Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-10-2009, 01:06 PM   #1
Site Supporter
Site Supporter
daacon's Avatar

Join Date: Mar 2007
Location: Alberta,Canada
Photos: Gallery
Posts: 20,831
Does my TC need repair ?

I have a Pentax 1.7x TC where autofocus more or less works. I have found that on some lenses at some times I have to go MF to kind of kick start the AF - when I get close in MF I the AF usually starts to work. Almost like cranking an old motor.

Sometimes it goes back to not working after I change FL say from 200 to 70 and I have to go do the MF trick again. (The MF is usually done with a quick shift on the lens iteself).

So my question is do you think my TC is malfunctioning ? Is is suppose to work 100% all the time with no degradation in AF speed ?

Some non Pentax Lens I have to switch SR off before I turn on the camer (Thanks for that info Marc !!) otherwise it will ask my for FL. I think this is ok - it's more the auto focus that I am cocncerned about.

Edit: do I just need to give it a good cleaning perhaps ? If so how would I do that ?

04-10-2009, 05:28 PM   #2
Pentaxian
hinman's Avatar

Join Date: Oct 2006
Location: Fremont, CA
Photos: Albums
Posts: 3,427
QuoteOriginally posted by daacon Quote
I have a Pentax 1.7x TC where autofocus more or less works. I have found that on some lenses at some times I have to go MF to kind of kick start the AF - when I get close in MF I the AF usually starts to work. Almost like cranking an old motor.

Sometimes it goes back to not working after I change FL say from 200 to 70 and I have to go do the MF trick again. (The MF is usually done with a quick shift on the lens iteself).

So my question is do you think my TC is malfunctioning ? Is is suppose to work 100% all the time with no degradation in AF speed ?

Some non Pentax Lens I have to switch SR off before I turn on the camer (Thanks for that info Marc !!) otherwise it will ask my for FL. I think this is ok - it's more the auto focus that I am cocncerned about.

Edit: do I just need to give it a good cleaning perhaps ? If so how would I do that ?
As far as I know, that is the normal behavior in Pentax F-1.7x AF TC, you need to manual focus to close proximity to your target in order for the TC to engage in AF. It is as if the AF resides in the TC but the catch is that you need to move the focusing ring close to the position of your intended object. In a way, it is partial AF as you need to manual focus first to a close point.

Regarding the SR focal length, you can enter it by
  1. power off, then on
  2. menu button -> followed by one UP arrow

And I always count on the 2nd method on SR focal length when I am using a zoom lens. Perhaps, other can jump in with better explanation.

Thanks,
Hin
04-11-2009, 04:46 AM   #3
Site Supporter
Site Supporter
daacon's Avatar

Join Date: Mar 2007
Location: Alberta,Canada
Photos: Gallery
Posts: 20,831
Original Poster
Thanks Hin - I don't use it often , good to know that is normal behaviour. Perhaps I need to buy a DA* 300 ummmmmmmmmmm
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!
af, fl, k-mount, lens, mf, pentax, pentax lens, slr lens, tc
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
DA 16-45 repair ma318 Pentax SLR Lens Discussion 17 05-19-2014 03:54 PM
Nature Way beyond repair Larsenio Post Your Photos! 12 12-20-2009 05:05 AM
FA 80-320 repair foxx510 Pentax SLR Lens Discussion 0 03-14-2009 03:56 PM
MX Repair sticknv Pentax Film SLR Discussion 3 08-31-2008 02:57 AM
Help with repair w6wat Pentax DSLR Discussion 0 06-17-2008 06:16 PM



All times are GMT -7. The time now is 11:54 AM. | See also: NikonForums.com, CanonForums.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