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SMC Pentax-FA 645 150-300mm F5.6 ED [IF] Review RSS Feed

SMC Pentax-FA 645 150-300mm F5.6 ED [IF]

Reviews Views Date of last review
7 30,885 Thu March 5, 2020
Recommended By Average Price Average User Rating
71% of reviewers $1,212.00 8.00
SMC Pentax-FA 645 150-300mm F5.6 ED [IF]


Autofocus zoom lens with an angle of view from medium tele to tele.

SMC Pentax-FA 645 150-300mm F5.6 ED [IF]
©, sharable with attribution
Image Format
645 film
Lens Mount
Pentax 645
Aperture Ring
Yes (A setting)
Automatic, 8 blades
15 elements, 13 groups
Mount Variant
645 AF
Check camera compatibility
Max. Aperture
Min. Aperture
AF (screwdrive)
Min. Focus
200 cm
Max. Magnification
Filter Size
67 mm
Internal Focus
Field of View (Diag. / Horiz.)

645 Digital: 21-10.5 ° / 17-8.4 °
645 Film: 26-13.3 ° / 21-10.7 °
Lens Cap
Plastic clip-on
Weather Sealing
Other Features
Push-pull AF/MF Focusing Ring
Diam x Length
132 x 198 mm (5.2 x 7.8 in.)
920 g (w/o attachments) (32.5 oz.)
Production Years
(in production)
$1796 USD current price
Engraved Name
smc PENTAX-FA 645 ZOOM 1:5.6 150-300mm ED(IF)
Product Code
User reviews
Two ED elements

Screwdrive AutofocusInternal FocusingAperture RingAutomatic ApertureMedium-Format SupportAdapter needed for DSLRs
Purchase: Buy the SMC Pentax-FA 645 150-300mm F5.6 ED [IF]

Add Review of SMC Pentax-FA 645 150-300mm F5.6 ED [IF] Buy the SMC Pentax-FA 645 150-300mm F5.6 ED [IF]
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Junior Member

Registered: August, 2015
Posts: 35
Lens Review Date: March 5, 2020 I can recommend this lens: Yes | Price: $300.00 | Rating: 10 

Pros: Light, sharp, robust
Cons: A bit unwieldy
Sharpness: 9    Aberrations: 10    Bokeh: 8    Handling: 9    Value: 10    Camera Used: Fujifilm GFX 50R   

My Fuji GFX 50R serves mainly as a medium format back on a Toyo VX23D camera. I’m using Pentax 645 lenses with this setup because they’re excellent and provide a large enough image circle for shifting and tilting. I also occasionally use my Pentax 645 lenses with a Fotodiox P645 to GFX tilt-shift adapter.

Overall, this is an excellent lens. The extremely negative review it received from one reviewer is wildly out of line with my experience.

Given the focal lengths it covers, it’s a “light” 645 zoom lens. The hood mounts reversed, and the case is well made, so it transports well. Packed in its case it is a bit bulky, but that’s relative to the smaller Pentax 645 lenses I also use. When I’m not planning to do long lens work, but want a “just in case” telephoto option, I carry my tiny SMC Pentax-A 645 150mm f/3.5. Otherwise this is now my go-to telephoto option.

At the time of writing this review, my other Pentax 645 lenses are manual A lenses. I was concerned that manual focus would be a problem on this FA lens. It’s not. The focus ring isn’t as smooth and pleasant to use as the A lenses, but it’s perfectly fine. It has hard stops at either end, which I appreciate in the age of focus-by-wire lenses. I wouldn’t mind a slightly stiffer zoom ring like the one on my SMC Pentax-A 645 45-85mm f/4.5. The zoom ring on the 150-300mm is not loose, but I have accidentally zoomed when changing the aperture in the tight space of my recessed VX23D board.

In the focal lengths covered by this lens, I have two other telephoto lens against which I can compare this zoom: the SMC Pentax-A 645 150mm f/3.5, and the long end of the SMC Pentax-A 645 80-160mm f/4.5. I compared my copies of these lenses side-by-side at various distances and types of scenes. The 150-300 is quite a bit better at 150mm and 160mm than the 80-160. At f/5.6 the 150/3.5 is sharper, but from f/8 on the 150/3.5 and this 150-300/5.6 are very close. Depending on the scene I often think the 150-300 is a bit sharper and more contrasty. Depending on the scene, even f/5.6 pictures on my GFX 50R can be used because they respond very well to a bit of texture and contrast in Lightroom.
At f/8 contrast and detail are much improved across the frame, and problems at the extreme edges have disappeared; f/11 is even better. I found f/16 to be very good and even f/22 is quite usable.

I also evaluated resolving power of this 150-300mm zoom lens at 180mm, 200mm, 225mm, 250mm, and 300mm to see how it performed at all apertures between f/5.6 and f/22. Performance seemed the same as at 150mm, in other words, softer at f/5.6, much improved by f/8, excellent at f/11 and still very good at f/16. I have no complaints.

Wide-open, the 150-300/5.6 can have extremely small amounts of chromatic aberration in some places (and I do mean extremely small); CA is effectively gone by f/8. The 150/3.5 has quite a bit more CA at f/5.6, and CA is still present at smaller apertures; that’s not to suggest the 150/3.5 has a major CA problem – it just has more than the 150-300/5.6.
The lens may show a small amount of simple barrel distortion at 150mm. I didn't evaluate this at other focal lengths because it's so minor.

As mentioned at the outset I use this lens as part of my tilt-shift outfit. I only tested shift performance at 150mm because the image circle doesn’t change (see below). It offered excellent shift performance out to 10mm. Shifting 15mm is possible at the 150mm focal length, but it’s starting to vignette. The SMC Pentax-A 645 150mm f/3.5 is a better shift lens; it provides excellent shifts out to 18mm with no noticeable vignetting from f/8 on.

On my SMC Pentax-A 645 45-85mm, the image circle is smallest at 45mm, significantly larger at the mid-point of the zoom range, and then smaller again at the long end (but still larger than at 45mm). The image circle of the 150-300/5.6 does not change across the zoom range (which is a shame for shift purposes).

One caution for people planning to use this lens on any kind of adapter: check for “drooping” that causes a bit of undesired tilt. On my setup, the lens mounts to my Toyo VX23D using the front part of a Fotodiox Pentax 645 to Fuji GFX adapter. Lighter lenses are held solidly by the springs in this adapter, but the 150-300/5.6 is both heavy and long. That combination overwhelms the springs in the adapter that are supposed to hold the lens mount flush to the adapter when it’s mounted. My 45-85/4.5, which is also heavy, does not have this problem. I mitigated the drooping by tightening the springs on the adapter (an easy adjustment to the adapter if you’re comfortable taking it partially apart to get at the springs). Importantly, on my Fotodiox P645 to GFX tilt-shift adapter, the lens mounts properly and doesn't droop.

All in all, I highly recommend this lens. It’s an excellent professional-grade photographic tool that is available for ridiculously low prices.
Site Supporter

Registered: October, 2018
Location: Quebec
Posts: 539
Lens Review Date: October 24, 2019 I can recommend this lens: Yes | Price: $260.00 | Rating: 10 

Pros: Extremely sharp and well-made photographic tool.
Cons: Front-heavy when mounted on the 645Z.
Sharpness: 10    Aberrations: 9    Bokeh: 9    Handling: 9    Value: 10    Camera Used: PENTAX 645Z   

300 mm handheld

300 mm + tripod

150 mm + tripod

Someone here rated this lens a "1" ... I can't understand that. This lens is an awesome photographic instrument, extremely well-made and solid. I use it for landscape photography, tripod-mounted on a heavy Manfrotto 028 and I always close my Pentax 645 lenses @ f/11. This lens provides magnificent colors, excellent contrast and awesome resolution on the 645Z. A lens has to be good to be mounted on a 50 Mpx sensor, all possible defects would show. When your technique is adequate, it provides irreproachable images. New it sells for 2696 U.S. $, I found a like-new used copy on eBay in Tokyo for 260 $ complete with caps and sunshade.

Registered: February, 2008
Posts: 432
Lens Review Date: April 16, 2019 I can recommend this lens: Yes | Price: $800.00 | Rating: 10 

Pros: light weight, sharp and framing
Cons: slow
Sharpness: 9    Aberrations: 9    Bokeh: 8    Handling: 10    Value: 10    Camera Used: 645Z   

This is one of my favorite lenses for the Z and the D before that. Very light and portable. Good sharpness, color and contrast. I have compared this to : 67 300mm M; 645 200mm A; 645 200mm FA; 150mm A and the 150mm FA. At f/8 or f/11 ( the apertures I mostly use) there is no significant difference between this zoom and the primes. The precise framing a zoom allows makes up for any slight shortcomings. Highly recommended.
Junior Member

Registered: March, 2018
Posts: 32

2 users found this helpful
Lens Review Date: February 20, 2019 I can recommend this lens: Yes | Price: N/A | Rating: 9 

Pros: lightweight - sharp - handy
Sharpness: 9    Aberrations: 9    Bokeh: 8    Handling: 8    Value: 9    Camera Used: 645Z   

I've hesitate to buy as the first review was so bad ... But, as i had the opportunity to buy one at a cheap price, I however decided to buy this zoom which was in a fair second hand state.
I found this lens sharp at all aperture, very well constructed, very handy and not too weight. The minimal focus distance is a plus (only 2m, with the 300 F5.6 = 2,2m and the 300 F4= 3m) even if at 150mm, 2m min. focusing distance is perhaps a little too long (1,50m would be best). Internal focusing is also pleasant (no front part which extend and change the way you have to hold the camera as you zoom in or out).
Perhaps a little prone to flare, without sunhood, against heavy light. I found this lens very convenient and usefull with very good quality. I use it mostly at F8 with a 645Z and a speed of 1/250 min. (in 150mm mode) or 1/500 min. (in 300mm mode)
New Member

Registered: September, 2015
Location: Fresno, CA
Posts: 21
Lens Review Date: February 28, 2016 I can recommend this lens: No | Price: $2,700.00 | Rating: 1 

Pros: cheap and light
Cons: where do I begin?
Sharpness: 1    Aberrations: 1    Bokeh: 5    Handling: 10    Value: 1    Camera Used: 645z   

This is the most overpriced lens in the world. Build quality is "Made by Mattel". It feels like a plastic toy, literally. Yet, IF you can shoot it adequately stabilized, and IF you have time to allow the AF to find a focus AND hold that focus, then it can generate a great picture, very sharp indeed. But therein lies the rub.

I shoot with a Manfrotto 475B, a massive tripod weighing 11.5 pounds. I have a Really Right Stuff BH-55 (the largest) ballhead. I'm not sure you can get any more solid than that. I shoot mirror-lock-up and 2-second timer. And yet this setup still manages to produce far more vibration blur than you would expect. The reason? This lens is rather long and has no barrel support. This setup needs a barrel support mount to reduce vibration and reduce strain on the camera mount and body. The slightest breeze can create vibration in your shots. It is absolutely necessary to use the 2-second timer and mirror lockup to eliminate equipment vibration.

But here's the part that just angers me; I was using a polarizer on the lens, and did not have the right size, so I took an oversized polarizer and just hung it off the edge of the lens and it instantly went out of focus. I've done this on many Nikon and Canon lenses and images stay in focus. On the Pentax, not at all. After much analysis and trial-and-error, I discovered that putting a filter over the lens throws it out of focus. Move it off, and it comes back in focus. Are you kidding me??? AND... the AF switch is a push-pull ring switch. In trying to establish a focus, I established an AF focus, then turned off the switch so I could recompose, the lens went instantly out of focus. Simply turning off the focus-ring switch kills your focus. OMG. I tried it over and over and the same thing happened.

AND when you actuate the AF on a solid color (say, the sky) the AF motor rotates to a fully zoomed-in position and just grinds the motor with a sound that resembles fingernails down a chalkboard. Seriously???

Pentax has a lot of balls charging $2,700 for this piece of junk. I might give $900 for this lens, but $2,700 for a poor quality 5.6 is completely ridiculous.

I am hunting down my Pentax rep for "consultation".
Junior Member

Registered: November, 2009
Posts: 29

4 users found this helpful
Lens Review Date: August 9, 2011 I can recommend this lens: No | Price: $2,000.00 | Rating: 8 

Pros: light weight, convenient
Cons: not sharp until f11
Sharpness: 8    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 7   

I already had the 150FA, the 200FA and the 300/5.6 FA when I bought the 150-300 zoom. I figured that the 150-300 zoom could handle all of them and be great for travel. Some of the images I'd seen in the Pentax 645 book (in Japanese) looked great. However, all the images were taken at f16 or so.

Once I got zoom (new in the box), I compared it to the above 3 prime lenses. The 150-300 zoom lacked the bokeh of the 150 and 200. And it did not have the sharpness of either until all were stopped down to f11. The 300/5.6 was sharper wide open and at f8 than the 150-300 zoom at the same f-stops. The two lenses only equally each other at f11. To me, this explained why the Pentax book's photographers had stopped the lens to the f16 range: wide open it was not so sharp, but it was convenient to carry in the field.

I ended up selling the 150-300 zoom. Instead, for light travel, I take the 150FA and the 300/5.6.

Registered: December, 2007
Location: Norway
Posts: 3,447

3 users found this helpful
Lens Review Date: March 20, 2008 I can recommend this lens: Yes | Price: N/A | Rating: 8 

Pros: Great optics and built
Cons: Peculiar color rendition under certain circumstances

Sharp at all apertures with very high resolution. Metal built quality. Mine has aquired some whining sound while manual focusing similar to my FA* 200/4 Macro.
Also, colour rendition is yellowish when shooting at certain angles to the sun but not when shooting in other directions!
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