Is there a product out there that acts as a level for dslr's? I have a canon 5 d mark ii. I thought I saw something that goes in the hot shoe and acts as a level, but I will still be wanting to use my flash.
Although I do not advertise this portion of my business, I do govt, mechanical and engineering imagery. All structure based in some way or the other.
I simply use a small level (lwalmart, lowes etc) and place under the body and then on the side. Always on a tripod of course, and then review the image to make sure lines are good depending on what lens I use. I do a lot of this with a wide angle lens and of course fix till my heart is content in PS. Yes, I do stitch images as well depending on the shots. but you can get a tripod head with a level, but that wont necessarily level the body. Remember, the body has to attach to the plate and then the tripod. Use the body.
If you are going to stitch images, you'll want the tripod head to be level as well. To level the head, you can use the tripod legs, or get a leveling plate to go between the tripod and the head. They are especially useful when setting up in a location with uneven terrain.