I bought these to align a tripod which was not included. While there is no substitute for alignment in the frame, I often shoot from uneven surfaces and zooming in by adjusting your feet saves a lot of time as only minor adjustments are needed to get good results. It's not true that they only have two positions, horizontal or not. . They're small, which makes the changes dramatic, but that doesn't mean you can't tell up close if you need to make subtle adjustments and in what direction. A level is a level, they don't lie. If you have another app e.g. a player, these might not be enough, but I would suggest buying a bigger app. I can throw them in my camera bag and they take up almost no space. The only thing I don't like is that they come in a pack of 4 and I only need one. Hey, $6 is $6, I get 4 bacon cheeseburgers for that.
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