[joip]

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.

[biz-engineer]

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.

[Ex Finn.]

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?

[UserAccessDenied]

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?