topic Re: 580EX II on a 6D - issues with exposure in Speedlite Flashes

580EX II on a 6D - issues with exposure

javapop — Sat, 10 May 2014 00:00:46 GMT

I have a new 6D, and I am trying to do some 'test' portraits with my 580EX II. I'm using ETTL mode; and aperture priority. I was able to adjust exposure compensation when using my previous camera (1D3) but I can;t seem to be able to soften the intensity of the flash either on camera, r off camera with my Yongnuo 622C triggers.

Any suggestions? attaching one sample.

Re: 580EX II on a 6D - issues with exposure

MikeSowsun — Sun, 11 May 2014 12:32:05 GMT

You can never "soften" the flash intensity, you can only adjust the flash exposure using "Flash Exposure Compensation". (FEC)

The 1D Mk III had an exposure scale on the right side of the viewfinder, but setting FEC is also very easy on the 6D.

FEC is adjustable both on the camera and on the flash. The flash FEC will over-ride the camera FEC so make sure both are at "0 FEC", and then adjust one as needed.

Since you are using YN-622C triggers, I would always stick to using just the 6D's flash menu to set FEC.

In the photo you posted the "XMP" EXIF data shows -1 FEC. I am not familiar with XMP data. Does that mean it was done in Post Processing?

Re: 580EX II on a 6D - issues with exposure

javapop — Sun, 11 May 2014 20:03:25 GMT

Thanks for clariying. I did make sure that the FEC on the flash was 0. Also made sure that AEB was disabled. I just exported these out of Aperture, so not sure if the XMP is anything more than part of the metedata info.

One thing, I shot these in AV mode. (I just noticed you responded on the PONT board regarding this... testing later this afternoon!

Thanks, David

Re: 580EX II on a 6D - issues with exposure

TCampbell — Sun, 11 May 2014 22:10:06 GMT

There are three different topics...

"Exposure Compensation" determines whether the entire exposure is adjusted (regardless of where the light comes from).

"Flash Exposure Compensation" determines how much of the light in the exposure should be contributed by the flash. This is often used if, for example, you want the flash to be treated as "fill" light to weaken the shadows created by ambient light sources.

And then there's the idea of "soft" light.

By soft light, we don't actually mean that it is dim -- it could be quite bright (look up examples of high-key photography).

To soften light, you want the light to seem to originate from a broad light source rather than from a pin-point light source.

Pin-point light sources create shadows that have a very distinct edge. Broad sources of light create shadows that gently transition from dark to light -- "soft" edges... and that's why we call it "soft" light -- it's more about how the transition between shadow and light behave then just looking at the "light" itself. To create good light... you need good shadows.

Soft-boxes, shoot-through umbrellas, and many other types of lighting modifiers are designed to make the light appear to originate from a source that is many square feet -- vs. the unmodified flash head which appears to have an area of only a few square inches. It also helps if these softening devices are reasonably close to a subject. The farther away they are... the samller they will seem to be in your image. The Sun is 109 times wider than our entire planet... but as it's 93 million miles away, it behaves more like a pin-point source than a broad source of light.

You could probably pick up a "shoot through" umbrella (white translucent fabric) for about $10. I use a Lastolite EzyBox softbox (this is a softbox designed for use with speedlite flash units.) A soft-box will be a little more expensive than a shoot-through umbrella (depening on the size it could conceivably be a lot more expensive.) If you're outside you can get the subject out of direct sun and use a reflector to create a soft source of light. Collapsable reflectors are fairly inexpensive. Incidentally these typically come in a silvery reflective surface (color neutral - it just reflects light) as well as gold/bronze toned reflective surfaces (which might accentuate the look of having tanned skin if you were shooting swimsuit models... but can be a bit much for general purpose lighting.)

Re: 580EX II on a 6D - issues with exposure

Skirball — Mon, 12 May 2014 18:09:05 GMT

I assumed it was a semantics issue, and by "soften" you mean reduce the intensity.

My 622s did something similar when I first got them out of the box; they shot full power regardless of what I did. I played around with them a bit and suddenly they worked fine. Unfortunately I don't know what it is I did, but I haven't seen the issue again over the past year+ that I've had them. Sorry I can't recount what I did, but it doesn't look like your flash is triggereing full power. Honestly, based on the image above, I'd up the power a nudge.

One thing to note though. If you're shooting a bare flash and using a large aperture you could easily bump up against the lower limit of the flash. Even at 1/128 power the flash can provide a lot of light when bare and close proximity.

Re: 580EX II on a 6D - issues with exposure

javapop — Mon, 12 May 2014 18:27:12 GMT

Thank you, yes, thats what I meant regarding soft. I generally use a DIY midifier... need to post a photo of it!

It seemed to work nnicely yesterday, here's a with and withut flash shot. I am pleased!