Pentax K-Mount Lens Series Explained: The differences between various Pentax lens series

In a nutshell  
There are several series of Pentax K-mount lenses; the ones currently being produced include the DA (digital), DA L (cheap digital kit), D FA (full-frame, digital optimized), and FA (full-frame) series. While all Pentax K-mount lenses are currently compatible with the Pentax DSLRs (and the new K-01), there are siginificant differences between each lens series and each has different features. We'll be exploring those differences in this article. Read more about K-mount lens/camera compatibility.  
Feature
Auto-Aperture
Auto-Focus
Quick Shift
Aperture Ring
Full-Frame
DSLR-Compatible
Mount Name
DA Series
Yes
Yes
Yes
No
No
Yes
KAF2 / KAF3
DA L Series
Yes
Yes
No
No
No
Yes
KAF2
D-FA Series
Yes
Yes
Yes
Varies
Yes
Yes
KAF2
FA J Series
Yes
Yes
No
No
Yes
Yes
KAF2
FA Series
Yes
Yes
No
Yes
Yes
Yes
KAF2
F Series
Yes
Yes
No
Yes
Yes
Yes
KAF
A Series
Yes
No
N/A
Yes
Yes
Yes
KA
M Series
No
No
N/A
Yes
Yes
Yes
K
K Series
No
No
N/A
Yes
Yes
Yes
K

Yes = Yes No = No Varies = Varies
For a full list of Pentax lenses, visit the lens database at PentaxForums.com.
 
smc PENTAX-DA, smc PENTAX-DA L, smc PENTAX-DA*  
  • The current generation of lenses for APS-C Digital SLRs
  • Autofocus
  • No aperture ring
  • Automatic aperture setting is available
  • Image format: APS-C sensor format (18 x 24mm)
  • Suited for DSLRs with APS-C sized sensor
  • Sub-categories: DA* (professional), DA Limited (high-end pancake) and DA L (budget kit)
  • Introduced in 2004
  • In production

The smc PENTAX-DA, smc PENTAX-DA L, and smc PENTAX-DA* lenses are designed to be used exclusively on digital cameras with an APS C sized sensor (the K and *ist D digital camera series). Their image circle covers only the 18 x 24mm format of APS C sized sensors so the corners of the image will come out dark if the lens is used on a 24 x 36mm film camera.

DA lenses (except for the 18-250 mm zoom) feature a Quick Shift focusing system that allows the focus to be fine tuned with the focusing ring on the lens without setting the camera focus selector to "MF".

DA L lenses are a light weight edition of their DA counterparts. They have a bayonet mount made of plastic rather than stainless steel and they do not have the quick shift focusing capability.

DA* Lenses: The DA series includes a number of "star" lenses (DA*) with top notch optical and mechanical engineering. All DA* lenses have the Quick Shift focusing system and - despite not having the WR designation - are also weather sealed.

DC or SDM: Lenses with the SDM designation feature a built-in autofocus motor. Newer cameras (K100D Super, K10D, and later) will take advantage of this motor and not use the screw-drive mechanism.

Some DA lenses are SDM-Only (KAF3 mount), such as the smc PENTAX-DA* 55mm F1.4 SDM prime lens and smc PENTAX-DA 17-70mm F4 zoom lens. These lenses lack the traditional screw drive autofocus coupler and will therefore only autofocus on the K10D, K100D Super, and newer Pentax cameras.

XS: Lenses with an exterior design by Mark Newson matching the Pentax K-01. The lenses will, however, work on any Pentax DLSR with an APS-C sized sensor. WR: Lenses with the WR designation are weather resistant. They are sealed so that they better withstand use in light rain and blowing dust.

Note: Many users report that the smc PENTAX-DA 40mm F2.8 Limited, also known as "the pancake," covers the full 24 x 36mm frame. Optically it is based on an earlier lens in the M series.

smc PENTAX-DA 40mm F2.8 Pancake

 
smc PENTAX-D FA  
  • Current generation of autofocus lenses for Film as well as Digital SLRs
  • Automatic aperture setting is available, and there is an aperture ring

Remarks: smc PENTAX-D FA lenses work like FA lenses. They have been optimized optically for digital sensors but work equally well on a 35 mm film camera. Their image circle covers the full 24 by 36mm negative format. These lenses provide an easy way to manually fine tune the subject distance set by the autofocus system ("quick shift" focusing system).

The second generation SMC Pentax-D FA 100mm F2.8 Macro WR does not feature an aperture ring, unlike its non-weather-sealed D-FA predecessor.

smc PENTAX-D FA 100mm F2.8 Macro

 
smc PENTAX-FA  
  • The second generation of autofocus lenses
  • Autofocus with screw drive system
  • Aperture ring
  • Automatic aperture setting is available*
  • Certain zoom lenses feature the power zoom function**
  • Image format covered: 24mm x 36mm
  • Suitable for APS-C digital sensor format and 24mm x 36mm film format
  • Sub-groups: FA* (professional) and FA Limited (compact high-end) series
  • In production: Only five of the original 42 lenses are still in production (as of May 2010: FA 35, FA 50, FA 30/43/77 limited)

The FA series lenses are autofocus and allow for certain modern cameras (film and digital) to automatically set aperture (Tv mode), shutter speed (Av mode), or both (Program mode). You can also set exposure manually if the camera body allows for this. On recent camera bodies (e.g. *ist and all digital SLR cameras) you use dials on the camera body to set the aperture value (the aperture ring on the lens must be in the "A" position at all times). On older models (such as ZX-5N, MZ-5N, LX, ME, MX, K1000) the aperture is set with the aperture ring on the lens.

Three FA "Limited" lenses were made available in 2001. Except for these and the 35mm f/2 and 50mm f/1.4, the FA series, which consisted of 42 lenses total, has been discontinued.

While FA lenses are identical in operation to F lenses, they feature improved electronics that support the MTF program line.

The FA series also includes 11 "star" lenses (FA*) that employ the finest of Pentax optical and mechanical engineering.

*Exceptions: The smc PENTAX-FA Soft 85mm F2.8 and smc PENTAX-FA Soft 28mm F2.8 lenses have no "A" setting on the aperture ring. Hence they work like smc PENTAX-M lenses with respect to exposure; they are still autofocus. The "A" setting has been removed because the degree of image softness is controlled by the aperture ring and it would be meaningless to let the camera decide the setting.

**Power zoom is only supported by certain camera bodies. The following lenses feature power zoom:

-SMC Pentax-FA 28-80mm F3.5-4.7
-smc PENTAX-FA 28-105mm F4-5.6
-smc PENTAX-FA 70-200mm F4-5.6
-smc PENTAX-FA 100-300mm F4.5-5.6
-smc PENTAX-FA* 28-70mm F2.8 AL
-smc PENTAX-FA* 80-200mm F2.8 ED [IF]
-smc PENTAX-FA* 250-600mm F5.6 ED [IF]

smc PENTAX-FA 50mm Macro F2.8

smc PENTAX Star 80-200mm F2.8 ED [IF]

 
SMC Pentax-F  
  • First generation autofocus lenses
  • Automatic aperture setting is available

Remarks: Lenses in this series work just like FA lenses; see above for features and limitations.

The F series consisted of 20 lenses is now fully discontinued.

The F series also includes 3 "star" lenses (F*) that employ the finest of Pentax optical and mechanical engineering.

 

SMC Pentax-F 50mm F1.4

 
SMC Pentax-FA J  
  • A small series of 3 autofocus zooom lenses
  • Automatic aperture setting is available, but there is no aperture ring

Remarks: SMC Pentax-FA J lenses lack the aperture ring but otherwise work like an FA lens set permanently to the “A” position. Due to the lack of an aperture ring these lenses cannot be used on camera bodies where use of an aperture ring is mandatory (such as LX, ME, MX, K1000), but can be used on e.g. the ZX-5N in Program and Tv mode. These lenses provide full functionality on all recent bodies like the *ist, *ist D series and K (digital) series

SMC Pentax-FA J 18-35mm F4-5.6

 
smc PENTAX-A  
  • The third generation of manual focus lenses
  • Automatic aperture setting is available

Remarks: smc PENTAX-A lenses are manual focus. Regarding exposure control they work like FA lenses.

The A series also includes 9 "star" lenses (A*) that exemplify the finest in Pentax optical and engineering.

smc PENTAX-A 135mm F2.8

 
smc PENTAX-M  
  • The second generation of manual focus lenses (generally smaller than K lenses)
  • Manual aperture

Remarks: smc PENTAX-M and smc PENTAX (commonly know as "K") lenses are manual focus and have no "A" setting on the aperture ring. These lenses allow for the camera to automatically set shutter speed (if it has the Av auto-exposure mode). You can also set exposure manually if the camera body allows for this. The ZX-5N is an example of a body which provides Av mode as well as manual exposure mode with M and K lenses. Almost all K and M lenses have an automatic diaphragm.

Some recent bodies cannot use M and K lenses or only with some limitations. An example are the *ist D and K (digital) series. In M mode you set the aperture using the aperture ring on the lens; the camera will set the shutter speed when you press the green button (or AE-L button if the camera has no green button). Or you can set the shutter speed manually (there is no exposure read out in the finder to assist you).

The M series includes a single "star" lens (M*) that exemplies the finest in Pentax optical engineering. That is the smc PENTAX-M* 300mm F4.

smc PENTAX-M 135mm F3.5

 
smc PENTAX  
  • The first generation of manual focus lenses
  • Manual aperture
smc PENTAX 18mm F3.5

 
Non-smc PENTAX Lenses  

Pentax also produced several "budget" lenses that lacked the SMC lens coating. Most of these lenses are identical to their SMC counterparts but feature different coloring on their barrels.

  • Takmuar Bayonet lenses work in the same way as smc PENTAX lenses
  • Takmuar-A and PENTAX-A lenses work in the same way as smc PENTAX-A lenses
  • Takmuar-F and PENTAX-F lenses work in the same way as smc PENTAX-F lenses

 

Pentax-A 28-80mm F3.5-4.5

 

"smc" stands for Super Multi Coating, Pentax's multi-layer lens coating which does a great job of reducing flare. DA, D FA, and some FA lenses have an improved "ghost less" coating that is even more effective than the original coating. Furthermore, there are reasons to believe that the SMC coating has been improved from series to series.

The following abbreviations are used in lens names:

WR: Weather Resistant. The lens is sealed against dust and light rain.
DC or SDM: The lens has a built-in super-sonic motor for autofocus (K10D, K100D and newer cameras can take advantage of this).
XS: Lenses with an exterior design by Mark Newson matching the Pentax K-01. Works like an ordinary DA lens.
IF: Internal focusing. Focusing is achieved by moving lens elements within the lens. The lens barrel doesn't move. IF lenses generally focus faster than ordinary lenses.
AL: Aspheric Lens. Special lens elements that improves the optical quality. Particularly valuable in wide angle lenses.
ED: Extra-low Dispersion. Special glass material which helps reduce chromatic aberration. Particularly valuable in tele photo lenses.

Conclusion:

A, F, FA and D FA lenses work on all Pentax bayonet cameras ever produced. Exceptions: 1) A lenses do not work on the MZ-60/ZX-60, 2) the D FA 100mm F2.8 WR lens works like a DA lens.

FA J, DA and DA L lenses work on cameras which have Tv and Program auto-exposure mode. Av mode and manual exposure is supported on some of these camera bodies. DA should only be used on digital cameras with an APS C sized sensor (16 x 24 mm).

M and K lenses work on all cameras except the MZ/ZX-30, MZ/ZX-50 and MZ/ZX-6. They work with limitations on the *ist film camera. They work with stop-down metering on the *ist D series and K series digital SLRs provided that a custom function is set appropriately.

For more information on lens compatibility, please visit our Lens Compatibility Chart.

 

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