[Top] [All Lists]

Re: [OM] Keeper--yes, no, or can't tell?

Subject: Re: [OM] Keeper--yes, no, or can't tell?
From: Moose <olymoose@xxxxxxxxx>
Date: Sun, 2 Apr 2023 15:45:06 -0700
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

Good Luck!


What if the Hokey Pokey *IS* what it's all about?
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/

<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz