540 let me down Christmas Day

Started Dec 26, 2007 | Discussions
(unknown member) Veteran Member • Posts: 9,762
Hmm...

Think about this, if you meter something white and only add +1 EV then you're still a stop under regardless.

Anyway, something I thought of when talking to Erik was the way the Nikon DX and Canon E-TTL II flashes work...

Basically, those systems added a 3D measurement where we had issues with underexposed flash as well but setting the camera to TTL (Auto) and not D-TTL (Auto) gave better flash exposure so look into trying that as it maybe a case of 3 different Monkies (Nikon, Canon and Pentax) all making the same mistakes before they fix it (unfortunately only Nikon has fixed this issue thus far but they were also the first to make the mistake).

Let me know how that works.

Oh and if you don't eliminate the user then you can't accurately determine if there is a problem.

DS_Dave wrote:

Huh?

A total of +1 EV comp for the flash (implying some user knowlege of
exposure) and it is still underexposed...hmmm I think you proved my
point.

I know how to meter, and I still get seriously underexposed pics with
my DS and flash - unless I dial in loads (more than I should have to)
of +'ve comp...and it aint always the obvious miniscule specular
highlight that is to blame. Best results are obtained at ISO 400 and
better (even in a small room filled with a myriad of different
colours etc), even with a fully P-TTL flash.

I rarely had any issues with tranny's using my Z-20 and an auto
thyristor Metz-45 or Vivitar 283..

I really dont like people leaping to the old chestnut of implying
that a poster is dumb as a first response. Perhaps wording the same
message in a less accusatory way might be better for the future?

Dave
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'The probability that we may fall in the struggle ought not to deter us from the support of a cause we believe to be just; it shall not deter me.' -- Abraham Lincoln

DS_Dave Senior Member • Posts: 2,261
Re: Hmm...

Pete Perry wrote:

Think about this, if you meter something white and only add +1 EV
then you're still a stop under regardless.

I dont know about the K10D, but one is still 1.5-1.8 stops under with my DS when I checked its clipping point last year. I did think about that though, and then I thought "I doubt the poster lives in a pure white house, so +1 EV probably aint too far off".

Oh and if you don't eliminate the user then you can't accurately
determine if there is a problem.

True, but from the info, it sounded like the poster was doing most things right (+1EV with a multi- coloured/shaded normal house room) - even if it was without expert knowledge, so, I normally am willing to deal with the "problem" then explain the solution/concept after it is dealt with (or better yet during the solving process), rather than just saying "well, you were kind of stupid werent you...this is what ya should have done in the first place..." I find that my students respond better to my may of "teaching"...

Dave

DS_Dave wrote:

Huh?

A total of +1 EV comp for the flash (implying some user knowlege of
exposure) and it is still underexposed...hmmm I think you proved my
point.

I know how to meter, and I still get seriously underexposed pics with
my DS and flash - unless I dial in loads (more than I should have to)
of +'ve comp...and it aint always the obvious miniscule specular
highlight that is to blame. Best results are obtained at ISO 400 and
better (even in a small room filled with a myriad of different
colours etc), even with a fully P-TTL flash.

I rarely had any issues with tranny's using my Z-20 and an auto
thyristor Metz-45 or Vivitar 283..

I really dont like people leaping to the old chestnut of implying
that a poster is dumb as a first response. Perhaps wording the same
message in a less accusatory way might be better for the future?

Dave
--
GMT +9:30
http://www.colourpixels.net
Click on Dave on the menu

-- hide signature --

'The probability that we may fall in the struggle ought not to deter
us from the support of a cause we believe to be just; it shall not
deter me.' -- Abraham Lincoln

-- hide signature --

GMT +9:30
http://www.colourpixels.net
Click on Dave on the menu

kenyee Senior Member • Posts: 1,522
yep, the urn made it into the matrix area on the 2nd shot

OPTMEKX7 wrote:

Could it be that the second shot is underexposed because of the
reflection from the copper urn and the wider white wall to the left,
thus the camera is preventing blownhilight as shown on the example by
manual focus.

I also agree w/ this. The K10D was probably set to matrix metering and the reflection of the urn was definitely in the matrix metering area in the 2nd shot whilst it was outside the area on the first shot...

FYI, this happens w/ Canon and Nikon flashes as well.

Here's a good test for those new to p/e/i-TTL: take any reflective object (e.g., the back of a toy box your kids probably got for xmas, a mirror, etc.)...put your camera on a tripod. Move the object slowly across your frame while you take pictures. This will give you a sense for where the metering happens.

You could run it in Auto-thyristor mode, but then you'd have to worry about a whole set of other things that'll cause under/over exposure

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Brad99 Veteran Member • Posts: 3,145
Re: yep, the urn made it into the matrix area on the 2nd shot

I think it would be hard to get an evenly, properly exposed photo with any camera and any single flash with these shots. Don't forget that a photo is a 2D representation of a 3D space, and in these photos, the right half is much further away than the left half. You would have to bounce the flash back over your right shoulder at the opposite wall to get reasonably even lighting on the whole wall length.

Jonson PL Veteran Member • Posts: 3,600
Re: 540 let me down Christmas Day

manual_focus wrote:

I just finished shooting a dinner with a K10D and AF540 with Stofen
diffuser in a hotel ballroom with high ceilings painted reddish brown
and lots of glassware and sparkly things. To get ready for this I've
been practicing and reading this forum for the last several weeks.
While the Owner's Manual is a bit obtuse, I whole heartily agree with
both the last two posters, "nosnoop" and "wlachan" on what is going
on. The P-TTL system ensures you don't blow highlights and it
doesn't matter what metering system you use.

I shot around 120 images of which I saved 70 and posted 38 for all to
see. For about half of these I needed to increase the exposure some
amount, although there was no single amount of adjustment needed.
Its not like I could dial in a single exposure adjustment when I was
taking the images and everything would then be correct. Luckily doing
this type of adjustments is easy to do in SilkyPix.

What I liked was I started with no blown highlights so I was able to
make exposure adjustments which resulted in nice looking images. I
was also constantly varying the flash position from straight forward,
45 degrees, to straight up towards the ceiling to get the best
combination of light. This was the most difficult lighting
environment I've shot under.

In practicing before the event, I tried using both Automatic and
Manual flash modes. Automatic had a tendency to slightly overexpose,
and Manual is simply not suited for this type of environment. Too
much variation in exposure and the action is too fast paced.

Hi manual_focus,
Thanks for you input and showing your work.

It is impressive how you were able to save the picture that was underexposed. (I guess one has just got to make sure to shoot in RAW).

It is great to have an experienced flash photographer come in and give tips on how to get the most out of the P-TTL system. I use it so rarely, that every time, it seems I have to learn it again.

It is good to hear and see that with the proper knowledge and experience, you can get great work out of P-TTL photography.
Thanks for taking the time.

Here is an older thread with flash tips, if you have further pointer you're welcome to chime in :
http://forums.dpreview.com/forums/readflat.asp?forum=1036&thread=23749539

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Kind regards
Sune

EISA European Camera of the Year 2007-2008, Pentax K10 Best Product

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