SW 120x600mm Refractor "first" light

[pgc hunter]

Looking outside the window last night, I saw something which doesn't happen here in New Antarctica .... Stars!! Although it was partly cloudy, I decided to try out my recently aquired 120x600mm richfield refractor. Fully assembled on the Stellarvue M1 mount it is actually quite heavy and a fairly large setup, but still grab n go, as I was out at the eyepiece within 5 minutes.

Pointed the scope at M42, with the 22mm LVW in place giving 27x and 2.4ºTFOV. Stars were nice pinpoints of light, no obvious abberations (except for slight astigmatism - in my eye :( ) and all 4 trapezium stars were easily reesolved.

Next I checked out the Eta Carina region. Chromatic abberation was very minimal, stars appeared their natural colours. Using the 13mm LVW for 46x, the nebula showed up well, with some texture and the keyhole visible. The homunculus could be seen as a tiny fuzzy elongated smudge with Eta blazing in its centre. Again, stars were nice pinpoints with nearly no CA visible. I scanned over the many clusters in the area, all appeared nice and crisp.

I also tried the 5mm LVW for 120x, however at this mag things start to go pear shaped, with serious CA and violet halos engulfing bright stars. However I didn't get to test higher mag views out thoroughly as clouds moved in.

I can see this being a fantastic scope for low power DSO viewing-- that's what it is intended for, not high power, and the entire package (scope and mount) cost me just $350 second hand (plus an additional $60 for a diagnal). Performance is very good at up to 50x so far, I have yet to test the 50-100x envelope.

[Lismore Bloke]

Hey SAB, That scope sounds like a real bargain. Just the thing to chuck on the car seat for a trip to dark skies, or a camping weekend. Not surprised it won't stand much magnification though. How's progress on the SDM modification?

[pgc hunter]

Second hand shopping rules, ALL my astro gear (except my filters and barlows) are second hand and as such I've saved several hundreds of $$$, perhaps even a grand or two. All the money saved by buying second hand would've probably payed for the SDM!

It will make a great grab n go, definately not a magnification machine (the SDM will fill that role LoL), but it certainly fulfills its intended purpose. THe Trapezium appeared well resolved at 120x, but didn't get to make a proper evaluation. I reckon it will handle powers up to 100x fine, but I have yet to test this, so until then....

Not sure, might give Peter a buzz and find out :) He did however say that the mirror is of exceptional quality, and that it's "as good as the best" :D He also measured the focal length, it turns out the F/L is actually 1333mm (52.5"), or F/4.4, rather than the 1415mm I was told by the previous owner.

[Lismore Bloke]

It's not unusual that mirrors aren't the same focal length as advertised. My old 10" was sold to me back in the 80's from Astro Optical Supplies as a f6, but it has f5.7 written on the back. The mirror is excellent. One day I will rebuild that metal monster into something more useful. Some pics attached, for your amusement. Most of the gear is home made or modified.

[pgc hunter]

Interestingly mine has "F/5" written on the back. Maybe it was a botched F/5 job that was re-figured later on or something.... or it was an F/5 originally, but then perhaps got sold to someone who wanted a shorter F/L for whatever reason....

btw, that's a nice rig you've got there, I would love to have one of those old school newts with the several finders on it to make it look all high tech and awesome :D In an observatory ofcourse ;)

[Dave47tuc]

I had a similar SW refractor. As you said good low power scope nice in a dark site ( so you will be coming to Snake Valley Sab wont You???)

It serves its purpose.

Nice shots of the old scope Paul??

[Lismore Bloke]

I don't use the old 10" much at all these days. The contortions to reach the eyepiece are a literal pain in the neck. The 12" dob is a lot easier to use. The 10's base is heavy steel and the optics are fine. Everything in between really needs replacing, but I can't decide on what to do with it. The mirror deserves a better fate than just sitting there.

[pgc hunter]

turn it into a super planetary newt, refurbish the GEM, build an observatory around it and most importantly, add more finders.

[Lismore Bloke]

The old scope's "finder" is a very nice Unitron 114 refractor, my first decent scope. It also needs a scrub up. I could mount the Meade 4.5" onto it, it's just sitting here. The mount is another thing, I'm not rich and not an engineer.

[pgc hunter]

I wanted to take the scope to Renmark but l was minus a diagonal so I couldn't :(

Not sure about Snake Valley.

[Rob_K]

Good stuff pgc, sounds like a winner for the purposes you want! :thumbsup:

And go to Snake Valley, ya wouldn't regret it! ;) :lol:

Cheers -