Alec: What I would like to clarify is lines per millimeter vs. line PAIRS per millimeter. Because the proper unit in the spatial frequency / lens sharpness context is a line pair per millimeter (a black line and an adjacent white line, whose loss of contrast is evaluated).
I hope this is a simple typo (like "calories" is commonly used whereas it's in fact kilocalories i.e. thousands of calories, but everyone understands). But I'm also not ruling out that we're being duped, and instead of 50 line pairs per millimeter they're actually talking about literally 50 lines, and thus 25 line pairs, per millimeter.
...Which would be a shame (from film days we know sharp lenses' spatial response extends to 100 line pairs per mm and beyond),... and a sham (akin to the pundits in the early days of digital pledging that 6 or 8 megapixels was "film quality" - whereas Hollywood with real money riding on asset longevity, sticks to film even in the days of 4K).
It will be line pairs, as he is also speaking of 10 & 30, which cannot be lines per mm.
Interesting. that '1000 times less light than on earth' is something one doesn't realise.
CameraLabTester: If the camera was panned a little more to the left, he would have captured a DOUBLE RAINBOW (also a rare weather spectacle).
You can see the two arcs sandwiching the lightning on the left.
Here is how a FULL DOUBLE RAINBOW looks like:
A double rainbow is quite common.
It's not exactly 'once'!
Reminds me of Buster Keaton playing all instruments in an orchestra directed by Buster Keaton. Without computers quite skillful... 3 musicians at a time and 9 dancers. The Playhouse: https://www.youtube.com/watch?v=eRo36k1ipkE
"Using a Clauss precision pan-and-tilt head" That thing looks far too unstable for an 800mm.
Distortion of the 7-14 seems to be better corrected than in my old Oly 7-14. Would like to read more about distortion of this beast.
Weia: Angle of view on 57x57 mm is 1.33 degrees. Same vertical angle on full frame gives f=1031, on Canon APS/C 636 mm, on Four Thirds 559 mm. Not very special.
Thanks for the link mosc, I get it. And I can make the calculations now.
Interesting points, although I do not understand it completely. I would love to see an article on diffraction, with many illustrations and tests. On my old Olympus E3 (10 megapixels) with an apo Sigma 150 macro f/11 is OK, but f/13 clearly is worse thanks to diffraction. F/16 gives more depth of field but in fact is worthless.
70 mm is the width of the film, with (as in Hasselblad) perforations on both sides, leading to 57x57 or 56x56 mm.
Angle of view on 57x57 mm is 1.33 degrees. Same vertical angle on full frame gives f=1031, on Canon APS/C 636 mm, on Four Thirds 559 mm. Not very special.
A famous Dutch naturalist said about a century ago: when you cannot find a miracle within 100 meters of your door, you'll never find it.
It would be nice to add to all the measure of the sensor (not all are mentioned) and the optical zoom range.
Weia: Where can I find more about diffraction limits and sensor size? Fourthirds, APSc and full frame. Especially in macro.
DOF is independant of sensor size or pixel density, so I wonder why diffraction effects should depend on sensor size. I need higher f-numbers because I mostly picture insects of 1-5 mm length. I've tested my Sigma apo 150 on my good old E3 and f/11 is mostly my choice. f/10 maybe is a little bit better, f/13 definitily is worse.
Where can I find more about diffraction limits and sensor size? Fourthirds, APSc and full frame. Especially in macro.
brumd: Great article! It really helps me appreciate the amount of work and care that is put in making these lenses, not only Sigma, but in general.
It would be nice to be able to compare this production process with the Leica factory and their "handmade lenses": http://blog.leica-camera.com/leica-news/the-leica-manufacturing-process/
In what ways do these production processes actually differ?
"It really helps me appreciate the amount of work and care that is put in making these lenses, not only Sigma, but in general."I was thinking the same. Every tiny part has been in someones hands, all lines and signs are printed or even drawn by hand...
They love optics above all, it seems. Nice read.
Distortion quite much, always the difficulty with these focal distances.
Weia: I left Photoshop since the cloud version is the only one. Bye bye.
I meant: I stopped wanting updates!