With pictures I have found that typically what a level indicates may not be what your eyes perceive as level. Basically other objects near the picture or a curved archway may in fact make a level picture look unlevel. I always depend on my eyes to make a picture look level.
I assume that levels with magnets stick to the studs in
Probably not correct, they "might" stick to steel studs that are in some more modern homes but mostly to stick to iron work. The magnets may in fact distort the level if most of the area you are working is non-ferrous and you have an odd object that the level is attracted to. I doubt that magnets on a level will pull through sheet rock.
That said, there are "Gecko" spelling? levels by B&D IIRC. They have a super surface that will almost stick to a vertical wall. Not totally unlike the material used on the guide rails on the new style circular saws that require no clamps to stay in place.
Any other uses for a "magnetic level"? I'm
Are you working with steel pipe or steel beams?
Stanley makes several, basic version from
Do you think you can see the tilt in a picture that is only .1 degrees out of level?
I would anticipate also
Nothing in my shop, 7' long TS, drill press, planer, router table work bench, drum sander, lathe, band saw, etc is level nor do any of them need to be level. Why would you need for them to be level?
I expect that a Starrett combination
The longer the level, the more accurate the results. The shorter levels are good for ball park settings but for larger objects like cabinets or doors yo want longer. Irregular surfaces on what you are trying to make level or plumb have less adverse results when using a longer level.
Reliability is important, if the level is calibrated correctly to begin with and you don't drop it very much there is not much that can go wrong with a liquid in a tube.