Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
01-25-2012, 03:03 AM   #1
New Member




Join Date: Jan 2012
Location: Ireland
Posts: 3
Flash problem, red underexposed picture

Hi there,

I am new with DSLR and happy owner of a Pentax K-r.
However I experience an issue using the build-in flash, I did a lot of tests and cannot get the flash to work properly

Every single picture I take with flash is way underexposed even though flash seems to work
So I tryed to use manual exposure mode:
With 1/10 exposure time, F8, iso 3200, +-0EV, Auto white balance
I took one picture without flash=> picture looks fine
Tryed picture with flash using exact same settings=> picture appears very red but not overexposed (I thought with flash using these settings on close object I should get a picture way overexposed)
I tryed the same test setting white balance for flash and get exactly the same picture

I also tryed taking a picture in front of a mirror using the flash to see if it would show on the picture, same problem picture looks red (walls red instead of white) but no sign of flash on the picture
I don't understand because I can clearly see the flash flashing while taking the picture and it seems powerfull enough.

I tryed to reset camera settings to default, upgrade to latest firmware and still get same results.

Could you help me understand the problem,
Am I doing anything wrong?

Thanks.

01-25-2012, 04:41 AM   #2
Veteran Member
Philoslothical's Avatar

Join Date: May 2011
Posts: 1,723
Strange. It sounds almost like the flash is firing a bit too early. Can you get a local camera shop to look at it, and help you diagnose it?

You'll probably have to either exchange it or get it repaired by Pentax, depending how long you've had it and where you bought it from. It's not a common problem with the K-r, I can say that much.

Oh, and welcome to the forum. Sorry it's under such circumstances.
01-25-2012, 05:23 AM   #3
Veteran Member
sterretje's Avatar

Join Date: Dec 2008
Location: Roodepoort, South Africa
Photos: Gallery | Albums
Posts: 3,534
QuoteOriginally posted by zinzin Quote
Tryed picture with flash using exact same settings=> picture appears very red but not overexposed (I thought with flash using these settings on close object I should get a picture way overexposed)
If your flash works normally, the given settings result in a GN of approx. 64. Divide by the aperture (f/8) and the maximum subject distance is approx 8 meters; minimum subject distance is approximately 0.8 meters. So if the subject is somewhere in this range, pTTL will result in correct exposure.

It is also possible that your flash actually did not fire; the flash that you saw might have been the pre-flash used for pTTL metering and not main flash. I think that that might explain why they turn out red (WB set by camera to flash, but no flash fired during exposure). This can indicate that the pre-flash is fired at full power instead of low power and there is no power left during the actual exposure; this is a camera fault.

You can test this by using the 2 second timer. You should see two flashes; one when the shutter is fully pressed (pTTL metering) and one when the actually image is taken (2 seconds later). During this time, the viewfinder will be black so just look 'over the camera' if you stand in front of a mirror. Also, use normal shutter speeds and ISO like 1/90s and ISO200 for this test.

If you're results are better with the 2 second timer (those two seconds also give the flash time to recharge), I suspect the camera to be broken. If you don't see the second flash, the camera is broken.
01-25-2012, 11:07 AM   #4
New Member




Join Date: Jan 2012
Location: Ireland
Posts: 3
Original Poster
QuoteOriginally posted by sterretje Quote
You can test this by using the 2 second timer. You should see two flashes; one when the shutter is fully pressed (pTTL metering) and one when the actually image is taken (2 seconds later). During this time, the viewfinder will be black so just look 'over the camera' if you stand in front of a mirror. Also, use normal shutter speeds and ISO like 1/90s and ISO200 for this test.
Thank you for that,

I done more tests folowing your answer.
I tested using the 2 second timer... I see 2 flashes but get the same red tones pictures, also second flashing seems less intense than the first one (don't know if normal or not)

I also tried using trailing curtain sync; using this mode I get proper results: picture is bright and colors are normal.
Using trailing curtain sync I see 2 flashes even if I don't use the 2 seconds timer.

the fact that I get correct pictures using this mode for flash seems to confirm that my flash in normal mode would flash too early I believe.

Is there any setting to sync the flash (make it flash later for example)
or any other idea?

Thanks.

01-25-2012, 08:27 PM   #5
Veteran Member
sterretje's Avatar

Join Date: Dec 2008
Location: Roodepoort, South Africa
Photos: Gallery | Albums
Posts: 3,534
Get it repaired or swapped. If timing is indeed off, it will also affect external flashes. There are no adjustments.

Still under warranty?
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
balance, camera, exposure, flash, k-r, kr, pentax k-r, picture, settings
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Total picture distortion. Left 4/5 th of images is underexposed.. Redbip Troubleshooting and Beginner Help 11 12-08-2011 08:44 AM
Problem Of Taking Picture Of Red Flower violini Photographic Technique 7 06-23-2011 06:59 PM
Underexposed pics with new Sigma EF 530 DG Super Flash. What I'm I doing wrong? ismaelg Flashes, Lighting, and Studio 8 02-09-2011 01:46 PM
picture problem TaoMaas Photographic Technique 6 04-30-2010 06:25 AM
Total picture wash flash problem MikesChevelle Troubleshooting and Beginner Help 55 01-24-2010 10:56 AM



All times are GMT -7. The time now is 01:21 PM. | See also: NikonForums.com, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top