Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
02-09-2017, 08:54 PM   #16
Loyal Site Supporter
Loyal Site Supporter




Join Date: Dec 2013
Location: Colorado
Photos: Albums
Posts: 1,556
QuoteOriginally posted by biz-engineer Quote
And so where does one draw THAT line? Am I pro because I make a decent amount every year selling my work for the past 6 years? Or am I an amateur because it's not enough to allow me to quit my day job? I take very good care of my equipment to the best of my abilities, but I'm using my gear in the field and sometime s(&(&t happens. If I'm an amateur does it mean I'm at fault for this issue? If I'm a pro, does it mean Pentax has a design issue?
Given how many times this issues happened with the DFA150-450, I agree that it is a design flaw and I don't want to blame anyone for bad usage. My point is to highlight what may cause the issue and what may prevent to have to sent it for service. While it is possible to zoon in / out with reasonable speed with the DFA150-450, there is a significant amount of friction so that zooming in / out quickly it counter nature for this zoom. My 2 cents. Of course, if that issue would happen to me, I not be content, I fully understand that.

This same thing happened to me at about the same 180 mark. Were you using the lens manual or automatic? If I remember correctly, every instance I've read of the 150-450 sticking has been around 180. Would that 180 mark play in somehow as to how & where the force being created locks at that spot. Not an engineer just trying to think like one! My 150-450 was sent back from the factory & it works perfectly fine. I will remember not to press it in the future. Wish they would come up with a fix that prevent us from having to worry about it.

02-10-2017, 11:04 AM   #17
Veteran Member




Join Date: Feb 2015
Photos: Gallery | Albums
Posts: 8,000
QuoteOriginally posted by joip Quote
This same thing happened to me at about the same 180 mark. Were you using the lens manual or automatic? If I remember correctly, every instance I've read of the 150-450 sticking has been around 180. Would that 180 mark play in somehow as to how & where the force being created locks at that spot. Not an engineer just trying to think like one! My 150-450 was sent back from the factory & it works perfectly fine. I will remember not to press it in the future. Wish they would come up with a fix that prevent us from having to worry about it.
I don't know, but I noticed something surprising on my copy of DFA150-450. When the zoom is fully retracted, there is still about 5mm space between the body and the moveable part of the lens (it is not the 180mm position), which seems not to be a space by original design. If you think about it , Ricoh may have added a limit to prevent the zom to retract fully and the sealing to drop.... if that's the case, that would explain why my 150450 never failed , and also, it could be that the failure happen to first production batches sold. And issue corrected by mechanical limit on the next batches.
02-10-2017, 04:17 PM   #18
Site Supporter
Site Supporter
Ex Finn.'s Avatar

Join Date: Nov 2007
Location: Southern Maryland.
Photos: Gallery | Albums
Posts: 7,844
QuoteOriginally posted by biz-engineer Quote
I don't know, but I noticed something surprising on my copy of DFA150-450. When the zoom is fully retracted, there is still about 5mm space between the body and the moveable part of the lens (it is not the 180mm position), which seems not to be a space by original design. If you think about it , Ricoh may have added a limit to prevent the zom to retract fully and the sealing to drop.... if that's the case, that would explain why my 150450 never failed , and also, it could be that the failure happen to first production batches sold. And issue corrected by mechanical limit on the next batches.
I just measured and it is 2.85mm. Give or take 0.02mm...
I am not sure that has anything to do with an o-ring dislodging from its groove?
03-10-2017, 08:10 AM   #19
Pentaxian
UserAccessDenied's Avatar

Join Date: Jan 2015
Location: Maryland
Photos: Gallery | Albums
Posts: 1,674
I was strongly considering replacing my DA*300 with the DFA 150-450... But after reading all of this I'm concerned.

Can we get a lens that doesn't have some sort of issue?
Whether it's SDM failure or Zoom ring locking, there always seems to be some lurking mechanism failure to be weary of...


Any update of this?
Is there evidence this is a first production issue and was fixed on further releases of the lens?

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!
dfa, pentax service, repair, service, warranty
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Simple lens shootout Pentax HD DFA 150-450 vs Canon 100-400 II vs Sigma 150-600 C beholder3 Pentax SLR Lens Discussion 46 07-25-2016 12:33 AM
DFA 150-450 Price rise Mikesul Pentax SLR Lens Discussion 2 04-03-2016 03:50 PM
DFA 150-450 lens creep gumbee Pentax SLR Lens Discussion 12 03-22-2016 07:53 PM
Nikon D7200+ Sigma 150-600 S vs Pentax DFA 150-450 Shanti Non-Pentax Cameras: Canon, Nikon, etc. 43 12-13-2015 09:02 AM
DFA 150-450 aperture biz-engineer Pentax SLR Lens Discussion 14 06-01-2015 09:42 AM



All times are GMT -7. The time now is 11:02 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