I have two Baader Hyperion eyepieces, the 21 mm and the 13 mm. By removing the front group of lenses that reduces to 1.25", the 21 mm becomes a (roughly) 32 mm that fits into my 2" diagonal. The 13 mm comes a (roughly) 23 mm with the front group removed. My question is this, are the two front groups optically identical? I strongly suspect that they are, but I lack the bench setup to test them, and I have not found the answer on the interwebs. I find that I most commonly want to use both a 30ish mm EP and a 20ish mm EP. I usually pull both front sets off, so I don't have to drop a reducer into my diagonal when I change, but I'm paranoid about mixing up the parts.