Help w/ Mila Grid diffuser

[kekoa]

Hey guys, i just purchased the above diffuser that was recommended to me by a guy from bh photo. I'm getting very inconsistent results w/ it. I usually shoot in AV mode w/ auto flash (580ex). Some shots come out ok and others are way over blown. Pics are coming out totally white. I'm shooting indoors with weak light.

What am i doing wrong, this flash photography is getting frustrating for me.

thanks

[egordon99]

Have you been able to get decent E-TTL shots without the grid? How much you know about flash photography? E-TTL?

Basically, you should NOT be shooting indoors in Av mode (for the most part, unless you set Av mode to lock the shutter at the X-sync speed)

Just trying to discern if it's a problem with your understanding of flash photography, or if it's something specific to the Mila (of which I'm not familiar with, but I'm pretty well versed in E-TTL)

[tjongkristian]

@egordon99: Please help a newbie to understand. Why Av mode should not be used for indoor shooting? Thanks.

[egordon99]

Av mode sets the shutter speed without taking into account your use of flash. Which means if the room is dark, you'll end up with a VERY slow shutter speed.

Basically, with flash, the FLASH exposure is solely determined by flash power (actually duration, how long the bulb is actually firing for), aperture and ISO. Ambient exposure is determined by ISO, shutter speed, and aperture (just like without any flash), so the trick is balancing the two. If I'm indoors in a smallish room (such as in someone's house), I usually just forget about ambient since the flash is powerful enough to light up the entire room (hence the 1/250s below, if the flash didn't fire, I'd have a more or less black picture) Now although you're shooting MANUAL Mode, that's only for the ambient exposure (the exposure needle in the viewfinder will blink warning you about underexposure, but ignore that). The camera's E-TTL metering will determine the needed flash output for a proper exposure.

Here's something I wrote on another forum -
"Easy" recipe for great E-TTL flash shots -
1)Point flash at ceiling
2)Put camera in MANUAL mode on the mode dial
3)Set FEC to +2/3 on the flash head


4)Shoot RAW (this allows you to recover some highlights that might get blown as a result of #3 above)

5)Set ISO to 200 (to start)
6)Set shutter speed to 1/250s (or 1/200s if using a Rebel body)
7)Set f-stop to whatever DOF you want


Now if the flash runs out of "power" because of high ceilings, you can raise the ISO or open up the f-stop to compensate. Or you can slow down the shutter to bring more ambient light into the exposure (in addition to adjusting ISO/f-stop) If the ceiling is REALLY high (like in a church), you may need a reflector to throw some of the light forward (I use the Joe Demb Flip-it).

Quick and dirty outdoor fill flash tutorial -

Basically, if your subject is in shade and the background is bright (ie under a tree) or majorly backlit, fill flash is your friend. Think of those times when you got a properly exposed background, but the subject was almost pitch black.

Put camera into Av mode, metering will set the shutter speed to expose the overall shot (which in the situations that call for fill-flash will generally be the background) based on your selected aperture/ISO.

Make sure flash is set to HSS (in case your shutter speed go faster than 1/250s) and E-TTL. Fire away! The shutter speed/f-stop/ISO will expose the background, and the flash should output enough power to light up the foreground.

Now to control the background exposure, you use exposure compensation on the camera body (which would adjust the shutter speed), to adjust how much fill for the flash exposure, you use Flash exposure compensation. The trick is balancing the two (as it is with indoor work), and that comes with experience/experimentation.

[kekoa]

egordon, i'm not at the level to shoot in manual mode yet. If I use, TV mode will that work ok too? Also, what is that FEC you refer to?


thanks

[egordon99]

FEC - Flash exposure compensation

Tv mode would work better than Av mode, but M mode is the best for indoors where the light is providing most of the illumination. Tv mode set to 1/250s would at least take care of avoiding a slow shutter speed, and if the light is low enough, the camera would just select the widest aperture to TRY and properly expose the ambient, but what if you want to shoot at f/8?

Like my tutorial stated, you really need to be shooting in M mode when using the flash indoors. Av mode would work ok if you're outside though.

[kekoa]

FEC - Flash exposure compensation

Tv mode would work better than Av mode, but M mode is the best for indoors where the light is providing most of the illumination. Tv mode set to 1/250s would at least take care of avoiding a slow shutter speed, and if the light is low enough, the camera would just select the widest aperture to TRY and properly expose the ambient, but what if you want to shoot at f/8?

Like my tutorial stated, you really need to be shooting in M mode when using the flash indoors. Av mode would work ok if you're outside though.

ok, so that means you are getting 2/3 full flash power? How do you set the FEC on the 580. The manual confuses me, but i think I need to read it a few more times.

i appreciate all your help.

[egordon99]

No, it means that if E-TTL decides you need 1/8 power for the shot (based on it's pre-flash metering of the ambient lighting, the ISO, and the aperture), setting FEC to +1 will then FORCE the flash to fire at 1/4 power (twice as much power), similar to how exposure compensation works with the ambient exposure (Av mode, camera selects 1/1000s, setting EC to +1 will then take the shot at 1/500s)

ok, so that means you are getting 2/3 full flash power? How do you set the FEC on the 580. The manual confuses me, but i think I need to read it a few more times.

i appreciate all your help.

[DerekW]

egordon, i'm not at the level to shoot in manual mode yet. If I use, TV mode will that work ok too? Also, what is that FEC you refer to?
thanks

Easiest way to practice with manual for most situations with a flash, is to set it to an arbitrary number like 1/125 and adjust the aperture and/or ISO from there..
start at ISO 200 and f/8 and see where you are at.. too bright, go f/11... too dark, go f/5
want to see more back ground... go 1/60.... background too light...go 1/200. Way too bright still?...go ISO 100
Once you go manual, you'll realize that it is not at all complicated. I do still use AV and TV, but with a flash, I go right to manual

I've spent hours and hundreds of deleted pictures just sitting in different rooms at different times of the day, snapping pictures of nothing in particular to understand what will happen if I do "this". Cards are re-usable, batteries are rechargeable.

P.S. the histogram is your friend, get to know it.

[kekoa]

Easiest way to practice with manual for most situations with a flash, is to set it to an arbitrary number like 1/125 and adjust the aperture and/or ISO from there..
start at ISO 200 and f/8 and see where you are at.. too bright, go f/11... too dark, go f/5
want to see more back ground... go 1/60.... background too light...go 1/200. Way too bright still?...go ISO 100
Once you go manual, you'll realize that it is not at all complicated. I do still use AV and TV, but with a flash, I go right to manual

I've spent hours and hundreds of deleted pictures just sitting in different rooms at different times of the day, snapping pictures of nothing in particular to understand what will happen if I do "this". Cards are re-usable, batteries are rechargeable.

P.S. the histogram is your friend, get to know it.

thanks. i like that advice.