[Entropy]

That means, you don't have that long delay between pushing the shutter release button and the actual image taking, which you have in P-TTL.

This is false. P-TTL preflash or not, that mirror has to flip up to take a picture no matter what. The mirror flipup constitutes most if not all of the interval between preflash and main flash.

[rogerstg]

All in all, it is a good alternative to P-TTL, because it doesn't need the pre-flash, P-TTL affords. That means, you don't have that long delay between pushing the shutter release button and the actual image taking, which you have in P-TTL.

That's not a P-TTL issue, it's a red-eye reduction issue. Closed eyes and time delay are the main reasons not to use red-eye reduction with any camera. For me, there is no discernible difference between pre-flash and the actual flash of P-TTL.

Besides, red eye is not an issue if you are holding the flash off to the side or bouncing. Also, the 540 give the the ability to link wirelessly to the camera and use the built in flash for all sorts of flash compensation arrangements.

[Ben_Edict]

This is false. P-TTL preflash or not, that mirror has to flip up to take a picture no matter what. The mirror flipup constitutes most if not all of the interval between preflash and main flash.

Sorry, my notion is not wrong. I can even clearly see(!) the pre-flash, while still looking through the viewfinder, before the mirror goes up. (I am used to see such single short events, since I worked as as a quality assurance technician for a tv production when I was a student.) I have not come up with an idea how to actually measure the delay, as I cannot connect the camera to a computer for measurig these events (I am not an electronics expert) - but I can actually see the pre-flash, it is real.

As I am unable to make these measurements I cannot debate, whether the time, the pre-flash takes to fire and the camera needs to calculate the flash-output is significant, compared to the mirror action.

And it has nothing to do with red-eye reduction, as this is the first thing I always switch off.

Besides the noticeable, albeit not measured, delay in shutter action, the main drawback of the P-TTL (and that is the same with E-TTL, iTTL, ADI etc... Pentax is not alone in this field) is, that the time between pre- and main-flash is long enough for people to close their eyes - which very often happens. And if you take your time to search for exactly these experiences, you will find many other comments by photographers about these effects.

Ben

[Entropy]

Sorry, my notion is not wrong. I can even clearly see(!) the pre-flash, while still looking through the viewfinder, before the mirror goes up.

You can see it because the mirror is "masking" the main flash when it flips up.

If you were to view it from the outside and did not have assistance (one of the flashes being mechanically blocked from your vision), it would be next to impossible to discern the difference between the two.

[Ben_Edict]

You can see it because the mirror is "masking" the main flash when it flips up.

If you were to view it from the outside and did not have assistance (one of the flashes being mechanically blocked from your vision), it would be next to impossible to discern the difference between the two.

Can you give me numbers, as to make it easier to understand for me, what "next to impossible to discern" actually means. I am used to discern discrete changes during time intervalls of 1/25s.

regards
Ben

[rogerstg]

Can you give me numbers, as to make it easier to understand for me, what "next to impossible to discern" actually means. I am used to discern discrete changes during time intervalls of 1/25s.

regards
Ben

I'm not sure it's relevant because the whole point of this is that you stated in your post that P-TTL preflash causes a "long delay" that "often disturbs the object."

It seems that my and others' opinions are that the barely discernible preflash (without your special training) does not constitute a long delay, nor do subjects normally close their eyes, in my experience.

It appears that our definitions of "long delay" are simply different.

[Ben_Edict]

I'm not sure it's relevant because the whole point of this is that you stated in your post that P-TTL preflash causes a "long delay" that "often disturbs the object."

It seems that my and others' opinions are that the barely discernible preflash (without your special training) does not constitute a long delay, nor do subjects normally close their eyes, in my experience.

It appears that our definitions of "long delay" are simply different.

I totally agree with your last sentence.
Whether the pre-flash leads people to blink their eyes and having them closed for the real shot has been discussed quite often in different forums, which reflect my own experience:
Camera with no preflash or unnoticable preflash? Eyes always closed!: Open Talk Forum: Digital Photography Review
Discussion Forums @ Nikonians - pre-flash delay with D80 or D200 perhaps
http://www.3blooms.net/blinkies/
Sony A350 flash question - Page 2
A Minolta/Sony Alpha Flash Compendium - Flash Timing Diagrams
The last link is quite interesting, because it leads to the only measurements I have foiund so far. And these show a delay of 1/7s between pre-flash and main-flash on a KM7D. This is enough for the "typical" eye blinking.

I don't want to press that subject. There is clear evidence, that the delay causes some problems in portraiture and wildlife photography. And I am not referrring to red-eye-reduction... Whether the delay is "long" or "not so long" is perhaps just a matter of personal definition.

regards
Ben

[Andreas]

I'm not sure it's relevant because the whole point of this is that you stated in your post that P-TTL preflash causes a "long delay" that "often disturbs the object."

It seems that my and others' opinions are that the barely discernible preflash (without your special training) does not constitute a long delay, nor do subjects normally close their eyes, in my experience.

It appears that our definitions of "long delay" are simply different.

Roger, there is no doubt that some people tend to blink after the pre-flash. It's reported too many times. I once made a series of 4 pictures of my brother with the built-in P-TTL flash of my Ds, and I had 4 blinkies in a row, after which I gave up. Some people exhibit this behavior, some do not -so you are both right. But as I said earlier in this thread, if it happens to be the bride, you are in trouble. This item has been discussed many times.

[rogerstg]

I suspect that the TTL pre flash issue is flash model or camera system specific. I reveiwed a number of photos last night, including three shots of the same group of 33, and no one had their eyes closed or closing. In particular, those were taken with the 540 shooting directly at the group, as opposed to bounced. I have not noticed it with on board flash either.

That's my actual experience with the 540- it has not caused any blinking in my photos so I would have to disagree with Mr. Edict's conclusion that P-TTL with the 540 FGZ often causes blinking. I know this is opposed to general internet babble where most of the responses are repeats of others'. It makes me wonder how many respondents to this thread actually have much time behind the flash in question.

[Andreas]

I suspect that the TTL pre flash issue is flash model or camera system specific. I reveiwed a number of photos last night, including three shots of the same group of 33, and no one had their eyes closed or closing.

Then you were very very lucky; the pobability of having 33 persons not blinking 3x in a row is smaller than 0.01 (about 1 time out of 160 -assuming random blink behavior, 12 blinks/min on average, 250msec blink duration, and a shutter speed of 1/125s.)

That being said I don't doubt that you have more luck with P-TTL than e.g. I have. You would not claim it if it was not so. I make a lot of *portraits* and lots of them of my own children (a subgroup), that could explain some of the differences.

Some people suffer from it; some don't.

[rogerstg]

Then you were very very lucky; the pobability of having 33 persons not blinking 3x in a row is smaller than 0.01 (about 1 time out of 160 -assuming random blink behavior, 12 blinks/min on average, 250msec blink duration, and a shutter speed of 1/125s.)

That being said I don't doubt that you have more luck with P-TTL than e.g. I have. You would not claim it if it was not so. I make a lot of *portraits* and lots of them of my own children (a subgroup), that could explain some of the differences.

Some people suffer from it; some don't.

I'm afraid that your logic is flawed. Random behavior does not exist when people are aware that a photo is about to be taken.

[Andreas]

I'm afraid that your logic is flawed. Random behavior does not exist when people are aware that a photo is about to be taken.

In that case it's not my logic, it's one of the premisses.

I'm sure you managed to lead your audience into non-blinking behavior, three times in a row.

That's my last word on it!

[Ben_Edict]

I would have to disagree with Mr. Edict's conclusion that P-TTL with the 540 FGZ often causes blinking.

I did not write that. You obvíously read something into my post, which is actually not written anywhere, or - if you find such a notion - it was written by accident.

I only wrote about P-TTL and the delay this technology introduces. Nowhere did I single out the Pentax 540 flash. gun. If you read my posts, you will (more to the contrary) find, that I am explicitly talking about switching off P-TTL on the Metz flash guns, as these offer a very capable alternative, aka the Metz Auto-Mode.

I did not write about the 540, because I don't have one. I have a couple of older Pentax flasher and a couple more Metz flash guns. So I deliberately wrote about different technologies, which are shared by flash guns from different brands...

Ben

[philbaum]

Hi Matt

Having weighed-up all the various pros and cons of each brand and model, like yourself I finally decided to plump for the Metz 48 AF-1 and have been trying to find my way around it's operational modes.

However, I have to say in the Metz 48 AF-1's favour that the responsiveness of this model is a great improvement over the built-in P-TTL pop-up flashgun, so spontaneous flash photography is now firmly back on the agenda. Obviously the pop-up flashgun has to draw current from the LIon rechargeable battery along with the rest of the camera's internal circuitry which slows matters down somewhat, whereas the Metz 48 AF-1 flashgun reacts in a quicker manner, as it's powered by 4 dedicated AA batteries.

Best regards
Richard

P.S. I've already obtained a Stofen diffuser for the Metz, so I'm hoping that might help with direct flash scenarios ?

Richard,
I also just received my Metz 48 AF-1 just two days ago. I haven't had a lot of time to play with it, but have taken a few photos and read a bit. It seems to perform quite well just out of the box. My kind of accessory.

I've read several adverse comments about PTTL, but the Metz seems to take it all within stride and deliver the pictures. Without following any step by step instructions, I was taking HSS fill pictures in a high contrast situation, PTTL pictures at night of a tree 28 feet away, bounce pictures in my living room, I especially like the fact that the Metz 48 has a built in diffuser option that allowed flash pictures iwth my ultra wide angle Sigma 10-20 without any fall-off on the sides.

Finally had to stop because my K10 battery ran out of juice.

Fun Flash. I think its one minus is that it can't act as a controller but just a slave. But this doesn't stop me from using it with radio triggers which is eventually where i want to go. Until then its supposed to be remote triggered with the K10 onboard flash, but haven't tried that yet.

Phil B.

[Confused]

Hi Phil

Thanks for your informative message. Regrettably I couldn't reply to you before now, as I've been away for a few days staying with elderly relatives and unfortunately they don't yet have internet access (never likely to either, by the look of things)...it's an "age-related" kinda thing.....LOL !!!
Anyhow, thus far I've discovered that my Metz 48 AF-1 is a hell-of-a-sight quicker than the integral flashgun on the K10D, so the pre-flash "eyes-closed" issue has been virtually resolved by replacing it with the Metz 48 AF-1.
Somebody elsewhere on this forum once kindly mentioned that when employing the pop-up flash, one should try to avoid using it in conjunction with the K10D's "anti red-eye" feature, as this dual process slows down the overall response of the camera even more. In fact it used to drive me slightly round the twist every time I attempted to use the pop-up flash to take portraits until I found out about this annoying niggle, as there would always be an infuriating one-second delay between depressing the shutter-release and the flash actually firing. Not what you might tend to describe as being wholly conducive to taking spontaneous photographs !!!

Best regards
Richard

P.S. If you have any useful tips you might like to pass on, especially about obtaining correctly exposed bounce-technique images without needless time-wasting or experimentation, then please feel free to chip-in with any suggestions.