The phrase "an opacity of" is correct and usable in written English.
It can be used to describe a lack of clarity or transparency regarding a subject or issue.
Example: "The report revealed an opacity of information that left many questions unanswered."
Alternatives: "a lack of clarity" or "a cloudiness of".
After writing the above, however, I read the final thirty pages of Fisher's amazing book and collided with a wall of incomprehension, an opacity of averages.
The visibility of a surface at a given depth is computed as (mathop prod nolimits_{{p_{z} < z_{i} }} (1 - alpha_{i} )), where z i and α i are a depth and an opacity of a surface.
To render motion blurred shadows, authors assign a random time for each sample and all samples at the same depth are averaged together to an opacity of a surface.
Age-related cataract, also called mature onset cataract, is an opacity of the eye lens that occurs relatively late in life, arising as a consequence of light scatter.
Cataract was defined as an opacity of the crystalline lens in the pupillary area and causing VI (presenting VA <6/18 and not improving with pinhole).
TT was defined as the presence of at least one eyelash touching the eyeball or evidence of epilation of eyelashes; CO was defined as easily visible opacity that obscured the papillary margin; and cataract was defined as an opacity of the lens that appeared greyish or white when examined with oblique light, under a shaded area [ 17].
For these observers, the image was first presented with a semiopaque gray overlay, created in Adobe PhotoShop by adding a black (red-green-blue values set to 0) layer with an opacity value of 65%.
The UV-induced degradation of ATP tested at 4.1 W m−2 UVC (200 280 nm), −10 °C, 7.1 mb, 95% CO2 gas composition, and an atmospheric opacity of τ= 0.1 yielded a half-life for ATP of 1342 kJ m−2; or extrapolated to approximately 22 sols on equatorial Mars with an atmospheric opacity of τ= 0.5.
a Chest radiography shows a longstanding opacity of the entire left lung with gradual development of a large air bubble in the lower part.
AS-OCT is a useful tool in cases when a child presents with a corneal opacity of unknown or unclear etiology.
However, this is an averaged opacity of the ordinary (O) and extraordinary (X) modes of the free-free emission, and these two modes have different optical depths in a magnetized plasma.
