Robert_T
27-12-2005, 09:07 AM
Hi All, Santa's sleigh brought an end to a weeks worth of superb seeing in Brisbane - pleased I got the chance for some quality imaging :) but sad to see mars back to wallowing in the usual soup :sad:
The seeing for these pics was around 4-5/10 compared with 8-9/10 for previous. Still I was surprised at the amount of detail I could still extract given Mar's disc is now down to around 12" or less (from a max ~20" at opposition). I repeated my recent experiment comparing images taken using the 2.5x power mate and a cheap 3x barlow plus ext tube (equating to ~3.5x), and once again found I could get better detail with the high amplification provided by the barlow/ext tube versus the powermate despite the latter's superior optical quality. SO even under mediocre seeing there can be an advantage in pushing up the image amplification at the scope versus doing this via resampling in registax.
Barlow/ext tube image at left and 2.5x powermate image at right.
cheers,
The seeing for these pics was around 4-5/10 compared with 8-9/10 for previous. Still I was surprised at the amount of detail I could still extract given Mar's disc is now down to around 12" or less (from a max ~20" at opposition). I repeated my recent experiment comparing images taken using the 2.5x power mate and a cheap 3x barlow plus ext tube (equating to ~3.5x), and once again found I could get better detail with the high amplification provided by the barlow/ext tube versus the powermate despite the latter's superior optical quality. SO even under mediocre seeing there can be an advantage in pushing up the image amplification at the scope versus doing this via resampling in registax.
Barlow/ext tube image at left and 2.5x powermate image at right.
cheers,