Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
03-05-2014, 08:44 AM   #1
New Member

Join Date: Mar 2014
Posts: 1
Confused on lenses

Good day to all! Am just new to DLSR and wanted to start with Pentax k3 which my friend is offering me with a super discounted price, however it does not come with a lens. What are my options of lenses that can be compatible with k3? I've been browsing the web, I just understand a little bit. Can anybody please help me understand what lens are compatible with k3? Thanks. =)

03-05-2014, 08:53 AM   #2
Site Supporter
Site Supporter

Join Date: Sep 2011
Posts: 1,529
It's all depending on your needs. But the PENTAX DA 18-135MM F3.5-5.6 ED WR Is a good start.
us what you want to photograph and we can give you more advice.
Anything that says DA -F -FA is fully compatible
Anything that says -A is compatible but Manual focus(PKA)
Anything else that is K mount will fit but needs more help from the user to get a correct exposure Manual Aperture and Focus
If any of the above are labled Q ,110, 645, 6x7 then they are not suitable

Last edited by Sliver-Surfer; 03-05-2014 at 09:01 AM.
03-05-2014, 08:55 AM   #3
Loyal Site Supporter
Loyal Site Supporter

Join Date: Nov 2013
Location: Alabama
Posts: 2,450
All Pentax K mount lenses are compatible with your K-3. From M (manual focus, manual aperture) all the way through modern DA (digital APS-C) lenses.

As Silver-Surfer stated, if you tell the fine folks here what your goals are, they'll happily spend your money for you!
03-05-2014, 09:02 AM   #4
Site Supporter
Site Supporter
boriscleto's Avatar

Join Date: Dec 2009
Location: North Syracuse, NY
Photos: Gallery
Posts: 13,831
Pentax K-Mount Lenses Explained: The differences between various Pentax lens series

03-05-2014, 09:20 AM   #5
paulh's Avatar

Join Date: Sep 2010
Location: DFW Texas
Photos: Gallery | Albums
Posts: 16,976
Since you're new to DSLRs, I would suggest keeping it simple. The DA 18-135 would be an excellent all-purpose lens to start with. If funds are limited, go with the DA 18-55. After shooting with those for awhile, you'll get a feel for what you want to accomplish with your photography.
03-05-2014, 09:53 AM   #6
Site Supporter
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 30,245
Definitely the 18-135 for the first lens. After that the 35mm 2.4. 35 mm is a "standard lens" on Pentax, so if you really want to go cheap get it first. It's a quality lens that you'll probably use into the future. The 18-55 (and the 55-200), I would consider "throw away lenses" in that once you get a better lens (Tamron 17-50, Pentax DA 18-135, Sigma 16-50 Pentax DA 16-50, Sigma 18-35, Pentax DA 20-40, almost any other lens you can buy in it's focal length) you won't use it any more, and it's too cheap to make much money selling it. Where as the 35 mm 2.4 is a nice lens that will always be of use from time to time.
03-05-2014, 01:06 PM   #7
pete-tarmigan's Avatar

Join Date: Apr 2009
Location: Conception Bay South, New-fun-land
Photos: Gallery
Posts: 1,154
That page would be handy but for one confusing item.

They appear to use the term "Auto-aperture" incorrectly (first column on the left), because they show the M and K series as lacking auto-aperture. Those two series do indeed have auto-aperture. Auto-aperture means that if you set the aperture to f 5.6, for example, the iris stays wide open while the light meter measures the light intensity coming through the lens, but gives you the meter reading as if the iris were closed down to f 5.6. The iris closes down to f 5.6 only when you trip the shutter. ( Early thread-mount Pentax lenses were not auto-aperture, but later SMC Takumar thread mount lenses had a switch on the barrel to choose auto- or manual aperture.

However, the M and K series do not have the electrical contacts on the lens mount to allow the use of "shutter-priority" auto-exposure mode on cameras equipped with that mode. In this mode of auto-exposure, the user sets a desired shutter speed and the auto-exposure system on the camera measures the light, then tells the lens which f stop to close the iris down to when the shutter is released. The creators of that web page should have titled the left hand column "Shutter-Priority Capable" or something similar.

Having said that, to use an M or K series lens on a K-3, you have to set the exposure mode to Manual, manually set the aperture on the lens, manually set the ISO, then meter by using the Green Button. Pressing that button stops down the lens before metering the light, then sets the shutter speed for the correct exposure. After this process you trip the shutter. This mimics the process called "stop-down metering" that you would have to use when a manual-aperture lens is mounted on a film camera. You focus with the iris wide open, then close the iris to the desired f-stop, then meter the light to see whether your combination of f-stop and shutter speed needs more or less light.

Last edited by pete-tarmigan; 03-05-2014 at 01:31 PM. Reason: added link to definition
03-06-2014, 12:49 PM   #8
Moderator PEG Judges
Loyal Site Supporter
Kerrowdown's Avatar

Join Date: Aug 2008
Location: Highlands of Scotland.
Photos: Gallery
Posts: 38,460
Well you had lots a good advice already, I'll just welcome you the the forum.

03-06-2014, 01:30 PM   #9
Veteran Member
peterjcb's Avatar

Join Date: Dec 2013
Location: Weddington, NC
Posts: 468
Welcome to the forum!
Great advice offered above. One thing to keep in mind... lenses that are FA will not only fit your K-3 but will also work on full frame cameras as well....including a possible Full Frame camera coming sometime in the future from Pentax.
I'd recommend the FA 28-105 SMC-Pentax FA 28-105mm F4-5.6 Reviews - FA Zoom Lenses - Pentax Lens Reviews & Lens Database. While it doesn't have the range of the 18-135 it is a great lens that you can pick up for less than $100 and can be used with FF cameras. Post some photos!

Example of 28-105 lens on a K-7

Last edited by peterjcb; 03-06-2014 at 01:36 PM.
03-07-2014, 01:51 AM   #10
Site Supporter
Site Supporter
Jean Poitiers's Avatar

Join Date: Apr 2011
Location: Lost in translation ...
Photos: Gallery | Albums
Posts: 17,210
Bonjour from France and welcome to PF, lennon007 ... I would agree with Norm (normhead); the DA 35/2.4 is a great bang for the buck (known as the "Plastic Fantastic" - ) and shoots like a 50mm on a cropped APS-C sensor ... hope to see some images soon ... Salut, J

  • 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!
k3, lens, lenses, pentax k3
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
Confused by Pentax Lenses - Which ones are compatible with K-5? theraven871 Pentax SLR Lens Discussion 4 03-01-2014 04:46 PM
Really confused on Third Party Flash for Pentax K30 rp_dxn Flashes, Lighting, and Studio 12 09-21-2013 08:54 PM
DXOMark latest lenses on K50 compared to K5 has me really confused Erictator Pentax K-5 8 08-27-2013 01:28 PM
confused about lenses - still! slr_neophyte Troubleshooting and Beginner Help 15 05-25-2011 06:14 AM
K2000 DA or DAL lenses confused? Mgrmitch Pentax DSLR Discussion 9 06-30-2009 11:53 AM

All times are GMT -7. The time now is 03:14 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]