Hi Dave
Congrats! You are going to have fun!
Binoviewer - not sure. You need to be able to reach focus - some will and some won't, in your GSO focusser, as I understand it. Adding a barlow can allow you to achieve focus but the weight you have to balance goes up considerably. Plus you need to double your eyepieces. Plus you are dividing your light in half and sending a half to each eye. My experience of a binoviewer on my previous 8" reflector was a preference to shove all the light into one eye through a single eyepiece. I don't plan on buying a binoviewer. I suggest you wait until you can borrow a binoviewer at an astro night and see for yourself. Perhaps on the Moon and quite bright objects (Jupiter? and globulars Omega Centauri and 47 Tuc?), a binoviewer performs the best.
For every finderscope, some form of illumination is useful in very dark skies when chasing targets through faint starfields. Your crosshairs just disappear in the dark. Best option - buy a finderscope with illumination. Second option - drill hole and fit a red led just in front (eye side) of the crosshairs - make the crosshairs "light up". Can be done - easy to stuff up as well. Third option - fit some red leds inside a dew shield at the field lens end. They make the sky a little brighter so the crosshairs stand out. Downside is that it's a bit harder to see faint stuff in the sky. This approach doesn't stuff the finder. I found a ciggie ash cup in the Reject Shop that was just the right size for a dewshield when I cut the base off and fitted four red leds with adjustable brightness control. If you stuff up - finder is untouched. Fourth option - search for those glow bracelets in novelty shops. Buy some red ones - 50c or $1? Hopefully when you activate one and wind it into a circle, it can fit inside the dewshield and provide the illumination you need for a few hours.
Straight through versus right angle finderscope: Right angle easier on back and neck, but you have to be pointing at the right bit of sky to be effective - so suggest you need a red dot finder or a laser pointer to get there first. Straight through can be used alone because the technique is to keep both eyes open and superimpose the image seen by the eye looking at the sky on the image seen by the other eye through the finderscope, then move the scope until the location of interest is in the finderscope FOV. Works well (neck and back hurts - but we all suffer for our hobby!)
There are erect image versions of both finderscopes (different makes - I bought this one - illuminated, straight through, erect image - it's great
http://www.iceinspace.com.au/forum/s...ad.php?t=29890 Yen/AUD exchange rate is probably less favourable now.)
Filters - which ones do you plan on getting?
Eric
