Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
06-19-2009, 10:25 PM   #1
Veteran Member
fccwpe's Avatar

Join Date: Mar 2009
Location: Perris, CA
Photos: Gallery
Posts: 380
Nubi question about 16-45 DA

I have read loads of reviews and I am confused. Some people say the the Pentax 16-45 f4.0 fixed is really great at f8.0 or f22 etc. How does one change a fixed aperture? Maybe I am not looking at the obvious?

06-19-2009, 11:21 PM   #2
Loyal Site Supporter
imtheguy's Avatar

Join Date: Mar 2009
Location: Virginia Beach
Photos: Gallery | Albums
Posts: 2,950
Its only "fixed" in that the lens keeps the same maximum aperture of f/4 through its entire zoom range of 16-45mm unless you change it. You can manually (with the camera, there is no aperture ring on the lens) change to a smaller aperture like f/8 or f/11 at any focal length from 16-45mm. Most zooms can not keep the same maximum aperture throughout the zoom range.

Hope that helps.
06-19-2009, 11:40 PM   #3
Community Manager
Loyal Site Supporter
Ash's Avatar

Join Date: Mar 2007
Location: Toowoomba, Queensland
Photos: Gallery | Albums
Posts: 22,695
People generally prefer a zoom with a 'fixed' wide open aperture, that is, the biggest aperture the lens can achieve throughout its focal range.

Like the Tamron 28-75. At 28mm, it can be set at f/2.8, and at 75mm also at 28mm.
Contrast that with the Sigma 17-70. At 17mm, it can be set at f/2.8, but the widest aperture it can achieve at 70mm is f/4.5, which is less flexible when wanting to limit depth of field (range of in-focus parts of image). Sorry if I'm explaining this poorly.

Ultimately, it depends what you're looking for in a lens: the 16-45 is a stellar lens, but f/4 is its largest aperture. The DA* 16-50 can open up to f/2.8 throughout its focal range, and so adds that much more versatility. The choice is yours as to what you're looking for in a lens.

Last edited by Peter Zack; 06-20-2009 at 03:38 AM.
06-20-2009, 03:35 AM   #4
Veteran Member
rparmar's Avatar

Join Date: Jan 2008
Photos: Gallery
Posts: 8,783
You'll be happy with the DA16-45mm. Not only is it cheaper and lighter than the faster weather-sealed lens, but it is actually sharper too. No compromises in IQ here!

I use it at f/4 without problem, though as with any lens would prefer to stop down a couple notches to increase resolution.

06-20-2009, 03:43 AM   #5
Moderator Emeritus

Join Date: May 2007
Location: Edmonton Alberta, Canada
Photos: Gallery | Albums
Posts: 10,648
The DA16-45mm is a great lens, even wide open at f4 (when many lenses doen't perform well wide open). As the others have said, it's a fixed f4 through the focal range (wide open) as opposed to a variable lens like the ones that say 55-300mm f4-5.6 and so on. Not that these variable lenses aren't good. Just limiting in a couple of areas that many would like to avoid if possible.

  • 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, pentax help, photography
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
A Question for Everyone Fl_Gulfer Photographic Technique 34 11-02-2010 03:33 PM
Kx question. Unr3a1 Troubleshooting and Beginner Help 5 08-30-2010 09:06 AM
KM question jdg Pentax DSLR Discussion 4 06-08-2009 01:07 PM
An Answer to a question and a question. granitic Pentax DSLR Discussion 5 02-23-2007 09:28 AM

All times are GMT -7. The time now is 12:44 AM. | See also:, 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?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]