Barlows and Powermates

[Spectre486]

Other than the magnification differences on the powermates - what is the difference between a Barlow and a Powermate?

Is it just Televue's snazzy marketing?

[Cornelius Varley]

Read this thread http://stargazerslounge.com/equipment-discussion/139699-powermate-design.html Powermates and barlows work in different ways. A barlow increases the focal length of the telescope, a Powermate magnifies the image.

Peter

[Merlin66]

One main difference is that the Powermate ( and similar extenders) are telecentric - this basically means the enlargement factor doesn't change with backfocus - so a x2 powermate with a camera 20mm behind the lens will still be x2 when the camera is 100mm behind the lens - this is NOT possible with conventional barlow lenses.

[Spectre486]

Ah I see - thx for the info!