Hi , Nick from Melbourne Australia , I have one of your older Bt 100-45"s , with the big fork mount, still works perfectly. Just wondering how the new ones are with higher magnification on the planets in terms of chromatic aberration.
Hi Nick- sorry for the late reply! The older BT-100-45 is an achromat, so the higher you go in magnification, the worse the CA (chromatic aberration) will be. We recommend limiting it to 8mm (75x) for that model. The new XL's use special glass, so CA is greatly-minimized (ED glass), or eliminated (SD glass), and therefore can go higher in magnification without CA becoming a problem.
Hi , Nick from Melbourne Australia , I have one of your older Bt 100-45"s , with the big fork mount, still works perfectly. Just wondering how the new ones are with higher magnification on the planets in terms of chromatic aberration.
Hi Nick- sorry for the late reply! The older BT-100-45 is an achromat, so the higher you go in magnification, the worse the CA (chromatic aberration) will be. We recommend limiting it to 8mm (75x) for that model. The new XL's use special glass, so CA is greatly-minimized (ED glass), or eliminated (SD glass), and therefore can go higher in magnification without CA becoming a problem.
I can tell you that the BT-100XL-SD for viewing planets and the moon at 80x with the XL7mm ep’s shows no discernible CA what so ever.
@AAE-cg1il yep, looks like a beauty . Just not sure about shipping it all the way here .
I’m so pumped about your products, especially your ED binos. 👍👍🔭