An adapter for 2 inch barrel to 1.25 inch may give problems with getting to focus.
Also a 3x Barlow has to be good quality to work well.
Televue make good Barlows and similar up to 5x. (Powermates?).
However, one can alter the power depending on the position in the light train, but this may need removing bits of tube.
With a spotting scope this is probably more difficult than with an astro scope.
If the longer focal length eyepieces are particularly high quality a Barlow, say 2x might work. There are ones with short tubes, but I think they have to be high quality.
Russian Barlows are often good but may be uncoated.
Also Russian 1.25 inch fitting may not be quite the same as other 1.25 inch.
Remarkably, there is no Standard worldwide for 1.25 inch fitting.
I discussed this with Al Nagler, who said he tried to get standards, but this did not come into being.
Re. sizes, ovality, tapering , tolerances etc. Also chromium plating can alter the size.
I measured numerous eyepieces and was surprised how many different sizes there actually are.
Also a 3x Barlow has to be good quality to work well.
Televue make good Barlows and similar up to 5x. (Powermates?).
However, one can alter the power depending on the position in the light train, but this may need removing bits of tube.
With a spotting scope this is probably more difficult than with an astro scope.
If the longer focal length eyepieces are particularly high quality a Barlow, say 2x might work. There are ones with short tubes, but I think they have to be high quality.
Russian Barlows are often good but may be uncoated.
Also Russian 1.25 inch fitting may not be quite the same as other 1.25 inch.
Remarkably, there is no Standard worldwide for 1.25 inch fitting.
I discussed this with Al Nagler, who said he tried to get standards, but this did not come into being.
Re. sizes, ovality, tapering , tolerances etc. Also chromium plating can alter the size.
I measured numerous eyepieces and was surprised how many different sizes there actually are.
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