subjects.

So I lowered the exposure 3 stops and though my subject was well lit my background didn't look good at all.

Is there a way to set intensities less than 1/128 on a speedlite?

You are probably having procedural issues, not flash intensity issues!

'Normal' lens full power from 580EX is about GN150. 1/128 power is -7EV from that! So instead of GN150, it has a GN of about 14...you use f/2 to shoot something 7' away.

You need to provide info about your camera settings (ISO, shutter, f/stop) so we can try to provide guidance about getting your existing equipment to do the job, because it can!!!

My setting was f/2, 5 feet away. So at 1/128 I was getting about twice the intensity I needed.

PS, Actually I was getting about 8 times the intensity at ISO 400.

shutterfiend wrote in post #5606142
My setting was f/2, 5 feet away. So at 1/128 I was getting about twice the intensity I needed.

PS, Actually I was getting about 8 times the intensity at ISO 400.

Must have been a pretty dark background if you were trying to match the flash to the ambient.

Regardless, if you want to shoot manual and set the flash power yourself, you can always modify the flash output farther by simply putting some sort of diffuser over the flash head. I've used everything from napkins, (white of course) tissue paper, wax paper and plain old paper. Doubling whatever you use will knock back the light even more. In fact, I rarely shoot with the flash head unmodified. Adding a bit of diffusion will soften the shadows.

shutterfiend wrote in post #5606142
My setting was f/2, 5 feet away. So at 1/128 I was getting about twice the intensity I needed.

PS, Actually I was getting about 8 times the intensity at ISO 400.

So why not simply choose f/2.8 ?! (or f/5.6 for ISO 400)

I know I could use a diffuser or close down or back up to get the same effect. I just found it odd that ETTL permitted a lower intensity than what's available manually.

shutterfiend wrote in post #5605798
I decided to try manual settings for casual photography and quickly found the approach almost unusable.

Read this thread:
https://photography-on-the.net/forum/showthre​ad.php?t=348609

shutterfiend wrote in post #5605798
I decided to try manual settings for casual photography and quickly found the approach almost unusable.

When I set my exposure for the background, even a 1/128 intensity resulted in blown subjects.

So I lowered the exposure 3 stops and though my subject was well lit my background didn't look good at all.

Is there a way to set intensities less than 1/128 on a speedlite?

If you want both your subject and the background lit almost equally, assuming the background isn't that far away from the subject, point the flash head towards the ceiling and bounce the light off of it. With direct flash, you'll never succeed in lighting them both up equally. One or the other will either be blown or underexposed.