Any difference could not be found between recent Saturn image and last apparition image in the Near-Infrared light region as shown in the density profile curve.

#1 Image:
Jul.31,1999 19h36m48s UT, I = 293.9, III = 216.7, De = -23.0
11 frames composite
#2 Image:
Jan.05,1999 13h46m36s UT, I = 299.3. III = 325.9, De = -15.6
5 frames composite

Both images are taken with
Telescope : C11 (SC) D=280mm fl=2800mm
Camera :Minolta DimageEx1500 Digital Camera both taking lens and IR-cut filter are removed
Processed with PhotoShop Ver.4   
NOT USE ANY spatial filtering process. Only composite each frame images for noise reduction. 
The density profile is created by Scion Image


#1 Image:
Effective F No.:28 (XP24mm Eyepiece Projection)
Filter:R60 (Approx. imaging band 600nm-960nm)
Exposure:1/8 sec

#2 Image:
Effective F No:45(Or18mm Eyepiece Projection)
Filter:R64 (Approx. imaging band 640nm-960nm)
Exposure:1 sec