@TanMan what do you use and why?
I have a 3.5 and a backup 4.5x loupe from orascoptic. I primarily use the orascoptic 3.5x with their endeavour XL light. The benefit of higher magnification is overrated... often countered by proponents of higher mag that you can't refine what you can't see. I know that 3.5 is sufficient because I can see my own preps with the omnicams. This is not to say all my preps are perfect, but they are pretty good after evaluating them on the CEREC. I believe that 3.5x is sufficient for most, if not all of the dental procedures that I perform. At 2.5x, you might as well not wear loupes. Also, the weight of the 4x+ is more front heavy, which tends to drag your loupes down
If you're working on a quadrant of restorations or back to back MOD/MO/DO's, I need to have that expanded field of vision. If I'm working on a bridge, I want to be able to see the draw of my preps in one swipe. If I'm working on single/multiple implant placement, I need to make sure that my osteotomies are parallel or at the center of the proposed occlusal surface of my implant restorations. The higher the magnification, the lower the light visibility. I tried the XV1 at ~4x and subsequently returned it... the light was too weak for conservative endo access. If you really need to see and you want the utmost magnification, get a microscope. Even for endos, I don't think I need the higher magnification since I perform the access and locate the canal orifices via tactile sensation of my 557/finishing endo-z bur. When I'm in there, I don't see where my bur is drilling, but I know where the orifices are based on the feel of root dentin (furcal dentin feels different from root dentin and enamel).
In dentistry, your vision comes secondary to tactile sensation in restorative and endodontics. You use your vision to see where your bur needs to start. Your brain should already know what you need to remove based on radiographs, clinical appearance, and most importantly, clinical feel of a handpiece bur/endodontic file. If I cut a class II, I need to see where my bur enters, cut until I feel no decay left, verify visually/tactile, refine as needed, and restore. If you're doing a root canal, you should be able to feel via tactile sensation when you enter a chamber, whether you're cutting into enamel, dentin, root dentin, or furcal dentin. They all cut differently. For access, you just need to make sure you stay within the long axis of the tooth. If your magnification is too high, you might lose your orientation. Once you get your access and located the orifices (and ensure no perforation/fracture), in most instances, you don't need direct visual confirmation of where your endodontic file is going. You should already know in your mind where the orifices is located so you can pre-bend your hand file/rotary file to slip into that orifice. That part does not require extremely high magnification. Even if you have an MB2 that you couldn't detect with your bur initially, you have the endo explorer to feel for it, if there's a roof over the orifice, severely calcified, etc... Although I use a laser or ultrasonics to find orifices that I suspect are there, they have their own feel based on what you're removing. Er:Yag laser/Nd:Yag lasers react differently and that's based more on seeing the hard tissue interaction v. ultrasonics have a lot less tactile sensation and require more directional control.
I'm not saying you can do procedures blindly, because you always have to verify by looking. However, I don't think you need the highest magnification either.
Anyway, going on a tangent, you need to look at not just the brightness of the light, but the color of the light. In my office, I have yellow/warm recessed lighting but my lights are white. There's a reason for that...When I'm removing caries/diagnosing, I find that white light allows me to see caries better during ops procedures during the visual confirmation stage. However, when I do restorations, I like to look at them under two light settings... under the brightness of my white light and under the more naturally yellow sunlight. I want to make sure my hue/value/chroma are correct. Combined with my Vita easyshade and 3shape scanner/shade taker, I get most of the colors correct (although translucency is still difficult to communicate to the laboratory)
