Focal Lens Orientation - What are Shenhui users doing?

[Nick Foley]

While the manual says to orient the focus lens convex-down (edit - whoops, no, it doesn't - the lens just came installed this way...), the internet, institutions, and other manufacturers, say convex-up. (This post has a lot of good reasons to use convex-up: http://oplaser.co.uk/opsupport/viewtopic.php?f=22&t=212 )


My question:
Theory and other manufacturers aside, what orientation are Shenui users going with? Is there a noticeable difference?

[Rich Harman]

There is nothing different about the Shenhui lenses that would warrant installing them upside down. I install them the correct way.

However, the difference it makes may not be measurable for the typical work that these machines are used for. Correct focus and alignment are far more important.

[Nick Foley]

Thanks! I see now that the manual does say to set the lens concave-down... it had just arrived installed the wrong way. Most of the diagrams in the manual draw an exaggerated version of the lens, showing a convex-down orientation... I was definitely confused by that, and I suspect whoever was assembling my laser was as well.

[Rich Harman]

All my lenses are plano-convex - flat on one side, convex on the other. The convex side faces upwards.

[George M. Perzel]

Ditto on what Rich said
Best Regards,
George
Laserarts

[john banks]

Ditto, and it may change the focal length by flipping it (mine did, sounds odd but if you look at diagrams of scatter from a plano-convex the wrong way round there is a change in position and depth of field) which may not match the supplied focus stick (mine didn't) - establish it by testing.

[walter hofmann]

thats correct I can see difference in depth detail if I flip the lens to convex side down
greeting
walt