Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
02-01-2015, 08:26 AM   #1
Veteran Member




Join Date: Jul 2009
Location: Ottawa, Canada
Posts: 342
Repair a sub-standard kit lens?

It seems my first 18-55 AL II kit lens that I got many years ago was a "good copy". Unfortunately, it was messed up badly in a fall and isn't anymore. When I was upgrading to a K30, I got one with a 18-55 WR, expecting it to perform just as well as my old kit lens, with the bonus of WR. It's obviously not possible to do a direct A/B comparison between the two, but over time, I've got the impression that this newer lens isn't as good. It seems to be softer in the corners at the wide end.

I know it isn't really fair to expect too much from a kit lens, and that there are better lenses, but I thought it might be nice to have this as an option for when I need WR.

I'm pretty sure the newer lens is still under warranty, but I have no experience with sending a lens in for repair ( and it seems that the Pentax Canada repairs are contracted out as of last year ) . Would the warranty department regard this as a legitimate defect covered by the warranty? Even if they do accept it for warranty repair, is it likely that the calibration procedure will correct something like this? Or might it come back in worse shape than it went in?

I've got another normal zoom, so I don't mind having the lens in for repair. However, I'm disinclined to sink money into getting it repaired.

Any suggestions or experiences that anyone would care to share would be appreciated.

02-01-2015, 10:11 AM   #2
Site Supporter
SpecialK's Avatar

Join Date: Dec 2006
Location: So California
Photos: Gallery
Posts: 14,912
QuoteOriginally posted by arkav Quote
I'm pretty sure the newer lens is still under warranty...However, I'm disinclined to sink money into getting it repaired.
If it is under warranty and defective, where is the cost, other than shipping?
02-01-2015, 11:03 AM   #3
Veteran Member




Join Date: Jul 2009
Location: Ottawa, Canada
Posts: 342
Original Poster
QuoteOriginally posted by SpecialK Quote
If it is under warranty and defective, where is the cost, other than shipping?
I'm just wondering if they will actually accept that this is defective. Maybe they will claim that a bit of softness at the wide end is normal for this lens, and possibly levy an "estimate charge" just for looking at it.

Like I said, I have no experience sending Pentax equipment in for repairs. I've sent in Tamron Lenses, but they were pretty clearly defective.
02-01-2015, 01:26 PM   #4
Veteran Member
EarlVonTapia's Avatar

Join Date: Oct 2012
Location: Vancouver
Photos: Gallery
Posts: 1,153
The new Pentax camera is going to have a fancy collapsible kit lens. I suspect that when it's announced (any time now), DA 18-55s of all stripes will tank in price. You could probably get one super cheap then.

02-01-2015, 02:18 PM   #5
Site Supporter
lsimpkins's Avatar

Join Date: Feb 2013
Location: SE Pennsylvania
Photos: Gallery
Posts: 172
QuoteOriginally posted by arkav Quote
I'm just wondering if they will actually accept that this is defective. Maybe they will claim that a bit of softness at the wide end is normal for this lens, and possibly levy an "estimate charge" just for looking at it.

Like I said, I have no experience sending Pentax equipment in for repairs. I've sent in Tamron Lenses, but they were pretty clearly defective.
Why not contact Pentax of Canada by phone or email and ask them directly if service to address corner softness would be a)possible and b)covered by warranty? Good luck with this and let us know their position.
02-01-2015, 02:44 PM   #6
Pentaxian




Join Date: Mar 2010
Location: Frankfurt am Main
Posts: 1,094
You said you were upgrading to the K30, but you haven't told about your previous model.
In case it offered less than the 16MP of the K30, could it be the old kit was (resolutionwise) outperforming the sensor, and now the k30 sensor is outperforming the kit lens in certain conditions?

The first 18-55 kit was designed for the 6MP sensors, and with the 10MP sensor of the K10/K200D/K2000 was already at its limit.
For the 14MP sensor of the K20/K-7, Pentax had to introduce the much improved 18-55/II. But for the 16MP sensor edges may get problematic (specially when fully open plus zooming wide).
And: do you keep in mind that this lens is not a flat-field one like typical macro lenses? This means when shooting a flat wall with shallow DOF the center will be in focus, the borders not (as they are farer away).

I think it is possible, that your present lens isn't the best because of sample variation, but still within Pentax specs.

Calibration, if properly done, should at least not worsen the problem.
02-01-2015, 09:00 PM   #7
Veteran Member




Join Date: Jul 2009
Location: Ottawa, Canada
Posts: 342
Original Poster
QuoteOriginally posted by RKKS08 Quote
You said you were upgrading to the K30, but you haven't told about your previous model.
It was a K200D. I guess I can put the WR on the K200D and see if I see softness - but unfortunately, I can't do a direct A/B comparison with the old lens anymore.

QuoteOriginally posted by RKKS08 Quote
In case it offered less than the 16MP of the K30, could it be the old kit was (resolutionwise) outperforming the sensor, and now the k30 sensor is outperforming the kit lens in certain conditions?
That's possible, but I think I'm seeing the softness without pixel peeping to the point that sensor resolution is coming into play. I'll have to dream up a test that's a bit more objective than the subjective impression I have from looking random images.

QuoteOriginally posted by RKKS08 Quote
For the 14MP sensor of the K20/K-7, Pentax had to introduce the much improved 18-55/II. But for the 16MP sensor edges may get problematic (specially when fully open plus zooming wide).
Yes, my old ( now broken ) kit lens was the 18-55/II. I don't typically shoot wide open when zooming wide. I was mostly use it for landscapes. I've got a Tamron 17-50 now, so the WR kit lens doesn't see any action.

QuoteOriginally posted by RKKS08 Quote
This means when shooting a flat wall with shallow DOF the center will be in focus, the borders not (as they are farer away).
I had thought of that, and that's why I haven't tried the simple brick wall test.

QuoteOriginally posted by RKKS08 Quote
I think it is possible, that your present lens isn't the best because of sample variation, but still within Pentax specs.
Yes, that's a good point.
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!
camera, kit, lens, pentax help, photography, repair, repair a sub-standard, sub-standard kit, troubleshooting, warranty, wr
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
wanting to uprate from the standard 18-55 kit lens lancer3397 Pentax SLR Lens Discussion 9 01-06-2014 11:24 AM
Best sub 200$ kit lens ?? photoshoper Pentax K-30 & K-50 20 07-16-2013 08:43 AM
Pentax Q + 01 Prime Standard Lens Kit $199.99 + free s/h systemA Pentax Price Watch 39 01-16-2013 11:18 AM
For Sale - Sold: K-5 with standard kit lens 18mm-55mm $650 JCRGuevara Sold Items 6 09-11-2012 11:25 PM
Looking for versatile sub $500 kit lens replacement tnis0612 Pentax SLR Lens Discussion 13 12-28-2010 12:27 PM



All times are GMT -7. The time now is 09:28 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