On 4/2/2023 1:55 PM, Mike Gordon via olympus wrote:
Will be using this lens wide open or nearly so for astro in a couple weeks
Laowa 6mm f/2 zero-d is now in stock at B&H . . .
so made another exchange with B&H to try and get a sharp/centered copy. A
target is fine but my chimney is easy and readily available and good enough to
check for even sharpness in corners at infinity.
Third copy seems pretty well centered based on corner sharpness:
I am not sure it is as sharp in the center and left side as the second copy but
the testing conditions were different. The chimney was heavily backlit both
times but more severe with the third copy and that might washout some contrast
which can give the impression of poorer resolution. I put the center images in
separate tabs in my browser and went back and forth. All the images are cropped
SOOC jpegs so processing is the same.
Center comparison at F2.8:
Apples (f2.8) to oranges (f1.4)? What the labels and EXIF claim. Fingers
crossed in file naming?
Right Lower Corner at 200% second copy vs third copy:
Perhaps I'll repeat a couple shots w/o the backlight and be sure the center is as
good on the current third copy as the second. B&H closes for Passover soon so
have to decide quickly. The Center F2.8 comparison bothers me, though the lighting
differences may negate a valid comparison. Dustin Abbott's comparisons at
different apertures showed the contrast is nearly as good at F1.4 and maxes out
near F2.8. The sharpness improvement at F2.8 vs 1.4 was dramatic in my testing of
all 3 copies. I'd rather have a bit sharper copy in the center that was mildly
My Sigma 14-24/2.8 is very sharp at F2.8 especially at 14mm.
Pixel peepers and any other comments welcome, Mike
What if the Hokey Pokey *IS* what it's all about?
Themed Olympus Photo Exhibition: http://www.tope.nl/