Flash causing lines on photo

marlon · 09-02-2008, 12:29 AM

Pentaxmen

I have a strange occurence, and Im posting my question here since I feel it is related to me being a complete noob when it comes to using flashes.

Here is a 100% crop from an example:
http://vudu.za.net/ttl/whatthe.png
Just note, its about 500KB

I used my K20D and AF360FGZ flash for the above, and lightened the image a bit to show the phenomena a bit more.

Now look closely at the darker area of the tap, especially around the washer. There seems to be vertical lines across the image. This does not happen using the pop up flash, and it does not happen shooting without flash. I also haven't noticed it happening with my camera's raw fromat (but I might be wrong). It appears to only be visible in DNG.

It's confusing, and everything is brand new, so my only idea could be the flash mode, or _something_ related to HOW I do it, but you guys would know better than me.

Thanks, hope to get good news

Regards
Marlon

little laker · 09-02-2008, 02:25 AM

To me it looks like some electrical interference, most likely coming from the flash.

If you bought it all locally try going back to the store, and try another flash.
Any good camera store will let you, and if you don't have the same problem with the test flash it'll be the flash unit.

If you still have the lines try another body. Using your same battery, memory card, and lens.
If the problem goes away it's the body.

After you discover what the problem is the store owner should help you with the warranty repair, or replacement.

Lots of luck with it.

marlon · 09-02-2008, 03:19 AM

Thank you.
That makes sense I suppose, I hope it's the flash really, exchanging bodies in SA is a daunting nightmare.

I will do some testing.

Regards
Marlon

debbie · 09-02-2008, 07:46 AM

I had the same problem and had the k20d body exchanged. It was more visible in some shots with a flash but showed up in other situations too.
There have been a couple of others with the same problem if you search the forum.

But I have latley been noticing the same stripes but very subtle in the darker areas of some pictures, so it seems like Pentax has some kind of problem on some of the K20d:s sensors.

marlon · 09-02-2008, 12:57 PM

Debbie, thanks.
So what you are saying is that you have been seeing it again, even after the exchange?
I have tried all day to re-produce the problem, but had no luck. Im not sure If I want to go through the effort of exchanging. Local shops here are hard to work with.

marlon · 09-15-2008, 05:09 AM

Just an update on this issue (to whom it may concern).
After 1000 photos of not having the problem in post #1 again, last night, I managed to hit it again on 2 or 3 shots.
Same vertical lines as with the original photo (here: http://vudu.za.net/ttl/20dnoise.png )

But, new info, I used a plain old kit lens last night, no flash, no popup flash, nothing weird.

No one else got this yet beside me? Its only visible on 100% view (if and when it occurs)

AVANT · 09-16-2008, 09:30 AM

You're doing fine if you're only have 2 or 3 vertical banding issues in 1000 shots. That shot looks under exposed anyways which would only exaggerate the effect. Try lowering the ISO and overexpose a little bit more and I bet you'd never be able to tell even with 8x10 prints.

You should see some of banding problems on ISO 1600 with my K10D... eeeeep