There are lots of good loupes to choose from. It just depends on how much you want to spend. I use a 6X Nikon loupe on my 4x5 I bought used, and it's great. I have never seen one of these before, and I have no idea if they still make them. Otherwise, any of the German optics are usually wonderful, if a little pricy, also Peak makes nice loupes. I have two other loupes made in Russia by Horizon, a 4X for 120 viewing, and an 8X for 35mm. These are great loupes, very sharp, nice coatings, and very reasonably priced. I don't think these are available any more, but probably can be found used. Confused now? Hope it helps a little.