Comparison of Samsung 30 and 45mm vs the 20-50 and 18-55

Prime vs Zoom, which is better?
Overall Image
SAM_0553-3
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An extremely boring comparison between some various Samsung lenses on the NX300.

My thoughts are the primes are best, but not much better above f/5.6. The main advantage to the prime lenses are the wide aperture. Notice that at 45mm both the kit zooms are already at f/5.6, this is 5.6 to 4 to 2.8 to 2 to 1.8, or 3 1/3 f/stops. This amounts to 10 times as much light entering the 45mm wide open (nearly 10 times the shutter speed). Similar with the 30mm, both kits are at f/4.5 at 30mm, or 2 1/3 f/stops smaller aperture, or 5 times the amount of light with the 30mm wide open.

The 18-55mm is noticeably better than the 20-50mm wide open at 45mm, but the 20-50mm is much better at 30mm in the corners. This fits with my previous impressions for the lenses, the 20-50mm is the better wide angle, but drops off quicker toward the telephoto end, where the 18-55mm is better at the telephoto, but loses some edge performance at wider angles.

Note, I don’t believe my 20-50mm actually stepped down for the 30mm comparison, notice how the entire image got notably brighter? Maybe a sticky aperture since the camera did adjust shutter speed. It seemed to work okay at 45mm. Because of this I think the 20-50mm should have done slightly better at f/5.6 and 30mm.

Center Performance at 45mm

Lens Image
Center 45mm f/1.8 SAM_0553
Center 20-50mm f/5.6 SAM_0555
Center 18-55mm f/5.6 SAM_0559
Center 45mm f/5.6 SAM_0554
Center 20-50mm f/8 SAM_0557
Center 20-50mm f/8 SAM_0562

Corner Performance at 45mm

Lens Image
Corner 45mm f/1.8 SAM_0553-2
Corner 20-50mm f/5.6 SAM_0555-2
Corner 18-55mm f/5.6 SAM_0559-2
Corner 45mm f/5.6 SAM_0554-2
Corner 20-50mm f/8 SAM_0557-2
Corner 18-55mm f/8 SAM_0562-2

Center Performance at 30mm

Lens Image
Center 30mm f/2 SAM_0563
Center 20-50mm f/4.5 SAM_0567
Center 18-55mm f/4.5 SAM_0571
Center 30mm f/5.6 SAM_0564
Center 20-50mm f/5.6 SAM_0568
Center 18-55mm f/5.6 SAM_0572

Corner Performance at 30mm

Lens Image
Corner 30mm f/2 SAM_0563-2
Corner 20-50mm f/4.5 SAM_0567-2
Corner 18-55mm f/4.5 SAM_0571-2
Corner 30mm f/5.6 SAM_0564-2
Corner 20-50mm f/5.6 SAM_0568-2
Corner 18-55mm f/5.6 SAM_0572-2

4 Comments

  1. hootsmon says:

    Hi Eric,
    Thanks, and well done. Not boring at all ;D

  2. Hi Eric,

    thanks for your work. Did you test version III of 18-55mm lens? I will try to verify your findings in real live: better edge performance at 45mm for 18-55mm lens (compared to small Samsung Kit-lens). I always deducted from the findings of Klaus Schroff (photozone.de) that the 20-50mm lens should be superior even at the long end. Here the resolution figures for 50 & 55mm wide open (center / middle / corner).

    Samsung 18-55mm@55mm /F5.6 2520 2115 1925
    Samsung 20-50mm@50mm /F5.6 2733 2411 2336

    Thanks a lot so much for your excellent tests of A7 with manual focus lenses.

  3. admin says:

    Thanks! Mine is version 2, I don’t have a version 3. My NX300 came with 20-50 version 2 (I think this is 2, the new style). There could be some variation too, and my chart is about 10 feet or so at 45mm. Might differ at infinity.

    Looking back at my tests on NX11 (could differ) they are closer than I was remembering. So probably lens variations would make the difference. It is pretty obvious that the edges of the 20-50mm are better with this sample at 30mm. Like you said, could verify with some scenic shots.

  4. Username* says:

    Thank you for your effort.
    Awaiting for your review on the 10mm fisheye