Wednesday, May 13, 2015

Imperfection / Unvollkommenheit

Looking farther than clean-room technical constructions, real life is imperfect in many facets, human creations even more so.
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Wenn man weiter schaut als im Reinraum hergestellte technische Konstruktionen, ist das echte Leben in vielen Facetten unvollkommen, menschliche Schöpfungen umso mehr.

Dashboard of worn-out fire brigade vehicle
aesthetic design wasn't invented yesterday


Wall mural of fire fighters

Friday, May 8, 2015

The last word on 1670-1650-18105

After having received my repaired 1670 back from Sony, I made another and final test round to assess its image quality compared to my 1650 and 18105.

I then compiled the results into some tables (see below) and stored the sample shots on a Google drive.

Here the last words on this subject (at least from me :-) ):

The last word on.......…..the 1670:
+ good central sharpness through entire range except 16 mm f4
+ good range wide 16 mm wide and 70 mm tele
+ f4 throughout
+ low visible distortion in OOC JPGs
+ lens hood included

- poor IQ on sides for 16, 24 and 70 mm unless stopped down to f8 where it gets at least ok
- strong amount of CA in OOC JPGs, improved when using ARW in C1 and manual CA calibration
- regular price is debatable
- risk of getting subpar copy
- power-up delay 1 seconds

Personal view: The 1670 is a nice, good-feeling all-in-one zoom lens, not too large or heavy with good central image quality throughout the entire focal range. However, image quality on the sides needs stopping down to f8 for the wide and tele end to go from poor to at least ok results. If you want to check the impact of this versus the 18105, take a look here at the examples I posted there. Then there is the risk of a subpar copy and the high list price not really reflected in image quality, since my 1650 is equal or better from 16-35 mm f5.6-f8. Positive is, that if you can live with the CA on the sides, the OOC JPGs are already well-usable.



The last word on.......…..the 1650:

+ good central sharpness through the entire range from 5f.6 to f8.
+ good IQ on sides at 24 mm at all apertures, for f8 also at 50 & 35, rest ok except for 16 mm f4.
+ good range wide 16 mm through 50 mm. At 16 mm OOC JPG, it is visible wider than the 1670, probably effectively 15mm.
+ low visible distortion in OOC JPGs
+ low amount of CA
+ inexpensive
+ extremely compact and light-weight

- low IQ at 16mm f4
- effectively a stop slower than the other lenses for 35mm and above, low DOF not really possible.
- lack of lens hood. I use adapted 1855 hood, see blog.
- power-up delay 1.5 seconds

Personal view: The 1650 is a impressive zoom lens, considering its collapsible design and low price. If used well, that means always stopping down to at least f5.6, it delivers good image quality all over the frame. It matches or exceeds the 1670 under these preconditions from 16 to 35 mm. It is a shame that no lens hood is provided, since this greaty improves the image quality (contrast). However, this can be fixed with low effort by either buying a screw-on hood or adapting the 1855 hood as I did. Distortion is well corrected incamera and in Raw. I quickly got used to the power zoom, operate it through the zoom ring and actually missed the visual zoom info in the EVF when using the 1670.



The last word on.......…..the 18105:


+ central sharpness: good to very good at 50-70 mm. Very good at 105 mm. Ok to good from 18 to35 mm.
+ good image quality on sides from 22 to 70 mm if stopped own to f8, else ok.
+ good range from 18 to 105 mm.
+ f4 throughout
+ lowest depth-of-field achievable with this zoom lens. Well suited for portraits.
+ lens hood included
+ fixed length design

- visible distortion in OOC JPGs for geometric scenes. Using ARW in Capture One default, well compensated though.
- due to distortion compensation, more like a 20 to 105 mm range.
- strong amount of CA in OOC JPGs, improved when using ARW in C1 and manual CA calibration
- largest and heaviest lens. Though for some, looks „serious“ :-)
- power-up delay 2 seconds

Personal view: The 18105 is a well-built and affordable zoom lens that handles smoothly. Image quality is enjoyable from normal to tele and this lens can be well used for portraits with low DOF or getting close with a twist of hand. Due to the distortion compensation, it actually is not really wide at effective 20 mm starting point. Since in-camera distortion compensation does not work that well, using RAW is a must to get the most out of this lens if your scene is geometrical.



Conclusion:

The combination of 1650 & 18105 equals or beats the 1670 in image quality, but of course requires using two lenses instead. A side effect is of course the versatility to have a small system with the 1650, and have the long tele at effectively FF 155 mm in the second setup. So you have choices to make, all three options will deliver good images if used well.
Comparison of the zooms over all range and aperture combinations
If you stick to f8 to get maximum image quality, things look like this:
Just looking at f8
 If you compare the combined image quality of 1650&18105 versus the single-lens option of the 1670, and also only consider where central image quality is at least good and side quality at least ok, this looks like this:
1650 used from 16 to 35 mm, 18105 from 50 mm upwards
And lastly, to lighten up with something like a photo:
I noticed that with Capture One, the shots with the 1650 from 16 to 24 mm actually have more Pixels than the original 24 Mpx. At 16mm it's 28.4 Mpx, at 24 mm still 25 Mpx. So there you go Samsung :-).
Reason is of course that the 1650 has strong distortion in the UWA range. Instead of discarding all of this, Capture One allows you to set cropping to the maximum box possible. Now before you complain that the edge IQ is bound to be low, it is - for f8 - about similar to the 1670 at 16 mm & f4.
In the end, this results in a focal length of 14.9 mm for the 1650 at 16mm. So with the SEL1650, you have an UWA on your fingertips!


I stacked the different pictures of 1650, 1670 and 18105 on top to calculate the effective focal length, with the SEL18105 turning out at 19 mm when set to 18mm (using the 1670 as reference).
1 - corrected 1650 b&w, 2- 1650 same but cropped rectangular by C1 16=14.9mm, 3- SEL1670 at 16 mm, 4 - SEL18105 at 18=19mm

Gear stuff: Zeiss pop - well not in this case / nun, zumindest nicht in diesem Fall

1670 at 70 mm f4

18105 at 66 f4
There are long discussion ongoing about the so-called Zeiss pop. In my view, this is frequently the effect of low depth of field coupled with good central sharpness caused by high microcontrast. In the case of my in the meantime repaired second copy of the Sony Zeiss 1670, I can't really see it. But check for yourself, crops for 1670 - 18105. I see differences in Bokeh and color, but that still might be partly due to changes in natural light and AF accuracy.
Furthermore, when you go to 105 mm wide open, bokeh of the 18105 looks also very nice.
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Es gibt längere Diskussionen über den sogenannten Zeiss Pop in manchen Bildern. Ich denke, dass dies oft der Effekt von niedriger Tiefenschärfe verbunden mit guter Schärfe in der Bildmitte, durch hohen Mikrokontrast, ist. Im Fall meines mittlerweile reparierten zweiten Exemplares des Sony Zeiss 1670 kann ich den nicht wirklich sehen. Aber schaut selbst, Crops vom  1670 - 18105. Übrigens, wenn man auf ^105 mm aufgeblendet geht, ist das Boke des 18105 auch sehr nett.
18105 at 105 f4






Sunday, May 3, 2015

Yet another cat photo / Noch ein Katzenfoto

Liked the reflection, shot from below.
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Mir gefiel die Reflektion, von unten aufgenommen.