Bounch flash w/ P-TTL?

Javaslinger · 05-20-2011, 07:29 PM

I'm shooting a K5 w/ 18-135 and a Metz 50 AF-1. It seems to underexpose quite a bit when I bounce flash.

Is this normal? Should I be shooting on manual? I suppose there camera may have no way of knowing how far/good/etc the bounce is thus can't correctly determine the flash power for exposure...

How should I be doing this?

Thanks,

Ken

mtansley · 05-20-2011, 07:44 PM

It may be that the flash can't push out any more power or just that the P-TTL isn't quite reading the scene properly.

If I have that issue and it's because of the second reason, I just manually adjust the flash compensation on the camera itself up a bit. That way, the flash pumps out a bit more power.

You could also experiment with manually adjusting the zoom head on the flash.

I find sometimes that this automation does quite well for a lot of the time but sometimes totally screws up.

Hope this helps.

Michael

**Ash** · 05-20-2011, 07:56 PM

Until you're comfortable with using the Metz in P-TTL mode with your K-5, I'd suggest shooting manually. P-TTL can behave differently with K-5s around, so it's hard to gauge what the issue is with yours. But start with bouncing in small rooms with bright surfaces/walls and see if this is a consistent finding. Getting used to your own camera's nuances also helps in your confidence in using the P-TTL system.

It was this way even with the K10D and K20D - lots of complaints initially. Then users got used to their cameras and 'know' what works for them in P-TTL.

**Digitalis** · 05-20-2011, 08:09 PM

I actually prefer to use my AF540 in "A" mode - it provides more consistent output.

reeftool · 05-20-2011, 08:12 PM

I find pttl a crapshoot most of the time

slip · 05-21-2011, 06:18 AM

I don't know about your flash type, but with my sigma, it works better if you put my k10d in either P mode or shutter priority. p-ttl will never have as consistent output as manual flash, though.
try bouncing off a wall instead of a ceiling. you can also use a longer shutter speed in shutter priority mode to get more ambient light in the scene

hope this helps in some ways

cheers

wjax · 05-21-2011, 09:25 AM

Originally posted by Javaslinger

I'm shooting a K5 w/ 18-135 and a Metz 50 AF-1. It seems to underexpose quite a bit when I bounce flash.

Ken

What aperture and ISO settings are you using when you bounce the flash? I find that I usually need to crank up the ISO to 400-800 if my aperture is stopped down more than about F5.6 or so, depending on the lighting particulars of the room. The good news is that the K5 can handle higher ISOs extremely well.

05-20-2011, 07:29 PM	#1
Javaslinger Senior Member Join Date: Jan 2009 Location: Blacksburg, VA Photos: Albums Posts: 286	Bounch flash w/ P-TTL? I'm shooting a K5 w/ 18-135 and a Metz 50 AF-1. It seems to underexpose quite a bit when I bounce flash. Is this normal? Should I be shooting on manual? I suppose there camera may have no way of knowing how far/good/etc the bounce is thus can't correctly determine the flash power for exposure... How should I be doing this? Thanks, Ken

05-20-2011, 07:56 PM	#3
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	Until you're comfortable with using the Metz in P-TTL mode with your K-5, I'd suggest shooting manually. P-TTL can behave differently with K-5s around, so it's hard to gauge what the issue is with yours. But start with bouncing in small rooms with bright surfaces/walls and see if this is a consistent finding. Getting used to your own camera's nuances also helps in your confidence in using the P-TTL system. It was this way even with the K10D and K20D - lots of complaints initially. Then users got used to their cameras and 'know' what works for them in P-TTL. Last edited by Ash; 05-21-2011 at 08:44 PM.

05-21-2011, 06:18 AM	#6
slip Veteran Member Join Date: Oct 2006 Location: 2 hours north of toronto ontario canada Photos: Gallery \| Albums Posts: 3,535	I don't know about your flash type, but with my sigma, it works better if you put my k10d in either P mode or shutter priority. p-ttl will never have as consistent output as manual flash, though. try bouncing off a wall instead of a ceiling. you can also use a longer shutter speed in shutter priority mode to get more ambient light in the scene hope this helps in some ways cheers Last edited by slip; 05-22-2011 at 05:57 AM. Reason: clearification

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Difference between TTL and P-TTL flash.	rod_grant	Pentax DSLR Discussion	46	11-15-2017 10:05 PM
P-TTL flash for K-x	Pentax Bob	Ask B&H Photo!	7	04-15-2011 04:46 PM
P-TTL flash - is it necessary ?	Squier	Pentax DSLR Discussion	35	10-27-2010 12:55 PM
Non-P-TTL AF Flash	trailrider	Pentax DSLR Discussion	5	07-21-2010 06:04 PM

05-20-2011, 07:44 PM	#2
mtansley Veteran Member Join Date: Oct 2008 Location: Ajax, Ontario, Canada Photos: Gallery Posts: 1,139	It may be that the flash can't push out any more power or just that the P-TTL isn't quite reading the scene properly. If I have that issue and it's because of the second reason, I just manually adjust the flash compensation on the camera itself up a bit. That way, the flash pumps out a bit more power. You could also experiment with manually adjusting the zoom head on the flash. I find sometimes that this automation does quite well for a lot of the time but sometimes totally screws up. Hope this helps. Michael

05-20-2011, 08:09 PM	#4
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	I actually prefer to use my AF540 in "A" mode - it provides more consistent output.

05-20-2011, 08:12 PM	#5
reeftool Pentaxian Join Date: Dec 2007 Location: Upstate New York Photos: Gallery \| Albums Posts: 9,555	I find pttl a crapshoot most of the time

05-21-2011, 09:25 AM	#7
wjax Forum Member Join Date: Sep 2010 Posts: 51	Originally posted by Javaslinger I'm shooting a K5 w/ 18-135 and a Metz 50 AF-1. It seems to underexpose quite a bit when I bounce flash. Ken What aperture and ISO settings are you using when you bounce the flash? I find that I usually need to crank up the ISO to 400-800 if my aperture is stopped down more than about F5.6 or so, depending on the lighting particulars of the room. The good news is that the K5 can handle higher ISOs extremely well.