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SMC Pentax-A 645 45mm F2.8 Review RSS Feed

SMC Pentax-A 645 45mm F2.8

Reviews Views Date of last review
6 60,106 Sun December 1, 2019
Recommended By Average Price Average User Rating
100% of reviewers $188.00 8.80
SMC Pentax-A 645 45mm F2.8


Manual focus wide angle lens with a field of view corresponding roughly to 30mm in the 24x36mm film format.

smc Pentax-A 645 45mm F2.8
©, sharable with attribution
Image Format
645 film
Lens Mount
Pentax 645
Aperture Ring
Yes (A setting)
Automatic, 8 blades
9 elements, 8 groups
Mount Variant
645 A
Check camera compatibility
Max. Aperture
Min. Aperture
Min. Focus
45 cm
Max. Magnification
Filter Size
67 mm
Internal Focus
Field of View (Diag. / Horiz.)

645 Digital: 63 ° / 52 °
645 Film: 75 ° / 64 °
RH-RA 70mm screw-in
Lens Cap
Plastic clip-on
Weather Sealing
Other Features
Diam x Length
74 x 66.5 mm (2.9 x 2.6 in.)
400 g (w/o attachments) (14.1 oz.)
Production Years
Engraved Name
smc PENTAX-A 645 1:2.8 45mm
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: 3,274

1 user found this helpful
Lens Review Date: December 1, 2019 I can recommend this lens: Yes | Price: $200.00 | Rating: 9 

Pros: Useful focal length for landscapes, sharp at middle apertures, light, very well-made..
Cons: Much maligned in technical reviews but not so bad.
Sharpness: 9    Aberrations: 8    Bokeh: 8    Handling: 10    Value: 10    Camera Used: PENTAX 645Z   

The bottom half of the picture has been magnified and holds great sharpness in fine details right up to the extreme corners of the image. Taken handheld,1/320 sec @ f/9. This lens is very usable in landscape photography. Maybe there was a great variability in the production of the lens, I consider myself lucky as this particular optic has always given me excellent pictures, contrasty and sharp from corner-to-corner.

Very uniform sharpness corner-to-corner.

No ghosting, no veiling.
Loyal Site Supporter

Registered: November, 2011
Location: pontiac mi.
Posts: 392

2 users found this helpful
Lens Review Date: March 3, 2019 I can recommend this lens: Yes | Price: N/A | Rating: N/A 

Pros: light.good iq
Cons: none really
Sharpness: 9    Aberrations: 3    Bokeh: 5    Handling: 9    Value: 9   

I bought this lens for wide angle work, but as I picked up on the crop factor between the film and digital models, I found it to be s normall lens for the 645D.
the 75mm f2.8 now becomes a good portrait lens. others may see the 55mm as better, but to my eyes the 45mm is just fine.
Site Supporter

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

4 users found this helpful
Lens Review Date: August 21, 2014 I can recommend this lens: Yes | Price: $200.00 | Rating: 9 

Pros: small, good IQ, smooth focus ring. good price
Cons: not as sharp as the A35, but faster and less $
Sharpness: 8    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 10    Camera Used: 645D   

This focal length fits perfectly between the 35 and 55 and for its compact size, i find it a useful lens. Build is excellent, on par with the other sturdy metal A-lenses and the focusing ring is super smooth. I find the A35 to edge this out slightly in sharpness, but I would not avoid using the lens for that reason, as the results are very nice and the price is right.

Here are some pics using my A45/2.8
The Gold Coast (Explore #100)

China Camp (Explore #38)

Black Diamond Sunset
New Member

Registered: February, 2013
Posts: 11
Lens Review Date: April 16, 2013 I can recommend this lens: Yes | Price: $260.00 | Rating: 8 

Cons: Dispersion is heavy than the DA lens
Sharpness: 8    Aberrations: 9    Bokeh: 8    Handling: 8    Value: 9    Camera Used: K-5 IIs   

Senior Member

Registered: September, 2009
Location: LA, CA
Posts: 131
Lens Review Date: December 3, 2010 I can recommend this lens: Yes | Price: $130.00 | Rating: 9 

Pros: Pretty sharp, even wide open. Low CA. Amazing durability.
Cons: A bit heavy for field shooting, loose aperture ring

I'm constantly impressed with Pentax medium format primes, and the to shoot wide angle & sharp at 2.8 for low light and some portrait work has really come in handy. It shoots sharper and is faster compared to Mamiya RZ67 65mm f/4 and that's amazing. The barrel distortion is minimal as well.

I did lug it around backpacking in Kashmir and I take it hiking every so often. It definitely weighs a bit, but if you're shooting in the field with MF - you know what to expect. That said, the lens has taken quite a few falls, bumps, and immersion in mud, snow, etc. without any issue. My lens has a loose aperture ring that doesn't have a firm click. I bought it used, cheap so no surprises and no issues.
Veteran Member

Registered: October, 2008
Location: Albuquerque NM
Posts: 9,830

1 user found this helpful
Lens Review Date: July 14, 2010 I can recommend this lens: Yes | Price: $150.00 | Rating: 9 

Pros: Sharp, compact and fast
Cons: Manual focus only

I lusted after the 35mm, but this is the widest I could afford. The IQ has been terrific for me so far, and the field of view, about like a 28mm on 135, is extremely useful. It is part of my "compact" kit for the 645.
Add Review of SMC Pentax-A 645 45mm F2.8

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