These days I prefer to operate my DSLR in HD video mode with manual exposure and the ISO fixed at 400 I then adjust the exposure during the eclipse to suit. I use a Megrez 72 and x2 Barlow operating at around f/13. I tend to take my filter off around a minute before second contact and adjust the exposure so that I get correct exposure on the inner corona which is visible even before C2. This leaves an overexposed photosphere but generally works well then for the diamond ring and prominences. You can see an example of this at around 0:25 in to this video. For Baily’s beads You would leave the filter on until C2 and use the same exposure that you use for the thin crescent.
During totality an example exposure for prominences, inner corona and chromosphere at f/13 is around 1/1600 at ISO800 which is what I used for the attached image. This is a raw image just scaled to 50%. This would be good for the diamond ring at C2 and C3 without a filter but you would wind up the exposure to get more corona. Depending on your field of view of course since really long exposures are only worth doing if you have a shorter focal length.
A huge advantage of digital over film is that you can see things in real time using live view so you can adjust exposures to suit the conditions. If this is your first eclipse though I would strongly suggest that you don’t spend too much time imaging but use binoculars and the naked eye to enjoy the view.