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Beginners telescope

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Mikea

Mikea

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Hold a pea at arms length and thats about the size Jupiter will be at 240x (5mm EP). Saturn is a bit smaller and Mars is a lot smaller.

QUOTE]

Mavis come and look at the neighbour again...he is doing wierd things with vegetables now...

I was going to ask if you meant frozen or tinned pea ;), but then I decided that was so very childish that I wouldn't.

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pvaz

pvaz

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Ok, maybe I should rephrase my query.

The definition I've seen (bands, rings etc) would not be visible on something the size of a pea at arms length so I guess there must be some other equipment involved.

Infact, visiting the site again, the images I've seen are more accurate when 2x barlow is selected.

So maybe I've answered my own question there.

You would need a 2x barlow lens.

Does that figure?

Actually you can if you look long enough. The eye adapts well to the conditions and you start picking details. Adding a barlow adds more glass in the way. Depending on the quality it can make the image look less sharp making details harder to pick. Training your eye to see is a part of the hobby, as bad as that may sound ;).

A 2x barlow doubles the mag of any given EP, so if you use a 10mm ep + barlow or an individual 5mm EP you get the same results. If you increase the mag too high then the image looses quality and you notice less details.

Regular planet observation is something like:

1) you collimate the scope the best you can

2) you let it outside to cool to minimize air currents

3) you start with lower mag (around 100x) and increase till you find a mag where the planet doesn't look like it's on boiling water (this happens at high mags due to atmospheric problems, thus they launch scopes in space to avoid it)

4) You observe for long periods and, at spaces, you get what is known as "pockets of seeing" where the planet gets sharp for a few seconds and you get to see some details

It's pretty much a patience game. I often take tea or coffee and just let time slip by when observing.

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Daz Type-R

Daz Type-R

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i'm a fellow newbie too, and i have one piece of advice.

Take your time!

too much info in one go doesn't sink in and only confuses you more (well it did with me)

i've taken my foot of the gas so to speak and i'm starting to understand what scope would be most suited to myself, admittadly i still have a ton of questions that need answering but i'm gonna wait till i've got my head round the ones i've already asked before i a decent scope.

Mark

P.S. i've had a lot of sound advice so far from everyone on here, even if most of it did confuse me at the time but its all slotting into place nicely now.

Same here, I was completly confused by all the advice I received on here but now (like you) I have taken a step back, looked at what was said, done more research and it is now starting to fall into place. Still not bought a scope, but off to my local meeting on Thursday for the first time, so hopefully get to have a look at some scopes there. I have just been using Stellarium (sp?), using my eyes, learning where the stars are etc, ready for when I buy a scope. FYI, looking to get the Skywatcher 200p dob, from what I hear, for a newbie, you cant go wrong!!!

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Ags

Ags

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I think its best to forget about peas! When you are looking at a planet with great concentration, it starts to look pretty big in your mind. And yes, you can see lots of detail. More detail than I've ever seen on a pea.

The moon to the naked eye is only half a degree across, and it can look huge under the right circumstances.

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pvaz

pvaz

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The angular diameter of Jupiter is between 30 and 50 arcsec, so a 240x magnification will yield a diameter of 2 to 3.3 degrees or 4 to 6.6 lunar diameters.

If your peas are that size at an arms length you either have VERY short arms or your peas are on steroids :)

I think we use steroids on our peas here in Portugal... and I'm a bit short so that may explain it! :)

Still the planets looks small at 1st look, then after a couple of minutes detail is easier to pick. I find the GRS to be one of the hardest to pick. Something simple like a black cloth over my left eye so I can observe with both eyes open (instead of squinting) usually makes it much easier.

Main thing is not to expect voyager like pictures. Lots of things influence the detail you can pick and the amount of time you spend at the EP is also very important.

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pvaz

pvaz

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The angular diameter of Jupiter is between 30 and 50 arcsec, so a 240x magnification will yield a diameter of 2 to 3.3 degrees or 4 to 6.6 lunar diameters.

If your peas are that size at an arms length you either have VERY short arms or your peas are on steroids :)

PS-> Though I agree with the "pea at arms lenght" description of a planet I'm not the one to coin it. Just search the forum for "pea" and you'll see what I mean... :)

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brantuk

brantuk

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When viewing objects, what you see depends so much on a combination of several factors including the following:

Scope cool down, object elevation above the horizon, "seeing" conditions, magnification, eye piece quality and size, dark adaption of the eyes, darkness of the site, moon phase, time of year, aperture size, focal length, use of filters, size and brightness of object, averted vision, etc, etc.

It takes time to build up a good understanding of all these factors and then "get it right on the night". And then you need a good night and the time/inclination. So it makes it hard to define exactly what you'll see.

It's a lengthy learning process that requires a lot of patience, research and understanding before you even start looking through the eyepiece.

For now though - planets will be coloured, dso's mostly black/white/grey except some doubles. You need 16" apertures and upwards to start seeing hints of colour in dso's.

The colour photos you see of dso's are mostly filtered and long exposure shots picking up wavelengths of light invisible to the human eye. :)

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michael.h.f.wilkinson

michael.h.f.wilkinson

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Regarding my pea comment, don't forget that the larger the apparent FOV the smaller the planets seems to be, because our mind always goes for relative sizes. When I first tested my 8mm Radian, it seemed to give less magnification than a 9mm Vixen LV, because the size of Jupiter relative to the FOV is smaller in the case of a Radian. The effect causes moon and sun to appear larger when they are low in the sky, because you are comparing them to distant, large objects (buildings, trees), rather than near, small objects (birds and bats).

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msinclairinork

msinclairinork

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When viewing objects, what you see depends so much on a combination of several factors including the following:

Scope cool down, object elevation above the horizon, "seeing" conditions, magnification, eye piece quality and size, dark adaption of the eyes, darkness of the site, moon phase, time of year, aperture size, focal length, use of filters, size and brightness of object, averted vision, etc, etc.

It takes time to build up a good understanding of all these factors and then "get it right on the night". And then you need a good night and the time/inclination. So it makes it hard to define exactly what you'll see.

It's a lengthy learning process that requires a lot of patience, research and understanding before you even start looking through the eyepiece.

For now though - planets will be coloured, dso's mostly black/white/grey except some doubles. You need 16" apertures and upwards to start seeing hints of colour in dso's.

The colour photos you see of dso's are mostly filtered and long exposure shots picking up wavelengths of light invisible to the human eye. :)

:) Wow when you wright it all down like that, it makes me wonder why anyone does it?! are we all a bit mad? :)

Michael

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msinclairinork

msinclairinork

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:)

Well after reading that I have come to the conclusion so am I...that goes for the all the others on SGL too I think...

We must be when you think about it?! All that to consider + the costs all for a few cold nights out a year? barking....absoloutly barking! hehe

Michael

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