The problem with modern digital cameras is that they meter like the old cameras, for 18% gray. That means, the camera takes the entire scene, and says, "on average, the exposure should be for around middle gray." Take a black and white picture of a white person's skin, that's about 18%, for a frame of reference. The problem you run into is the extremes, like a black cat, or a beautiful pure white snake. Only remedy I can give ya is to see if you can manually override your settings. You might be ok then. Also, if you can get outside, green grass is about the same, again if taken black and white, as 18%, so if you meter off the green grass, or put your snake in the grass (funny) you should get a better exposure. Try open shade, meaning under a big tree where there's no direct sunlight hitting the snake. that way, (s)he's not lit up like fire works on fourth of July, and you can still get a decent exposure.
Hope this helps.
AJ
King Donut Eater
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1.0 Hypo Okeetee - Wesley (Princess Bride)
0.1 Ghost - Sydney (Scream)
2.0 Striped Amel - Jay and Aiden (Kevin Smith movies)
1.0 Snow - Silent Bob (Kevin Smith movies)
0.1 Anery - Columbia (Rocky Horror)
1.0 Creamcicle - Brandon (Mallrats)
0.1 Zig Zag Anery - Pepper (didn't name her)
0.1 Normal - Bindy (Croc. Hunter)
0.1 Motley - Craven (Underworld)