Zeiss D36 double loupe, 2 lenses combined = 10X

Summary 10X21 by Zeiss (10X magnification, 21mm diameter lens) Has two lenses on top of each other, approx. 6X and approx. 4X magnification, can be used individually or combined to give 10X magnification. It is achromatic (distortion-corrected) and aplanatic (colour-corrected) and coated (to prevent reflections.  NOTE Zeiss list this as 22mm diameter. To be precise, the visible lens is 20.5mm diameter, the remainder being hidden underneath the mount.  Also, according to the official Zeiss specification it's 3X + 6 = 9X together, but 36D means '36 dioptre' which is 10X.  This is the genuine Zeiss!  To help you compare the 10X loupes, a summary of this item is shown in blue: SIZE  (magnification X diameter of lens in mm): 10X12 - 10X13 - 10X14 - 10X16 - 10X18 - 10X20 - 10X21 - 10X22 - 10X23  * useable diameter of this lens (allowing for the rim that holds the lens in place) 20.5mm OPTICAL QUALITY: basic - good - very good – EXCEPTIONAL There are also reviews of loupes, click here. Comments As a 10X Zeiss this really is the best quality of all the large loupes. Whenever I get a sample of a new loupe that is meant to be "the best" I compare it with this one, then I sigh and concede that this Zeiss is still the best on the market.  It is Aplanatic-achromatic (distortion-free right the very edge, and colour-corrected).  I use this as a 'test' on our exhibition stand - if a customer insists on having the best but can't see the difference between this and a £4.50 loupe - it's time for them to give up and go to see their optician. A note about the magnification. Zeiss used to quote the magnification as 6.66X with 3.33X = 9.99X combined; then they decided to name it "6.6X with 3.4X" = 10X combined. I think their customers were getting confused with all the numbers, so now they call "3X with 6X = 9X combined. It's all the same loupe! Technical Magnification / total lens size in mm: 10X22 Useable diameter of this lens (allowing for the rim that holds the lens in place) 20.5mm. Lens material: plastic Lens type: Unknown, probably a triplet. Type: jeweller's loupe (small, pocket-size, folds into its plastic casing) Origin / brand: genuine Zeiss by Carl Zeiss Vision Ltd (the old "West German" Zeiss, not to be confused with the lesser quality "East German" brand of Zeiss Jena. Casing: plastic Finish: cream and grey Presentation / extras: cardboard box and polythene bag Further information Everything you need to know about magnifiers and magnification. See information about (and reviews of) loupes (small high-power folding jewellers' magnifiers). See information about (and reviews of) binocular (head-worn) magnifiers- especially the surgeons-type. See a guide to magnifiers for the partially-sighted. See loupes with UV lights. Products: see pocket microscopes and phone microscopes, click here. With most magnifiers* magnification and working distance are related. Download our Excel sheet, enter a magnification to see the resulting working distance, enter a working distance to see the resulting magnification. * excluding surgeons-type, digital & phone magnifiers, and microscopes.