Celestron Ultima Barlow Vs Meade Series 5000 TeleXtenders

[bus_ter]

I'm looking at higher end Barlows and FLO sell both of these for about the same price. I know the Celestron Ultima Barlows are very popular and that would be my first choice, however the description for the Meade barlow got my interest..

"Their advanced 4 element design delivers a flatter field-of-view with sharper edges than even the best 3 element apochromatic Barlows."

The Ultima's are are of course a 3 element design, so reading between the lines Meade are saying their Barlows are better than the Celestrons..

Is that a fair assumption? Can anyone confirm the 4 element Meade barlows produces better images than the Celestron Ultima?

[brianb]

There is a difference - the TeleXtenders maintain there magnification (more or less) with varying extension, the Ultima is an ordinary barlow, though with an apochromatic lens.

Visually, I'd prefer the Ultima. For imaging, the TeleXtender (or the Televue Powermates which have a similar optical design) will probably work better ... actually the Ultima works pretty well for imaging, though, I used to use one but upgraded to a 2.5x Powermate which I find gives almost exactly the same scale, with my Imaging Source cameras. The Powermate magnification is correct by actual measurement.

[John]

I had the 2" 2x Meade TeleXtender for a while and optically it was rather good for visual use although a very bulky / heavy piece of equipment. The Ultima is a fine optic as well though.

I've also owned a Powermate 2.5x and agree with Brian's assessment - a superb piece of kit.

I felt the main benefits of the TeleXtender, as with the Powermate, were that the focal position did not change and the eye relief of the eyepiece remains the same as the eyepiece alone, which can be an advantage with some eyepieces.

Visually I found the Ultima will cause some vignetting when used with eyepieces with wide field stops, eg: 32mm plossl, 24mm Panoptic.

[michael.h.f.wilkinson]

I have both the 2x and 3x Meade Series 5000 TeleXtenders (both 1.25") and am very pleased with them. I use them mainly for imaging, but have occasionally used them visually as well. I found the 2x combined with a Meade UWA 14mm gave the same optical performance or better than a Vixen LV 7mm, but with a much wider FOV (82 deg vs 45 deg). No vignetting was visible. I did this on a night of exceptional seeing (pushing the scope to 288x) and got very crisp images of Mars indeed. They are very well-made pieces of kit, with excellent optical performance. I do not know the Ultima Barlows, so cannot directly compare them.