Two new lenses for Pentax !! - Printable Version +- Opticallimits (https://forum.opticallimits.com) +-- Forum: Forums (https://forum.opticallimits.com/forumdisplay.php?fid=4) +--- Forum: Pentax (https://forum.opticallimits.com/forumdisplay.php?fid=15) +--- Thread: Two new lenses for Pentax !! (/showthread.php?tid=4636) |
RE: Two new lenses for Pentax !! - thxbb12 - 05-03-2020 I disagree. This is why for certain lenses, you will see people raving about it while some people would say they suck. It's happened and it will keep happening unless QC is very tight. Of course, it depends on the lens model. Lensrentals.com have shown this: a good sample of a an inferior lens could give better overall MTFs than a bad sample of a better lens. RE: Two new lenses for Pentax !! - Brightcolours - 05-03-2020 (05-03-2020, 01:30 PM)thxbb12 Wrote: I disagree. Lemsrentals has never said that the differences are not due to centering issues. So what other "QC issues" do you want to put forward? RE: Two new lenses for Pentax !! - thxbb12 - 05-03-2020 (05-03-2020, 09:24 AM)davidmanze Wrote:(05-02-2020, 09:43 PM)Kunzite Wrote: Changing the optics to accommodate Pentax' SDM ring motor doesn't make any sense, as that is a standard "ultrasonic" ring-type motor. Those are made by various companies, it's not a Pentax exclusive. (05-03-2020, 04:01 PM)Brightcolours Wrote:(05-03-2020, 01:30 PM)thxbb12 Wrote: I disagree. Let me rephrase your convoluted sentence (double negations should be avoided). You wrote: "Lemsrentals has never said that the differences are not due to centering issues." Which becomes, when the double negation is removed: "Lensrentals has always said that the differences are due to centering issues." Now, here is an lensrentals.com article that compares 25mm MFT lenses and talk quite a bit about the results of the various lenses and copy-to-copy variation: https://www.lensrentals.com/blog/2018/01/finally-some-m43-mtf-testing-25mm-prime-lens-comparison/ I don't see them mentioning anywhere that differences are solely due to centering issues. RE: Two new lenses for Pentax !! - Kunzite - 05-03-2020 (05-03-2020, 09:24 AM)davidmanze Wrote:(05-02-2020, 09:43 PM)Kunzite Wrote: Changing the optics to accommodate Pentax' SDM ring motor doesn't make any sense, as that is a standard "ultrasonic" ring-type motor. Those are made by various companies, it's not a Pentax exclusive. The Ephotozine review actually found a drop in resolution at the longer end, 70mm being consistently very good: https://www.ephotozine.com/article/pentax-hd-d-fa-70-210mm-f-4-ed-sdm-wr-review-34615/performance But weren't we discussing something else? |