Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
02-01-2008, 09:48 PM   #1
Forum Member




Join Date: Jan 2008
Location: Eugene, Oregon, US
Posts: 97
Yeow, "automatic" zoom?

I've stumbled over a problem with a Pentax DA 18-250mm f/3.5-6.3: with the weight of just a filter and the hood, the lens will extend on its own when you point it down, for example while it's draped around your neck. And it'll retract when you point it up.

Very frustrating. Makes it impossible to take an almost-macro picture of a flower from directly above! This lens does have a zoom lock, but that engages only at the 18mm (fully retracted) position so the lock is not very useful.

The Pentax 18-250 is said to be basically a re-badged Tamron, and indeed someone here mentioned the 18-250 Tamron was marginal in this regard, too. But my Pentax 50-200 behaves perfectly.

So my question is, is this creep a common problem with "economy" (< $500) zoom lenses? Other Pentax lenses? Would a DA*, with its weatherproofing seals be immune? Is this one of the reasons you pro's avoid the ultra-zoom "vacation" lenses?

Is there any practical way to increase the friction of the mechanism so it stays wherever you put it?

02-01-2008, 10:27 PM   #2
Veteran Member




Join Date: Mar 2007
Location: Sydney, Australia
Posts: 439
My DA 18-250 shows zoom creep too, but from what you write it doesn't sound like it's as bad as yours. The camera has to be 'shaken' or nudged, like if I have it pointing down while I'm walking down stairs. It won't creep solely under the influence of gravity.

I can see how a very slick one would be frustrating. I'd think it will tighten up over time with the ingress of dust into the zoom mechanism. But maybe it will loosen up as the oils distribute themselves more thoroughly.

I hate to have to say this, but a bit of electrical tape on the barrel over the lapped sections once you have zoomed might do the job for the macro-type situation you describe. Sounds like a very agricultural solution for an otherwise fine lens, though. I say electrical tape as in my experience (but not for the suggested use) it's less likely to leave adhesive residues.

Last edited by G M Fude; 02-01-2008 at 10:31 PM. Reason: Tidied up the grammar so you can understand what the heck I'm saying!
02-01-2008, 10:49 PM   #3
Veteran Member




Join Date: Nov 2007
Location: Albuquerque NM
Photos: Albums
Posts: 379
I had exactly same problem and i place call to Pentax technical support.And receive very nice response." dont worry this normal lens behavioral'' lens just fine.
02-01-2008, 11:04 PM   #4
m8o
Veteran Member
m8o's Avatar

Join Date: Jul 2007
Location: 40░-55'-44" N / 73░-24'-07" W [on LI]
Photos: Gallery | Albums
Posts: 3,095
QuoteOriginally posted by infosyn Quote
So my question is, is this creep a common problem with "economy" (< $500) zoom lenses?
Yup, both my zooms creep ... it's common with many many zooms, even expensive ones from my readings.... it's sucky. Search for |zoom creep| for all the mentions of it on here.

02-01-2008, 11:32 PM   #5
Inactive Account




Join Date: Nov 2007
Location: Grosse Pointe Farms, Michigan
Posts: 189
QuoteOriginally posted by m8o Quote
Yup, both my zooms creep ... it's common with many many zooms, even expensive ones from my readings.... it's sucky. Search for |zoom creep| for all the mentions of it on here.
From what I have read in this thread. First of all if one lets a camera body with lens attached "fly freely from a neck tether" to "fly free and KNOCK up against things" in ones travels. The lens has not half a chance of focusing properly.

This is not quite difficult to explain. Move along with your equipment in your carrying bag, then pull it out of the bag, and shoot.

Just plain common sense
02-01-2008, 11:50 PM   #6
Veteran Member
clawhammer's Avatar

Join Date: Sep 2007
Location: Logan, Utah
Photos: Gallery
Posts: 972
zoom creep has always been a problem with these 'superzoom' lenses, that's why they have the locks on them. You really just have to learn to work around it; for me if I'm hand-holding the camera (ie not using a tripod) I usually always have at least a finger on the zoom ring, and that should be enough to keep it from creeping. However, in tripod situations I can see where it would become a pain in the neck.

They're 'do-it-all' lenses, not 'do-it-all-perfectly' lenses (except perhaps Canon's 28-300 L series behemoth, that thing is insane).
02-02-2008, 06:43 AM   #7
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 16,216
I don't know why people are now just discovering zoom creep. it has been around since the early 1980's

my vivitar Series 1 70-210 f3.5 did it when new.

The fact of life is that many zooms, especially those who's front elements move significantly while zooming, will creep to some extent due to the weight of the elements.

Some makers have put locks on the lens, my tamron 28-75 f2.8 for example to lock it at minimum length for carrying (around your neck on the camera strap)

Others, I believe hav a brake that can hold the zoom ((i have read this but never seen one myself)

it is natural, but can be frustrating if you are attempting to do macro or more importantly copy functions with the lens pointed streight down.
02-02-2008, 10:52 AM   #8
m8o
Veteran Member
m8o's Avatar

Join Date: Jul 2007
Location: 40░-55'-44" N / 73░-24'-07" W [on LI]
Photos: Gallery | Albums
Posts: 3,095
QuoteOriginally posted by WendyB Quote
From what I have read in this thread. First of all if one lets a camera body with lens attached "fly freely from a neck tether" to "fly free and KNOCK up against things" in ones travels. The lens has not half a chance of focusing properly.

This is not quite difficult to explain. Move along with your equipment in your carrying bag, then pull it out of the bag, and shoot.

Just plain common sense
Ok... valid but different point.... not sure why you quoted my post.

02-02-2008, 10:56 AM   #9
m8o
Veteran Member
m8o's Avatar

Join Date: Jul 2007
Location: 40░-55'-44" N / 73░-24'-07" W [on LI]
Photos: Gallery | Albums
Posts: 3,095
QuoteOriginally posted by Lowell Goudge Quote
I don't know why people are now just discovering zoom creep. it has been around since the early 1980's
What I've seen a lot of late of a major influx of new D/SLR users. infosyn just joined and may be new to this stuff (dunno). Being in that boat in as little as just a 1/2 year ago, I can understand. Search is your Friend yes, but but one needs to know the terms to search for. I struggled with that too.
02-02-2008, 01:45 PM   #10
Inactive Account




Join Date: Jul 2007
Location: Sault Ste Marie, Ont, Canada.
Posts: 563
Lots of zooms exhibit the same behaviour. More so if they are a push pull design. As someone else has mentioned, some lenses have an adjustable brake, but this can bet rather annoying to use. I do believe the Canon 100-400L has such a mechanism, and I hear a few people complaining about that also.

The Tamron and Pentax 18-250 does this, and is the reason why they were nice enough to give use a lock for transportation. I haven't found this to be an issue out in the field myself. At least they do give you a lens lock. I can remember constantly walking around with my camera held up with one hand, so that the push pull zoom wouldn't extend during travels.
02-02-2008, 02:44 PM   #11
Veteran Member




Join Date: Mar 2007
Location: Sydney, Australia
Posts: 439
QuoteOriginally posted by WendyB Quote
This is not quite difficult to explain. Move along with your equipment in your carrying bag, then pull it out of the bag, and shoot.
Ha ha, if I had to muck around doing that every time I wanted to take a photo, I wouldn't bother taking photos!

Camera around neck... always ready for that 'moment'. Haven't damaged a lens in 35 years.
02-02-2008, 03:56 PM   #12
Veteran Member




Join Date: Nov 2007
Location: Albuquerque NM
Photos: Albums
Posts: 379
QuoteOriginally posted by Lowell Goudge Quote
I don't know why people are now just discovering zoom creep. it has been around since the early 1980's

my vivitar Series 1 70-210 f3.5 did it when new.

The fact of life is that many zooms, especially those who's front elements move significantly while zooming, will creep to some extent due to the weight of the elements.

Some makers have put locks on the lens, my tamron 28-75 f2.8 for example to lock it at minimum length for carrying (around your neck on the camera strap)

Others, I believe hav a brake that can hold the zoom ((i have read this but never seen one myself)

it is natural, but can be frustrating if you are attempting to do macro or more importantly copy functions with the lens pointed streight down.
Yes all this is not fresh news ,but i have older minolta zoom and this lens creep very slowly '
Yes i have look 18mm position on my Pentax 18-250.
But i never saw before when i slightly turn lens to macro target for example 100mm position or more and turn lens probably 10-15* down .Lens just very fast fly to 18 mm position.
When i talk with Pentax sevices response look like mostly was " what do you want .what you paid what you have."Its normal good buy.
I have small magnet device what i use for work system,but i don't know how this magnet will be effective to chip and all camera itself.I try this before for film camera without any problem ,but digital????
02-02-2008, 05:29 PM   #13
roy
Inactive Account
roy's Avatar

Join Date: Sep 2006
Location: D/FW area, Tx.
Photos: Gallery
Posts: 1,712
another work around is to take a wide rubberband and put it on the zoom ring with part of it touching the barrel to add some friction.. i know it works with the A70-210/4.. yes, i know ''why do i have to do this with a NEW 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!
k-mount, lens, lenses, lock, pentax, pentax lens, slr lens, tamron
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
What does "Automatic Aperture Setting" mean? Todd Adamson Troubleshooting and Beginner Help 6 10-22-2010 02:29 PM
Which Zoom Lens? "Tamron AF 18-250mm", "Pentax-DA 18-250mm" or "Sigma 18-250mm" hoomanshb Pentax SLR Lens Discussion 4 07-30-2010 09:50 AM
"Hunger for a DA*50-135?" or "The DA*50-135 as a bird lens!" or "Iron age birds?" Douglas_of_Sweden Post Your Photos! 4 08-13-2008 06:09 AM
Workaround for "automatic" nr on K20 jeffkrol Pentax DSLR Discussion 4 07-15-2008 05:56 AM
Anyone else with a "Kalimar MC Automatic" 28mm? rparmar Pentax SLR Lens Discussion 9 05-26-2008 06:57 PM



All times are GMT -7. The time now is 10:34 PM. | 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