Camera Labs

Taking this from another thread on Pentaxforums.com

I just got my DA* 50-135mm from the mail today and I was testing it out just now. I noticed how the manual focus ring felt "loose". Is this normal?

*edit*
When I turn the focus ring and try to focus, i have to turn the ring just a little tiny bit before anything changes on the distance window.

*edit* Also noticed it only happens when I change directions. It is very slight but still noticeable and I'm afraid my lens is defective

Senior Member



Join Date: Feb 2009
Location: Sugar Land, TX
Gallery Photos: 0
Posts: 124
*update*
Everything else worked perfectly fine, but the MF still bothers me just a little. I have to twist an extra 1mm or less (in the opposite direction) to get the distance scale to change.

(2posts)

_________________
Samsung GX-10, , SA 18-55mm
Canon 5D Mark II, 40D, EF 17-40mm f/4 L, EF 24-105mm L IS, EF 50mm f/1.4

www.flickr.com/glxlr

I bet ReiVillo could tell me if it is normal or not!
Someone said this is due to the "qucikshift" mechanism unlocking in the lens. Not sure and not confirmed yet.

It is hardly noticeable in regular use (I didn't even notice it actually ;-D) but it just scares me to have a "defective" product. I don't even think it is worth spending shipping money on and waiting weeks for it to come back, but I am very curious if it might be an even BIGGER problem or will lead to a bigger problem.

_________________
Samsung GX-10, , SA 18-55mm
Canon 5D Mark II, 40D, EF 17-40mm f/4 L, EF 24-105mm L IS, EF 50mm f/1.4

www.flickr.com/glxlr

Bonjour GLXLR,

I'm sorry to read you have questions about your brand new DA* 50-135mm .

I tried differents protocols on my DA* 50-135mm attached to a K10D, trying to replicate your problem:

• SDM auto-focus then quick-shift
  After the beep saying the auto-focus is done by the built-in SDM motor, the manual focus ring has something like a 1° hysteresis: moving the ring does not affect the focusing inside.
  It is more noticeable when the subject is close.
  The quick shift mechanism is rather sophisiticated: the SDM motor works without moving the manual focus ring but then, moving the manual focus ring does affect the lenses inside.
  
• Manual focus
  No hysteresis found.

I checked the other DA* lenses: it apperas to be just the same when using quick-shift. Just a 1° hysteresis (or even less) when using the manual focus ring.

On my lenses, this hysteresis is hardly noticeable, and I haven't noticed it so far, until I get your message.

If you want to check your DA* 50-135mm, try the following tests:

• Focus on something far (more than 30 feet - 10 meters) then something close (3 feet - 1 meter) and check the auto-focus and the SDM motor are work fine, quickly and silently. Do the same on manual focus.
  
• Select continous auto-focus and focus on something close (3 feet - 1 meter) then look around: the auto-focus and the SDM motor should respond quickly and silently. Try the same on manual focus mode.

I always realize those tests to be familiar with a new lens. It's part of the learning curve to fell comfortable with one's gear

In any case, if you still have doubts, do not hesistate to pay a visit to your dealer or to send back your gear, and ask for a change or a refund.

I hope your lens is fine after the tests and so you could enjoy it shooting dramatic pictures This lens is just amazing

_________________
--- rei_vilo
Pentax K-5 + BG4 + DA* 16-50 + DA* 50-135 + DA* 60-250 + AF-540FGZ
reivilophotography.weebly.com

THANKS REI!!! Gave me a bunch of relief! I looked at the photos I took with it, and the colors/contrast/sharpness are MUCH better than my 100mm FA Macro whcih was supposed to be a fantastic performer. The focusing ring doesn't bother me while I'm outside or inside actually shooting, but It was just something I noticed when I was playing around with it. I don't think it is a big enough problem to send back to Pentax (and others have said they have the same "problem"). I do have a 1 degree hysteresis in BOTH AF (with quickshift) AND MF, but in MF it only happens when I change direction of MF (closer or farther). I bought this lens from Amazon, and I don't really know how the warranty works yet, as I have yet to find a warranty card in the box. Thanks for your reply Rei!

*re-read your post and you said you didn't even notice this before. Mine is pretty noticeable (my Dad didn't notice even after 2 minutes playing around with it so it may just be me). Doesn't really bother me at all while shooting like I have said, and I think I will grow used to it (or forget about it all together ).

_________________
Samsung GX-10, , SA 18-55mm
Canon 5D Mark II, 40D, EF 17-40mm f/4 L, EF 24-105mm L IS, EF 50mm f/1.4

www.flickr.com/glxlr

Bonsoir GLXLR,

I glad you're feel relieved . However, amazon provides great service, so don't hesitate to ask for a change.

I hope to see some pictures you took with that great lens

Enjoy

_________________
--- rei_vilo
Pentax K-5 + BG4 + DA* 16-50 + DA* 50-135 + DA* 60-250 + AF-540FGZ
reivilophotography.weebly.com

Thanks! I don't really think it is worth to go change, but I think it will be quite easy to fix via a specialized lens fixing store (as I said I think the sharpness and color is EXCELLENT). Don't want to risk getting a "bad" copy.

*actually I might go to Amazon and ask for a change later this month (or go get it fixed). It does feel kind of lose and it bothers me. Is it possible to go to any type of store and get this fixed b/c I don't want to deal with shipping it back to Amazon and waiting for another copy.

_________________
Samsung GX-10, , SA 18-55mm
Canon 5D Mark II, 40D, EF 17-40mm f/4 L, EF 24-105mm L IS, EF 50mm f/1.4

www.flickr.com/glxlr

I am going to return and exchange for another 50-135mm.

_________________
Samsung GX-10, , SA 18-55mm
Canon 5D Mark II, 40D, EF 17-40mm f/4 L, EF 24-105mm L IS, EF 50mm f/1.4

www.flickr.com/glxlr

Bonjour GLXLR,

I think it's the best option. I've always had the best service with amazon.fr.

Now, the hardest part is to remain patient and wait till the new one arrives

Good luck

_________________
--- rei_vilo
Pentax K-5 + BG4 + DA* 16-50 + DA* 50-135 + DA* 60-250 + AF-540FGZ
reivilophotography.weebly.com