EF-530 DG and K100D underexposed

hoser · 12-23-2009, 12:59 AM

I have a Sigma EF-530 DG (not the super) Flash on a K100D that always underexposes.This is in P ,Tv, Av, modes and flash in auto pa-ttl.
If I give it 2+ EV COMP then the shots are good.
The other day I made a diffuser from a windshield wiper container, just a retangular piece over the flash front and with the diffuser the pictures come out properly exposed with no EV COMP.
Any idea why the flash with a diffuser results in proper metering ?
I thought using a diffuser would further underexpose.
By the way tried this on a K7 with very similar results.
Confused

Igilligan · 12-23-2009, 01:12 AM

I will take a shot... this is a complete guess pulled out of my ____.

The amount of light hitting the scene is cut down from the diffuser, so there is less reflected light bouncing off of surfaces. The camera meters for the more even/lower lighting and exposes up for the less bright conditions, instead of down for the brighter reflected light.

12-23-2009, 12:59 AM	#1
hoser New Member Join Date: Aug 2009 Location: CANADA Posts: 12	EF-530 DG and K100D underexposed I have a Sigma EF-530 DG (not the super) Flash on a K100D that always underexposes.This is in P ,Tv, Av, modes and flash in auto pa-ttl. If I give it 2+ EV COMP then the shots are good. The other day I made a diffuser from a windshield wiper container, just a retangular piece over the flash front and with the diffuser the pictures come out properly exposed with no EV COMP. Any idea why the flash with a diffuser results in proper metering ? I thought using a diffuser would further underexpose. By the way tried this on a K7 with very similar results. Confused

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12-23-2009, 01:12 AM	#2
Igilligan Guest	I will take a shot... this is a complete guess pulled out of my ____. The amount of light hitting the scene is cut down from the diffuser, so there is less reflected light bouncing off of surfaces. The camera meters for the more even/lower lighting and exposes up for the less bright conditions, instead of down for the brighter reflected light.

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