Borescope Info ?

I borrow a friends of mines Snap On scope just the other day, so you know it wasn't a cheap one. I was trying to tell if a 273 I had was indeed a Commando engine. But the image just wasn't good enough to tell exactly which pistons it had. This was the second attempt. I finally had to tear a head off of it to put my two 65 year head scopes on it. I was not impressed with this Snap On unit.