Pentax Digital SLR Cameras and Lenses
a photo.net guide by Hannah Thiem
All Pentax digital SLR bodies are compatible with older Pentax film
lenses (FA, F and A mounts) as well as newer lenses (DA and DA*
mounts). The Pentax K10D is the cheapest weather-sealed digital SLR
body on the market. Pentax offers a different approach to image
stabilization than market leaders Canon and Nikon. The Pentax DSLR
bodies electronically shake their sensors to compensate for camera
shake, rather than adding image stabilization to specific lenses. The
Pentax system is not as effective as in-lens image stabilization and
it isn't very effective for long telephoto lenses, but it does work
with all lenses, including old designs from the film years.
This article covers every current Pentax product and some good
third-party components.
If you are new to photography, you might want to read "Building
a Digital SLR System". The same principles can be applied to the
Pentax DSLR system.
Josh Root
Bodies
All Pentax digital
SLR bodies incorporate an APS-C sized
sensor. The sensor size is 23.5x15.7mm, smaller than the standard
35mm film frame (36x24mm). The small or "crop" sensor on the Pentax
DSLR bodies means that lenses don't function the way that they do on a
film camera. Multiply focal lengths by 1.5x to calculate the "35mm
equivalent". A 50mm lens that would be "normal" for a film camera,
for example, will function as a good portrait lens on a Pentax digital
body. This magnification will be welcomed by wildlife photographers
and cursed by owners of high-quality high-speed wide-angle lenses (a
dramatic 21mm gives a boring 31mm equivalent perspective).
- Pentax K20D, $650 (review), 14 MP, this model replaces
the K10D, offers in-camera image stabilization, and extensive weather
and dust seals.
- Pentax K10D, $899 (review),
competes with similarly priced cameras from Canon and Nikon by
offering similar 10-megapixel image quality, similar sensor cleaning,
in-camera image stabilization (1 or 2 f-stops), and superior
dust/weather-sealing. The K10D is also available as a kit with a low
quality mid-range zoom: Pentax K10D, 18-55mm kit, $1000 (review).
- Pentax K200D, $508, released January 2008, similar to
the K10D with the same 10-megapixel image quality, but with a simple design
and layout for new DSLR users.
- The Pentax K100D comes in three variants, all of which have the
same
6.1 megapixel sensor:
- Pentax *istDL, 18-55mm kit, $485, released June 2005
and for some reason still available; no image stabilization and a
primitive 3-point autofocus system. Pentax's lightest body.
Nomenclature
Josh Root
"DR" is the Pentax-original Dust Removal system, which helps keep the
CCD surface dust-free.
"DA" refers to the series of lenses engineered exclusively for digital
cameras. All DA-series lenses feature a responsive "Quick-Shift Focus
System" that allows photographers to instantly switch the focus mode
from auto to manual with a slight twist of the focus ring.
"DA*" refers to the series of lenses designed for exclusive use with
Pentax digital SLR cameras. The DA* lenses feature tightly sealed,
weather-resistant and dust-resistant construction for use in rain or
dusty conditions.
"FA" specifies the autofocus lens series compatible with both film and
digital SLR bodies.
"AL" stands for "aspherical lens."
"FA-J" designates a line of cheaper autofocus lenses
without an aperture ring, compatible with both film and
digital SLR bodies.
"A" designates a line of old manual focus lenses.
"SP" refers to a Super Protect lens coating applied on all Pentax
lenses, where the surface is coated with a special fluorine compound
to repel dust, water and grease, making it easy to wipe off
fingerprints and cosmetics.
"ED" is "extra-low dispersion" glass, a more expensive and higher
quality glass that reduces chromatic aberration, in which light of
different colors takes different paths through the lens, which would
result in a dot of white light being fuzzed up by the time it reaches
the film or sensor.
"IF" is internal focus, meaning that the lens does not change physical
length as you focus on subjects that are closer or farther away.
"SDM" is "Supersonic Drive Motor", the Pentax equivalent to Canon's
in-lens ultrasonic motor. SDM makes autofocus faster and facilitates
simultaneous use of manual and autofocus, which Canon calls "full-time
manual focus" and what Pentax calls "quick-shift focus system".
Normal Lenses
Josh Root
A normal lens is light in weight and approximates the
perspective of the human eye. Normal lenses generally have large
maximum apertures, indicated by small f-numbers such as f/1.4 or
f/1.8, and thereby gather much more light than zoom lenses. It may be
possible to take a photo with a normal lens in light only 1/8th or
1/16th as bright as would be required for the same photo with a
consumer-priced zoom lens. Also, the viewfinder will be brighter and
therefore easier to use in dim light, due to the fact that the large
maximum aperture stays open for viewing and stops down to whatever
aperture you have set just before taking the picture.
- Sigma 30mm f/1.4 EX DC for Pentax and Samsung, $429, (effective 45mm),
ideal for low-light photography without flash.
- Pentax FA 35mm f/2.0 AL, (effective 52.5mm), although a
stop slower than the Sigma, this lens is a tack sharper wide
open.
- Pentax DA 40mm f/2.8 Limited, $300 (review), (effective 60mm), reasonably fast
and remarkably light and compact.
- Pentax FA 43mm f/1.9 Limited, $530, (effective 64mm), same idea as the
40mm, but designed to cover the full 35mm frame and one f-stop
faster.
- Pentax FA 31mm f/1.8 AL, $890, (effective 46mm), a great lens
from the film era, but ridiculous overkill for a small sensor
camera with a tremendous waste of glass.
Wide-to-Telephoto Zoom Lenses
A wide-to-tele zoom is what you get as a standard "kit" lens with a
consumer-grade digital SLR body. The range goes from moderately wide
through
normal to moderately telephoto. They are good when you are too busy
to change lenses, e.g., at a wedding reception. A 16mm focal length at
the wide end
will capture a table of guests; the 45-55mm long
end is good for a flattering portrait. The main weakness of these
lenses
is that the cheaper ones have a very small maximum aperture, e.g., f/4
or f/5.6, and can only be used in bright light, on a tripod, or with a
blast of on-camera flash that gives everyone a moon face.
- Pentax DA* 16-50mm f/2.8 ED AL IF SDM, $640, (effective 24-75mm), high quality
zoom lens with a fast 2.8 aperture and SDM technology for fast,
accurate, quiet focus, this lens offers improved contrast, clarity and
edge-to-edge sharpness.
- Pentax DA 16-45mm f/4.0 ED AL, $400 (review), (effective 24-67.5mm), offers
similar quality at the cost of one f-stop, and a little range at the
long
end.
- Pentax DA 18-55mm f/3.5-5.6 AL, $63, (effective 27-82.5mm), the
standard kit lens; potentially adequate for outdoor photography on
sunny high-contrast days.
- Pentax DA 18-55mm f/3.5-5.6 AL II, $120
- Pentax DA 18-250mm, (effective 27-375mm).
Wide-angle Zoom Lenses
Telephoto Zoom Lenses
Josh Root
- Pentax DA* 50-135mm f/2.8 ED IF SDM, $770, (effective 75-202.5mm), 685g,
the function of a standard full-frame 70-200/2.8 lenses at less than
half the weight (Canon's 70-200/2.8 is a shoulder-breaking 1470g);
Canon and Nikon should be ashamed of themselves for not making a lens
like this for their small sensor bodies.
- Pentax DA 50-200mm f/4-5.6 ED, $180 (review), (effective 75-300mm), 260g,
longer reach and much lighter weight at the cost of two f-stops in
light-gathering ability; bring a tripod unless you're going to use
this in bright sunlight.
cheap slow low-quality lenses from Pentax's film years
- Pentax FA-J 28-80mm f3.5-5.6 AL, $50, (effective 42-120mm on a
full-frame camera), this provides an unusual normal-to-telephoto
range.
- Pentax FA-J 75-300mm f/4.5-5.8 AL, (effective 112.5-450mm),
potentially useful for wildlife photographers on a budget, as long as
the wildlife is standing in very bright sunlight.
Wide-angle Prime Lenses
Wide-angle lenses let you get close to your subject while still
showing a lot of background information. A dramatic wide angle for a
small sensor Pentax DSLR is 16mm or shorter.
- Pentax DA 14mm f/2.8 ED (IF), $700, (equivalent to a 21mm
perspective on a full-frame camera), high quality, high contrast,
internal focus.
- Pentax DA 21mm f/3.2 AL Limited, $470 (review), (effective 31.5mm), ultra-thin
pancake design, a popular but not very wide perspective similar to
the wide end of a point and shoot camera.
Telephoto Prime Lenses
A telephoto
prime lens offers excellent image quality at long focal lengths
due to a large maximum aperture and magnification of the subject, and
can be handheld in low-light situations. When comparing a telephoto
prime to a normal-to-telephoto zoom, although zoom lenses cover wide
ranges, they usually have a smaller maximum aperture on the long end.
Keep in mind that on a small sensor, the effective
focal length of a telephoto prime is multiplied by 1.5.
- Pentax A 50mm f/2.0, $70, (effective 75mm), manual focus,
cheapest road to high quality portraits.
- Pentax FA 50mm f/1.4, $245, (effective 75mm), a good choice
for portraits.
- Pentax DA 70mm f/2.4 Limited, $475 (review), (effective 105mm), thin and
light.
- Pentax FA 77mm f/1.8 Limited, $699, (effective 115mm), specifically
designed for portrait photography on old film SLRs; the wide maximum
aperture enables the photographer to choose a very narrow depth of
field, throwing distracting backgrounds out of focus.
- pentax_200/2.8, (effective 300mm).
- Sigma 300mm f/2.8 EX DG for Pentax and Samsung, $2999, (effective 450mm), can be
extended
with matched teleconverters:
- Sigma 1.4x Teleconverter for Pentax, $249, increases magnification by
1.4X, so a 300mm lens functions like a 420mm, reasonably good quality
with some lenses, notably the 300/2.8 preceding, loss of one f-stop of
light.
- Sigma 2x Teleconverter for Pentax, $209, doubles magnification, low
contrast and quality with
all lenses, loss of two f-stops of light, but possibly useful if you
are photographing extremely bright scenes.
Note that Pentax does not make any teleconverters for its autofocus
lenses.
Macro Lenses
Josh Root
Macro lenses let you
photograph physically small objects. The longer the focal length of
the macro lens, the more space you can put between the camera and the
subject. Extra working distance is helpful in lighting scenes or
keeping insects calm. A macro lens that goes down to "1:1" can be
used to take a frame-filling photo of something that is roughly
23x16mm in size, the dimensions of the APS-C sized sensor on a Pentax
digital body. The macro lenses below can be used for ordinary
photographic projects as well, i.e., they will focus out to infinity
if desired.
Flashes
Straight ahead on-camera flash blasts the subject with an unflattering
light. Pictures will look just as you saw them with your
eyes... assuming you are in the habit of walking around with a
spotlight on top of your head. The built-in flash of Pentax bodies
only points forward and is therefore mostly useful outdoors for
filling in harsh shadows. The accessory flashes below can be titled
up towards the ceiling or used at a distance from the camera for more
natural-looking lighting.
- Pentax AF 540 FGZ Flash, $340, guide number 148 (ISO 100)
bounce up, bounce to the side, zooms, wireless through the lens (TTL)
exposure metering.
- Pentax AF 360 FGZ Flash, $210, most of the utility of the 540
at a slightly lower power, guide number 119 (ISO 100).
- Pentax AF-200FG Flash, $105, same straight-ahead blast as
the in-body flash, but with more power.
- Pentax makes a variety of wired connecting cords and shoes for
their flashes, but if you want a simple way to hold a flash
off-camera, try the Promaster
off-camera cord.
Accessories
For a camera body and one lens, the average professional photographer
would not use a case at all. To hold a camera system, it is
best to visit a nearby professional camera shop and see how your gear
fits in various bags. See the photo.net
camera bag article for some ideas.
Recommended Starter Pentax Digital SLR
Systems
Josh Root
The tight budget:
The average family:
The serious photographer on a trip:
More
Links to Photo.net Reviews of
Discontinued Pentax Cameras and Lenses
Digital Cameras
• *istDS
Film Cameras
• MZ5
Lenses
• 200mm/4 Macro A
• 300mm/2.8 A
• 100/2.8 FA
• 28-200mm/3.8-5.6
FA
• 28-80/3.5-4.7 FA
• 50/1.7 FA
• 24/2 FA
• 300/4.5 FA
• 85/1.4 FA
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