Does using light magic make you easier to detect? I read that torches do but I cant find anything on using magic.

The light spells will make you easier to see/detect.

The night eye spells will not. Night eye does make it harder for you to determine which areas around you are in shadow so indirectly, can make it a little harder for you to perhaps stay in the shadows and avoid detection.

Thank you for the reply. I figured it must otherwise it would make it pretty unrealistic that the enemies cant see this bright glowing mage easier.

Don't forget that casting spells gives off momentary bursts of light as well, making you easy to spot for a split second or two.

I've found that the shadows really don't have a huge impact? Am I just stepping too loudly? My sneak skill is growing, and I have shoes on vs. boots, but I'll get busted in the shadows and can sneak past people in broad daylight. I dun know....

The line of sight calculation to see if anyone can see you is also a bit dubious. A lot of apparently opaque objects can't be hidden behind, as they're not considered that way by the logic.

I do find that shadows have a big affect on sneaking. I believe the game uses the amount of light that falls on your character as a big factor in the calculation. As mentioned above Line of Sight is also very important. And distance.

And whether the NPC or Creature is looking toward your character. You might be able to sneak behind someone in daylight and not be detected. But sneak in front of someone in shadows and be detected.

Also very important is the target's sneak skill. If they have high sneak skill that can detect your character more easily even in shadows.

And as mentioned above Light spells (or potions or enchantments) are horrible for sneaking. Night Eye is much better since it doesn't generate light. The only problem with the default night eye, is that it may make it harder to see where there are shadows to sneak in.

EDIT: by the way sneak in this game is very impressive I think. Because of all the realistic factors it takes into account. It is one of the best features of the game, again in my opinion.