SMC Pentax DFA 100mm f/2.8 Macro WR on Sony A7R

SMC Pentax DFA 100mm f/2.8 Macro WR on Sony A7R

This 100mm f/2.8 macro is as small as they come, so how is it as a general purpose lens?

When I picked this lens up I was surprised by the cold metal. The outer barrel is a nice quality metal, giving it a Limited lens feel. The build quality is nice and the lens is very compact for an 100mm macro. The distance scale is a nice touch with a modern lens, but the focus ring could be a tad larger.

The lens is fairly dense, weighing in at 340 g. It has 8 aperture blades making a circle at large apertures, and a standard for the class minimum focus distance of 0.3 m, providing a maximum magnification of 1x. It has a 9 elements in 8 groups, with no specialized elements. It has Pentax standard 49mm filter threads.

Lens curtesy of Lloyd Shell. Check out his great work at: http://lloydshell.zenfolio.com/.

SAM_1007 SAM_1006
SAM_1008 SAM_1009
SAM_1010

Optical Performance

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Please click on the tab you want to view. Only 1 tab may be active at a time. MTF, Distortion, and Lat CA data acquired using Imatest
MTF20 Chart maxes at vertical resolution of the sensor which is 4912 LW/PH for A7R. Anything above that is meaningless. The MTF50 chart is set at the value where the best lenses perform in the center, or about 3850 LW/PH on the A7.
Note: 4k video is 2160 LW/PH
Note: HD video is 1080 LW/PH

Comments on the Results

The resolution on this lens is very good to excellent at all settings. The corners see a nice bump at f/5.6. Sharpness is good as well, wide open it is a bit hazy (high contrast edges have some purplish hues to them)

Distortion is negligible at 0.1% barrel.

Lateral CA is fairly severe. Longitudinal CA is fairly strong at large apertures, but typical for the class, which will cause some purple fringing at large apertures.

Flare resistance: Not specifically checked, but does well enough in contra light.

Measured Focal length is 103mm at 1:35 magnification.

Pros and Cons

Effective Resolution

The colors are selected based on overall MP, don’t compare the colors between systems. So relative to max sensor resolution a lens doesn’t do as well on the A7R as it would on the A7 relative to its (lower) sensor resolution, but it still resolves more detail on the A7R then it does on the A7.

Aperture Weighted Center Partway Corner
f/2.8
24.8 MP
28.5 MP
22.7 MP
16.5 MP
f/8
29.5 MP
31.9 MP
28.4 MP
23.6 MP

Bottom Line

With all the interest with Internal Focus macros, what people forget is how much larger that makes the lens. Since this lens is largely external focusing it keeps the size of the lens very small. With the hood on you won’t notice the extension at all.

This is a great general purpose macro lens that can double as a telephoto. Some macros I have tried don’t hold up at even modest distances, like the Kiron 105mm f/2.5 (http://erphotoreview.com/wordpress/?p=4374).

The only real issue is it has is the CA leads to a sort of hazy appearance at large apertures and distant focus. You are best to avoid high contrast lighting in these situations. Stopped down it is better, but some of the color fringing still persists. Using the CA correction in Lightroom (eye dropper tool on fringe edge) can help a lot.

I don’t have any setup to test macro lenses specifically, so at this point I just test them as general purpose lenses, but always get some close up shots in my sample gallery, so please check those out.

Buy this great macro at:
Amazon: Pentax 100mm f/2.8 WR D FA smc Macro Lens for Pentax Digital SLR Cameras
B&H Photo: SMC Pentax DFA 100m WR Macro

Consider donating, it is about $50 a lens to rent.





Photos are all © Eric Tastad, 2013-2014. and may only be used for personal evaluation of the lenses. Download full sizes by clicking on image which will take you to Zenfolio. Hover over the image, in the upper left of the image click on the menu, Download, and Original (or all available).

Tip: You get brownie points if you can find the great horned owl in the photos.

See photos at Zenfolio: http://viking79.zenfolio.com/p676710183

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

Eric Tastad: SMC Pentax DFA100mm f/2.8 Macro &emdash;

1 Comment

  1. mrfocus says:

    thanks for the review, looking forward the pentax full frame to try out my copy of the DFA100wr