Barlow lens

[Bokkers]

Hi all, If you get a 2 or 3 x Barlow lens is this quite a good magnificational difference or just a slight difference on viewing?

[AlexB67]

A 2x will double the magnification, or approximately half the FOV or half the diameter  of the amount of sky you will see, a 3x times barlow will magnify 3x times as much etc. so yes, it is an appreciable difference. Another way of looking at it is that it turns a 10mm eyepiece into effectively a 5mm eyepiece. Technically it does not work like that, it neither doubles the focal length of the scope nor halves the focal length of the eyepiece, but in calculation terms that is a useful to look at I,  just to cover the more purist viewers and a very common explanation of a barlow, though it is bit misleading.   It will also affect perceived image brightness of course and various other things, suffice it to say, things will look noticeably different with a 2x barlow, just as a 5mm or 10mm eyepiece would I should add, but depending on the quality of the barlow you may pay more of a penalty in quality reduction compared to a single eyepiece.

[Bokkers]

A 2x will double the magnification, or approximately half the FOV or half the diameter  of the amount of sky you will see, a 3x times barlow will magnify 3x times as much etc. so yes, it is an appreciable difference. Another way of looking at it is that it turns a 10mm eyepiece into effectively a 5mm eyepiece. Technically it does not work like that, it neither doubles the focal length of the scope nor halves the focal length of the eyepiece, but in calculation terms that is a useful to look at I,  just to cover the more purist viewers and a very common explanation of a barlow, though it is bit misleading.   It will also affect perceived image brightness of course and various other things, suffice it to say, things will look noticeably different with a 2x barlow, just as a 5mm or 10mm eyepiece would I should add, but depending on the quality of the barlow you may pay more of a penalty in quality reduction compared to a single eyepiece.

Thanks for that explanation AlexB57  very helpful