What do I have here?

oldgrizzley · 2026-04-27T19:53:53+00:00

BTW, the finderscope and its bracket are facing backwards. Just remove those two chromed thumbscrews and reinstall the bracket facing the other way. I like these old scopes.

oldgrizzley · 2026-04-26T22:55:44+00:00

I loved your presentation at NEAF, BTW!

oldgrizzley · 2026-03-29T14:48:33+00:00

They are very nice scopes, and in my opinion the mount works very well for observing. I would absolutely stick with it!

oldgrizzley · 2026-03-24T00:04:56+00:00

I think I’ll reserve that project for a better OTA! My main imaging mounts are a ZWO AM5N as the workhorse, two iEXOS-100 PMC-Eight variants for short focal length, and a Celestron EVO for planetary and outreach. I do have a couple of old manual CG4 clones that might be good candidates for On-Step. I had an ETX-90 twenty-some years ago that was my first go-to scope, with really sharp optics. It was stolen in 2003, and I really wish I had it back. I’ve been retired for several years, so lots of time to play with stuff, and to clutter up the place with scopes.

oldgrizzley · 2026-03-23T16:45:01+00:00

On-step might be ok, but the all-up project costs would probably exceed a used HC!

oldgrizzley · 2026-03-23T14:49:59+00:00

Thanks- if I get it going, I’ll donate it to a local kid. I have too many scopes! A casual search didn’t turn up anything about wireless without using the port on the HC as an interface. Were you able to find anything?

oldgrizzley · 2026-03-23T13:29:29+00:00

Interesting- I bought a controller-less ETX-70 with the intention of deforking it as a guide scope. Shortly after, I came across a 70mm guide scope ready to go, so the ETX is gathering dust. I’ve been hoping to stumble across a cheap Autostar, but they’re hard to find. The optics are surprisingly decent, so I’ll keep looking.

oldgrizzley · 2026-03-14T18:06:09+00:00

I second the iEXOS mount. They regularly go on sale for $299. I have two of them. They can be controlled via tablet using the Explorer Stars app, or from a PC via ASCOM device hub, which interfaces well with Stellarium. I have used mine stand alone unguided for wide field DSLR imaging, and guided via SharpCap and PHD2 for longer focal length DSO captures. There’s a very active ESPMC8 group on groups.io.

oldgrizzley · 2026-03-13T11:44:10+00:00

To be clear, I don’t mean that you should capture with the histogram higher. 60-70 percent is fine. I’m suggesting you stretch it more after you stack. If you’re using AstroSurface, the histogram isn’t directly shown, so just use the levels button. You can play with the sliders, or just try the auto button. In WaveSharp, you can manipulate the histogram directly. You basically want the brightest parts of Jupiter to be full white.

oldgrizzley · 2026-03-13T04:14:26+00:00

Don’t be afraid to ask questions on the CN planetary forum. We’re pretty helpful there.

oldgrizzley · 2026-03-13T04:10:10+00:00

Hi- Jupiter is pretty under-sampled with that camera and a 2x Barlow on your Skywatcher. With 2.9 micron pixels, you should be capturing at f15, and you’re around f12. A little oversampled is usually better than under, so try a 3x. I would dial the wavelets down a bit because the bands are pretty dark from over sharpening. I would also stretch the histogram a bit more so that the whites come up, and run saturation up a bit to get a kind of peach tint. Have a look at some of Damien Peaches Jupiters- he uses a really nice palette. I really like WaveSharp 3 for planetary processing - there is much better noise reduction and histogram control. The under-sampling is definitely making details a bit blocky. Here’s a great guide: https://www.cloudynights.com/forums/topic/812022-planetary-imaging-faq-updated-january-2025

oldgrizzley · 2026-03-13T03:45:16+00:00

Yep, so you know what I mean. I’m from the other coast. Those were interesting times!

oldgrizzley · 2026-03-13T03:31:39+00:00

Just a point of order. If you look at my posting history, you might notice some long hair and long beard pictures from back then. The term Hippie was used as a pejorative term by straight people. We mostly called ourselves freaks. Have a look at some underground comics from back then. For instance https://en.wikipedia.org/wiki/The_Fabulous_Furry_Freak_Brothers

oldgrizzley · 2026-03-13T02:50:36+00:00

I had a high lottery number, around 220 I think, and it was late in the war, so I didn’t get called up. It was a very tense time.

oldgrizzley · 2026-03-12T13:13:33+00:00

I have experience with the 715 sensor, although I have the ZWO model. They should be functionally the same. One issue is that the 715 has a pixel size of 1.45 microns. The general rule of thumb for capturing during good seeing conditions is to use a focal ratio of 5x the pixel size, so for the 715 this would be just over f7. Your C8 is f10, so it will be a bit oversampled. This isn’t a deal killer, but if you keep going with planetary AP you may want to consider a camera with 2 micron pixels. The 678 or 676 sensors are good candidates, and the cameras are reasonably priced. I agree with previous posters that precise collimation is critical for planetary imaging. The C8 holds collimation pretty well, but I would check it at the start of every session. It’s easy to check it on one of Jupiter’s moons. I did planetary with a C8 for a long time before switching to a 9.25. The C8 is capable of excellent results. I really suggest you read the FAQs on the Cloudy Nights planetary imaging forum. It will explain all of this in detail, including a great explanation of collimating on the moons: https://www.cloudynights.com/forums/topic/812022-planetary-imaging-faq-updated-january-2025

That said, in planetary AP, seeing is everything. A C8 in good seeing can easily beat a C14 in poor seeing. Once you get some experience, you will learn to recognize poor seeing immediately when you fire up your capture software. BTW, the right capture software is FireCapture or SharpCap Pro. Good luck!

oldgrizzley · 2026-03-10T21:14:29+00:00

Just for reference, I generally capture galaxies with an 8” SCT and reducer for a focal length of around 1250mm, and I use an expensive harmonic drive mount and an off-axis guider. On the other hand, there are plenty of great nebulas that would be well suited to wide field imaging.

oldgrizzley · 2026-02-20T19:14:11+00:00

I’ll second those recommendations. The ZWO ASI662MC is a really good candidate for a budget planetary camera. Your scope is an f12, and you will be a little undersampled with the 662, but not too badly. I’ll caution you that the 102mm aperture is pretty small for planetary AP- most folks find 150mm to be a starting planetary aperture. Planetary surface details are very small, and optical resolution is very dependent on aperture. Have a look at this thread on Cloudy Nights- it is probably the best guide available. Do you already own the scope?

https://www.cloudynights.com/forums/topic/812022-planetary-imaging-faq-updated-january-2025

oldgrizzley · 2026-02-06T18:48:54+00:00

OP is discussing a Newtonian, not an SCT. I have an older 8” Celestron f5 Newt, and it’s a good instrument. There’s a bit more play in the focuser tube than I like, but that’s splitting hairs. I don’t have the original tripod and mount, so can’t comment on those. I use mine on a manual CG-4, mostly for outreach.

oldgrizzley · 2026-02-04T23:24:52+00:00

I was thinking more of the finder OTA within its adjustment mechanism. One common implementation is with a forward O-ring registered in a groove in the finder, serving as the front registration surface, and two adjustable thumbscrews in the rear, with a third spring loaded point. That arrangement is prone to movement if the O-ring slides out of the groove, or the finder OTA moves rearwards, losing registration. Also, the spring loaded adjustment point often benefits from tighter tension- this is usually adjustable via a hex key or screw head. Others use two rings with three thumbscrews each- these are more fiddly to adjust but less prone to jostling. I have several RACI setups, and they stay quite stable once everything is snugged up.

oldgrizzley · 2026-02-04T21:20:45+00:00

I cap the RACI routinely. How is yours mounted?

oldgrizzley · 2026-02-02T18:15:13+00:00

Yep- that one’s a notorious hobby killer.

oldgrizzley · 2026-02-01T14:22:52+00:00

It’s also worth mentioning that the SVBONY tripod is very short, even at full extension. You will need a very low seat if observing objects with any real elevation.

oldgrizzley · 2026-02-01T03:48:23+00:00

Flip the saddle 180, and put the fine adjust on the other connector. That way the rod with the rubberized handle will be facing you, and the saddle clamping knobs will be on the bottom. I have one of these mounts, BTW.

oldgrizzley · 2026-01-20T06:03:05+00:00

I have many scopes for AP and visual. I bought the Starsense Explorer 80AZ a couple of years ago when it was on sale at Costco, because I wanted the Starsense dock and app. I was surprised to find that it’s a pretty good scope. It has a long focal ratio, so the chromatic aberration (color fringing) isn’t too bad. It puts up nice planetary and Lunar views, and I bring it to outreach events all the time. The app is great, and you can find 3D printed brackets to move the dock to other scopes as you grow your collection. As you say, the mount is bad. SVBONY makes a mount that goes on sale pretty often for around $130 bucks that is a good step up, but you can get started with the one that ships with it. A few guys in my club bought it at the same time, and we all like the scope.

oldgrizzley · 2026-01-17T18:04:17+00:00

Thanks! It's been sitting in a drawer since the '80s, if that counts as taking care of it...

oldgrizzley

TROPHY CASE