color correction

When manufactures mention color correction like 8X color corrected on refractor lense what exactly are they comparing the color correction to?

Lets take synta as a comparison for example.

1. Best of the bunch achromat
2. an average achromat ?
3. Below average achromat?

Because of quality control your going to get quite a variety of amount of color in a normal achromat.. what are they comparing to?

And then go a step further... Synta's 100f6 ed says "Zero" color while Burgess 101f5.5 says 8 times color color correction.. Both use fpl53? glass.

Thanks

Mark Visser

Does Synta make an 100mm F6 scope? I was under the impression that the only scope 100mm ED refractor that Synta made was the 100mm F9.

It's a lot easier to make an F9 APO "color free" than an F5.5

8X better, as you say, better than what.

You probably ought to post this somewhere that Roland Christen will likely read it, probably the equipment or refractors forums.

That way you will get a simple staight answer.

jon