|
did you use a slower exposure for the hi mag image? - if so you would have more blur from seeing. But I agree, it does look like an underperforming Barlow.
FWIW, I had 3 GSO Barlows over the years. A 5x was so bad that it had to be replaced and the replacement, although generally OK, still would not focus quite well enough for hi res imaging with my f4 scope. A 2.5 was sharp, but had a tiny bit of wedge somewhere which resulted in detectable colour fringing. My 2x 2" is excellent and only just a slight bit behind my TV big Barlow - I use it all the time for visual. In my experience, GSO Barlows can vary a bit in quality.
If you are using the standard Plossl eyepieces that come with scope packages it is worth getting a good Barlow, since the Barlow can improve the performance of cheapies, presumably by reducing the light cone angle that they have to deal with (quite a large improvement is possible). And a good Barlow is essential for hi res imaging. I found the 3x TV Barlow to be excellent and it would probably be a good match for your scope. You can get out about 5x if you use an extension tube (which you can make by taking the glass out of your existing Barlow if it turns out to be inferior). regards Ray
|