This afternoon is overcast in SE Wisconsin, a good day to play with my 4” APO FL = 714mm, 2X and 3X Barlows and eyepieces during daylight hours.
So I compared a (Celestron X-Cel LX 7mm eyepiece & Celestron X-Cel 2X barlow) combination with a (Celestron Ultima 10mm UFF eyepiece & Meade 3X barlow).
Doing the math, the X-Cel combo should yield 204X. The Ultima/Meade combo should yield 214X.
However, after carefully examining the images, it was clear the X-Cel combo is yielding more magnification than the Ultima/Meade combo. I would guess the X-Cel combo is yielding images that are at least 20% larger.
Comparing the Ultima/Meade combo with an ES 52* Series 4.5mm eyepiece, the images of the Ultima/Meade combo were only slightly larger, about 10% larger than the 4.5mm eyepiece. That would make the 10mm Ultima a 4mm eyepiece when used with the Meade 3X barlow.
Based on my observations I did a recalculation and came to the conclusion that the Meade 3X barlow is really a 2.5X barlow. Does anyone have more information on that Meade 3X barlow?
BTW: The images were very good with all combinations.
Edited by JimOfOakCreek, 08 May 2021 - 04:54 PM.