Barlow Question

Trying to decide between two Tele Vue Barlow's - the standard 1.25" inch 2x barlow and the 1.25" 2.5x Powermate barlow.

Besides the obvious magnification difference and the price difference would there be a visual quality difference when used with a 10" f/4.5 scope and the following EPs:

24mm Panoptic
13mm Nagler T6
9mm Nagler T6
6mm Radian

Thanks,

Mark

Mark,

My experience has led me to believe this:

1. The Powermate gives better edge performance, especially when used with longer focal length eps on short focal ratio scopes.
2. The Powermate generally yields better contrast, especially when used with shorter focal length eps and most noticeable on the planets.
3. The Powermate adds no lateral color. If you see lateral color when using a PM, look to the eyepiece. If you don't see lateral color with an eyepiece, but you do when you use it with a Powermate--still look at the eyepiece.

The TV barlows are very nice and if I were using them only at F8 or above, I would save the bucks and get the barlow. For shorter F ratios, the Powermate is demonstrably better.

That is my experience. Others may vary.

Randy

IMHO, neither.
Because of your ep spread, either one duplicates(or near) something you already have.