My f/4.9, 1500 mm

Jasii · Jul 16, 2015

That is heavy artillery for me and must say was fun oogling at it

The read too was lovely. Hoping to see more of it in days to come.
Jasii

480sparky · Jul 17, 2015

KmH said:
...........It doesn't zoom, but I can change eyepieces to get different magnification for my eye...............

There are zoom eyepieces available. But one word describes them: Junk.

KmH · Jul 17, 2015

Yep. Kinda like a 10x+ superzoom camera lens.
Convenient, but with a variety of image quality issues.

480sparky · Jul 17, 2015

Well, you can always use it to hold your Norton's Star Atlas open.

KmH · Jul 22, 2015

My observing chair is nearing completion. Needs a bit more work and when done I will prime the wood and paint the whole thing.
The seat height is variable any where I need it to be from the bottom of the front leg to about 37" high.
I angled a 2x4 block between the seat supports so the 4" face is parallel to the face of the front leg.
I got a 4" long piece of 3/4" fuel line, cut the fuel line length wise, then unrolled, and nailed the fuel line to the face of the block.
The rubber provides traction against the front leg so the seat stays in place when sat on.
I put smaller fuel line on the rear bolt to get a little more traction and to cover the bolt threads so they don't chew up the back face of the front leg.

Derrel · Jul 22, 2015

This entire set-up looks mighty sweet, Keith! I hope you enjoy the heck out of it for a long time! I'm marveling at the idea of a 1500mm f/4.9 aperture/focal length pairing....that seems mighty fast to me. I mean f/4.9 and fifteen hundred millimeters of length!

Woodsman · Jul 22, 2015

Just color me green with envy. Seeing those pics just made my day. I always wanted to get into backyard astronomy, it is just so fascinating, and have dabbled at it but just cannot justify the cost of a decent setup. Wonderful to see yours. Thanks for sharing

KmH · Jul 22, 2015

You don't need a 12" to have a decent setup.
8" is a decent size and one mounted like mine (dobson mount) costs less than 1/2 as much.
Being a shorter tube and lighter weight you can go with a solid tube instead of truss rods.

Ihave to cover the truss rod section to maintain contrast, postpone dew forming on the main mirror when that can happen, and to keep dropped eyepieces or flashlights from pranging the main mirror at the bottom of the tube.

DarkShadow · Jul 22, 2015

This is super cool.Good luck and have fun with it.

KmH · Jul 24, 2015

Got my observing chair done.

DarkShadow · Jul 24, 2015

Nice but whats the rope for?

KmH · Jul 24, 2015

While the seat usually stays in place by itself, a bump to the chair can cause the seat to fall.
The 'safety line' prevents that.

The line at the bottom keeps the 2 legs from getting further apart and collapsing the chair.

Designer · Jul 24, 2015

It's an interesting chair design, but I thought the eyepiece was located at around standing height (average).

KmH · Jul 24, 2015

When the telescope is pointed near the zenith (straight up) the eyepiece is at my chin.
From this latitude in Iowa, Polaris, the north star (and the close to Polaris north celestial pole) is only 42° above the horizon, not even 1/2 way to straight up. That's when the observing chair comes in handy.

I plan an observing session to look at as much as I can near the zenith and/or near the meridian (a line from the north celestial pole to the south celestial pole), but more often than not the good stuff isn't that high in the sky.
To see some of the good stuff I would need to go down to southern Texas or into the southern hemisphere.

Just as it gets dark the star Vega (in Lyra) is near the zenith. As are a double cluster near Vega, and bit further away from Vega a planetary nebula known as the Ring Nebula (M57). BTW - Vega was the first star (not counting the sun) to be photographed (daguerreotype) - July 17, 1850 - by William Bond.

Saturn is towards the south but lower than Polaris is to the North, and Saturn won't be getting any higher in the sky this year.

I was at the club's observatory site tonight, but we got clouded out before astronomical twilight (2 hours after sunset this time of year).
The humidity was near 100% and dew was already starting to form. Dew sucks if it forms on your optics.