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milesy · 08-13-2010, 05:06 AM

HI Guys

trying to get my head around this so hopefully some of you can give some feedback.

Reading about using flash for fill, and what i read says to expose for the background - reduce by 2 stops and use flash to fill. Right so if i have the flash on the camera, and i press the green button - it always sets the shutter speed to suit the flash (like 1/60 or 1/180 ), so the question is how do i do the above.

Short of turning the flash off and using manual to set the speed etc then turngin the flash back on - i cant work it out

any advise here??

thanks

**Ash** · 08-13-2010, 05:19 AM

G'day mate.
You have a P-TTL flash on a P-TTL capable camera - the whole idea of P-TTL is to be an automatic fill-flash, so you don't have to fiddle around with settings to get adequate fill exposure on your subject. Theoretically.

We all know that P-TTL is not the most accurate system, but it does a reasonable job. Try it out: set the flash to HSS (to allow for the ability to expose for the background), leave the flash in P-TTL mode at 0EV on camera and flash, then shoot a shaded subject and see the fill-flash effect in your results. Should work out OK.

The method you explained above is more working from first principles, which is fine as well, but assumes you use the flash in manual/auto mode.

Adam · 08-13-2010, 05:19 AM

I believe that you'll want to reduce the intensity of the flash itself. Set it to -2 and you should be all set.

**Digitalis** · 08-13-2010, 05:40 AM

I usually set mine to -1.5. I just find that ratio of fill flash to be more aesthetically pleasing.

milesy · 08-13-2010, 05:50 AM

thanks for the replies......ok ill give it a shot.

second question is i played around the other night and tried adjusting the flash compensation on both the flash and camera - neither seems to make a blind bit of difference to the finished photo, the histograms were almost identical......am i missing something here?

**Ash** · 08-14-2010, 12:22 AM

They should both be adjusting the flash's intensity - unless you've already maxxed out the flash.
It'll be more obvious if you're not in HSS mode and have a not too small aperture.

**Ash** · 08-14-2010, 12:26 AM

Originally posted by Adam

I believe that you'll want to reduce the intensity of the flash itself. Set it to -2 and you should be all set.

This works fine if there is at least some light falling on the shaded subject with a bright backdrop. A totally shaded subject will still be underexposed if -2EV fill is used, so some consideration may be required to get the right result.

milesy · 08-14-2010, 05:50 PM

Ash you are exactly right - the flash was maxed out already - going +1 on the compensation made now difference but going - (1 or 2 etc) did, so because i was bouncing the flash i was maxed out.

i cant beleive how much there is involved in flash photography

jjdgti · 08-25-2010, 12:26 PM

Originally posted by Ash

G'day mate.
You have a P-TTL flash on a P-TTL capable camera - the whole idea of P-TTL is to be an automatic fill-flash, so you don't have to fiddle around with settings to get adequate fill exposure on your subject. Theoretically.

We all know that P-TTL is not the most accurate system, but it does a reasonable job. Try it out: set the flash to HSS (to allow for the ability to expose for the background), leave the flash in P-TTL mode at 0EV on camera and flash, then shoot a shaded subject and see the fill-flash effect in your results. Should work out OK.

The method you explained above is more working from first principles, which is fine as well, but assumes you use the flash in manual/auto mode.

Ash, thanks for the info. I'll try and see what I come up with.

08-13-2010, 05:06 AM	#1
milesy Veteran Member Join Date: Jan 2009 Location: Melbourne Photos: Gallery Posts: 379	K-7 and AF540 fill flash HI Guys trying to get my head around this so hopefully some of you can give some feedback. Reading about using flash for fill, and what i read says to expose for the background - reduce by 2 stops and use flash to fill. Right so if i have the flash on the camera, and i press the green button - it always sets the shutter speed to suit the flash (like 1/60 or 1/180 ), so the question is how do i do the above. Short of turning the flash off and using manual to set the speed etc then turngin the flash back on - i cant work it out any advise here?? thanks

08-13-2010, 05:19 AM	#3
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,608	I believe that you'll want to reduce the intensity of the flash itself. Set it to -2 and you should be all set. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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08-13-2010, 05:19 AM	#2
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	G'day mate. You have a P-TTL flash on a P-TTL capable camera - the whole idea of P-TTL is to be an automatic fill-flash, so you don't have to fiddle around with settings to get adequate fill exposure on your subject. Theoretically. We all know that P-TTL is not the most accurate system, but it does a reasonable job. Try it out: set the flash to HSS (to allow for the ability to expose for the background), leave the flash in P-TTL mode at 0EV on camera and flash, then shoot a shaded subject and see the fill-flash effect in your results. Should work out OK. The method you explained above is more working from first principles, which is fine as well, but assumes you use the flash in manual/auto mode.

08-13-2010, 05:40 AM	#4
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	I usually set mine to -1.5. I just find that ratio of fill flash to be more aesthetically pleasing.

08-13-2010, 05:50 AM	#5
milesy Veteran Member Join Date: Jan 2009 Location: Melbourne Photos: Gallery Posts: 379 Original Poster	thanks for the replies......ok ill give it a shot. second question is i played around the other night and tried adjusting the flash compensation on both the flash and camera - neither seems to make a blind bit of difference to the finished photo, the histograms were almost identical......am i missing something here?

08-14-2010, 12:22 AM	#6
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	They should both be adjusting the flash's intensity - unless you've already maxxed out the flash. It'll be more obvious if you're not in HSS mode and have a not too small aperture.

08-14-2010, 12:26 AM	#7
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	Originally posted by Adam I believe that you'll want to reduce the intensity of the flash itself. Set it to -2 and you should be all set. This works fine if there is at least some light falling on the shaded subject with a bright backdrop. A totally shaded subject will still be underexposed if -2EV fill is used, so some consideration may be required to get the right result.

08-14-2010, 05:50 PM	#8
milesy Veteran Member Join Date: Jan 2009 Location: Melbourne Photos: Gallery Posts: 379 Original Poster	Ash you are exactly right - the flash was maxed out already - going +1 on the compensation made now difference but going - (1 or 2 etc) did, so because i was bouncing the flash i was maxed out. i cant beleive how much there is involved in flash photography

08-25-2010, 12:26 PM	#9
jjdgti Veteran Member Join Date: Jun 2008 Location: NJ Posts: 1,824	Originally posted by Ash G'day mate. You have a P-TTL flash on a P-TTL capable camera - the whole idea of P-TTL is to be an automatic fill-flash, so you don't have to fiddle around with settings to get adequate fill exposure on your subject. Theoretically. We all know that P-TTL is not the most accurate system, but it does a reasonable job. Try it out: set the flash to HSS (to allow for the ability to expose for the background), leave the flash in P-TTL mode at 0EV on camera and flash, then shoot a shaded subject and see the fill-flash effect in your results. Should work out OK. The method you explained above is more working from first principles, which is fine as well, but assumes you use the flash in manual/auto mode. Ash, thanks for the info. I'll try and see what I come up with.

K-7 and AF540 fill flash

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