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SMC-Pentax FA 28-105mm F4-5.6 Review RSS Feed

SMC-Pentax FA 28-105mm F4-5.6

Reviews Views Date of last review
21 149,289 Thu December 20, 2018
Recommended By Average Price Average User Rating
100% of reviewers $85.33 8.24
SMC-Pentax FA 28-105mm F4-5.6

SMC-Pentax FA 28-105mm F4-5.6
SMC-Pentax FA 28-105mm F4-5.6


The FA 28-105mm is a handy lens that features a large zoom range and the Power Zoom function. However, the extent of support for Power Zoom depends on the camera body. Check the camera specifications in our database to see if your camera supports power zoom.

SMC Pentax-FA 28-105mm F4-5.6
©, sharable with attribution
Image Format
Full-frame / 35mm film
Lens Mount
Pentax K
Aperture Ring
Yes (A setting)
Automatic, 9 blades
13 elements, 11 groups
Mount Variant
Check camera compatibility
Max. Aperture
Min. Aperture
AF (screwdrive)
Min. Focus
43 cm
Max. Magnification
Filter Size
58 mm
Internal Focus
Field of View (Diag. / Horiz.)

APS-C: 55-16 ° / 46-13 °
Full frame: 75-23 ° / 65-19 °
Lens Cap
Plastic clip-on
Weather Sealing
Other Features
Power Zoom
Diam x Length
72 x 96 mm (2.8 x 3.8 in.)
515 g (18.1 oz.)
Production Years
1992 to 1999
Engraved Name
smc PENTAX-FA 1:4-5.6 28-105
Product Code
User reviews
Screwdrive AutofocusPowered ZoomingAperture RingAutomatic ApertureFull-Frame SupportDiscontinued
Sample Photos: View Sample Photos
Price History:

Add Review of SMC-Pentax FA 28-105mm F4-5.6
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Loyal Site Supporter

Registered: July, 2010
Location: Ohio
Posts: 1,876

1 user found this helpful
Lens Review Date: December 9, 2013 I can recommend this lens: Yes | Price: N/A | Rating: 10 

Pros: Sharp, great color, focal length, 3D appearance
Cons: Not too much, perhaps physical size
Sharpness: 9    Aberrations: 9    Bokeh: 9    Autofocus: 9    Handling: 9    Value: 10    Camera Used: PZ-1P and K30   

This is a very good lens, especially for the price you can pick one up for. It is sharp with good color. It's not the fastest or lightest lens available but it produces excellent results in the right circumstances. It's certainly not up to a prime but it's a nice walk around lens, especially given it's focal length.


Registered: January, 2007
Location: Brooklyn, New York
Posts: 1,070
Lens Review Date: December 9, 2010 I can recommend this lens: Yes | Price: $115.00 | Rating: 10 

Pros: Great intense , color like from a film camera
Cons: has some CA fixable on Photoshop.
Sharpness: 10    Aberrations: 9    Autofocus: 10    Handling: 9    Value: 10   

I always wanted a 28-105 Pentax but they stopped making them.
Recently I thought about finding one of the older models but did not
want the Tamron built model.
Tried shooting flash indoors but lens not as suitable as my 16-45, so I'll use the 28-105 outdoors.
My first pictures taken outdoors were delightfully good, with really intense color similar to the filmy color I used to get from my Canon 28-105 USM lens.
I was able to shoot skylines with my new lens with better sharpness than my
other lenses and loved the results. The model I bought is the powerzoom model. Powerzoom doesn't work with modern cameras but I'm fine with manual zooming. It was originally made for film cameras. It is generally considered a better lens than the non-powerzoom models floating around.
There is sometimes CA to deal with but Photoshop easily handles it.
All in all I think I have a real bargain in this sweet little baby. (I shouldn't say baby because it is rather heavy, l lb., but fits nicely in my camera bag.)
I like the weight because it helps keep my K100D camera steady. Seems very
well made and the copy I got is excellent. I did have to buy a lens hood and
lens cap which cost me about an additional $15. The seller did not have those
with the camera as sold to me. I recommend this lens and I intend to have fun with it and know I'll come up with some really great shots. P.S. since this review I had several awards for photography with the lens. And at that time I hadn't taken more than 100 shots.
Veteran Member

Registered: April, 2017
Posts: 308
Lens Review Date: August 3, 2018 I can recommend this lens: Yes | Price: $40.00 | Rating: 9 

Pros: Acceptable sharpness
Cons: Small width of rubber band
Sharpness: 9    Aberrations: 7    Bokeh: 6    Autofocus: 9    Handling: 8    Value: 9    Camera Used: KS 2   

My experiment shows a steal to what i have paid. Auto focus noise is acceptable but quick but not quick shift focus like the new lens made. Heavy weight camera plus lens is a good practice/handling to counter act the shake and create a body tripod like position. Photos are sharp in a lens default position ranging from 12 to 20 feet from camera. Indoor using flash gives a better auto white balance although I did not use a hood to block the stray light. Since i was new to this lens after installing the lens the screen says " F-- " is flashing in red and it took time for me to realized to set the aperture ring to " A " position and the camera works and the red F is gone. Good combination of steel/plastic lens body. This will not be chosen by women due to its weight.
Veteran Member

Registered: August, 2012
Posts: 645

1 user found this helpful
Lens Review Date: February 6, 2017 I can recommend this lens: Yes | Price: $23.00 | Rating: 9 

Pros: Power Zoom, solid construction,
Cons: Autofocus is useless close up, soft focus in low light

This is the second Power Zoom lens I've acquired (I also have a 100-300mm model) and my first impressions of this one are far more favorable. Part of that has to do with me having more realistic expectations but part of it also has to do with just being an overall better performer. The auto zoom function is very quick, almost too quick. It can be difficult to zoom with precision. Fortunately, it's literally a snap to disengage it and zoom manually. Autofocus is lightning quick on this lens, although the camera initially wanted to recognize it as a manual focus lens. Turning the camera off and back on solved that issue, although it seemed to take a couple of shots to get it synched in. Once that was accomplished, I was pretty pleased with the results. The lens is sharp at both extremes of its focal range but at extremely close focusing distance, where the green macro flower icon appears in the distance window, autofocus is just about useless. Since the manual focus ring is little more than a milled edge on the front of the lens, it can be tough to operate until you get the feel of it. That said, the manual focus is nicely dampened, where it's easy to focus on exactly what you want. The one sort of odd characteristic of this lens is its bokeh. While I wouldn't exactly characterize it as harsh, it's definitely not creamy, either. It sort of reminds me of the light and dark banding of Damascus steel. I could see where it could have some interesting creative applications. While it may not get the same level of use as some of my other lenses, I'm beginning to see this one as a keeper.
New Member

Registered: February, 2012
Posts: 15

5 users found this helpful
Lens Review Date: July 4, 2013 I can recommend this lens: Yes | Price: $60.00 | Rating: 9 

Pros: Beautiful colour and very sharp
Cons: Rather bulky, and front element rotates; could wish it were faster
Sharpness: 9    Aberrations: 9    Bokeh: 9    Autofocus: 9    Handling: 8    Value: 10    Camera Used: Samsung GX20, Pentax K-X   

This lens currently occupies the middle slot in my auto-focus range, between the Tamron 17-50mm f2.8 Di II AF and the Sigma 70-300mm f4-5.6 DG AF. If I am going for a walk around town during the day, I would usually put this on the Pentax K-X, and the Tamron on the Samsung GX20, because the K-X high ISO is superior to the GX20, but it works well on either.

I own (LBA) the Pentax F 35-70mm f3.5-4.5, the F 28-80mm f3.5-4.5, the FA 28-70mm f4, the FA-J 28-80 f3.5-5.6 and the FA 28-90mm f3.5-5.6, and in terms of image quality I find this to be superior to all of them. Wide open it is as sharper, or sharper, than any of the others when they are wide open (though some of the others are a little faster) and in terms of colour only the FA 28-90mm f3.5-5.6 gets close.

The F 28-80mm f3.5-4.5, is nearly as sharp, but the FA 28-105mm PZ has better colour, less CA, is less affected by flare, and focuses closer.

The FA 28-90mm f3.5-5.6 almost matches FA 28-105mm f4-5.6 PZ's colour rendition, but the 28-90mm is slightly less sharp, and is less contrasty.

The F 35-70mm is as sharp, but the colours come out less saturated, and the zoom range is by comparison limited.

I have not found the bokeh to be a problem; in my pictures it is pleasantly blurred, and not busy at all. I imagine that the 9 bladed aperture is important, because in bright sunlight and Auto mode the lens is usually stopped down.

I have never mastered the Power Zoom (it works on the Samsung GX20). When I have tried to use it, I have hunted for the Zoom level I wanted; short, long; short, long ... So I leave it switched off.

On a sunny day, it is fast enough.

Indoors I get good results with a 'bounce' flash.

So what's not to like? Well, it is a bit large for my holster, and objectively it is large and heavy for its zoom range and slow speed. It would be nice if it went to 24mm at the short end. And the front element rotates, which might be a bit of a pain with a polarising filter and my screw-in petal hood. However, when I'm using the polarising filter I am likely focused far away, so once initially set up neither the hood nor the filter need much tweaking.

The final judgement; when I leave it at home, because I am chasing wild-life or having to use natural light in semi-darkness, or simply because I fancy a change, and then put the FA 28-105mm f4-5.6 AF Power Zoom back on the camera, and take a picture, I always look at the next image I take, and exclaim Wow! It's really that good.
Veteran Member

Registered: December, 2010
Location: Manila
Posts: 2,185

4 users found this helpful
Lens Review Date: April 18, 2012 I can recommend this lens: Yes | Price: $147.00 | Rating: 9 

Pros: FL, color rendition, sharpness, build, and long focus throw
Cons: rotating front element, slow and heavy!
Sharpness: 9    Aberrations: 9    Bokeh: 6    Autofocus: 8    Handling: 8    Value: 9    Camera Used: K-x   

It's been for several months with me now and I've had great projects with it. Time for a cumbersome review!

The FA 28-105 f4-5.6 PowerZoom is an old lens. There are no new ones out there, the latest copy probably produced by the end of the 90's. Not as old as other lenses, but considering its plastic shell, it's one tough lens. It's a substantial chunk of plastic and metal which now most parts are unusable due to PZ functions somewhat being obsolete. Nevertheless, its nice focal length, unprecedented sharpness and color rendition make it an excellent outdoor portrait lens.

Per aspect
Sharpness: (9.1/10)
Of all its features, this is probably most underrated. It's dang sharp stopped down by a half or one full from wide open (f/8~f/11). While it is true that such a peak aperture so small, still it's excellent for a budget lens and at this focal length. Wide open, the images are still usable but might be a tad soft for most photographers. Can't compare it to a prime of course, but the edges are sharp enough also at f/8 and beyond. Little vignetting too. Color is excellent, sometimes even giving a 3D effect with vibrance pumped up a bit.
It's also a bit soft at 105.

Aberrations: (8.8/10)
CA is well controlled by this lens, I don't know why. Maybe it was the camera doing it for me, but for the CA to really come out you'd have to do a really bad exposure of a brightly-lit subject.
(photo to be inserted here)

Bokeh: (6.2/10)
Ugly from 28-50. Even with a 9-blade diaphragm, the bokeh produced by this lens is far from creamy, especially at shorter focal lengths. Round, sure, but looks very busy. Only from 70mm to 85 does it start to look smooth. It takes some practice learning how to use the FL to smoothen the bokeh.

this photo was softened through pp, only because I also wanted the bokeh to look a little less nervous. This was shot at 100mm, f6.3

Autofocus: (8.1/10)
As with all AF screwdrives, it's noisy and hunts at low light. Nothing remarkable, but given its wide range, it's pretty fast. It's great for manual focusing too, though it doesn't have an MF clutch or the Pentax Quick-Shift feature.

Handling: (8.4/10)
So-so. It's sturdy and strong and all, but because of the PZ motor it's too heavy for superlatives. For some reason the weight helps me balance the lens for manual focusing at 105mm though, so I'm not complaining a lot. The front element also rotates, so using petal hoods won't work.

Bought a copy from a local Pentax user for Php6,300 ($147). It's pricier than I expected or hoped, but it's quite worth it. The copy was in very nice condition, showed little sign of wear. I guess aside from being taken care of a lot by the previous owner, its tough build shines through.

All in all, it's a performer. I replaced my 28-70 f4 lightweight lens with this, and I don't regret it. The former's bokeh might look better than this lens, but in color and sharpness the FA 28-105 PZ performs better. Setting aside weight issues and the rotating front element. If this was a constant f2.8, it's probably going to bomb other lenses. That would, in effect though, change the optical design altogether and compromises would have to be met.
New Member

Registered: January, 2010
Posts: 23
Lens Review Date: December 13, 2010 I can recommend this lens: Yes | Price: N/A | Rating: 9 

Pros: Sharpness; Color rendition
Cons: Front rotating element; heaviness

PZ stands for Power zoom. The lens is made in Japan, with 9 blade diaphragm and 58mm filter rim. Unlike the DA series Pentax lenses, this lens (or other lenses prior to DA series) does not has Full-Time Manual (FTM) focus (or called clutch system), which is a bit less convenient when trying to override the autofocus. Luckily, the autofocus is quite accurate on this lens. Although having autofocus functionality, the lens has auto/manual aperture ring, which is very convenient for Canon/Nikon users shooting in manual mode. However, the front element rotates when zooming and is therefore inconvenient for Polarizer filter users. The barrel is made of polycarbonate plastic and the body is heavy due to the power zoom mechanism. This is one of sharp, walk around zoom lenses made by Pentax. The lens has been highly rated by many other users and I found their statements are quite true. I wish the zoom range could be a bit longer, such as 28-135mm, but who cares as long as the lens is sharp.

The maximum aperture ranges from f/4 to f/5.6, which is not a fast lens. To be able to take indoor pictures hand held, a flash is usually required. The images are surprisingly sharp for a zoom lens like this. Color rendition and contrast are quite pleasant and would not get washed out like some of single-coating lenses. Note that, for the Canon/Nikon users, the adapter ring with AF confirmation could not fit onto the lens mount, due to the conflict with the additional electrical contact for the power zoom. To fit the lens in the Canon/Nikon cameras, you need to make compromise to use the adapter without the AF confirmation. If you could not live without AF confirmation, an alternative choice would be the non-PZ but IF (Internal Focus) version, which is lighter and usually made in China or assembled in Vietnam. The non-PZ version has a larger front element (62mm in filter size). The IF feature is nice, but the users have found it far less sharp and less contrast than the PZ version.
New Member

Registered: February, 2010
Location: Rayong Province
Posts: 1
Lens Review Date: March 23, 2010 I can recommend this lens: Yes | Price: $110.00 | Rating: 9 

Pros: Excellent Color,Sharp,Cheap
Cons: heavy,few noise

Lens optical quality is good for this price, a walk-around lens. I alway use its when i go to travel. I think,This is a Fantastic lens. It's now out of production, but if you can get one don't hesitate.
Lens Review Date: December 8, 2009 I can recommend this lens: Yes | Price: N/A | Rating: 9 

Pros: Very sharp and contrasty lens
Cons: Kind of slow but but great in good light

I bought this lens when I got my PZ way back when and it has been a great lens, and one of my favorites as a walk around lens. I have some 16x20" prints from this lens that are extremely sharp even close up using Kodachrome Slide film.

I have used the newer version of this lens and found it to be far less sharp and with less contrast than the PowerZoom version. I always used the PowerZoom on my PZ, along with some other features no longer available on the newer DSLR's and never had any problems with it.

Great lens, my daughter just got one used and loves it on her K10D too!

New Member

Registered: September, 2006
Location: Dallas, TX, USA
Posts: 21

1 user found this helpful
Lens Review Date: April 8, 2007 I can recommend this lens: Yes | Price: $125.00 | Rating: 9 

Pros: Ideal film SLR walkaround. Great value for money
Cons: loses wideness (28 becomes 42) on DSLR,

I bought this as the "kit lens" for my Z1 in Singapore when they both first came out. I was probably one of thefew users of the power-zoom aspects of this lens and I missed it when I switched to the *istD. (It's back with the K10D.)

This polycarbonate body lens has taken litterally thousands of pictures and only gave me one minor problem (one of the aspects of powerzoom that the K10D does not support) that Pentax fixed quickly under warrantee.

If you avoid both extremes of the zoom range, it has quite good optical qualities. Balances very nicely on the K10D and anti-shake makes it even better.

Larry in Dallas
Site Supporter

Registered: September, 2010
Location: Somewhere in the Southern US
Posts: 12,285

2 users found this helpful
Lens Review Date: December 20, 2018 I can recommend this lens: Yes | Price: $15.00 | Rating: 8 

Pros: Fast AF, Nice Colors, good range, PZ works well
Cons: Corner sharpness
Sharpness: 8    Aberrations: 8    Bokeh: 7    Autofocus: 9    Handling: 8    Value: 9   

The reviews here seem mixed. I thought it would be fun to try a PowerZoom and this one looked to be the best of the bunch optically. I found a copy that is in good working condition with clear optics. The PZ function is nice, and faster than I would have through given some of the comments I have seen over the years about these lenses. Focus was fast, faster than several other lenses roughly in this focal range. Colors are vivid with good contrast. Sharp stopped down, but it did not require too much stopping down to get sharp. Manual focus on this FA has better dampening than many and a longer throw than any other I can think of - which can be good or bad depending on your needs. It's longer than the IF version but slimmer (58mm vs 62mm). Overall, I like this version of the 28-105 much better for color, AF, sharpness, and manual focus than the IF version of the FA28-105.
Senior Member

Registered: May, 2009
Location: Finland
Posts: 215

1 user found this helpful
Lens Review Date: July 12, 2018 I can recommend this lens: Yes | Price: $55.00 | Rating: 8 

Pros: Good overall performance, zoom range
Cons: Corner sharpness at wide end, bokeh can be messy sometimes
Sharpness: 8    Aberrations: 9    Bokeh: 7    Autofocus: 9    Handling: 8    Value: 9    Camera Used: K-1   

In ideal conditions this zoom can produce very good results. Unfortunately in some lighting conditions images from this lens look strange. Corners at the wide end are sodt. Good thing is corners are not muddy, just some softness there.

Handling is good except power zoom. I prefer normal mechanical zooming.

Bokeh is what you expect from zoom like this. Not special and in most cases not bad.
Senior Member

Registered: September, 2012
Posts: 100
Lens Review Date: November 24, 2012 I can recommend this lens: Yes | Price: $75.00 | Rating: 8 

Pros: Builf quality, PZ, Pentax color, nice macro, cheap
Cons: soft at wide open, slow, no bokeh, heavy, rotate hood.
Sharpness: 8    Aberrations: 8    Bokeh: 6    Autofocus: 6    Handling: 8    Value: 7    Camera Used: K5   

Like other Pentax gear, i have some issue about AF in tungsten light. Althought adjustment the AF in body, still back focus when use macro.
However, it's a good lens for 75$
New Member

Registered: January, 2012
Posts: 1

3 users found this helpful
Lens Review Date: November 18, 2012 I can recommend this lens: Yes | Price: $215.00 | Rating: 8 

Pros: Sharpness, low price, constructive.
Cons: Hard, soft on the long end of the open aperture.
Sharpness: 8    Aberrations: 7    Bokeh: 7    Autofocus: 8    Handling: 9    Value: 8    Camera Used: K-x   

Good and not expensive lens with a wide range.
Good replacement whale primarily because of the greater range of focal lengths, the field kit is superior, but not much, at least in comparison to my instance. Constructs in very good. Only one drawback - heavy.
Sample photos
Junior Member

Registered: February, 2011
Location: Illinois
Posts: 43
Lens Review Date: February 19, 2011 I can recommend this lens: Yes | Price: N/A | Rating: 8 

Pros: Sharpness, build, contrast, quick focus, durability
Cons: slow aperture, focus ring rotates in AF, CA at full zoom sometimes

I got lucky when I bought a lightly used K10D. This is the lens the guy threw in with it. I got it + the lens for less than the K10D body alone cost at the time

This lens is excellent for daytime photography and edge to edge sharpness for high resolution prints. Indoor events would require something else or a flash. The power zoom works but I frankly I find it useless so I leave it turned off.

Having been spoiled by Canon L glass, this lens matches in IQ aside the CA and slight softness at the 105mm focal length.
Add Review of SMC-Pentax FA 28-105mm F4-5.6

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