Question for 16-50mm owners

avian · 10-22-2008, 11:30 AM

Originally posted by nulla

I too would name and shame.

If they come to the party and replace with a good one then name and fame them

Neil

Yeh, it would be good to know if its a store doing it, or CR Kennedy (the importer/distributor) themselves. If its the distributor then it wouldnt bode well for buying a DA* 16-50 locally.. Im going to be ordering one from Teds tomorrow so am very interested to see how it turns out.

Cooties · 10-22-2008, 05:24 PM

Here some test photos (that I also posted in the sticky at the top of this forum).

Newspaper test done at 29mm f2.8 :

100% crops:
Centre:

Right Bottom Corner:

Right Bottom Corner at f8.0 (still not acceptable - if this was f2.8 then it might be barely passable):

Left Bottom Corner (f2.8):

Real World Image (16mm f2.8):
Despite the small resize you can clearly see a haze over the right of the picture

I tried to just use it and see if it was noticeably bad in the real world, and the answer was definitely yes - even when stopped down significantly.

I must say though I'm looking forward to getting a good one, the sharp parts of the image were very good, the autofocus was great and its much more compact than I was expecting (I've been using a Sigma 24-70 f2.8)

To be fair the store has been good with responding to my email complaints so far and seem to be coming to the party with a replacement. I'll reserve my judgment until after the RA process is complete. I am going to very strongly recommend to them that they send this lens back to Pentax (or CRK). Or just chuck it in the bin and write it off at a loss - Surely its not worth the loss of reputation and future business for the sake of $900.

Edit: see below for resolution

TanGU · 10-23-2008, 06:00 PM

i did other tests today, with the focuschart again, without flash, using a tripod and remote to take pictures.

Left side: Picasa Web Albums - Toaster - Test 16-50mm
Right side: Picasa Web Albums - Toaster - Test 16-50mm

And a poster on a wall :
http://picasaweb.google.com/herouxb/Test1650mm#5260542065096615506
http://picasaweb.google.com/herouxb/Test1650mm#5260542222087051250
(you can always zoom in the picture)

I also went outside, i must say that the picture seem sharp enough for me... any way i can make sure that i have a problem?
look those:
Picasa Web Albums - Toaster - Test 16-50mm
Picasa Web Albums - Toaster - Test 16-50mm
Picasa Web Albums - Toaster - Test 16-50mm
Picasa Web Albums - Toaster - Test 16-50mm

I don't know what to think now!!!!

TanGU · 10-24-2008, 04:10 AM

anyone ?

i need some advice from you, the expert!

Cooties · 10-24-2008, 05:05 AM

Well I'm no expert ... but:

Its the inconsistency from one side to the other that indicates there may be a problem (look at the outline of Otto's hair in the poster photo). I haven't actually received a good one yet so I can't say how sharp the corners should be, but the inconsistency from left to right would be enough for me to get a replacement. The one I had for a day (before I sent it back yesterday) was much worse than yours, but I would still say there is a problem here.

But like you said you don't seem to notice it in real world pictures (although knowing it was there I would always be looking for it ...)

It doesn't seem to be so bad in that f9.0 picture

TanGU · 10-26-2008, 07:54 PM

Incredible...i went to 3 stores, i've tested 5 lens total, 4/5 were bad, some front-focused, other was decentered. The good one was a demo that i wasn't able to buy.

What is going on with this lens??? Incredible how Pentax do their Quality control, i am really not impressed. I'm really not happy with Pentax right now!

k100d · 10-26-2008, 07:56 PM

try out the Tamron 17-50

TanGU · 10-26-2008, 08:03 PM

i don't know... there isn't any Seal on it, that was make me interested in buying the 16-50. What's the point of having a weather seal body if you don't have any lens to go along with it? It's like having a ferrari, but with a speed limit of 100, what's the point?

k100d · 10-26-2008, 09:15 PM

yeah that's a bummer. i did get to try a good copy of the lens and it was fantastic. it seems like it depends on the luck of the draw. have you checked out the Serial Number thread too?

Cooties · 10-27-2008, 05:43 AM

Originally posted by TanGU

Incredible...i went to 3 stores, i've tested 5 lens total, 4/5 were bad, some front-focused, other was decentered. The good one was a demo that i wasn't able to buy.

What is going on with this lens??? Incredible how Pentax do their Quality control, i am really not impressed. I'm really not happy with Pentax right now!

How many were just front/back focused? Its the decentred ones that are broken. Back/front focus seems to be as much to do with the camera as the lens (especially with the K10D)

Could it be that shops only have dud ones left on the shelves and they wont order new ones until the current stock is sold?

Cooties · 10-28-2008, 01:09 AM

Ok an update on this:

The store has been very helpful in sorting out a replacement - its "in the mail" so to speak.
They were very adamant that they sell only new products and will be taking up this matter with their distributor - CR Kennedy.

A snippet from their email:
"Thank you for your feedback regarding your lens. I assure you that (company) sells all products guaranteed new from Australian Registered Suppliers. I am concerned that you have received a previously used lens and will be taking this up with our supplier, CR Kennedy, the sole authorised distributor of Pentax products in Australia."

They have requested a link to this thread so I thought I'd give an update and point out that this appears to be a supplier issue and not an issue with this store - again they have been very helpful in sorting out this issue.

Its a bit of a worry though when you cant trust the sole supplier for the entire country ...

TanGU · 10-29-2008, 04:46 AM

Originally posted by Cooties

How many were just front/back focused? Its the decentred ones that are broken. Back/front focus seems to be as much to do with the camera as the lens (especially with the K10D)

Could it be that shops only have dud ones left on the shelves and they wont order new ones until the current stock is sold?

only 1 of 5 were front/back focused, all other were decentered!

I return the lens to the store, they (and i) spoke with their Pentax representative (read: reseller?) and they wanted the lens back to do some test. I gave them some test pictures i took with my lens + some of the others i tested.

I don't know what to expect next, maybe a replacement, but with 5 lens and only 1 were OK, i don't expect much. But i do want a working lens some day, because this lens can take so good picture!

I just hope, like a lot of people already experienced, that i won't need 4 replacements to get the lens i want

avian · 10-29-2008, 10:18 AM

Thanks for the update Cooties. Makes me wonder if its even worth trying to buy a legitimate 16-50mm in Australia - instead of heading to grey market imports.

If my 16-50mm ends up having an identical serial number to a previously used lens in the lens database (or elsewhere), I think I'll be kicking up a storm, returning it, and ending my search for a good copy immediately. I'll just grab a few primes instead.

Cooties · 10-29-2008, 07:40 PM

Originally posted by avian

Thanks for the update Cooties. Makes me wonder if its even worth trying to buy a legitimate 16-50mm in Australia - instead of heading to grey market imports.

If my 16-50mm ends up having an identical serial number to a previously used lens in the lens database (or elsewhere), I think I'll be kicking up a storm, returning it, and ending my search for a good copy immediately. I'll just grab a few primes instead.

Well I received my replacement yesterday and my initial tests show it to be much better - F2.8 shows some softness in the extreme corners, but I think its acceptable (its better than the f8 picture above) and at least its consistent across all corners. Diminished by f3.5 and gone by f4.0.
It was a fairly new lens this one (serial number starts with 9026.... something) so it is possible to get a new/good one in Aus.

The reason I went with an Aus shop over a US one is the fact that its much easier and cheaper if I need to send it back for a replacement. And given the reputation of this lens I decided Aus was the place to buy from. Besides, the Dollar crash makes the price pretty much identical now.

bentax · 10-30-2008, 01:28 AM

Is the QC issues affecting the DA* 50-135mm aswell?

DA* 50-135mm NOT all its cracked up to be: Pentax SLR Talk Forum: Digital Photography Review

View Poll Results: Is this DA*16-50mm good or bad?
Keep it -- it's good.	23	88.46%
Return it or send it in for repair.	3	11.54%
Voters: 26. You may not vote on this poll

10-22-2008, 05:24 PM	#962
Cooties New Member Join Date: Oct 2008 Location: Brisbane, Australia Posts: 9	Here some test photos (that I also posted in the sticky at the top of this forum). Newspaper test done at 29mm f2.8 : 100% crops: Centre: Right Bottom Corner: Right Bottom Corner at f8.0 (still not acceptable - if this was f2.8 then it might be barely passable): Left Bottom Corner (f2.8): Real World Image (16mm f2.8): Despite the small resize you can clearly see a haze over the right of the picture I tried to just use it and see if it was noticeably bad in the real world, and the answer was definitely yes - even when stopped down significantly. I must say though I'm looking forward to getting a good one, the sharp parts of the image were very good, the autofocus was great and its much more compact than I was expecting (I've been using a Sigma 24-70 f2.8) To be fair the store has been good with responding to my email complaints so far and seem to be coming to the party with a replacement. I'll reserve my judgment until after the RA process is complete. I am going to very strongly recommend to them that they send this lens back to Pentax (or CRK). Or just chuck it in the bin and write it off at a loss - Surely its not worth the loss of reputation and future business for the sake of $900. Edit: see below for resolution Last edited by Cooties; 10-28-2008 at 01:10 AM. Reason: adding more words

10-23-2008, 06:00 PM	#963
TanGU Inactive Account Join Date: Jul 2008 Location: Longueuil, QC Photos: Gallery Posts: 90	i did other tests today, with the focuschart again, without flash, using a tripod and remote to take pictures. Left side: Picasa Web Albums - Toaster - Test 16-50mm Right side: Picasa Web Albums - Toaster - Test 16-50mm And a poster on a wall : http://picasaweb.google.com/herouxb/Test1650mm#5260542065096615506 http://picasaweb.google.com/herouxb/Test1650mm#5260542222087051250 (you can always zoom in the picture) I also went outside, i must say that the picture seem sharp enough for me... any way i can make sure that i have a problem? look those: Picasa Web Albums - Toaster - Test 16-50mm Picasa Web Albums - Toaster - Test 16-50mm Picasa Web Albums - Toaster - Test 16-50mm Picasa Web Albums - Toaster - Test 16-50mm I don't know what to think now!!!! Last edited by TanGU; 10-23-2008 at 07:32 PM.

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10-22-2008, 11:30 AM	#961
avian Forum Member Join Date: Sep 2008 Location: Melbourne Posts: 52	Originally posted by nulla I too would name and shame. If they come to the party and replace with a good one then name and fame them Neil Yeh, it would be good to know if its a store doing it, or CR Kennedy (the importer/distributor) themselves. If its the distributor then it wouldnt bode well for buying a DA* 16-50 locally.. Im going to be ordering one from Teds tomorrow so am very interested to see how it turns out.

10-24-2008, 04:10 AM	#964
TanGU Inactive Account Join Date: Jul 2008 Location: Longueuil, QC Photos: Gallery Posts: 90	anyone ? i need some advice from you, the expert!

10-24-2008, 05:05 AM	#965
Cooties New Member Join Date: Oct 2008 Location: Brisbane, Australia Posts: 9	Well I'm no expert ... but: Its the inconsistency from one side to the other that indicates there may be a problem (look at the outline of Otto's hair in the poster photo). I haven't actually received a good one yet so I can't say how sharp the corners should be, but the inconsistency from left to right would be enough for me to get a replacement. The one I had for a day (before I sent it back yesterday) was much worse than yours, but I would still say there is a problem here. But like you said you don't seem to notice it in real world pictures (although knowing it was there I would always be looking for it ...) It doesn't seem to be so bad in that f9.0 picture

10-26-2008, 07:54 PM	#966
TanGU Inactive Account Join Date: Jul 2008 Location: Longueuil, QC Photos: Gallery Posts: 90	Incredible...i went to 3 stores, i've tested 5 lens total, 4/5 were bad, some front-focused, other was decentered. The good one was a demo that i wasn't able to buy. What is going on with this lens??? Incredible how Pentax do their Quality control, i am really not impressed. I'm really not happy with Pentax right now!

10-26-2008, 07:56 PM	#967
k100d Veteran Member Join Date: Feb 2008 Location: Toronto Posts: 3,911	try out the Tamron 17-50

10-26-2008, 08:03 PM	#968
TanGU Inactive Account Join Date: Jul 2008 Location: Longueuil, QC Photos: Gallery Posts: 90	i don't know... there isn't any Seal on it, that was make me interested in buying the 16-50. What's the point of having a weather seal body if you don't have any lens to go along with it? It's like having a ferrari, but with a speed limit of 100, what's the point?

10-26-2008, 09:15 PM	#969
k100d Veteran Member Join Date: Feb 2008 Location: Toronto Posts: 3,911	yeah that's a bummer. i did get to try a good copy of the lens and it was fantastic. it seems like it depends on the luck of the draw. have you checked out the Serial Number thread too?

10-27-2008, 05:43 AM	#970
Cooties New Member Join Date: Oct 2008 Location: Brisbane, Australia Posts: 9	Originally posted by TanGU Incredible...i went to 3 stores, i've tested 5 lens total, 4/5 were bad, some front-focused, other was decentered. The good one was a demo that i wasn't able to buy. What is going on with this lens??? Incredible how Pentax do their Quality control, i am really not impressed. I'm really not happy with Pentax right now! How many were just front/back focused? Its the decentred ones that are broken. Back/front focus seems to be as much to do with the camera as the lens (especially with the K10D) Could it be that shops only have dud ones left on the shelves and they wont order new ones until the current stock is sold?

10-28-2008, 01:09 AM	#971
Cooties New Member Join Date: Oct 2008 Location: Brisbane, Australia Posts: 9	Ok an update on this: The store has been very helpful in sorting out a replacement - its "in the mail" so to speak. They were very adamant that they sell only new products and will be taking up this matter with their distributor - CR Kennedy. A snippet from their email: "Thank you for your feedback regarding your lens. I assure you that (company) sells all products guaranteed new from Australian Registered Suppliers. I am concerned that you have received a previously used lens and will be taking this up with our supplier, CR Kennedy, the sole authorised distributor of Pentax products in Australia." They have requested a link to this thread so I thought I'd give an update and point out that this appears to be a supplier issue and not an issue with this store - again they have been very helpful in sorting out this issue. Its a bit of a worry though when you cant trust the sole supplier for the entire country ...

10-29-2008, 04:46 AM	#972
TanGU Inactive Account Join Date: Jul 2008 Location: Longueuil, QC Photos: Gallery Posts: 90	Originally posted by Cooties How many were just front/back focused? Its the decentred ones that are broken. Back/front focus seems to be as much to do with the camera as the lens (especially with the K10D) Could it be that shops only have dud ones left on the shelves and they wont order new ones until the current stock is sold? only 1 of 5 were front/back focused, all other were decentered! I return the lens to the store, they (and i) spoke with their Pentax representative (read: reseller?) and they wanted the lens back to do some test. I gave them some test pictures i took with my lens + some of the others i tested. I don't know what to expect next, maybe a replacement, but with 5 lens and only 1 were OK, i don't expect much. But i do want a working lens some day, because this lens can take so good picture! I just hope, like a lot of people already experienced, that i won't need 4 replacements to get the lens i want

10-29-2008, 10:18 AM	#973
avian Forum Member Join Date: Sep 2008 Location: Melbourne Posts: 52	Thanks for the update Cooties. Makes me wonder if its even worth trying to buy a legitimate 16-50mm in Australia - instead of heading to grey market imports. If my 16-50mm ends up having an identical serial number to a previously used lens in the lens database (or elsewhere), I think I'll be kicking up a storm, returning it, and ending my search for a good copy immediately. I'll just grab a few primes instead.

10-29-2008, 07:40 PM	#974
Cooties New Member Join Date: Oct 2008 Location: Brisbane, Australia Posts: 9	Originally posted by avian Thanks for the update Cooties. Makes me wonder if its even worth trying to buy a legitimate 16-50mm in Australia - instead of heading to grey market imports. If my 16-50mm ends up having an identical serial number to a previously used lens in the lens database (or elsewhere), I think I'll be kicking up a storm, returning it, and ending my search for a good copy immediately. I'll just grab a few primes instead. Well I received my replacement yesterday and my initial tests show it to be much better - F2.8 shows some softness in the extreme corners, but I think its acceptable (its better than the f8 picture above) and at least its consistent across all corners. Diminished by f3.5 and gone by f4.0. It was a fairly new lens this one (serial number starts with 9026.... something) so it is possible to get a new/good one in Aus. The reason I went with an Aus shop over a US one is the fact that its much easier and cheaper if I need to send it back for a replacement. And given the reputation of this lens I decided Aus was the place to buy from. Besides, the Dollar crash makes the price pretty much identical now.

10-30-2008, 01:28 AM	#975
bentax Senior Member Join Date: Jan 2008 Location: West Australia Posts: 190	Is the QC issues affecting the DA* 50-135mm aswell? DA* 50-135mm NOT all its cracked up to be: Pentax SLR Talk Forum: Digital Photography Review