[cadmus]

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I just purchased a used Tamron AF 18-250mm F/3.5-6.3 Di II LD from a reputable shop. When it is held lens down, or put in my holster, the lens extends (zooms) by the force of gravity. I have many AF and manual zoom lenses and none do this. Not even a little. But everyone is talking about "creep" on this lens or the pentax version. So I have to ask if the creep is so bad that gravity will 100% zoom the lens when held at any angle less than 45deg from downward.

Is there a way to fix this problem? or should I return it?
Is this common on this model?

Thanks in advance for the help,

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Last edited by cadmus; 03-31-2015 at 08:02 PM.

[vonBaloney]

Yes, they all do that. The Pentax version has a little lock it keep it closed when you're not using it (does the Tamron have that?). The solution is a big rubber band or "LensBand", which you put around the lens (at the back, right at the body), at an angle, half on the stationary part (which is why it has to be at the back, the only stationary part) and half on the zoom ring -- creates friction...

[manacho2005]

I hear it is very common on the superzooms. My 18-135 does it on long walks, and my sigma 170-500 does it really bad. A way to prevent it is a lensband.
Lensband Lens Band Stop Zoom Creep The Easy Way Gold | eBay

[cadmus]

Yes the Tamron has the lock. sadly it only locks when retracted (zoomed out).
I rock climb, so one handed down shots are common for me.
I will look into a lens band, it seams a little silly to have to ADD friction. One would think that could be designed into the lens pre-production.

OK, if this is the norm I can not return it then. It is great otherwise and i guess that is just the price you pay when the lens goes from 18 to 250.

---------- Post added 03-31-15 at 09:26 PM ----------

Also, since it says (IF) on it, is this one of those lenses where it is a big no-no to manually focus when I am still in "AF" mode? Is this one of those lenses that can be damaged by accidentally zooming or focusing while the lens is not attached to the body?

[K57XR]

Yes, barrel/zoom creep is notorious with this particular lens. I had the Pentax version DA 18-250 and the creep on copy was quite severe. I thought about the lens band but never really tried it since I just got used to holding the zoom ring during a shot. Of course, rock climbing with this lens might be a different story.

[todd]

Yep, but any wrist band like the lens band will do the trick. I just use one that one of my kids got for free somewhere...

I actually had to get my Tam18-250 serviced because I fell at the beach and a bunch of sand got in my copy... When I got it back I was excited because there was no creep at all.. But after a couple outings it was back to full creep mode, so the band had to go back on...

[Des]

OK, if this is the norm I can not return it then. It is great otherwise and i guess that is just the price you pay when the lens goes from 18 to 250.

If you look at the PF user reviews, lens creep is just about the first thing everybody mentions: https://www.pentaxforums.com/userreviews/tamron-af-18-250mm-f-3-5-6-3-di-ii-ld.html

It has never bothered me. I did get a lens band but haven't used it. But then I don't rock-climb with it!

It is a fine lens given the design parameters. Every comparison I have seen puts it ahead of the 18-55 and 50-200, and the convenience of such a wide range is great. In good light, stopped down a bit, it has very good contrast, colour and resolution. Photozone summied it up when they said, "the resolution characteristic is fairly amazing regarding the extreme zoom range." If you shoot RAW and use good PP software to correct distortion, vignetting etc, images come up very well, especially at the wider end.

Also, since it says (IF) on it, is this one of those lenses where it is a big no-no to manually focus when I am still in "AF" mode?

You shouldn't do that, but not because it says IF. IF just means internal focus (that is, the lens doesn't change in length when focusing). Whether a lens is IF or not, you should never force manual focus if the lens doesn't allow manual focus override (the 18-250 doesn't).

Is this one of those lenses that can be damaged by accidentally zooming or focusing while the lens is not attached to the body?

No. I have often turned the zoom ring or focus ring when it is not attached to the camera. It doesn't do any harm.

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Last edited by Des; 03-31-2015 at 09:44 PM.

[vonBaloney]

The screw drive will not disengage unless the body is set to MF and the ring does not move freely, so yeah do not manually focus when in AF mode ever. Manually focusing with it isn't that great even if you put the body in MF because it is still moving the gears around in the lens when you manually focus, so you'll want to use AF pretty much always if you can.

As far as the friction, put a LensBand or similar on it and forget it, works very well.

[todd]

I agree with Des about the fineness of this lens. Had strong want for this one 7 years ago when I first got into photography, as my first lens purchase after the kit lens that came with my K100d, but ended up choosing a prime (FA50) because it was cheaper, then never circled back to the Superzoom... Went on to purchasing other expensive primes etc over the years but then last year stumbled on a used copy on craigslist in great condition for only $175 and couldn't resist. it's really a lot of fun to shoot with and i enjoy the challenge of trying to milk the most out of it that I can.

[focusr3]

When i was looking at super zooms I didn't want creep. So i bought the Sigma 18-250mm F3.5-6.3 DC Macro HSM it has no creep at all. If you are climbing with your gear you might want to take a look. Maybe the shop you bought it from could do an exchange or you could test it out if they have one. It's on sale here http://www.adorama.com/SG18250PXM.html?

[cadmus]

Sigma 18-250mm F3.5-6.3 DC Macro HSM it has no creep at all.

It was one i was considering. I do not recall why i ruled it out. I might do just that. I wish I had brick and mortar shops to demo lenses.

---------- Post added 04-01-15 at 08:19 AM ----------

you should never force manual focus if the lens doesn't allow manual focus override (the 18-250 doesn't).

I have read this on numerous threads here and elsewhere. But no one ever says how one determines if the lens allows manual focus override.

Manually focusing with it isn't that great even if you put the body in MF because it is still moving the gears around in the lens when you manually focus, so you'll want to use AF pretty much always if you can.

Hard habit to break if i shot a k-1000 through all of high school and college. For most photos AF is fine. But sometimes it fails to focus exactly where i want, just a little off. I likely wouldn't even notice it without the focusing screens help. So i often have to give it just a little nudge on the focus ring, happy to switch the MF switch but i doubt i can give up the MF ring all together. I know others feel the same.

---------- Post added 04-01-15 at 08:23 AM ----------

If you look at the PF user reviews, lens creep is just about the first thing everybody mentions: Tamron AF 18-250mm F/3.5-6.3 Di II LD Lens Reviews - Tamron Lenses - Pentax Lens Review Database

Yeah, i read all those long ago, in hindsight it makes sens. But at the time i thought creep was minimal subtle changes in focus or zoom. This is not creep this is walk or run.

[vonBaloney]

Hard habit to break if i shot a k-1000 through all of high school and college. For most photos AF is fine. But sometimes it fails to focus exactly where i want, just a little off. I likely wouldn't even notice it without the focusing screens help. So i often have to give it just a little nudge on the focus ring, happy to switch the MF switch but i doubt i can give up the MF ring all together. I know others feel the same.

I think you'lll find little nudges just aren't practical with this lens, like most consumer zooms since the FA era they are built with little regard for manual focus. However with practice you can get the AF to hit what you want, or "nudge" it with that. It is not a fast lens, so there is some leeway there with the focus, I really haven't had trouble hitting what I want with this lens. I love manual focus, but I have a million other lenses for that, this one just isn't suitable for it.

Yeah, i read all those long ago, in hindsight it makes sens. But at the time i thought creep was minimal subtle changes in focus or zoom. This is not creep this is walk or run.

The creep really is no big deal. I put a LensBand on mine years ago and haven't thought about it since.

[blackcloudbrew]

I've owned this lens since 2009 and when I first had it, it clearly was prone to lens creep without the lock engaged. After a bit, I needed to get service on it for the grip (part of which came loose). I also asked Tamron to tighten the lens to reduce the lens creep, which after about a year of use had become very loose. They fixed the grip and tightened the lens, since then I have never had an issue with lens creep on this lens and it's still going strong 5 years after the fix. I've recently acquired the DA 18-270 which is Pentax rebranded Tamron lens and the decendent of the Tamron 18-250. While it's better at lens creep resistance, it's still got it and is not as good a resisting lens creep as my adjusted Tammy.

As this adjustment was done under covered service, I have no idea what Tamron might charge for this, but the point here is that it is somehow adjustable.

[Des]

no one ever says how one determines if the lens allows manual focus override.

That's true. You need to look in the specs and reviews. Pentax calls this feature QuickShift. I don't think Tamron or Sigma have a special name for it.

The answer can vary between different versions of the same lens: for example the Pentax DA-L 55-300 doesn't have QS, but the DA 55-300 does.

Not many Tamron lenses available in Pentax K-mount have this feature. Sigma HSM lenses do - and that includes the current version of the 18-250.

But, I agree with @vonBaloney, and I suspect these comments are equally applicable to the Sigma:

I think you'lll find little nudges just aren't practical with this lens, like most consumer zooms since the FA era they are built with little regard for manual focus. ... I love manual focus, but I have a million other lenses for that, this one just isn't suitable for it.

Just to develop this point: the MF ring is small and the focus throw is short, so it is not always easy to fine tune MF with this lens, especially if you have relatively short DOF to work with. Focus peaking helps, if your camera has it, but it's not perfect either. An aftermarket Katzeye or other focus screen would also help (I loved the split prism focus on my old Canon AE-1 Program) but most people don't bother with these unless they have a bag full of MF lenses.

As vonBaloney says, the better approach generally is to try to get the AF right. These lenses often need some fine AF adjustment in the camera (my Tamron front-focuses a bit). Use a single AF point if possible. Stop down to f8 if conditions permit, as this gives the best resolution and some leeway with DOF.

And the results can be good.

[cadmus]

... Manually focusing with it isn't that great even if you put the body in MF because it is still moving the gears around in the lens when you manually focus, so you'll want to use AF pretty much always if you can.

I think you'lll find little nudges just aren't practical with this lens, like most consumer zooms since the FA era they are built with little regard for manual focus. However with practice you can get the AF to hit what you want, or "nudge" it with that. ....

Not insulting you vonBaloney, i know you speak the truth about the design of modern lenses. Indeed, even in MF i hear and feel the gears complaining. I am griping about the lenses, not you.

Taking these comments into consideration i attempted to switch to manual or avoid manual for many shots. NOT POSSIBLE. AF will not hit what i want. I have tried pin point, full view and every setting in between. NO WAY will AF ever work for me. On most wide shots with no depth issues, sure. On fast moving objects like non-arboreal wildlife, it is faster than i am. But shooting through tree branches: nope. Shooting the derailed on my bike through the bike frame: nope, shooting a fish under water: nope. Shooting anything in my lab (lots of tubes and pipes and apparati): nope. And that is just this just the shots i took this afternoon. All month I have been perturbed by trying to use only AF. I love AF, i really do. I miss a lot of wildlife shots without it. But to not be able to nudge it with AF and make sure my focus prism is right where i want it on most still shots, it is killing me. I hope lenses in the future are designed to accommodate MF.

Also this lens band sucks. I think it needs to be coated in 1/4 felt in one side that would be the perfect amount of resistance as this creep is a pain even when shooting normal domesticated things. But I am afraid to do that because the felt would just become dust and end up on my sensor.

On a happy note, my trip to alaska was great and i only had to bring that one lens which worked great in a variety of settings. The lens creeping was always a pain especially while kayaking, but still, nice lens for the money.

---------- Post added 06-06-15 at 08:46 PM ----------

the lens band also does a nice job of keeping rain out of the mount seam (seam between camera and lens), so that is nice.