540 let me down Christmas Day

Started Dec 26, 2007 | Discussions
crocau Regular Member • Posts: 179
Re: 540 let me down Christmas Day

Paul Hunt wrote:

crocau wrote:

this is 100% wrong, there is difference, not to be rude but your post
idicates that you know very little about mettering system and how it
works if you came to such silly idea

His post indicates his own experience.

Rather than flaming, perhaps you would care to explain in detail the
interaction between PTTL and the various camera metering modes? Some
sample images would be useful.

Paul

i wasn't flaming.....

he claimed as it was a fact that there is no difference which is nonsense so i pointed that out.

point at the picture on the wall and fire with flash and you will get under exposured image change to centre weight and unless blown up flash reflection is close to centre you get well exposured image, now change to spot and do another test shot, unless you aim at flash reflection you once again get well exposured picture.

pttl works as it should, different mettering modes do work as intended with flash as well.

and now the flame you asked for....
most problems come from behind camera

if people use as much energy to ask questions and try to learn pentax metering/pttl flash system as much they use to whing about it they would endup with better pictures in no time and better understanding of mettering/pttl flash.

PTTL ROCKS

GaryDeM Veteran Member • Posts: 6,297
Re: What's missing....

FuzzyUno wrote:

I agree the manual is lacking. But on the other hand, I would think
that if a flash is set to "full auto" and reads the camera's
settings, a properly exposed picture should be able to be taken
without reading a manual. How many times have we opened a piece of
electronics and discarded the manual because the interface was so
intuitive? We should be able to mount the 360/540, turn it on and
shoot in the green setting.

why should you be able to mount the flash and shoot in green mode? dslrs and their flashes are compliceted pieces of electronic equipment.

with that said try the following-camera in manual mode, matrix metring, multiple auto selection of meter points. iso200. flash set to P-TTL, auto zoom. no exposure compensation used on flash and camera. turn camera on first then flash. on camera set shutter speed to 1/125 to 1/180sec and fstop to f8.0. if you are using a lens with and intial fstop near f3.5-4.0 the chart on the back of the 540 should be reading near 13meters. focusing on camera in auto. do not change any settings. take some test shots in a dim area of your home; dark interior hallway or basement.

with the above the camera/flash should be full auto to about 13meters or 39ft. it is not necessary to change any settings for your shots the flah will do all the calculating and adjust accordingly.

i use the above on my dslr and it works. took me 6eails and 5 phone calls to boulder colorado pentax tech and repair center before i found and got someone who worked with me to get it to work. i have a 360 flash and it works with same setup though with slightly less range at any fstop(the 360 is not as powerfull).

note-if you need more flash range you can get it by upping the iso, but you will be eliminating some short range ability to take a picture. for at f8.0 39ft is plenty in full auto flash. you cna also get more range by lowering the fstop you have set in M mode from f8.0 but you will be sacrificing dof. the reverse is also true.

Brad99 Veteran Member • Posts: 3,145
Agreed.

I just bounce with +0.5EV and every exposure seems OK to me indoors, at least with typical UK low white ceilings. Sigma EF500 DG Super + K100D, matrix metering. You really have to use bounce to get consistent metering as then it's rare to get any direct reflections back into the lens.

Steve_
Steve_ Senior Member • Posts: 2,876
Why?

... because if Pentax could even spell refinement, you wouldn't have to. That's why you pay somebody hundreds of USD to make a flash for you--in theory the complications become theirs, not yours. But of course if the Pentax faithful can make constant excuses for unimpressive exposure metering, lame AF, and essentially no telephoto lenses I guess anything is acceptable.

I have Panasonic P&Ss that nail the flash exposure every time, as did my old Nikon coolpixes. I don't care why Pentax can't do it right, DSLR or not. Until Pentax similarily doesn't care, they will remain a bit player in this market. When you design both the camera and the flash, you have every opportunity to try the two together and optimize the results. Unfortunately Pentax leaves this to the user, an unnaceptable lack of refinement considering their flashes cost as much as those that really work as well as they promise.

It's pretty easy to make a flash work. I have 30-year old ones that work fine, and without the benefit of a dedicated communication with the camera. With them, you have to know a bit about what you are doing and run a good bit of the show yourself. That's supposed to be the whole point of all the complexity of something like an AF540 flash--to automate all that rather than just produce enough settings to allow it to be set up very, very wrongly.

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crocau Regular Member • Posts: 179
Re: Why?

this is seriously laughable

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PTTL ROCKS IF YOU KNOW HOW TO USE IT

silvershoes Regular Member • Posts: 282
Re: What's missing....

What's missing is that you expect the equipment to give you what you want without learning the basics of flash exposure. There are a number of good tutorials on the web covering the subject. They're not brand specific, and once you understand how to use the equipment properly, you'll be very pleased with what you have.

The flash didn't let you down, you did.

crocau Regular Member • Posts: 179
Re: What's missing....

silvershoes wrote:

The flash didn't let you down, you did.

AMEN

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PTTL ROCKS IF YOU KNOW HOW TO USE IT

Michael Perham Senior Member • Posts: 1,349
Re: 540 let me down Christmas Day

Both the 360 and 540 are definitely inconsistant with the K10D. I can take a shot that appears underexposed, add a bit of exposure compensation, it seems overexposed, then move back to the original setting and it comes out perfectly exposed.

Now the flash is fully charged and shooting the same subject, so not sure what could be causing this inconsistancy other than the metering system with flash. I might add that metering without flash is dead on.

Mike.
--
http://www.mikespentaxianblog.blogspot.com/

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kenyee Senior Member • Posts: 1,522
samples of "bad" photos?

We can't guess what happened w/o seeing samples...

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Caligula Regular Member • Posts: 269
Re: 540 let me down Christmas Day

I have had these problems for a long time, but shooting very seldom with flash.

I can't figure out how to get a constant exposure using PTTL, thefore most used the 540 in A-mode untill now.
Plese do me a favour:
Set the flash in PTTL-mode and the camera in P-mode, ISO 200.

Take a pic, change to ISO 400, take a pic, change to ISO 800, take pic and compare the pics. Same object, same zoom and same setting except ISO!

When I'm doing this I get one pic underexposed, one pic more or less OK and one pic overexposed.
Why?
--
Erik

(unknown member) Veteran Member • Posts: 6,759
The proof is here

crocau wrote:

this is 100% wrong, there is difference, not to be rude but your post
idicates that you know very little about mettering system and how it
works if you came to such silly idea

I have done a quick test just to backup my claim that the chosen metering mode makes no difference when P-TTL flash is on. My conclusion is that matrix metering mode would be chosen automatically whenever P-TLL flash mode is on. So why Matrix but not CW? Because if CW were actually used, the P-TTL would not be fooled by the blown highlight as many have experienced. There are 6 shots below. The 1st 3 shots were pointing at the white wall, the last 3 shots at the black colour paper. The 1st & 4th shots w/o flash are showing that the spot meter of my camera is working and accurate. The 2nd, 3rd, 5th & 6th shots have identical exposure indicate the chosen metering have no effect whatsoever in P-TTL flash mode.

White - Spot - w/o flash

White - Spot - P-TTL flash

White - Matrix - P-TTL flash

Black - Spot - w/o flash

Black - Spot - P-TTL flash

Black - Matrix - P-TTL flash

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(unknown member) Veteran Member • Posts: 9,762
Wow Brilliant!

You just proved my point that it is absolutely the user! Try metering the subject accurately and see for yourself what you get out of the flash system... Ever heard the saying, "Garbage In Equals Garbage Out".

DS_Dave wrote:
Ah, of course...P mode on the cam, +0.7 flash EV and +0.3 overall EV
inside a typical lounge room of a house, naturally one would expect
underexposed flash shots LOL...

Pete Perry wrote:

A lot of people jump into this game and think that Flash is an
automatic thing that will just light up the scene exactly how you
wanted it... Well guess what? If you don't have the exposure right
to begin with then you won't get the image you want out of the
camera... In short, if you think you can start with an underexposed
image and the flash will automatically correct it you're wrong as it
relies as much on the proper exposure as not having a flash at all.

Another note, you should always expose for your subject and not worry
and let the rest of the scene take care of itself. One way to do
this is to learn how to use a spot meter and another is to get a
reading from both in front of your subject and behind your subject
while making adjustments.

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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

(unknown member) Veteran Member • Posts: 9,762
Re: Agreed

Very much agree, if the exposure is bad the flash won't help at all!

blende8 wrote:

Flash is no super power brain, that knows more than you.
It is not idiot proof.
You need some experience to use it and wrongly exposed shots happen.

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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

(unknown member) Veteran Member • Posts: 9,762
Could be several reasons...

You have to operate within the confines of the camera. Did you have the camera set to sync at the max flash speed sync speed of 1/180? If so that will force the shutter to 1/180 and if it can't obtain a correct exposure because your lens has a minimum aperture that isn't wide enough to compensate for the extra shutter speed then you need to bump the ISO.

The ideal way to use the flash for basic bounced lighting would be something like 1/60 (set the camera to sync the flash with the meter and not to force it to 1/180) and then set the ISO to 1/400 with something between F/5.6 and F/8 (5.6 should be enough... That will get enough stability but if you wanted to go down to ISO 200 you could go 1/30 with the shutter and ISO 200... If you still wanted to go all the way down to ISO 100 you could go 1/30 @ F/4 and ISO 100. Either way you should get a decent bounced shot.

Caligula wrote:

I have had these problems for a long time, but shooting very seldom
with flash.
I can't figure out how to get a constant exposure using PTTL, thefore
most used the 540 in A-mode untill now.
Plese do me a favour:
Set the flash in PTTL-mode and the camera in P-mode, ISO 200.
Take a pic, change to ISO 400, take a pic, change to ISO 800, take
pic and compare the pics. Same object, same zoom and same setting
except ISO!
When I'm doing this I get one pic underexposed, one pic more or less
OK and one pic overexposed.
Why?
--
Erik

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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

Michael Perham Senior Member • Posts: 1,349
Here are examples...

Both frames @ ISO 200 1/60 and f/5.6 ...as you can see one is a bit overexposed compared to the other.

The camera was hand held so framing is not exact, but I don't think the subject is such that it should cause this difference in exposure.

Mike.

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Brad99 Veteran Member • Posts: 3,145
Re: Here are examples...

The first shot is overexposed because it's mostly direct flash (going by the shadows) and the left half of the frame is nearer than the right half. Inverse square law and all that. Nothing you can do about it with a single direct flash. If it was a bounce card being used, then there's too much card bounce and not enough bounce off the ceiling, i.e. the card is too big.

The second has much more ceiling bounce, and looks quite good to me, but the fall off on the right is due to much the same reason as the first shot, your light is aimed up and is hitting the ceiling above the left half more than the right. A wide angle diffuser would help a bit, but there's still some inverse square law effect going on here despite bouncing off the ceiling. The light just has further to go on the right half to get to the subject. It's just limitations of using a single flash in both cases IMHO.

Caligula Regular Member • Posts: 269
Re: Could be several reasons...

Pete Perry wrote:
You have to operate within the confines of the camera. Did you have
the camera set to sync at the max flash speed sync speed of 1/180?
If so that will force the shutter to 1/180 and if it can't obtain a
correct exposure because your lens has a minimum aperture that isn't
wide enough to compensate for the extra shutter speed then you need
to bump the ISO.

The ideal way to use the flash for basic bounced lighting would be
something like 1/60 (set the camera to sync the flash with the meter
and not to force it to 1/180) and then set the ISO to 1/400 with
something between F/5.6 and F/8 (5.6 should be enough... That will
get enough stability but if you wanted to go down to ISO 200 you
could go 1/30 with the shutter and ISO 200... If you still wanted to
go all the way down to ISO 100 you could go 1/30 @ F/4 and ISO 100.
Either way you should get a decent bounced shot.

Caligula wrote:

I have had these problems for a long time, but shooting very seldom
with flash.
I can't figure out how to get a constant exposure using PTTL, thefore
most used the 540 in A-mode untill now.
Plese do me a favour:
Set the flash in PTTL-mode and the camera in P-mode, ISO 200.
Take a pic, change to ISO 400, take a pic, change to ISO 800, take
pic and compare the pics. Same object, same zoom and same setting
except ISO!
When I'm doing this I get one pic underexposed, one pic more or less
OK and one pic overexposed.
Why?
--
Erik

Have you at all tried what I suggested?

When set in P-mode with the flash on, the cam suggests 1/60 f/8, which sound pretty OK to my experience. As I wrote I'm not very experienced in flash shooting, I more or less have to start from the beginning every time because I use it seldom.

The settings stay 1/60 and f/8 when changing ISO from 200 to 400 and 800 and the exposure changes one stop from 200 to 400 and another stop from 400 to 800. Camera was pointing on exactly same object and distance was same approx. 5 meters.
Can't understand this. If you can you explain I would be most gratefull!!

-- hide signature --

Erik

nosnoop Senior Member • Posts: 1,694
Re: 540 let me down Christmas Day

wlachan wrote:

Something I have discovered is that the choice of metering makes no
difference when it comes to P-TTL flash. Matrix, CW, spot, bright &
dark subjects in any combinations, I tried/tested them all but the
exposure would be just the same. This leds me to believe that unlike
Nikon, Pentax P-TTL flash employs a fixed metering mode (matrix I
believe).

But the main idea is the "Link AE to AF" in matrix metering mode. This definitely works. By selecting your focus point, the meter would bias towards that metering segment (note it is bias only, not spot metering on that segment), and reduce the "underexposure" problem people are seeing. But I don't like to use the word "underexposure" as the meter does exactly how it is supposed to behave, just that the metering segment it concentrates on (highlights) is not the one you want.

nosnoop Senior Member • Posts: 1,694
Re: The proof is here

wlachan wrote:

I have done a quick test just to backup my claim that the chosen
metering mode makes no difference when P-TTL flash is on.

Try doing a test with Link AE with AF with Matrix metering, and you will see a difference.

GregT Contributing Member • Posts: 643
Re: 540 let me down Christmas Day

Hi:

The flash manual states that if you have not used the flash for a while to pop the flash in test mode to fully discharge it. Apparently this resets the flash and can then be used reliably. Hope this is of some help.
--
Regards,
GregT
F8 and be there.

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