"unfavorable light" is a correct and usable phrase in written English.
You could use it when you want to express that someone or something is viewed unfavorably: The candidate was portrayed in an unfavorable light in the media.
Dickens portrays Wackford Squeers in an unfavourable light, mocking his physical and sartorial defects.
When voters do consider health reform, they view it in an unfavourable light.
Cleon is represented by Aristophanes and Thucydides in an extremely unfavourable light, but neither can be considered an unprejudiced witness.
And on top of all this, a new biography by Tom Bower presents Sir Richard in an unfavourable light.
She cites a stream of books, television programmes, and articles which she says are significantly responsible for portraying state education in an unfavourable light.
As a result of this political complacency, publishers today are reluctant to bring out novels in which Islam is presented in an unfavourable light.
If you're shooting in low light, or if you don't have very steady hands, this will ensure that you can get sharp shots without camera shake in all but the most unfavourable lighting.
We therefore suggest that the non-cortical lichens can be characterized ecologically as light-demanding plants with physiological traits that appear unfavourable for the exploitation of low light conditions of the forest interior.
These factors include unfavourable climatic conditions; lack of space, light, or a suitable substrate; deficiencies of necessary chemical compounds or minerals; and the inhibiting effects of predators, parasites, disease organisms, or unfavourable genetic changes.
Eleven patients (28%) who showed loss of pupillary light reflex had an unfavourable outcome.
In addition, the microscopic examination revealed that none of the organs from the extract treated rats showed any alteration in cell structure or any unfavourable effects when viewed under the light microscope using multiple magnification powers.
