Why P-TTL? Follow-up
Lawrence Kwan wrote: And in case of *ist, it can give priority in the matrix metering area corresponding to the focal point. Off centered subjects is one example where P-TTL should be better. For this to work I assume one would have to use either the multi-point focusing (letting the camera decide what to focus on) or the selected point focusing. Using only the central sensor with focus lock on something off-center wouldn't work. Am I correct? Thanks, Joe
Re: Why P-TTL? Follow-up
On Thu, 18 Dec 2003, Joseph Tainter wrote: Lawrence Kwan wrote: And in case of *ist, it can give priority in the matrix metering area corresponding to the focal point. Off centered subjects is one example where P-TTL should be better. For this to work I assume one would have to use either the multi-point focusing (letting the camera decide what to focus on) or the selected point focusing. Using only the central sensor with focus lock on something off-center wouldn't work. Am I correct? One of the custom function allows you to link the matrix metering with the focal point. I presume what you said above was correct when that custom function was set. If that custom function setting was turned off, then it should behave as traditional matrix metering with no focus information taken into account. -- --Lawrence Kwan--SMS Info Service/Ringtone Convertor--PGP:finger/www-- [EMAIL PROTECTED] http://www.vex.net/~lawrence/ -Key ID:0x6D23F3C4--
Re: Why P-TTL?
on 16.12.03 17:51, Joseph Tainter at [EMAIL PROTECTED] wrote: Can someone who owns the AF360FGZ confirm that P-TTL has given you better exposures than ordinary TTL? Yes, P-TTL is significant upgrade to plain TTL. It usually tries to expose picture so as the flash would be as weak as possible to obtain proper exposure, resulting in more natural results. In what conditions? For instance if you have some object that are nearer than main subjext, that you have focussed your camera on. In P-TTL main subjext is usually well exposed, while neareer, out-of-focus objetcs are overexposed. In plain TTL, reflected light from nearer object would foul flash automatic, properly exposing near object and leaving underexposed main subject(s). Actually this is possible because P-TTL uses distance information coming from F and later series lenses and of course it works only when flash head is directed straight (not tilted). I could write about more real-world examples, but I think there's no comparison - P-TTL is simply better, period! It's just pity there's no stronger than AF360 flash that would work in P-TTL. Maybe because Pentax has filed this year new patent for flash metering system using not only multi-segment metering, but also taking in consideration different reflectivities of various colors? Will there be C-TTL (or something) in next Pentax DSLR? It yet has to be seen, as many of the patents remain just patents... -- Best Regards Sylwek
Why P-TTL?
Can someone who owns the AF360FGZ confirm that P-TTL has given you better exposures than ordinary TTL? In what conditions? Thanks, Joe
Re: Why P-TTL?
On Tue, 16 Dec 2003, Joseph Tainter wrote: Can someone who owns the AF360FGZ confirm that P-TTL has given you better exposures than ordinary TTL? P-TTL uses matrix metering, so in theory, it should give better results when center weighted metering could be fooled. And in case of *ist, it can give priority in the matrix metering area corresponding to the focal point. Off centered subjects is one example where P-TTL should be better. Other reasons for P-TTL: multiple wireless TTL flash, high-speed sync TTL flash and flash exposure compensation. -- --Lawrence Kwan--SMS Info Service/Ringtone Convertor--PGP:finger/www-- [EMAIL PROTECTED] http://www.vex.net/~lawrence/ -Key ID:0x6D23F3C4--
Re: Why P-TTL?
On Tue, 16 Dec 2003 09:51:33 -0700, Joseph Tainter wrote: Can someone who owns the AF360FGZ confirm that P-TTL has given you better exposures than ordinary TTL? Yes In what conditions? In images with a wide contrast range, such as a light coloured subject on a dark background or vis-a-versa. Or where a single point of highlight from a reflection would normally cause the whole image to be underexposed. And in fact everywhere. I use slides for a lot of macro pictures and it has reduced my need for bracketing considerably. Leon http://www.bluering.org.au http://www.bluering.org.au/leon
Re: Why P-TTL?
At 09:51 AM 12/16/2003 -0700, you wrote: Can someone who owns the AF360FGZ confirm that P-TTL has given you better exposures than ordinary TTL? I've found it to be much better when shooting macros of things like damselflies that don't fill much of the area in the frame. With plain TTL I'd always have to estimate some degree of negative flash compensation based on how much of the frame the bug filled, how close the background was, etc. P-TTL nails these kinds of shots and pretty much eliminates the need for flash compensation in that kind of situation. - MCC - Mark Cassino Photography Kalamazoo, MI http://www.markcassino.com -
Re: Why P-TTL?
I am surprised it took Pentax so many years to offer matrix metering in TTL flash mode. I still remember my sold F801s had spot, centre-weight and matrix modes for TTL flash. The first thing I noticed when I bought the Z-1p was that the manual said nothing about this. Yours regards, Alan Chan http://www.pbase.com/wlachan P-TTL uses matrix metering, so in theory, it should give better results when center weighted metering could be fooled. And in case of *ist, it can give priority in the matrix metering area corresponding to the focal point. Off centered subjects is one example where P-TTL should be better. Other reasons for P-TTL: multiple wireless TTL flash, high-speed sync TTL flash and flash exposure compensation. _ The new MSN 8: smart spam protection and 2 months FREE* http://join.msn.com/?page=features/junkmail http://join.msn.com/?page=dept/bcommpgmarket=en-caRU=http%3a%2f%2fjoin.msn.com%2f%3fpage%3dmisc%2fspecialoffers%26pgmarket%3den-ca
Re: Why P-TTL?
well i've had some interesting times with the 360 on the istD first time i used there was a glass brick wall behind the head table the first flash would reflect right back so all my pictures came out blank... but aside from that one incident, its worked very well for me. arnie - Original Message - From: Joseph Tainter [EMAIL PROTECTED] To: pdml [EMAIL PROTECTED] Sent: Tuesday, December 16, 2003 11:51 AM Subject: Why P-TTL? Can someone who owns the AF360FGZ confirm that P-TTL has given you better exposures than ordinary TTL? In what conditions? Thanks, Joe
