K10D Faulty Flash

Hi Guys,

I have taken 100s of superb pics with my K10D, most of them daytime, however, I always wondered why when using the flash the pics do not look good.

This week I had to take pics indoors and noticed most of them were terribly underexposed. Strangely I notice that when I take the picture I can see the flash burst through the viewer before it disappears when the mirror pulls up. This happens in probably 4 out of 5 times.

It appears that when I take the picture the flash fires a fraction of a second before the picture is taken, leaving only a minute of flash bouncing off the subject.

I spoke to Pentax and they were very attentive. They asked me to email them with all details and pics to demonstrate. I will do this soon, but I am wondering if anyone here has had the same problem. Or if perhaps if there is something stupid I am doing... cannot think of anything wrong.

I had bought a Sigma EF 500 with the camera but sent it back because I thought it was faulty. They refunded me the money as they had stopped doing this model. Now I notice it is the camera at fault.

So what flash are you using now :
I use the AF-360 set too P TTL and let the camera decide the shutter and Aperture and i have got many good pics. The odd 1 or 2 might not be the best but thats down to me not the camera.
Post a couple of the pics you are concerned about i would be interested to see them and compare them with the ones i have taken.

What settings do you have the flash on? it may be set to a few stops under power, it may be set on trailing curtain sync (or whatever its called).

You are seeing the P-TTL (Preflash Through The Lens). The flash fires first to gauge the exposure before actually firing for the main. That's why you see it through the viewfinder

I suspect you are probably trying to push the pop-up too hard - it's only a little flash after all!

Check out this detailed thread first:
https://www.pentaxuser.com/forum/viewtopic.php?t=4950

HTH,
Matt

With P-TTL flash guns (the K10D's built-in is one), there are two flashes. The first one you'll see in the viewfinder, since the camera uses the return from it to do its metering, which takes place with the mirror down.

Then the mirror pops up, the shutter opens, and the second flash takes place during the actual exposure.

So seeing a flash in the viewfinder is as it should be.

But there does need to be a second one. I suggest you check that the second one is happening - they do happen far enough apart to see them both.

If you're only getting one flash, then it's a problem. If two, then your underexposure may not be a fault with the camera.

It hasn't been determined what flash he is actually using as yet :
I was just using the 360 as an example.

Edit: i just re-read his post and i now realise he is using the built in flash

Blimey, you are so quick to help. Thanks.

Ok... more info here.

The flash I am referring is the pop-up flash. When I used the Sigma EF500 I returned it the next day as I thought it was IT at fault, however, all pics with it where completely underexposed. I even set the flash at full power (manual) and took a picture on a subject 3m away... underexposed completely.

Now to help you understand what I mean I posted some of the many pics I have on picasa. They are holiday snaps and I am not good at all in photography, also some of them are leaning more than the tower of Pisa despite taking care to align straight before shooting... so please don't laugh at me.

Here we go...

http://picasaweb.google.com/nuttyscientist/PentaxK10DFlash

Pics with the same number are taken within seconds or minutes from each other. You will notice that e.g.

Pic 1a is perfectly exposed while 1b and 1c are under - fill in flash.

Pics 2 are all under exposed but to different degrees.

Pics 3 are underexposed but b is better. You can see some of the flash reflection in the buttons of the shirt and my daughter golden chain.

Pic 4a completely underexposed, 4b is fine (few seconds in between)

Pic 5b well exposed, the others different underexposure value... look at 5d!

Pic 6a is a good example of good fill in flash... so it works when it wants.

Pic 7b is fine but 7a taken seconds earlier is not

Pics 8 taken last week which alerted me to the problem. 8a from 2m away completely underexposed (infact I took another 5 and are all the same). An hour later I took 8b (well exposed) and 8c underexposed)

In all instances the flash is firing but as I explained above I could see the burst of the flash just before the mirror pulls up. So concluding, there is a software problem that is not timing the flash correctly with the shutter. However, this inconsistency is inconsistent, because it varies the time the shutter fires (hence different values of underexposures) and it is only on 1 out of 5 times that the flash fires at the right time.

Ok, points:
1) Upgrade the firmware - you have v1.00 Pentax updated the flash exposure and functions (allowing wireless flash etc)

2) In outdoor shots (like the procession) the pop-up flash will be as good as a candle. You can't light up a huge space with a tiny light source. You might be lucky and the flash may have an effect on the people nearest, but not on the scene as a whole.

3) Reflective items confuse the flash exposure. (e.g. sequins, mirrors etc). The camera reads the reflection as part of the scene and "corrects" the exposure.

Once you've upgraded the firmware, and read my guide to P-TTL flash, then give it a try again and let us know
(And note: as I keep mentioning, there will always be situations where the automatic exposure just can't get it right. I can explain more fully later, but let's start with the above points first!)

Matt

Everything that Matt said.

Also:

Seeing the pre-flash in the viewfinder is not evidence for your conclusion.

The pre-flash is supposed to happen, and it will be visible in the viewfinder.

If you keep thinking that it's not, it's likely to distract you from whatever the real problem is.

EDIT:
Ok, I see from the last couple of shots that you have upgraded

I really, really would suggest reading my guide... there's a lot in there, but it's worth understanding most of it

In my experience, there are situations where you go "Huh?!" with the flash exposure. However, there's usually a rational explanation, and a way around the situation (it's a bit like having to learn about exposure compensation when taking photos of all white, and all black objects).

For the most natural shots:
1) Use "M" mode on the camera
2) Choose an ISO appropriate to the scene (ie use a higher ISO in the dark!)
3) Put away the flash (or power off the external flash) and meter with the M button
4) You can adjust the exposure to around -1 underexposed
5) Turn on the flash and take the shot

The P-TTL (PRE FLASH - ie TWO flashes) will kick in, do its metering stuff and you'll get a shot where the whole scene is good... but looking at the scenes you have taken, most of them will need a tripod too.

You will notice the preflash particularly when the pop-up is working hard. If the preflash senses that it's going to need a lot of light, then there'll be a slightly longer pause before the shutter goes up (while it recharges the flash).

Hope that goes some way to explaining this (complex) topic
Matt

Thanks for your input. However, I am still convinced there is something wrong with it. It is not possible that at least 4 out of 5 pics taken by flash are completely underexposed if not blacked out. It is impossible that nearly all pics taken on Green mode are completely underexposed. It does not make sense that it takes 4 pics in a row underexposed and then low and behold without changing the settings the next one is perfect.


How can one explain that the K10D cannot cope with a simple point and shoot pic with flash such as pic 8a or fill in flash in 1b and 1c? Any mobile phone camera can do better than that. I am sure Pentax engineers have done a better job, above all, all reviews I read the praised the power of the small pop up flash.

Looking at all the pictures I have taken with flash since I bought it last July I only have around 10 properly exposed. Around 50 are not and only God knows how many I have deleted on the way!

I cannot think of getting the wrong setting everytime!

But now, thanks to you I recognise there is a pre-flash, the one I keep seeing through the view finder. I now wait for Pentax to get back to me and in the meantime if I find some free time I will run a test with flashes and follow the instructions posted here.

I will keep you informed.

How far apart in time are the photo's? Is it possible that you are trying to shoot too fast and the flash cannot recharge in time?

Another idea, off the wall, I'm sure ... erm, you do hold the camera with your left hand underneath the lens, not on top of it? It would be very easy to obscure the light from the flash if your fingers were on top of the lens while zooming, for instance.

Sorry if that's a really dumb suggestion, just thought it might be worth a mention.

There is enough time to allow the flash to recharge. In fact if you look at the exif you will note 'Flash Used'. There are no dumb questions it is good to pick on any thing that can cause this problem. I do hold the camera from beneath with my left hand, usually from the left grip.

In a way I am hoping I am doing something silly, but I have been taking pics and using SLRs for 15 years and cannot see what I am doing different.

I will put the camera on a tripod and point at a subject and use the Pentax remote control. Everything I am using is genuine Pentax. I will follow Mattmatic's instructions religiously and see the results.

Thank you all for trying, any more suggestions are welcome. I am still waiting to hear from Pentax but now is the weekend so I wait for Monday to hopefully hear from them.

Last night I performed a test, setting the camera on a tripod at a bookcase full of different coloured books, 2m distance. I used the remote control and took around 5 pics on each setting with different A values (if applicable). I also used M and X and all pictures turned out perfectly lit and exposed! All pics taken with the pop up flash.

This morning I took some pics of my baby and did not have any underexposure as experienced before, although I preferred the pics when I set the flash to +0.3.

So I do not know what the heck I was doing wrong before. In the meantime, Pentax sent me an email to send it back, however, I will not at the moment as I will look as a fool, unless I truly find there is a fault. I will do some more tests with fill in flash etc to make sure that the problem is me and not the camera.

A question now: Since the camera takes two flashes (as explained to me in the thread), if I want to use slaves how do I get around it? Will M or X do it? Assuming them two settings take only the one flash (if I am correct).

Thank you for your help.