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SMC Pentax 105mm F2.8 Review RSS Feed

SMC Pentax 105mm F2.8

Reviews Views Date of last review
13 86,005 Fri March 25, 2022
Recommended By Average Price Average User Rating
92% of reviewers $197.86 8.77
SMC Pentax 105mm F2.8

SMC Pentax 105mm F2.8
SMC Pentax 105mm F2.8
SMC Pentax 105mm F2.8

The SMC Pentax 105mm F2.8 is the only 105mm prime in bayonet mount to be produced by Pentax.

SMC Pentax 105mm F2.8
©, sharable with attribution
Image Format
Full-frame / 35mm film
Lens Mount
Pentax K
Aperture Ring
Yes (no A setting)
Automatic, 6 blades
5 elements, 4 groups
Mount Variant
Check camera compatibility
Max. Aperture
Min. Aperture
Min. Focus
120 cm
Max. Magnification
Filter Size
52 mm
Internal Focus
Field of View (Diag. / Horiz.)

APS-C: 16 ° / 13 °
Full frame: 23 ° / 19 °
Dedicated hard case
Lens Cap
Plastic clip-on
Weather Sealing
Other Features
Diam x Length
63 x 63 mm
294 g
Production Years
1975 to 1977
Engraved Name
SMC PENTAX 1:2.8/105
Product Code
User reviews
Manual FocusAperture RingFull-Frame SupportDiscontinued
Price History:

Add Review of SMC Pentax 105mm F2.8
Sort Reviews by: Date | Author | Rating | Recommendation | Likes (Descending) Showing Reviews 1-13 of 13

Registered: December, 2007
Location: In the most populated state... state of denial
Posts: 1,766
Review Date: March 25, 2022 Recommended | Price: $70.00 | Rating: 8 

Pros: Well built, great handling
Cons: too soft wide open, green and red CA
Sharpness: 8    Aberrations: 9    Bokeh: 7    Handling: 10    Value: 10    Camera Used: K5IIs - K3III   

Well built lens, and handles great

Very soft at 2.8, almost glowing, but from 5.6 onwards is excellent

Bokeh is neutral but pleasing

Color aberration (green and red) are noticeable wide open but almost gone at 5.6

At 2.8 can be useful for portraits and still life, as everything "glows" giving the soft/dreamy look
New Member

Registered: June, 2018
Posts: 2

1 user found this helpful
Review Date: October 13, 2019 Not Recommended | Price: $130.00 | Rating: 7 

Pros: Handles perfectly, low chromatic aberrations, very nice for portraits.
Cons: Lots of spherical aberration wide open (low contrast), not impressively sharp, corners don't improve much upon stopping down..
Sharpness: 7    Aberrations: 8    Bokeh: 9    Handling: 10    Value: 6    Camera Used: MX, X-T3, A7   

Wide open this lens isn't very impressive. It's got a lot of spherical aberration that causes low contrast, and resolution outside of the center isn't very good. Thankfully the image improves upon stopping down - contrast improves to good levels and so does sharpness but not by as much as one would hope. By f/8 the entire image is very sharp and contrasty but I noticed that the center always has more contrast than the rest of the frame. There's a tiny bit of focus shift that's only noticeable on digital, it goes away at f/8. Overall I never found the sharpness or contrast of this lens very impressive. Chromatic aberrations seem to be on the low side - something this lens does well. Bokeh is smooth if you consider your background, difficult backgrounds can appear busy. Flare control is only good and isn't in the league of Pentax's best (50mm 1.7M, 28mm 3.5K). Overall this lens has a character that's more suited for soft portraits, and unfortunately due to its rarity it's at a price that I would consider too high. The m42 SMC version is identical and isn't as rare or expensive, you should only consider this lens if you absolutely need the K-mount version.

Compared to the M 100mm 2.8, the M has more contrast overall (especially wide open) and sharpens up quicker in the edges. Neither lens show impressive performance in the corners, but the 100mm M is rather impressive in the center and mid-frame when stopped down a bit. Both lenses always have high central sharpness but the M always has higher central resolution due to overall higher contrast. The only areas I think the 105mm outperforms the newer 100mm is chromatic aberration correction and bokeh. Overall I personally prefer the 100mm M.
Senior Member

Registered: July, 2018
Location: Stockholm
Posts: 226

1 user found this helpful
Review Date: August 28, 2018 Recommended | Price: $150.00 | Rating: 10 

Pros: build, balance, sharpness, rendering
Cons: Weight, availability
Sharpness: 10    Aberrations: 10    Bokeh: 10    Handling: 9    Value: 7    Camera Used: Ricoh XR-1   

A very well built lens like most Asahi Pentax lenses, balances lovely on a medium size camera or a Pentax ME/MX with winder.
Renders beautiful, crisp and sharp images and handles flare relatively well compared to other lenses from the period.
One lens that I will try and get my hands on again.

It is difficult to find and they command a relatively high price which is very understandable, one the best of its focal length and creates great images. Perfect portrait lens!
New Member

Registered: January, 2016
Location: between Toulouse and Pyrenees Mountains
Posts: 2

2 users found this helpful
Review Date: February 20, 2016 Recommended | Rating: 10 

Pros: Nice Portrait lens
Cons: A bit soft wide open
Sharpness: 9    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 9    Camera Used: K-3   

A surprising lens, a little bit soft wide open. But sharp after f4.when in comparison with the 135f2.5 the 105 f2.8 is not far in results.
Diffraction is visible at more than f16
Very compact lens.
I d love to test it on the k-1 it can be fun ;-)
Senior Member

Registered: April, 2015
Location: Lower Saxony
Posts: 181

2 users found this helpful
Review Date: November 29, 2015 Recommended | Price: $160.00 | Rating: 10 

Pros: focusing is an enjoyment; long focus screw; sharp from f/4.0, as was said before
Cons: not yet
Sharpness: 10    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 10    Camera Used: Pentax K-5 IIs   

I got my copy 6 days ago, but had only 3 days with some light and less time to test so far...
and i am surprised and satisfied!
Very exact to focus, focus screws around ~ 250į; better than M 100mm 2.8 and M 85mm 2.0.

Some examples, all out of camera jpgs, Pentax K-5 IIs,with a long and tight (APS-C) 52mm in screwed rubber lens hood,
picture style monochrom + digital filter high contrast or picture style color natural.




f/2.8 - f/4.0 - f/?
Forum Member

Registered: December, 2012
Location: Warsaw
Posts: 83

2 users found this helpful
Review Date: April 15, 2015 Recommended | Rating: 9 

Pros: Compact, sharp, color rendering.
Cons: "Soft focus filter over the sharp image" at f/2,8.
Sharpness: 9    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 10    Camera Used: K5   

Sample - please click an view the original picture to see how this lens can perform.

Great lens!!! I agree with Yoshihiko Takinami, that it has all good feeling and the charm of the SMC-K 85mm f/1,8.

Actually those two lenses are very close at f/4, then the 85mm gets an edge up to f/8, but the 105mm equals again at f/11, and gets a visible superiority over the 85mm at f/16 - f/32.

This lens is compact, not much bigger than SMC-K 28mm f/3,5.

Lens has a dreamy effect on f/2,8 but it still has very good resolution. I could compare it to an effect created by Nikon Soft Focus #2 Filter on an analogue camera. The effect is minimal at f/3,5 and gone by f/4 as seen on the picture above. Up from f/4 the lens has a tear squeezing sharpness although keep in mind that up to f/5,6 you need to be precise with focusing as missing the focus is easy.

Overall: 9/10. I do admit here that my ratings on PForums are all subjective. I rather compare the lens to my expectations I had and the original purpose - the lens was designer for + usability/cost ratio.
New Member

Registered: May, 2013
Location: Jakarta
Posts: 2
Review Date: May 2, 2014 Recommended | Price: $200.00 | Rating: 7 

Pros: sharpness, fast, bokeh, colours render
Cons: price, very rare
Sharpness: 10    Aberrations: 10    Bokeh: 10    Handling: 10    Value: 4    Camera Used: K5, ME Super   

excellent beautifull lens, unfortunately it's to pricey (related to very rare on market)
here are the sample shoots:
Junior Member

Registered: March, 2014
Posts: 27

2 users found this helpful
Review Date: April 3, 2014 Recommended | Rating: 10 

Pros: Sharp, very precise focussing, size
Cons: rare
Sharpness: 9    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 8    Camera Used: KX, GH3   

Got this lens (mint) in combination with a black KX for 10 dollars on a second hand street market. Actually my mother bought it for me, not knowing if it would be of any use, since she doesn't know about photography that much... I guess the person that sold the camera & lens didn't know either. Thanks, mum!

I was amazed by the precise and smooth focussing. The focus throw is loooooooong; you find yourself turning that ring forever. I don't mind, it gives the feeling of a precision instrument which it in fact is. I think this lens is pretty 'exotic'. Compared to the K135mm 3.5 (which I got last week) it's much shorter, and it balances very well with the heavy KX body. On this site you can optically compare it to the M100mm 2.8;

The 105mm at f2.8 has better sharpness than the 100mm at f5.6! Sharpness is not the most important but it shows that the 105mm is in a different class... if you can get it for a reasonable price go for it!
Veteran Member

Registered: June, 2010
Posts: 753
Review Date: May 25, 2011 Recommended | Price: $395.00 | Rating: 7 

Pros: build, size, focus throw, resolution, compact, f 32
Cons: focus throw, metering on K20d, expensive and rare
Sharpness: 8    Aberrations: 7    Bokeh: 8    Handling: 8    Value: 5   

This is a very nice and compact lens, attached to k20d it feels right and balanced, even more with the grip. It's quite sharp, with nice rendering of details, although FA77 is a bit more contrasty. K105 renders colours better than 77ltd IMHO. Throw of focusing ring is very long which provides very delicate and exact focusing. It's an advantage if you have time but not really a great thing for snapshots. Huge minus for this lens is metering discrepancies with k20d - stop down metering doesn't provide equal results and you'll have to figure out exposure compensation for getting even exposures. In direct comparison to A100 2.8 i think this is optically better lens however A100 is more convenient to use on dslr.

edit: with K20/4 and FA31 this lens completes the trio of best balanced lenses on k20d for me.
Veteran Member

Registered: November, 2006
Location: former Arsenal football stadium
Posts: 431
Review Date: November 15, 2009 Recommended | Rating: 9 

Pros: small, light, very sharp stopped down
Cons: bokeh can be a bit agitated, bit iffy at f2.8

As per above reviews. f2.8 is very soft, stopped down to f4 much tighter. Specular highlights can look a bit fierce in OOF areas. The wide aperture makes it nice and bright for focussing. You don't see many around and they're not cheap but I'm glad I got mine - a worthy alternative to the FA135 2.8 for my purposes. More enjoyable to use as a piece of engineering.

Beautifully built, albeit without the built-in hood of the M135.
Site Supporter

Registered: October, 2008
Location: Vancouver, Canada
Posts: 7,962

8 users found this helpful
Review Date: August 15, 2009 Recommended | Price: $280.00 | Rating: 9 

Pros: Build, speed, sharpness and size.
Cons: Lots of competition in the portrait/telephoto focal length.
Camera Used: K Series film bodies (K1000, KM, KX, K2, K2DMD)   

The K105/2.8 is the middle of three portrait/telephoto lenses that Pentax released in 1975. (The other two are the K85/1.8 and the K120/2.8)
The K105/2.8 is the shortest & lightest of the three and shares a 52mm diameter lens hood with the K85/1.8 and the K100/4 Macro & Bellows lenses.

The K105/2.8 is fast & very sharp for a telephoto lens and gives the K85/1.8 a run for the money in this field. Itís also rated much sharper than its M series replacement, the 100/2.8.

The 105mm focal length makes for a good short to medium telephoto/portrait lens on a film camera, but itís also very close to an 85mm, 120mm or 135mm in angle of view. Most people will find that having both the 85 & 105mm is overkill and choose only one. The same scenario exists with the 120mm and 135mm focal lengths.

The K105/2.8 is a better telephoto lens than the K85/1.8, but the 85mm is faster and has the soft focus feature, so itís a better portrait lens. The K105/2.8 however can be picked up for half the price, so it may be a better option for those on a budget.

If you do decide on getting the K105/2.8 you wonít be disappointed and like all K series lenses the quality and build are superb.

One year update August 15, 2010:

Iíve been using the K105/2.8 a lot lately for a course Iím taking on natural portraiture. The K105/2.8 has impressed me as how good it is as a street and studio portrait lens. Its sharpness is outstanding and is perfect for head shots. Itís the equal of the K85/1.8 in all areas except speed; the 1 1/3 stop difference prevents the K105/2.8 from getting a perfect 10 like the K85. Iíve elevated my score for the K105/2.8 to 9.5!

Sample shots taken with the K105/2.8. Photos are medium resolution scans from original negatives.

Camera: KX Film: Ilford HP5 Plus ISO: 400

Camera: K2 Film: Ilford HP5 Plus ISO: 400

Senior Member

Registered: July, 2008
Location: France
Posts: 128

1 user found this helpful
Review Date: July 19, 2009 Recommended | Rating: 9 

Pros: Fast, easy to focus, great sharpness
Cons: No f/stop control with the camera

Bought used from a forum user, it was in really great conditions. Its excellent contrast and sharpness make it really easy to focus, and well suited for portraits.
Nice "poor-man" macro lens when used with extension tubes.

The only "issue", of course, is that its diaphragm cannot be controlled by the camera ...
Inactive Account

Registered: January, 2007
Location: Sweden
Posts: 13
Review Date: April 14, 2007 Recommended | Rating: 9 

Pros: Build quality
Cons: Manual

Benefits- Sharp, fast and accurate, and great build quality.
Downsides- Manual.
Add Review of SMC Pentax 105mm F2.8

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