80mm Refractor (400mm focal length) on a EQ 1 Mount?

[spacegalaxy]

Just as the title, I want to ask just how stable is 80mm refractor with 400mm diameter on a EQ 1 mount and is it good (The mount) for visual observation? Any help is appreciated!

(P.S I am looking for a good grab n' go scope, so please no comments like 'The telescope is useless!!')

Starry nights

 

Edited August 14, 2022 by spacegalaxy
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[Zeta Reticulan]

Does the scope look like this?

[spacegalaxy]

1 hour ago, Zeta Reticulan said:

Does the scope look like this?

Yep, it looks like that, but the finderscope is a bit smaller (or maybe just a trick of light)

[NGC 1502]

Sounds like your scope is like the Shortube 80, an 80mm objective with 400mm focal length.  It’s far from useless, I once had a very similar scope and can confirm it’s great👍

A short focal length achromat does have false colour (chromatic aberration) but don’t let that discourage you.  For deep sky observing that’s often not a problem.  You can enjoy great low to medium power views.

On brighter objects like moon and planets the false colour is seen, but again you can get great views if you don’t use too high powers, perhaps up to 100x or possibly a bit more.

So, to get back to your original question, how stable is that mount, at low to medium powers it will be fine.  If you don’t fully extend the tripod legs that helps, a lower mount is more stable. If the eyepiece is low then use a chair for seated observing.

If you can get away from a brightly lit town that helps greatly especially for deep sky observing.

Enjoy your astronomy. Best wishes from Ed in the UK👍

[happy-kat]

I think it's possible to use an eq1 like an altaz with left right up down movements which you might like for observing, there's probably a YT on how to do it. If you already have a photo tripod and suitable camera ball head you can also fashion that as an altaz pushto mount.

[spacegalaxy]

6 hours ago, NGC 1502 said:

Sounds like your scope is like the Shortube 80, an 80mm objective with 400mm focal length.  It’s far from useless, I once had a very similar scope and can confirm it’s great👍

A short focal length achromat does have false colour (chromatic aberration) but don’t let that discourage you.  For deep sky observing that’s often not a problem.  You can enjoy great low to medium power views.

On brighter objects like moon and planets the false colour is seen, but again you can get great views if you don’t use too high powers, perhaps up to 100x or possibly a bit more.

So, to get back to your original question, how stable is that mount, at low to medium powers it will be fine.  If you don’t fully extend the tripod legs that helps, a lower mount is more stable. If the eyepiece is low then use a chair for seated observing.

If you can get away from a brightly lit town that helps greatly especially for deep sky observing.

Enjoy your astronomy. Best wishes from Ed in the UK👍

Thanks for the answer, but I was looking at 120x magnification for Juipter and Saturn, so is it okay for that?

[Zeta Reticulan]

8 hours ago, spacegalaxy said:

Yep, it looks like that, but the finderscope is a bit smaller (or maybe just a trick of light)

Could be an Orion RACI. It's been a few years. 

Might be an EQ2. The ST80 is basically a widefield achromat.

I think an alt-az mount is more intuitive to use.

[Pixies]

30 minutes ago, spacegalaxy said:

Thanks for the answer, but I was looking at 120x magnification for Juipter and Saturn, so is it okay for that?

It's not the best scope for planetary viewing, but it's more than capable of showing Saturn's rings, plus Jupiter with cloud belts and moons. 120x is a bit high for that scope, in my opinion. You will get chromatic aberration and a lot of vibration. I usually stick to 80x max (100x at a push). Others may disagree.

[Zeta Reticulan]

41 minutes ago, spacegalaxy said:

Thanks for the answer, but I was looking at 120x magnification for Juipter and Saturn, so is it okay for that?

Technically it should achieve 160x as a theoretical maximum. A fast achromat will suffer from chromatic aberration, particularly noticeable at higher magnifications. TBH the ST80 is fairly well colour corrected. If the CA bothers you a yellow filter is an inexpensive way to ameliorate the cyan fringing.  An old trick is stacking it with an LP filter that naturalises the colour slightly (the LP takes out some Sodium lines).

A yellow filter absorbs all coloured light except yellow. Yellow is the colour wavelength between 575-585 nm. Green is the colour between cyan and yellow in the spectrum. It has a dominant wavelength of roughly between 495–570 nm.

A Wratten #8 or fringe killer/ minus-cyan filter is a longpass filter blocking visible wavelengths below 465 nm. Blue light is between 450-495 nm and cyan light is between 490-520 nm. Yellow light is between 570-590 nm and light produced from low pressure sodium lamps is around 589 nm  (589.0 ~ 589.3 nm) on average. Light pollution, Moon & Skyglow and basic contrast filters are designed to attenuate sodium light skyglow. A Wratten #8 will attenuate or block blue/cyan light below 465 nm and a contrast filter stacked behind it will further attenuate the 589 nm length of sodium light.The effect the stacked contrast filter has is to reintroduce a very slight blue tint to the image effectively slightly naturalising it. 

If you want to splash some cash you can stack a Baader Fringe Killer with a Baader Neodymium.

TBH, the cheaper stack is almost as good.

Edited August 14, 2022 by Zeta Reticulan

[NGC 1502]

53 minutes ago, spacegalaxy said:

Thanks for the answer, but I was looking at 120x magnification for Juipter and Saturn, so is it okay for that?

I think it depends on what you mean by “ok”.  At 120x the view is likely to be pleasing but not pin sharp.  For me I’d sooner have a smaller but sharper view.

If you wait until the planets are at their highest above the horizon that will help. No need for a dark site and if the moon is up it won’t spoil the view of bright objects.  Others have suggested using filters to improve the view so that’s worth exploring.

Considering the price the 80/400 refractors are a great buy.

[Zeta Reticulan]

Magnification with any scope will depend on conditions. I've had sharp views of the planets with an ST80 at 120x plus. Often higher. I wouldn't say it was the norm though. Refractors will always have better acuity/contrast as, unlike reflecting scopes, they have no central obstruction. 

I find I can quite regularly reach 125x with my ST102, especially lunar observing. I do use yellow filters however.

[happy-kat]

As Jupiter is so bright you could stop the lens down with a home made aperture mask out of cardboard to say 60mm, or if it has a lens cap with the middle bit that can be removed try that. You might find you get a smaller but clearer image with little CA. The quality of the night's observing also effects how clear the image you see is.

[Zeta Reticulan]

I've recently had a few early morning sessions with Jupiter and Mars using my 127mm Maksutov. A couple of them have been outstandingly good with magnifications ranging between 170x and 257x. The rest I've struggled to get 123x. It's more about the conditions than the scope.