Forgot Password
Pentax Camera Forums Home
 

View Poll Results: Is this DA*16-50mm good or bad?
Keep it -- it's good. 2388.46%
Return it or send it in for repair. 311.54%
Voters: 26. You may not vote on this poll

Reply
Show Printable Version Search this Thread
03-05-2008, 02:55 PM   #451
Senior Member




Join Date: Aug 2007
Location: Pittsburgh, PA
Photos: Gallery | Albums
Posts: 269
DA* 16-50mm: 3rd time is the charm

I just finished my infamous newspaper test on my 3rd copy of the DA* 16-50mm. The * lens definitely outperformed my kit lens in terms of sharpness, contrast and CA. Now, I am finally ready to move on to "real world" testing. I am very confident that this lens will perform exceedingly well in "real world" conditions. I'll post a few non-newspaper shots later.

Ted

03-05-2008, 02:58 PM   #452
Senior Member




Join Date: Aug 2007
Location: Pittsburgh, PA
Photos: Gallery | Albums
Posts: 269
Congratz, Buddha! Son of a gun, but I just received my 3rd copy of the DA* 16-50mm today and it passed my newspaper test!! Now I'm ready to enter the "real world" testing stage. I'll let you know how it goes, but I'm feeling mighty optimistic at this point.

Ted
03-05-2008, 03:01 PM   #453
Senior Member




Join Date: Aug 2007
Location: Pittsburgh, PA
Photos: Gallery | Albums
Posts: 269
QuoteOriginally posted by selar Quote



16mm f2.8




50mm f2.8


More test images @ Picasa Web Albums - Selar - DA16-50@2.8
--
Picasa Web Albums - Selar
I can only tell you that on the 50mm f2.8 image you submitted, the right side is definitely sharper than the left side. This is due to one of 2 causes: 1) sensor not exactly parallel to the wall 2) centering defect
03-05-2008, 03:07 PM   #454
Veteran Member
Buddha Jones's Avatar

Join Date: Sep 2006
Location: Charlotte, NC
Photos: Gallery
Posts: 2,591
You have minimal vignetting and almost no barrel distortion. You are free to go and start shooting. Do us proud.

03-05-2008, 03:19 PM   #455
Senior Member
ankit's Avatar

Join Date: Dec 2007
Location: Cambridge, MA
Posts: 140
Ted, that is great! Would you mind sharing your lens' serial number, and a full-res photo of the newspaper test (just to get a baseline of acceptable performance)?

thanks!
03-05-2008, 03:20 PM   #456
Veteran Member
Buddha Jones's Avatar

Join Date: Sep 2006
Location: Charlotte, NC
Photos: Gallery
Posts: 2,591
I just mounted the 50-135mm, man... I almost shed a tear. It is soo damn sharp, and the color is unbelievable. They are so fricken quiet, I am an SDM lover now. My Tammy's, esp the 70-300mm is loud as mofo. After not hearing these lenses I can't imagine taking it into the woods, I'd scare everything away. I only hope and pray that Pentax will make a DA* 300mm in a f/2.8 so I don't regret buying the f/4. But the 200mm is def on my radar now. After the 31mm and 77mm LTD's.
03-05-2008, 03:40 PM   #457
Veteran Member
selar's Avatar

Join Date: Jul 2007
Location: Sydney, Australia
Photos: Gallery | Albums
Posts: 2,035
QuoteOriginally posted by Buddha Jones Quote
You have minimal vignetting and almost no barrel distortion. You are free to go and start shooting. Do us proud.
You're a good man Buddha, very motivating.
03-05-2008, 03:48 PM   #458
Veteran Member
selar's Avatar

Join Date: Jul 2007
Location: Sydney, Australia
Photos: Gallery | Albums
Posts: 2,035
QuoteOriginally posted by Lowell Goudge Quote
what do you think the problem is?
Well, I think the corners are dismal at f2.8, average till f4, and quite good at f5.6. I usually shoot MTF line, and have noticed the body sets the lens at f5.6 by default at 16mm. Also have noticed quite a bit of PF from 16mm to 21mm.

In the 50mm shot, the right side is noticeably sharper than the 50mm shot. As another member has pointed out, it may be caused by sensor not being parrallel to wall or it could be centering defect. Even if sensor is not perfectly parrallel to wall, shouldn't DOF cover it? Haven't still worked out a way to get sensor parrallel to wall yet.

Things really came to a head when my Nikon friend called it a brick!

03-05-2008, 03:52 PM   #459
Senior Member




Join Date: Sep 2007
Location: Australia
Posts: 255
Does it have difficulties focusing at 16mm, f2.8 at infinity? Thats where most 16-50's seem to fail regardless if they focus well at close distance, and at 50mm.

Mine fails at the aforesaid test, focuses fine close up.
03-05-2008, 04:13 PM   #460
Veteran Member
barbosas's Avatar

Join Date: Apr 2007
Location: Lisbon
Photos: Gallery
Posts: 683
/joke

The image looks very bad and completely unusable.

Please feel free to send the lens to me so that i can destroy it properly
03-05-2008, 04:42 PM   #461
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,314
QuoteOriginally posted by selar Quote

Things really came to a head when my Nikon friend called it a brick!
I would have used the brick as it is intended, hit him over the head with it

I think this is just a nikon owner being a typical nikon owner, and having a go at your pentax inferiority complex.

Seriously though, having been given a verbal lashing by another poster who did not like my comment about his tests, and issue, Let me ask you for some more typical shots, so that we can see something that looks more normal.

I am beginning to think we need a discussion thread or perhaps a whole forum, jsut to discuss the issues of how to do a test, what you should look for and what you should expect.

Not to disappoint you but no lens is perfect, all of them are a compromise in one way or another. I don't own this specific lens, so I can't tell you if my copy is better or not.

In reality, I think we are going over the top in doing these tests and not taking pictures. Maybe we should do the tests IF we see something in the pictures.
03-05-2008, 05:04 PM   #462
Veteran Member
Buddha Jones's Avatar

Join Date: Sep 2006
Location: Charlotte, NC
Photos: Gallery
Posts: 2,591
QuoteOriginally posted by selar Quote
In the 50mm shot, the right side is noticeably sharper than the 50mm shot. As another member has pointed out, it may be caused by sensor not being parrallel to wall or it could be centering defect. Even if sensor is not perfectly parrallel to wall, shouldn't DOF cover it? Haven't still worked out a way to get sensor parrallel to wall yet.

Things really came to a head when my Nikon friend called it a brick!
There is my problem with the whole brick wall test, it is somewhat visually revealing but not very real world proven. Unless you are in a museum taking pictures of art, I cant see another reason why this would be much of a consideration, but that just me. I never focus on a full frame, DOF and bokeh covers up almost all lens flaws, so I hope. But it is what it is.
03-05-2008, 05:58 PM   #463
Senior Member




Join Date: Aug 2007
Location: Pittsburgh, PA
Photos: Gallery | Albums
Posts: 269
QuoteOriginally posted by ankit Quote
Ted, that is great! Would you mind sharing your lens' serial number, and a full-res photo of the newspaper test (just to get a baseline of acceptable performance)?

thanks!
Serial number is 9011xxx (I doubt there is any consistency with regards to the serial number patterns).

Sorry, I deleted my test photos once I saw they were good. Look for consistent sharpness between left and right, top and bottom of newspaper. I also directly compared with my kit lens at identical focal length/aperture combinations.
03-05-2008, 08:47 PM   #464
Veteran Member
selar's Avatar

Join Date: Jul 2007
Location: Sydney, Australia
Photos: Gallery | Albums
Posts: 2,035
What I'd really like to know is, should I send in the lens for repair (under warranty), and if I do what faults do I list?
03-05-2008, 08:59 PM   #465
Veteran Member
selar's Avatar

Join Date: Jul 2007
Location: Sydney, Australia
Photos: Gallery | Albums
Posts: 2,035
Here's a real photo from the lens.



If you look you can see the wadding from the cartridge flying out of the barrel.
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!
k-mount, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Question to K-5 Owners kevinschoenmakers Pentax K-5 3 10-19-2010 06:40 PM
Question for K-X owners. dimebagdave Pentax DSLR Discussion 6 04-29-2010 05:17 AM
PZ-1P question(for owners) LongLiveVelvia Pentax Film SLR Discussion 3 10-09-2009 10:51 AM
A question for K7 owners dafiryde Pentax DSLR Discussion 26 09-05-2009 02:52 AM
Question for FA 28-70/4 owners Ivan Glisin Pentax SLR Lens Discussion 8 08-13-2007 01:08 PM



All times are GMT -7. The time now is 04:17 AM. | See also: NikonForums.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