Barlow Question

Another one for the optics experts. When using a barlow with a refractor (either in front of or behind the diagonal) is the color correction improved along with the increase in effective focal length? Thanks

Bill

No, that would be too easy - Barlow magnifies the whole thing: diffraction disc and chromatic blurring around it to the same degree. It may add some chromatism of its own, but it is normally (with good Barlows) negligible.