The Astronomy hobby thread

[Eric Hahl]

Nice!

[masraum]

Originally Posted by dad911

I just printed the plastic for a friend for an OpenAstroTracker:https://openastrotech.com/#section-openastrotracker

That's very cool!

[Superman]

I have a probably-laughable Celestron DX-102AZ (102mm refractor). Using the highest-power eyepiece (10mm), Jupiter and Saturn are barely more than dots. I can see that Jupiter has moons and I can see that Saturn has rings, or is oblong. Jupiter is way too small to see any detail suggesting any cloud rings or colorings. Should I be able to see a larger image than this? Am I using it wrong?

[Eric Hahl]

Well, that eyepiece will give you 66x on that scope. Image is gonna be pretty small for sure. Even at 300x the planets are pretty small.

[Superman]

Thanks, Eric. I really enjoy your posts.

There is an accessory kit which can offer a bit more magnification and I'll just get that. It includes other eyepieces and a Barlow lens, allowing the equivalent of a 3mm eyepiece. It also has colored filters to see planetary details but heck, if the planet is just a spec then the filters will not help.

[Eric Hahl]

Yeah, filters won't help at all. They will just block light from a light limited scope. The accessory kit is probably not worth it either. Maybe invest in a higher quality eyepiece.

[masraum]

Originally Posted by Superman

I have a probably-laughable Celestron DX-102AZ (102mm refractor). Using the highest-power eyepiece (10mm), Jupiter and Saturn are barely more than dots. I can see that Jupiter has moons and I can see that Saturn has rings, or is oblong. Jupiter is way too small to see any detail suggesting any cloud rings or colorings. Should I be able to see a larger image than this? Am I using it wrong?

I used to have a very similar scope. They can support more magnification than 66x. A 2x barlow will double your magnification (132x) which will be more interesting for the moon, Jupiter, and Saturn. It will be interesting for other stuff too, clusters, and maybe galaxies and nebula.

[Superman]

Thank you, Steve and Eric.

Eric, please tell me more about this:

Originally Posted by Eric Hahl

Yeah, filters won't help at all. They will just block light from a light limited scope. The accessory kit is probably not worth it either. Maybe invest in a higher quality eyepiece.

Are you suggesting I can get an eyepiece that will make my telescope behave as if it were as big as yours? I'm kidding of course, but just wondering how far a fancy eyepiece can "push" a 102mm scope.

[masraum]

I've heard that the stuff in those kits is generally pretty low quality.

Let me check if I've got anything extra laying around that might help.

[Eric Hahl]

Generally the eyepieces and accessories supplied with introductory scopes are very poor quality. At least in the past they have been. Especially the barlows. You don't have to break the bank to get better quality though. Take a look here....
https://agenaastro.com/eyepieces/1-25-eyepieces.html

[Superman]

Well, I see a 3mm for $269 and a 2.5mm for $58. The 2.5mm eyepiece would magnify better than the 3mm one, right? So why would I pay the higher price? Sure, optics are presumably better but I'm just trying to see something larger than a spec on a black background. School me.

And what I can I expect from this 102mm telescope? Will I ever see the red spot on Jupiter?

[flatbutt]

Originally Posted by Superman

I have a probably-laughable Celestron DX-102AZ (102mm refractor). Using the highest-power eyepiece (10mm), Jupiter and Saturn are barely more than dots. I can see that Jupiter has moons and I can see that Saturn has rings, or is oblong. Jupiter is way too small to see any detail suggesting any cloud rings or colorings. Should I be able to see a larger image than this? Am I using it wrong?

I have the Williams Optics GTF 102 and while the specs of the Celestron are similar in terms of focal length etc. the huge difference is in the quality of the optics. A 102 refract is a good scope for general solar system viewing but the WO is particularly good for imaging. So, it's not the smaller aperture but rather the glass inside.

Further, people are always disappointed in what they see thru the OTA because of published images.

[Pazuzu]

Extreme eyepieces (anything under 10mm, and especially when you get in the 2-5mm range) are very hard to use, the eye stop (size of the actual illuminated circle) becomes very small. It's like looking through a straw. A few very expensive versions (hundreds each) can fix that, but not anything you're looking at.

A good quality barlow lense will double the magnification while keeping the other characteristics of the eyepiece the same (like, a decent 4mm eye stop size).

[Pazuzu]

Oh, filters will help with the planets and that scope, because the color fringing on it is probably terrible. Meaning, the blue, green and red parts of the planet are focusing differently, so you get very strong colored halos/fuzz around bright objects. A filter will at least cut out 2 of those 3 colors, meaning you'll get sharper views.

[flatbutt]

IDK how much filters will help with the inherent chromatic aberration of the DX.

[masraum]

Originally Posted by Superman

Well, I see a 3mm for $269 and a 2.5mm for $58. The 2.5mm eyepiece would magnify better than the 3mm one, right? So why would I pay the higher price? Sure, optics are presumably better but I'm just trying to see something larger than a spec on a black background. School me.

And what I can I expect from this 102mm telescope? Will I ever see the red spot on Jupiter?

THere's so much to EP that it would be easy to get analysis paralysis.

There's a huge difference in the views via different EP. And going to more expensive EP on the whole really does lead to much more pleasing views.

On that scope (and honestly most scopes) most of your viewing will max out at <200x, and for your scope, I'd initially max out at around 150x. Your best views will probably be in the 70-150x range. You may rarely be able to push up to around 200x, but that's rare for most folks due to "seeing" which is disturbance due to atmospheric conditions. (the "bad" seeing is like looking over the top of a hot street in the summer how the air shimmers and dances and distorts things in the background). The same thing happens when you're looking through the atmosphere which has multiple layers of different temperature.

I big part of the difference in price (other than the engineering involved in the lens layout, and the fit and finish of the build) is how wide angle the view is. I've had 2 different EP with my current scope such that they both had the same magnification, but one only showed part of the moon, and the other was able to show the entire full moon.

Then there's other details like is the view sharp only in the middle 50% of the view or almost the entire view.

[masraum]

Originally Posted by Superman

Well, I see a 3mm for $269 and a 2.5mm for $58. The 2.5mm eyepiece would magnify better than the 3mm one, right? So why would I pay the higher price? Sure, optics are presumably better but I'm just trying to see something larger than a spec on a black background. School me.

And what I can I expect from this 102mm telescope? Will I ever see the red spot on Jupiter?

Sent you a PM, sir.

[flatbutt]

I have some high end Tele Vue EPs and they are worth every dollar, if you're really into visual.

These are absolute beauties:
https://www.highpointscientific.com/brands/televue

[masraum]

Originally Posted by flatbutt

I have some high end Tele Vue EPs and they are worth every dollar, if you're really into visual.

These are absolute beauties:
https://www.highpointscientific.com/brands/televue

I got some last year, and I have to agree. I was astounded by the views through them.

[flatbutt]

When I mounted the Delos 10 on my GTF 102 for the first time and centered on the Trapezium I literally gasped. The stars were crystalline orbs and just jumped out of the nebula.