I didn't think it did affect the backdrop, only 3D objects should be affected by fog.
Do you have any code that we could look at that demonstrates this?
I'll have a play anyway but it might be something not so obvious in your code...
EDIT: Here's a simple test that shows the backdrop (whether image or colour) is not affected by fog. Maybe the problem is not quite what it seems?
sync on
sync rate 60
autocam off
load image "Sky.jpg",1,1
color backdrop rgb(255,255,255)
obj = 1
for x=1 to 50
for y=1 to 50
make object box obj,10,10+rnd(100),10
position object obj,x*10-250,-5,y*10-250
color object obj,rgb(rnd(255),rnd(255),rnd(255))
inc obj
next
next
fog on
fog distance 0,150
fog color 0,0,0
position camera 0,50,0
ink rgb(0,0,0)
do
pspace = space
space = spacekey()
if image = 0
center text screen width()/2,0,"Use mouse to look left/right | Press Space to swap to Image BG"
else
center text screen width()/2,0,"Use mouse to look left/right | Press Space to swap to Random colour BG"
endif
if space>pspace
image = 1-image
if image=1
texture backdrop 1
else
texture backdrop 0
color backdrop rgb(rnd(255),rnd(255),rnd(255))
endif
endif
camang = camang + mousemovex()
yrotate camera camang
sync
loop