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SMC Pentax-A 645 80-160mm F4.5 Review RSS Feed

SMC Pentax-A 645 80-160mm F4.5

Reviews Views Date of last review
7 44,958 Sun March 3, 2019
Recommended By Average Price Average User Rating
100% of reviewers $139.67 9.00
SMC Pentax-A 645 80-160mm F4.5


The Pentax-A 645 80-160mm lens is a manual focus zoom going from a very short to medium tele.

smc Pentax-A 645 80-160mm F4.5
©, sharable with attribution
Image Format
645 film
Lens Mount
Pentax 645
Aperture Ring
Yes (A setting)
Automatic, 8 blades
11 elements, 11 groups
Mount Variant
645 A
Check camera compatibility
Max. Aperture
Min. Aperture
Min. Focus
100 cm
Max. Magnification
Filter Size
77 mm
Internal Focus
Field of View (Diag. / Horiz.)

645 Digital: 38-20 ° / 31-16 °
645 Film: 47-25 ° / 39-20 °
RH-A 77mm screw-in
Lens Cap
Plastic clip-on
Weather Sealing
Other Features
Diam x Length
82.5 x 131 mm (3.25 x 5.2 in.)
1010 g (w/o attachments) (35.6 oz.)
Production Years
Engraved Name
smc PENTAX-A 645 ZOOM 1:4.5 80-160mm
User reviews
Manual FocusAperture RingAutomatic ApertureMedium-Format SupportAdapter needed for DSLRsDiscontinued
Price History:

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Loyal Site Supporter

Registered: October, 2018
Location: Quebec City, Quebec
Posts: 3,301
Lens Review Date: March 3, 2019 I can recommend this lens: Yes | Price: $125.00 | Rating: 10 

Pros: Extremely sharp and contrasty at middle apertures. Very useful focal range for the landscape photographer.
Cons: None.
Sharpness: 10    Aberrations: 10    Bokeh: 9    Handling: 10    Value: 10    Camera Used: Pentax 645Z   

New Member

Registered: July, 2018
Posts: 4
Lens Review Date: July 9, 2018 I can recommend this lens: Yes | Price: N/A | Rating: N/A 

Sharpness: 9    Aberrations: 10    Bokeh: 10    Handling: 7    Value: 10    Camera Used: Canon EOS 5DS R, 5Diii, 1DSii   

Hello everyone, I have been reading review from this forum for awhile, I thought it's time for me to contribute back to the society after some intense usage with them.

I am an architectural photographer using Canon 5DS R, 5D iii and 1DSii with Pentax 645 lens with Mirex adapter.

Pentax 645 A 80-160mm

tested at f11, after that, diffraction.

Very Good at all focal length, there is some barrel distortion but it' easily correctable in C1 or LR.

Old lenses like this give you that analogue film like feeling, detail yet not sharp sharp. Love it.

The only complain I have is the front filter rotate with the front focusing ring.
Site Supporter

Registered: February, 2018
Location: NoVA
Posts: 622

1 user found this helpful
Lens Review Date: June 30, 2018 I can recommend this lens: Yes | Price: $76.00 | Rating: 8 

Pros: Flexible, sharp enough stopped down
Cons: Slow, heavy
Sharpness: 8    Aberrations: 8    Bokeh: 9    Handling: 8    Value: 10    Camera Used: 645z   

The 645 A 80-160 zoom lens has a reputation for being very good, particularly at the short end of the zoom range. Given no change in optical design between the A version and the FA version, and the probability that this would be a secondary lens to primes, I opted for the A version. And it was cheap at $75 on ebay.

Like the 45-85, reasonable sharpness from this lens is available, but only by f/8. I would not, however, heitate to use this lens if I needed flexibility in this range and could bring only one lens. It might limit print size a bit, though.

As with the 45-85, I looked at three focal lengths: 80, 120, and 160. I only show the performance wide open and at f/8, but I explore a couple of other aspects, too. And I'll compare it to primes.


Here's the full image at 80mm:

And the 1:1 center crop, at f/4.5:

This is pretty soft. The bokeh is decent, but at f/4.5, it's hard to really paint the background with a wide, smooth brush.

Let's compare it to the 75 leaf shutter lens at f/5.6:

At maximum aperture for the zoom, the prime wins handily. What about the 45-85 at 85, wide open? Here it is:

So, the 80-160 is better wide open on the short end than is the 45-85 wide open at the long end. Buf if you want a wide aperture, use a prime.

As with the shorter zoom, the 80-160 sharpens up very well at f/8:

It's still not as good as primes, or as the FA 45-85 at f/8, but this is a snip from the middle of what would be a seven-foot print at the usual monitor resolution of 100 pixels/inch. This is quite usable.


Full image at f/8:

1:1 center crop at f/4.5:

Not too sharp. But let's look at it at f/8:

At 120mm, it's still getting sharper at f/8, but let's compare it to the 645 A 120 Macro, at f/8:

Again, the prime is better.


Full image at f/8:

1:1 Center crop at f/4.5:

A little soft, but no worse than at shorter focal lengths. In fact, I think it's rather better than the short focal lengths. So much for the conventional wisdom.

1:1 center crop at f/8:

As with 120mm, it takes until f/8 to get all the way sharp, and that's the only weakness at the long end that I can see. Wide open, it has a soft-focus effect and reasonable bokeh, with a similar effect to the 165/2.8 Pentax 67 lens.

So, how does it play at the edges, wide open? Here's the lower right corner at 1:1 and f/4.5, and 160mm. The grasses are near the focal plane, so a severe curvature would show them softer than they are. The field is pretty flat. I see some coma, where the safittal performance is perhaps not quite as good as the tangential performance. This would sharpen up pretty nicely with some unsharp masking.

I don't see any lateral color, either, or longitudinal color, though the contrast might not be high enough here to reveal it.

Now, let's explore a different application. Usually, lenses of this length are thought of as portrait lenses, where we will often use selective focus to bring attention to the subject. But let's say our real objective is a landscape, where we want everything sharp. We are often most afraid of diffraction, but this is an unreasonable fear. Diffraction takes the edge off the stuff right in the focus plane, but it adds sharpness to the foreground and background, and can therefore often make an image look sharper.

Here's that center crop again at f/22:

The center is fractionally less sharp than at f/8, but everything else in the photo is sharper. Nothing is ever fully sharp if it isn't in the focal plane, but make a big print (let alone a small print) of the above and those background leaves will seem sharp.

Continuing the examination of f/22, let's look at the upper left corner, which shows foreground material, and the upper right corner, which reveals background material.

Upper left corner at 1:1 and f/22:

The leaves, which are close to the focal plane, are sharp. The bark isn't sharp at this magnification, but in a moderate print at normal viewing distance it will seem sharp enough, perhaps, and some judicious sharpening will also help.

Here's the upper right corner, with pine trees in the distant background:

Out of focus is out of focus, even at f/22, but this magnification is pretty unforgiving. Of couse 160mm is long--too long for f/22. But it illustrates the point that being out of focus is a LOT worse than diffraction.

So, when people say a zoom is as sharp as a prime, well, no. In this focal range, I'll stick with primes, though this lens will serve if I have room for only one that has to cover this range.

Rick "it probably looked pretty good on film for those who didn't own a microscope or an enlarger with a drop bed" Denney
Site Supporter

Registered: January, 2009
Location: East Bay Area, CA
Posts: 6,397

1 user found this helpful
Lens Review Date: December 9, 2014 I can recommend this lens: Yes | Price: $150.00 | Rating: 9 

Pros: range is very convenient. decent IQ
Cons: lens creep. slow f/4.5 max aperture.
Sharpness: 9    Aberrations: 9    Bokeh: 8    Handling: 8    Value: 10    Camera Used: 645D   

This lens came with my kit and as I am usually not interested in using a zoom and have a full set of primes covering this range, I never actually tried this lens in the field.

Well, I was please all around with the performance. IQ is there and colors look good. The lens has some creep, that is, if I am shooting up or down at something, the focus ring might drift. That is probably something I can fix fairly easy.

here's a pic. HDR

Painted Ladies b

Palm Tract Sunset
Veteran Member

Registered: January, 2011
Location: Mt. Akagi, Gunma Prefecture
Posts: 374
Lens Review Date: April 13, 2014 I can recommend this lens: Yes | Price: $62.00 | Rating: 8 

Pros: great range
Cons: front heavy, focus creep
Sharpness: 8    Aberrations: 8    Bokeh: 8    Handling: 7    Value: 9    Camera Used: 645N   

I picked it up on a whim from the junk bin for 6,500 yen. I prefer primes but at that price decided I could take a chance. I've only shot three rolls thru it but am pretty pleased with the results. But it sure is heavy! And the balance is extremely front heavy. My right hand aches after every roll! And I think the heavy front elements combined with the smooth and light action focus ring are what leads to the focus creep. Zoom ring is plenty stiff so no zoom creep but the focus ring moves to MFD rather quickly when the camera is dangling around my neck.

But the great thing about this lens is the range. The 645 A-series lineup has a big hole between 75mm and 120mm. And the 120mm is big and bulky too so in practice it often ends up being a 75mm to 150mm gap. This lens covers that range beautifully. The other option is using the 67 adapter and the 90mm and 105mm, both of which are excellent performers but the range of this zoom really makes sense, unlike the WA zoom which is totally redundant with the primes.
New Member

Registered: January, 2010
Location: Auckland
Posts: 18
Lens Review Date: March 29, 2014 I can recommend this lens: Yes | Price: $125.00 | Rating: 10 

Pros: Sharp, little CA, little flare, Colours
Cons: Heavy, stiff zoom ring, harsh bokeh in some situations
Sharpness: 8    Aberrations: 8    Bokeh: 8    Handling: 9    Value: 10    Camera Used: Pentax 645D   

This is a sharp lens but not as sharp as prime lenses in the 645 / 67 line. It is sharp stopped down but a little soft wide open.The lens exhibits low level CA and I could get no flare even against bright sunlit skies. The colours are good and the lens has a good contrast profile differentiating many bands of grey in monochrome images.
My copy has a rather stiff zoom ring and the lens is a tad heavy. But it balances well on the 645D body.
The bokeh is somewhat harsh in some situations but this is a common features of short zoom lenses.
I paid only 125.00 USD for this lens and it represents good value for money.

Another gem and a bargain lens making the 645D system now highly competitive with high end 35mm DSLRs.
The following are hand held shots taken with this lens on the 645D:

8th April 2014
New Member

Registered: March, 2009
Location: Tennessee
Posts: 3

2 users found this helpful
Lens Review Date: May 21, 2009 I can recommend this lens: Yes | Price: $300.00 | Rating: 9 

Pros: Workhorse. Daily carry. Sturdy. Good optics.
Cons: None; exceeds expectations.

Daily carry. A good workhorse zoom.

Overall, it's in my bag everyday. I use it everywhere. If I've had a setup where I hadn't used this lens, it must have been for some special application. I've even used it with 645 Auto Bellows and been satisfied with its performance.

The manufacturer doesn't recommend it for use with bellows, but I tried it and liked it anyway. It's my most versatile lens. Just generally great.

77mm filter size; convenient. Goes down to f/4.5. There are no DOF markings on the lens, but that didn't even occur to me until I'd used the lens for nine months. The 645 has a DOF preview lever anyway.

I use this lens with 645 Adapter K on my small format equipment; it works well with 35mm (K1000 and ME Super) and DSLR (K200D). 100% completely satisfied. Someone should probably study this lens and build six more just like it.

Weight-wise, I have no qualms about mounting a K1000 on a tripod with this lens.

This is one of two lenses I keep with me all of the time. If that doesn't tell you I like it; I don't know what would.

Extremely durable; versatile; generally well made. It's zoom is two touch, and I like that. I carry this and a wide angle 645 lens. I have others, but this one's in the bag all the time. Every application from closeups to landscape. Every environment from studio tabletop to urban areas to my last setup, where I was scrambling over rocks through dense forest to get to a waterfall. I take it everywhere without a second thought.

Very durable. No prissy extras to clog up my usual all-manual line of thought. I like it; I'm surprised that everyone doesn't have one of these. It's utility is comparable to that of a good ole 50mm standard lens.

In 645, it's angle of view is from normal to short telephoto. It does everything I need.
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