Hi Les,
I thought I would follow up with the following observations.
I have the following in my collection:
- Tak x1.6 Extender (2 inch)
- Televue x2.5 Powermate (1 ¼ inch)
- Televue x4 Powermate (2 inch)
- Televue x5 Powermate (1 ¼ inch).
I think that I have only used the TV x4 and x5 (on my C92.5) less than 5 times in the 5 years I have had them. The seeing conditions just do not support the use of these on my Mewlon 180 and C9.25 ‘scopes although they have been useful for splitting double stars.
So, at my native focal lengths of 2160mm and 2350mm it comes down to the Tak x1.6 and TV x2.5 If the best accessory is the one that you use the most, then my Tak x1.6 Extender gets far more usage than my Televue x2.5.
If you want to explore high resolution lunar and planetary photography such as is being posted by the top practitioners on IIS, then you may need the TV x4 or x5, ideally a 10”-16” aperture instrument and the dedication to chase down those moments of exquisite seeing. I think these hi res wizards often operate at effective focal lengths of 10,000mm to 16,000mm and use good (expensive) cameras.
Of late I have found that the conditions have seen me shooting at the native focal length of my ‘scopes and only occasionally have I been able to use the Tak x1.6 with the TV x2.5 remaining in its box as I haven’t really synchronised my imaging sessions with the good seeing that supports its use.
As mentioned previously, on the planets and the moon I haven’t seen any noticeable difference between the Tak and TV units that can be differentiated above the image quality limitations placed on me by the local seeing conditions.
Cheers
Dennis