What to do about 16-50?

ksignorini · 04-10-2008, 09:14 PM

I think my DA* 16-50 may be a bad copy. It's blurry as heck wide open.

My Canon Elf SD1000 is clearer by far.

Is there a process that should be followed to get a replacement? Is it through the supplier? Through Pentax? ??

Thanks!

skaktuss · 04-10-2008, 10:02 PM

I wonder, why do people still buy this lens. We should boycott it and perhaps Pentax will start to think about the QC.

ksignorini · 04-10-2008, 10:05 PM

I guess I bought it because all the reviews I had read before I DID buy it said it was a good choice.

I guess if google would have served up the right reviews instead of the ones I read, I may not have.

But since I did buy it, and I may have a bad copy, and I didn't ask the question so that I could be made fun of, could someone please provide a constructive response?

Thanks again.

jsherman999 · 04-10-2008, 10:19 PM

If you bought it local, you should be able to bring it back to the store and either exchange it, return it for refund, or have them send it in to Pentax for adjustment.

If you bought it shipped from a place like Adorama or B&H, you can return it for exchange, and they are excellent in that respect.

You should also be able to send it to Pentax directly yourself if it's still under warranty, and they will adjust it or send you a new one.

I went through two of these, and wasn't going to even try for a 3rd, but I happened to be in a local shop which happened to have a copy - a good copy (tried it in the store,) so I bought it.

The reason people keep trying is because if you get a 'good' one, it's really excellent - sharp-sharp-sharp, really great contrast, color, and constant 2.8 from 16 - 50.

I don't know if I'd recommend trying to get one, at this point - just a lot of hassle and stress involved if you get a bad or even mediocre one. If you want to persevere, though, you're assured of getting a good one eventually.

Here are some snapshots showing what to expect from a good one - no brick wall tests, just snapshots --> S H O T S

.

Last edited by jsherman999; 04-11-2008 at 06:30 AM.

ksignorini · 04-11-2008, 06:00 AM

Wow!

Mine is not even close to that sharp.

I bought mine from B&H and I've now sent them an e-mail.

Thanks for your help.

ksignorini · 04-11-2008, 11:08 PM

I've changed my mind.

It's not my lenses. I've done numerous experiments now with my K10D, another K10D, a K100D, and my new (as of a few hours ago) K20D.

It's my K10D. It won't focus properly at all. My lenses are perfectly fine on all three other cameras. I even used Tim Jackson's (google him if you want the chart) focusing chart to do the tests. My K10D won't even come close to focusing at the correct spot...everything is extremely back focused.

Some thoughts...

I did replace/exchange the focusing screen a few times with a Katz Eye, but I'm back to the Pentax screen. Also, I had cleaned (very gently, with a sensor cleaning kit including optic cleaning solution and a gentle horizontal swab) the focusing screen and the bottom element of the prism (it was nastily dirty after one of the focus screen changes and blowing the dirt wouldn't work). As this solution works extremely well on optical glass, CCD's, etc. I can't imagine it had any effect.

Looking back at my images from my K100D to my K10D (bought 8 months later) I definately can tell the K10D is not as clear in many cases. I don't know how I never noticed it before.

Does anyone have any other thoughts?

**Canada_Rockies** · 04-12-2008, 01:21 PM

Originally posted by ksignorini

I've changed my mind.

It's not my lenses. I've done numerous experiments now with my K10D, another K10D, a K100D, and my new (as of a few hours ago) K20D.

It's my K10D. It won't focus properly at all. My lenses are perfectly fine on all three other cameras. I even used Tim Jackson's (google him if you want the chart) focusing chart to do the tests. My K10D won't even come close to focusing at the correct spot...everything is extremely back focused.

Some thoughts...

I did replace/exchange the focusing screen a few times with a Katz Eye, but I'm back to the Pentax screen. Also, I had cleaned (very gently, with a sensor cleaning kit including optic cleaning solution and a gentle horizontal swab) the focusing screen and the bottom element of the prism (it was nastily dirty after one of the focus screen changes and blowing the dirt wouldn't work). As this solution works extremely well on optical glass, CCD's, etc. I can't imagine it had any effect.

Looking back at my images from my K100D to my K10D (bought 8 months later) I definately can tell the K10D is not as clear in many cases. I don't know how I never noticed it before.

Does anyone have any other thoughts?

Is it possible that you have the focusing screen spacer on the wrong side of the screen? Did you perhaps drop it and lose it? (I almost did!) If your screen is in the wrong place, anything can happen.

ksignorini · 04-12-2008, 01:28 PM

The spacer never came out.

I just checked and it's nice and tight against the prism side, then the screen, then hatch that holds the screen.

(I suppose that's the right order since it never came out.)

aegisphan · 04-12-2008, 02:38 PM

There is a spacer? I put 2 Katz Eye screens on my K10 and K20, but I've never noticed any spacer before. To the OP, it seems your K10D is one of the few that has the problem. I don't have any problem with mine for all of my AF shots. But if you satisfy with the result on the K20D, then just use your lenses on the K20. I guess the K10D can be used for manual lens or you can just sell it.

frank · 04-12-2008, 04:46 PM

Originally posted by ksignorini

I've changed my mind.

It's not my lenses. I've done numerous experiments now with my K10D, another K10D, a K100D, and my new (as of a few hours ago) K20D.

It's my K10D. It won't focus properly at all. My lenses are perfectly fine on all three other cameras. I even used Tim Jackson's (google him if you want the chart) focusing chart to do the tests. My K10D won't even come close to focusing at the correct spot...everything is extremely back focused.

Some thoughts...

I did replace/exchange the focusing screen a few times with a Katz Eye, but I'm back to the Pentax screen. Also, I had cleaned (very gently, with a sensor cleaning kit including optic cleaning solution and a gentle horizontal swab) the focusing screen and the bottom element of the prism (it was nastily dirty after one of the focus screen changes and blowing the dirt wouldn't work). As this solution works extremely well on optical glass, CCD's, etc. I can't imagine it had any effect.

Looking back at my images from my K100D to my K10D (bought 8 months later) I definately can tell the K10D is not as clear in many cases. I don't know how I never noticed it before.

Does anyone have any other thoughts?

Exactly the same experience I had with my first copy on my K10D and K20D (and a friend's K100D who has my first DA1650 right now

). The lens was way BF on the K10D, especially the wide end. But it was spot on w/ my K20D and my friend's K100D. Ended up he has it for cheap, and I changed to another one (thanks again Hiep

). And again, this one seems to be an excellent copy, on my K20D.

I think it's not just the lens alone, it might because of the camera too. Most of my lenses focus much better on my K20D than the K10D.

ksignorini · 04-13-2008, 10:29 AM

Originally posted by frank

Most of my lenses focus much better on my K20D than the K10D.

I did a whack of tests last night. ALL my lenses focus MUCH better on the K20D than the K10D that I have (my friend's is far, far better, but it's also from a much newer batch).

I'll be sending my K10D in for warranty repair.

04-10-2008, 09:14 PM	#1
ksignorini Forum Member Join Date: Apr 2008 Location: Edmonton, AB Posts: 70	What to do about 16-50? I think my DA* 16-50 may be a bad copy. It's blurry as heck wide open. My Canon Elf SD1000 is clearer by far. Is there a process that should be followed to get a replacement? Is it through the supplier? Through Pentax? ?? Thanks!

04-10-2008, 10:02 PM	#2
skaktuss Senior Member Join Date: Feb 2007 Location: Latvia Photos: Gallery Posts: 259	I wonder, why do people still buy this lens. We should boycott it and perhaps Pentax will start to think about the QC.

04-10-2008, 10:05 PM	#3
ksignorini Forum Member Join Date: Apr 2008 Location: Edmonton, AB Posts: 70 Original Poster	I guess I bought it because all the reviews I had read before I DID buy it said it was a good choice. I guess if google would have served up the right reviews instead of the ones I read, I may not have. But since I did buy it, and I may have a bad copy, and I didn't ask the question so that I could be made fun of, could someone please provide a constructive response? Thanks again.

04-10-2008, 10:19 PM	#4
jsherman999 Veteran Member Join Date: Dec 2007 Photos: Gallery Posts: 8,237	If you bought it local, you should be able to bring it back to the store and either exchange it, return it for refund, or have them send it in to Pentax for adjustment. If you bought it shipped from a place like Adorama or B&H, you can return it for exchange, and they are excellent in that respect. You should also be able to send it to Pentax directly yourself if it's still under warranty, and they will adjust it or send you a new one. I went through two of these, and wasn't going to even try for a 3rd, but I happened to be in a local shop which happened to have a copy - a good copy (tried it in the store,) so I bought it. The reason people keep trying is because if you get a 'good' one, it's really excellent - sharp-sharp-sharp, really great contrast, color, and constant 2.8 from 16 - 50. I don't know if I'd recommend trying to get one, at this point - just a lot of hassle and stress involved if you get a bad or even mediocre one. If you want to persevere, though, you're assured of getting a good one eventually. Here are some snapshots showing what to expect from a good one - no brick wall tests, just snapshots --> S H O T S . Last edited by jsherman999; 04-11-2008 at 06:30 AM.

04-11-2008, 06:00 AM	#5
ksignorini Forum Member Join Date: Apr 2008 Location: Edmonton, AB Posts: 70 Original Poster	Wow! Mine is not even close to that sharp. I bought mine from B&H and I've now sent them an e-mail. Thanks for your help.

04-11-2008, 11:08 PM	#6
ksignorini Forum Member Join Date: Apr 2008 Location: Edmonton, AB Posts: 70 Original Poster	I've changed my mind. It's not my lenses. I've done numerous experiments now with my K10D, another K10D, a K100D, and my new (as of a few hours ago) K20D. It's my K10D. It won't focus properly at all. My lenses are perfectly fine on all three other cameras. I even used Tim Jackson's (google him if you want the chart) focusing chart to do the tests. My K10D won't even come close to focusing at the correct spot...everything is extremely back focused. Some thoughts... I did replace/exchange the focusing screen a few times with a Katz Eye, but I'm back to the Pentax screen. Also, I had cleaned (very gently, with a sensor cleaning kit including optic cleaning solution and a gentle horizontal swab) the focusing screen and the bottom element of the prism (it was nastily dirty after one of the focus screen changes and blowing the dirt wouldn't work). As this solution works extremely well on optical glass, CCD's, etc. I can't imagine it had any effect. Looking back at my images from my K100D to my K10D (bought 8 months later) I definately can tell the K10D is not as clear in many cases. I don't know how I never noticed it before. Does anyone have any other thoughts?

04-12-2008, 01:21 PM	#7
Canada_Rockies Loyal Site Supporter Join Date: Nov 2007 Location: Sparwood, BC, Canada Photos: Gallery \| Albums Posts: 12,385	Originally posted by ksignorini I've changed my mind. It's not my lenses. I've done numerous experiments now with my K10D, another K10D, a K100D, and my new (as of a few hours ago) K20D. It's my K10D. It won't focus properly at all. My lenses are perfectly fine on all three other cameras. I even used Tim Jackson's (google him if you want the chart) focusing chart to do the tests. My K10D won't even come close to focusing at the correct spot...everything is extremely back focused. Some thoughts... I did replace/exchange the focusing screen a few times with a Katz Eye, but I'm back to the Pentax screen. Also, I had cleaned (very gently, with a sensor cleaning kit including optic cleaning solution and a gentle horizontal swab) the focusing screen and the bottom element of the prism (it was nastily dirty after one of the focus screen changes and blowing the dirt wouldn't work). As this solution works extremely well on optical glass, CCD's, etc. I can't imagine it had any effect. Looking back at my images from my K100D to my K10D (bought 8 months later) I definately can tell the K10D is not as clear in many cases. I don't know how I never noticed it before. Does anyone have any other thoughts? Is it possible that you have the focusing screen spacer on the wrong side of the screen? Did you perhaps drop it and lose it? (I almost did!) If your screen is in the wrong place, anything can happen.

04-12-2008, 01:28 PM	#8
ksignorini Forum Member Join Date: Apr 2008 Location: Edmonton, AB Posts: 70 Original Poster	The spacer never came out. I just checked and it's nice and tight against the prism side, then the screen, then hatch that holds the screen. (I suppose that's the right order since it never came out.)

04-12-2008, 02:38 PM	#9
aegisphan Veteran Member Join Date: Nov 2007 Location: New Mexico Posts: 815	There is a spacer? I put 2 Katz Eye screens on my K10 and K20, but I've never noticed any spacer before. To the OP, it seems your K10D is one of the few that has the problem. I don't have any problem with mine for all of my AF shots. But if you satisfy with the result on the K20D, then just use your lenses on the K20. I guess the K10D can be used for manual lens or you can just sell it.

04-12-2008, 04:46 PM	#10
frank Veteran Member Join Date: Nov 2006 Location: Singapore Photos: Gallery Posts: 3,202	Originally posted by ksignorini I've changed my mind. It's not my lenses. I've done numerous experiments now with my K10D, another K10D, a K100D, and my new (as of a few hours ago) K20D. It's my K10D. It won't focus properly at all. My lenses are perfectly fine on all three other cameras. I even used Tim Jackson's (google him if you want the chart) focusing chart to do the tests. My K10D won't even come close to focusing at the correct spot...everything is extremely back focused. Some thoughts... I did replace/exchange the focusing screen a few times with a Katz Eye, but I'm back to the Pentax screen. Also, I had cleaned (very gently, with a sensor cleaning kit including optic cleaning solution and a gentle horizontal swab) the focusing screen and the bottom element of the prism (it was nastily dirty after one of the focus screen changes and blowing the dirt wouldn't work). As this solution works extremely well on optical glass, CCD's, etc. I can't imagine it had any effect. Looking back at my images from my K100D to my K10D (bought 8 months later) I definately can tell the K10D is not as clear in many cases. I don't know how I never noticed it before. Does anyone have any other thoughts? Exactly the same experience I had with my first copy on my K10D and K20D (and a friend's K100D who has my first DA1650 right now ). The lens was way BF on the K10D, especially the wide end. But it was spot on w/ my K20D and my friend's K100D. Ended up he has it for cheap, and I changed to another one (thanks again Hiep ). And again, this one seems to be an excellent copy, on my K20D. I think it's not just the lens alone, it might because of the camera too. Most of my lenses focus much better on my K20D than the K10D.

04-13-2008, 10:29 AM	#11
ksignorini Forum Member Join Date: Apr 2008 Location: Edmonton, AB Posts: 70 Original Poster	Originally posted by frank Most of my lenses focus much better on my K20D than the K10D. I did a whack of tests last night. ALL my lenses focus MUCH better on the K20D than the K10D that I have (my friend's is far, far better, but it's also from a much newer batch). I'll be sending my K10D in for warranty repair.