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03-06-2018, 04:09 AM - 1 Like   #1
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FF comparison: k15mm aspherical vs k15mm non-asp vs FA20mm

This is quick and dirty just to document the start of my evaluation of the K15mm 3.5 aspherical lens. I have a copy of this, the non-aspherical version and the FA20mm as a UWA modern reference.

Shots taken of a scene in the lounge room. All at iso 1600 and f3.5. LV manual focus. Cropped to show centre in bottom left third extending the the edge in the right third of the crop.

First observations.

1) non-aspherical noticeably softer and harder to remedy fringing
2) aspherical version more fringing than 20mm but easily remedied. Not as sharp as 20mm but that is likely due to sensor limitations 😀

First photo is non aspherical followed by aspherical version then the FA20mm

03-06-2018, 04:15 AM   #2
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I continue to be happy with my FA20, but my DFA15-30 is even better.
03-06-2018, 04:28 AM   #3
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Aye. The conflicts of a collector. The DFA15-30 looks great. I would love to test that lens direct with the k15mm aspherical. Not a fair challlenge but it would be interesting to see what 45 years of lens development means in the final wash up.
03-06-2018, 05:41 AM   #4
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I had a copy of the K15 which suffered from balsam separation down the centre of one of the element groups. That killed the centre sharpness. Just check that all is good with the lens as it really should be sharper.

03-06-2018, 11:04 AM   #5
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Nothing looks sharp in the non-aspherical 15mm example. Is that how the lens always works?
03-06-2018, 03:33 PM   #6
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My A 15mm f/3.5 is definitely better that that wide open, though it's noticeably happier at f/8.
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