Pentax 67 135 Macro Focus Moves When Vertical

[ChuckP]

I was using my Pentax 67 135 macro pointed straight down and noticed that the focus was slowly moving. Same thing happens straight up. Bare lens with no added hood or filters. OK horizonally. Wonder if anyone else has seen this? Would a CLA fix it? And who works on these lenses nowadays?

 

[runswithsizzers]

In the US, Eric Hendrickson gets a lot of recommendations for Pentax gear. I've had him do CLAs on my MX cameras and he fixed a sticky diaphragm on a 50mm f/1.4 for me.

Home-Pentaxs

pentaxs.com

Twenty Questions with Eric Hendrickson

Exclusive interview with the master Pentax repairman, Eric Henderson.

www.pentaxforums.com

 

[Neil Grant]

no, not seen it on that specific lens but helicoids can unwind under the influence of gravity or mirror/shutter shocks. Nikon made their 105mm f/2.8 his macro with a locking feature. Usually lenses stiffen up with age as lubricants dry out. Use a bit of light adhesive tape if it bothers you as an alt to a CLA.

 

[ChuckP]

Doesn't look like a common problem. I don't see it on my other Pentax 67 lenses. Thanks for the links. I'll try and contact him about repairs. Probably wait till after the holidays for the shipping to calm down.

 

[blee1996]

My version of 135/4 Macro for P67 is the later SMC Pentax type, and does not exhibit this problem. But focus creep or zoom creep is an easy fix, by yourself.

You just need black electrical tape, cut them into trapezoid shape, and stick to the focusing/zoom helicoid. You need to experiment with the length and width of the tape. Sometimes you might need to apply it to both sides. One visual example of Nikkor 75-150/3.5 Series E lens, which suffers from zoom creep, with the tape on.

 

[gone]

The electrical tape is a great idea. I had used rubber bands in the past, and they worked, but it wasn't the best solution. This tape idea looks much better.

 

[GLS]

I was using the 135mm macro with my Pentax 6x7 the other day, pointed straight down, and didn't notice this problem FWIW.

 

[flavio81]

I was using my Pentax 67 135 macro pointed straight down and noticed that the focus was slowly moving. Same thing happens straight up. Bare lens with no added hood or filters. OK horizonally. Wonder if anyone else has seen this? Would a CLA fix it? And who works on these lenses nowadays?

A technician can replace the focusing helical grease for a stiffer one.

But to tape the barrel with electrician tape sounds, to me, a more practical proposition...

 

[Randy Stewart]

I was using my Pentax 67 135 macro pointed straight down and noticed that the focus was slowly moving. Same thing happens straight up. Bare lens with no added hood or filters. OK horizonally. Wonder if anyone else has seen this? Would a CLA fix it? And who works on these lenses nowadays?

Focus creep is the cousin of zoom creep. A proper CLA should solve the problem, which can be annoying if you are using the lens hand-held. Pentax used to have factory authorized repair stations around the US. You might see if you can locate that list and pick a near one, just because they would be familiar with the equipment (In my area, that would be Advance Camera Inc, in Portland, Oregon). Frankly, any competent camera repair service should be able to do this job in 15 minutes on the bench. The only tricky aspect deferring DIY is having the right viscosity of lubricant to restore the normal function of the focusing helix.