Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
06-28-2013, 08:04 PM   #1
Senior Member




Join Date: Sep 2011
Photos: Gallery | Albums
Posts: 268
Is this normal behavior for SDM lens

I just bought another copy of a DA*200. When I was trying it out I was focusing on my daughter walking towards me and tried to take the shot and the shutter didn't fire. The centre point indicator and the green hexagon indicated focus but on pressing the button a number of times the shutter did not fire and the whole time the centre point indicator stayed lit. I suspect it is because she was walking out of focus that the shutter did not fire. The lens could not adjust focus fast enough to keep up. Is this correct?

06-28-2013, 08:12 PM   #2
Site Supporter
Sandy Hancock's Avatar

Join Date: Feb 2012
Location: Adelaide Hills, South Australia
Photos: Gallery | Albums
Posts: 5,245
Is it focussing properly with static subjects?
In the bodies I have owned, you can re-prioritise the interaction between the shutter activation and AF lock in the menu system.
06-28-2013, 08:36 PM   #3
Senior Member




Join Date: Sep 2011
Photos: Gallery | Albums
Posts: 268
Original Poster
QuoteOriginally posted by Sandy Hancock Quote
Is it focussing properly with static subjects?
.
Yes it is. No hesitation.
Maybe I am being over cautious but this is my fourth copy in 6 months and I have 10 days left to exchange it which I would rather do since my experience of Pentax Service over the last 6 months has been ......................... So far image wise it seems ok but I just wanted check this behavior is normal.
06-28-2013, 08:44 PM   #4
Pentaxian
aleonx3's Avatar

Join Date: Jul 2007
Location: Brampton, Ontario
Photos: Gallery | Albums
Posts: 3,873
are you using AF-S or AF-C for focusing mode? It shutter should trip if you are in AF-C mode. I use AF switch to lock focus instead of half-press shutter.

06-28-2013, 08:55 PM   #5
Senior Member




Join Date: Sep 2011
Photos: Gallery | Albums
Posts: 268
Original Poster
QuoteOriginally posted by aleonx3 Quote
are you using AF-S or AF-C for focusing mode? It shutter should trip if you are in AF-C mode. I use AF switch to lock focus instead of half-press shutter.
AF-S. I will explain again.
My daughter walks towards me fromm about 15m and when I press the button I see the indicators in the viewfinder showing the lens has focused but the shutter does not fire and on pressing the button several times it still does not fire. I cannot tell if the lens is trying to refocus as it is so quiet but the center point indicator stays lit.
06-29-2013, 04:45 AM   #6
Veteran Member




Join Date: Sep 2006
Location: WV
Posts: 1,484
QuoteOriginally posted by everydaylife Quote
AF-S. I will explain again.
My daughter walks towards me fromm about 15m and when I press the button I see the indicators in the viewfinder showing the lens has focused but the shutter does not fire and on pressing the button several times it still does not fire. I cannot tell if the lens is trying to refocus as it is so quiet but the center point indicator stays lit.
When in AF-S the lens should not be trying to refocus on a moving subject. What happens when you use AF-C?
06-29-2013, 05:32 AM   #7
Pentaxian
calsan's Avatar

Join Date: Nov 2008
Location: Perth, Australia
Photos: Gallery
Posts: 1,367
The red dots don't indicate focus, they just show which focus point is being used. The green hexagon indicates that focus is achieved.
06-29-2013, 09:36 AM   #8
Pentaxian
aleonx3's Avatar

Join Date: Jul 2007
Location: Brampton, Ontario
Photos: Gallery | Albums
Posts: 3,873
QuoteOriginally posted by everydaylife Quote
AF-S. I will explain again.
My daughter walks towards me fromm about 15m and when I press the button I see the indicators in the viewfinder showing the lens has focused but the shutter does not fire and on pressing the button several times it still does not fire. I cannot tell if the lens is trying to refocus as it is so quiet but the center point indicator stays lit.
I think you can try this setting and technique when the subject is moving. I would select AF-C shooting mode with high continuous drive mode; then use center-focus point only, set the camera to TAv mode, use your thumb to press the AF switch to lock the focus and index finger to trip the shutter (this is the reason why I think k-5 has the best ergonomics). When you see the green hexagon lit up in the viewfinder, fire away several shots at a time.

Here is an example of the shots I took during a recent event.
South Asian Canada Day-set 2 - a set on Flickr

Anyway, back to the original question, I have two DA* lenses and they both had problems before, and after they were repaired and replaced with the new SDM motor-assembly, they are now fine and I don't have any problems or sluggishness like that. One more minor point, when I am not using the lens, I usually put them in an upright position instead of lying flat; just my own personal observation and not any scientific proof of avoiding future SDM failure. The symptom before SDM failure on my 50-135 was that when I mount the lens after it was lying flat for weeks, it took a while to "wake-up". After a while, the SDM motor just get stuck.

Good luck, hope your lens does not have the same problem.

07-01-2013, 06:18 PM   #9
Senior Member




Join Date: Sep 2011
Photos: Gallery | Albums
Posts: 268
Original Poster
Thanks for all the replies. User error as usual. I set the camera to AFC and tried again and although not all shots were in focus the camera responded to every press of the button.

And another reason is that I think I am expecting to much for a lens to refocus on an object moving towards me that is with 3 meters of the minimum focus distance and the lens is close to wide open. DOH

Thanks again for the replies
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!
centre, fire, focus, indicator, k-mount, lens, pentax lens, shutter, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Rokinon 35mm f1.4: Is this lens flare normal? Douge Pentax SLR Lens Discussion 9 01-01-2013 08:05 PM
Normal Behavior for Takumar-A 2x Converter? Julie Pentax SLR Lens Discussion 2 07-27-2012 06:36 PM
Is this chromatic aberration normal for DA 14mm photomission Pentax SLR Lens Discussion 18 07-12-2012 10:12 PM
Normal behavior for DA 21mm lens? sahale Pentax SLR Lens Discussion 10 07-08-2012 09:24 PM
Is this normal size hot pixel for K20D? PPPPPP42 Pentax DSLR Discussion 3 02-01-2012 12:53 PM



All times are GMT -7. The time now is 04:26 AM. | 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