Jump to content

Wildly uneven results with 580EX Speedlite fill flash


chris_newkumet2

Recommended Posts

All:

Lately I've been getting some badly overflashed results in my attempts to use

my two 580EXs for fill flash outdoors. The results are inconsistent, but

mostly it occurs when I'm using my 70-200 2.8 lens, set wide open or close to

it, and cropped relatively tight for a portrait. I tend to set the flash down

1 or 1.5 stops and shoot in open shade. I frequently use high-speed sync in

these instances, though I can't swear it's always in high-speed when this

happens. I can't think of anything else I'm doing differently from before,

when all this seemed to work pretty well and consistently to add a little pop

to portraits. Any thoughts?

Link to comment
Share on other sites

What ISO, what camera bady, working distance, is the flash zoomed out, have you checked metering mode, what operation mode (AV,TV,M,P). I use AV for this situation, personaly. If it has always worked before (I am assuming here that it has) then it comes down to somthing changeing. Can you try another flash? Try cleaning the contacts of the flash and lens. If the lens is not reporting proper data, it can screw with metering in E-TTL II. Just some quick idea and good info to know to try and help ya.

 

Jason

Link to comment
Share on other sites

Could be a lot of things. What ISO are you using? What metering mode for the camera (spot, center/ eval)? What metering mode for the flash, ETTL, Manual (you said sometimes FP mode). Are you using Aperture priority or manual, or one of the scene modes like portrait. If Aperture mode, which custom function is it set to "Auto or 1/250th"? All these factors influence how the camera meter and the flash behave. A slight change in these settings and/or in lighting could make the flash assume it's the main light as opposed to a fill light. Which sounds like what the problem is.

Can you post a sample?

 

Some ideas, there are two ways to set flash comp, on the camera and on the flash, check both. Try shooting some in fully auto idot mode vs fully manual and compare. It's probably a setting you accidently changed. I do it all the time. Last time it happened to me, I had the flash in manual full power mode. With ISO over 200 and in close the Flash can not attenuate enough for a proper exposure.

Link to comment
Share on other sites

ETTL is inconsistent to begin with. Then, how can it know what kind of fill you have in mind? First check to make sure you have the flash metering set on evaluative (custom function 14). In this mode, ETTL will cut the flash (regardless of M, AV, etc.) when the ambient light level is above EV 10, up to 1.5 stops. You can cut it back even more by employing minus compensation. In averaging flash metering mode, the flash does not cut back on it's own, and even though you use minus compensation, the flash will still try to provide what it thinks is adequate flash exposure. I have had your same experience shooting engagement portraits in open shade outdoors and thinking I was getting way too much flash because I left the flash metering on averaging.

 

If the above is not the case, realize, as I said, that the camera/flash can't know what kind of fill you want, plus it is, of course, reacting to subject value. When figuring minus compensation, you should take that into account.

Link to comment
Share on other sites

<p>We need much more info. For instance:</p>

 

<p>There can be significant differences between E-TTL and E-TTL II, and you don't say which you're using, nor do you provide us with the name of your body so we can deduce which one you're using. If it's E-TTL II, have you set it in evaluative or averaging mode?</p>

 

<p>You can figure out whether it's in high-speed sync mode or not by comparing the shutter speed you used for the shot (it's in the EXIF data, assuming you're shooting digitally, which you didn't tell us, either) to the body's maximum X-sync speed: if the shutter speed is over max X-sync, it's HSS, and if it's at or below max X-sync, it's not.</p>

 

<p>How are you controlling these flash units? Wireless E-TTL? If so, tell us the settings you used. If it's something else, tell us.</p>

 

<p>Can you post a sample shot? Perhaps with a very crude diagram of where the camera, the two flash units, and the subject were in relation to each other?</p>

Link to comment
Share on other sites

OK...sorry for incomplete information...

 

I'm using a 5D, with metering set to evaluative, exposure mode is manual, and this tends to happen when I'm less than 10 feet from the subject... ISO is normally 400, though sometimes I have it down to 100... I'm away from my studio, but I'll try to post a few images when I get back...

Link to comment
Share on other sites

Only one other possibility I can think of (besides subject value). If you are shooting at f2.8 at ISO 400, at focal lengths longer than 85mm, and your flash automatically zooms to 105mm, you may be hitting the minimum distance the flash can manage, if, as you say, the subject is less than 10 feet away. So you'd get overexposure, regardless of how much you ramp the flash down. Don't know, but it's a thought.
Link to comment
Share on other sites

Personally I think Nadine is on to it. But we will know better when samples are posted with EXIF. It seems to me, ISO 400 in open shade(I assume on a sunny day) with direct flash less than ten feet away and the lens stoped wide open, would be a bit tough. But maybe my ignorance is showing.

 

Jason

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...