Hallo EGA – seems to have been lots of other posts about this…
Well I was a bit confused about which one to choose too – but I sat down at my workbench and tried to find a distance that was comfortable/about right when I was holding something to examine. It turned out that this was about 8" – so that settled the choice of lens for me – a DA5 with x 2.5 magnification. This seems to work well and be a useful magnification for most of the work I do.
I also purchased an Opti-Loupe which screws on (in my case) over my 'better' eye and provides a further x 2.5 magnification. It can also be swung in and out, the focal distance (with loupe down) is about an inch or two.
I tend to put the visor on when I go into the workshop but with it swung up out the way most of the time. It gets flipped down when reading Mics or Vernier scales, or when needing to check anything close up. I use the 'loupe' mainly to check cutting tool edges, examine/compare very small parts and (I'm afraid) to get the odd splinter out.
I did initially find that I had to take them off after while but really don't notice them being there so much now. In fact my wife has had to remind me to remove them before having lunch. I still occasionally forget to put them on and then find myself trying to flip a non-existent visor down – which is a somewhat confusing sensation.
I know you can get cheaper options and I'm sure most of them would be OK too. But I decided that my eyesight needed all the help it can get and frankly the extra cost (at least in this case) wasn't my prime concern, so I purchased what I considered to be the best product. Donegan (a US company) has been around a long time, the lens are optical/prismatic glass and I know I can get spare or alternative lenses if required.
As I said, they are something I should have purchased a long time ago….
Regards,
IanT