Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
10-25-2010, 09:35 AM   #1
Veteran Member




Join Date: Mar 2008
Location: CT / NY
Photos: Gallery
Posts: 822
P-TTL Issues: Body? Lens? Flash?

Okay, need some feedback here. Yesterday I had an event to shoot and I was using the following setup:


- Kx + DA*50-135 + AF540 mounted on camera (PTTL Mode)
- K10D + DA16-45 + AF360 mounted on camera (PTTL Mode)


The Kx setup was working perfectly, i was a bit surprised actually. Only thing is, I was abusing the flash (shooting at distance -135mm- and flash needed some time to recharge after 3 consectuive shots). But exposure was actually VERY controlled.


Now the issue: the K10D setup was NOT working AT ALL.. and same settings as the Kx. Too dark most of the times (despite adjusting exposure in the camera flash setting AND flash exposure setting) OR too bright other times. I havent checked the results, but I doubt I save 50% of the K10D shots... whereas the exposure on the Kx was perfect... saving the moments when the flash was not charged and I forced the shot.


Two thing I noticed while trying to figure out the issue with the K10D setup:

- the flash was constantly going from P-TTL to TTL all the time, on the backscreen. As I half-pressed te shutter, i could see the flashgun going to PTTL to TTL.

- the DA 16-45 was acting up as well... giving me issues focusing.



Thinking more about this, I guess I could easily swap the kits around and try to determine if the issue is the body, lens or flashgun. And I plan on doing this, but right now I have to deliver the photos from yesterday and I have another shooting friday.


So any inputs or experience with this? Flash contacts dirty? Lens contact dirty? Anything?


BTW, I was shooting on Av mode: f/5.6

10-25-2010, 09:52 AM   #2
Forum Member
Bobe416's Avatar

Join Date: Mar 2009
Location: Toronto
Photos: Gallery | Albums
Posts: 57
I have the K10D and AF540, and have experienced the flash not auto zoom as well as the switching from PTTL to TTL as you noted. I suspect the flash was not fully pushed forward into the hot shoe. Try cleaning the contacts on the flash and hot shoe just to be sure dirt is not an issue. Gve the flash a good push forward into the shoe before you set the lock
You could also try wireless mode to get it off the camera - hopefully it will work and most like give you better shots
10-25-2010, 10:17 AM   #3
Forum Member
Bobe416's Avatar

Join Date: Mar 2009
Location: Toronto
Photos: Gallery | Albums
Posts: 57
Forgot to mention a couple of other points - The K10D is a pain to focus in low light but with the 540 flash the spot beam comes on - this seems to resolve my focus issues. Also to save batteries I often shoot a at ISO 200 or even 400 (if the pictures are just going to be 4x6 it should be fine).
10-25-2010, 10:47 AM   #4
Veteran Member




Join Date: Mar 2008
Location: CT / NY
Photos: Gallery
Posts: 822
Original Poster
QuoteOriginally posted by Bobe416 Quote
I have the K10D and AF540, and have experienced the flash not auto zoom as well as the switching from PTTL to TTL as you noted. I suspect the flash was not fully pushed forward into the hot shoe. Try cleaning the contacts on the flash and hot shoe just to be sure dirt is not an issue. Gve the flash a good push forward into the shoe before you set the lock
You could also try wireless mode to get it off the camera - hopefully it will work and most like give you better shots
hi Bob,

I did try to remount the flash on the camera few times, because it did seemed like the communication between them was at fault... but it didnt help it.

Next time I am working on my gear, i'll make sure to check the flash contacts.



QuoteOriginally posted by Bobe416 Quote
Forgot to mention a couple of other points - The K10D is a pain to focus in low light but with the 540 flash the spot beam comes on - this seems to resolve my focus issues. Also to save batteries I often shoot a at ISO 200 or even 400 (if the pictures are just going to be 4x6 it should be fine).

I use the tricky with the ISO, hence the Kx had mounted the 50-135... so I could use ISO1600 and save some power... but the subject was pretty far away, and after the or four full blasts, I had to wait few secs for the next shot.


Now the K10D was also set to ISO 400 but the 16-45 was used much closer to subject, the camera should be able to absolutely handle the condition.

10-25-2010, 11:07 AM   #5
Veteran Member




Join Date: Jul 2008
Location: Var, South of France
Photos: Albums
Posts: 1,071
K10 and K20 are notoriously goofy with P-TTL: any reflection leads to severe underexposure.

K7 and Kx really improved on P-TTL (I got all 4, so I was able to compare!)
10-25-2010, 11:28 AM   #6
Veteran Member




Join Date: Mar 2008
Location: CT / NY
Photos: Gallery
Posts: 822
Original Poster
QuoteOriginally posted by dlacouture Quote
K10 and K20 are notoriously goofy with P-TTL: any reflection leads to severe underexposure.

K7 and Kx really improved on P-TTL (I got all 4, so I was able to compare!)

That actually makes some sense, because the event was a fashion show with losts of light beams everywhere and mirrors and shinny things...


But how about the P-TTL > TTL > P-TTL action going on? What would make the flash to swap between modes automatically?
10-25-2010, 11:43 AM   #7
Veteran Member
sterretje's Avatar

Join Date: Dec 2008
Location: Roodepoort, South Africa
Photos: Gallery | Albums
Posts: 3,534
A lens not set in the A-position will cause this behavior. The 16-45 does not have this option as far as I know; combined with your focusing issues this might point to bad contacts between lens and camera.

Just checked on a K10D with screw-mount lens and AF540
Default reading on flash is P-TTL when camera in Av mode; activating metering (half press of shutter) makes it switch to TTL.

Hope it helps to get closer to the cause of the problem.
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!
camera, dslr, exposure, flash, issue, k10d, kx, lens, mode, photography, pttl, setup
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Firmware v1.31 causes wireless P-TTL issues on the K10D? adamfogerty Pentax DSLR Discussion 10 01-12-2011 07:16 AM
Pentax 540af P-TTL issues imfinetoday Pentax Camera and Field Accessories 2 08-23-2010 11:36 AM
P-TTL flash with takumar lens? Big I Flashes, Lighting, and Studio 27 08-23-2009 11:43 AM
P-TTL flash issues Ash Pentax DSLR Discussion 28 02-17-2008 01:54 PM



All times are GMT -7. The time now is 08:39 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