Brent, I've always liked doublet refractors, and, like you, learned to "look past" the purple haze. One only has to examine the essentially perfect diffraction rings of even a mass-produced doublet to appreciate the resolving potential of the objective. But I think the apo advantage is an aesthetic thing and hard to pin down exactly, for me anyway. I haven't had enough experience with my own apo yet to really say with certainty that either it or the classical doublets have the "detail" advantage. The appeal is more like analog recorded music. It just sounds "alive" and "breathing" to me, whereas digital, though technically excellent, lacks that spirit, that spark, "life". At this point, it's still just a joy to use a refractor with no color to speak of. But now that you mention it, I'll be sure to see if I find myself leaning one way or the other as time passes. Without the unfocused color, the impression is certainly one of a sharper, more detailed image. Perhaps color, or spectrum, of the target has an effect on resolution in a classical doublet, eh? I would also ask if you've looked through as many apo's as doublets? Could the sample size be skewing the results? Interesting post. C. --- Brent Watson <brentjwatson@yahoo.com> wrote:
In my experience looking through refractors, I have been struck by the fact that the apos are not as sharp as the achromats. Now, I have seen some absolutely STUNNING images throuh an apo, but I think those of an achromat are superior. What has been the experience of this group?
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