because its underexposed. Doesnt matter how low of n ISO you shoot…if you dont expose properly you will get noise in the image. noise shows up in dark shadow areas alot more as well
in the first pic its not bad because the gauge was metered for the exposure so thats why the numbers are so bright…Now the 2nd pic has more noise because it looks like the metering came off the numbers so they are properly exposed leaving the rest of the guage underexposed and giving more noise on the face