cantab

Excellent guide, thanks.

Hi, Glad to have registered with stargazers lounge, read a few of the forums but getting bit bogged down with the vast numbers of differing telescopes.

I have looked at sky watcher 1145p Skyhawk, also sky watcher 130p and lastly Danubian Delta 30 catadioptric for first telescope.

Space is a premium for storage so 1145p appealed, however reading about the 130p and the slight difference in aperture will this make a big difference.

I would really welcome advice and what I am likely be able to see. I would like to be able to view lunar, planets and Deep sky objects. I have looked at celestron but been told sky watcher have better build quality. Help!.

I doubt there'll be much in the views between a 4 1/2 and a 5 inch mirror. However if you want something that will store fairly compactly, the obvious choice is the Heritage 130P. Tube collapses down and sits on its base out of the way, no tripods and mount heads to worry about.

EDIT: Of course, the Heritage 130P won't track. If you want something with tracking that won't be too bulky, maybe one of the Heritage Virtuoso scopes?

Of course they are as they are, just not listed.

The backdrop isn't to the same scale though. Which is a bit of a shame, but then I suppose the image wouldn't be as visually striking if it was.

Taking anything from this group and thinking its true/accurate makes as much sense as learning something from a rock.

Opportunity and Curiosity are learning plenty of things from rocks

How interesting you'll find Facebook largely depends on how much your friends share your interests, and on the groups you're in somewhat.

Stopping a scope down also increases the f-ratio. That might reduce eyepiece aberrations, especially if the scope is fast normally.

Something I wonder is if the main mirror could have the wrong focal length, either in the original manufacture, or from a repair attempt that swapped in an incorrect mirror. That would explain the inability to focus, but I don't know how to test for it.

I have to carry 2.. surely im not the only one?

This one is 'main' case; those in my signature. Not sure why I seem to be the only person who stacks them standing up.

I wondered about this myself. I had mine standing upright to begin with, it seems neater and I'll fit more in that way (not that I need to fit more in at present!), but got worried about touching the eye lenses when groping for the EPs in the dark. So I switched them to being sideways, but they don't seem to fit as well.

Do you wear glasses or contact lenses to correct strong astigmatism? If so, you'll probably need to wear them while using the scope. The same might apply if you have strong short or long sightedness. And, though it seems unlikely, try viewing with your other eye in case you've got some visual impairment you didn't know about.

If that makes no change, then I have to suspect either the eyepiece or the main mirror is faulty. Multiple eyepieces might be faulty if the previous owner took them apart and put them together wrong. Try and borrow a known good eyepiece for testing, or else try and test your eyepieces in a known good scope.

If it still doesn't work with a good eyepiece, or you confirm the EPs you have are OK, that just leaves the mirrors in my mind.

Not trying to focus on something too close are you? Scopes can't focus on stuff that's too close, and for astro scopes "too close" can be surprisingly far.

Celestron Skymaster 15x70s. Bought with Clubcard vouchers, I probably wouldn't have got them otherwise, but they fast became my most-used instrument. They do need the tripod but the optical performance compared to 10x50s makes up for it.

Bresser 10x50s. My first decent pair that I used for astro. Out of collimation now, 'they were fine before'

Auriol 10x50s. From Lidl, bought as a spare/loaner pair. They performed well on their couple of nights' use recently, seem about equal to the Bressers though I haven't compared them side-by-side. Just wish the eyecups weren't so rigid against my nose.

Auriol 12x32s. My compact pair. They're pretty naff though.

Godawful ruby-coated junk somethingx50s. Actually got my first look at the Pleiades through these. Then one of the objective barrels broke off, hardly a great loss. I hacked off an eyepiece for my scope, makes an OK low-power EP for no money.

Also recently bought my mum a Helios Ranger 7x32 monocular. General purpose use in mind, not specifically astronomy. Neither of us have used it much yet though, but the close focus did impress.

Since the forum reorganisation should this thread be moved into or linked to from Getting Started Equipment Help and Advice?

With the Barlow the focus may be quite different to without. Or it could just be no good, the Barlows that come with cheap scopes often are poor.

Seben are infamous for making some truly awful scopes, but I believe yours isn't one of them. It looks like a typical 3 inch Newtonian, wobbly mount and bottom-end eyepieces but hopefully even Seben will have put half-decent mirrors in it.

The terms "fast" and "slow" in this sense are photographer's terms. A photographer is most interested in the image scale - with no eyepieces involved, a long focal length lens gives a "zoomed in" telephoto view, while a short focal length lens gives a wide angle view. With two lenses with the same focal length, the "fast" one will require a shorter shutter speed to get the same image brightness as the "slow" one. The faster lens will have a bigger aperture.

For a visual observer it's less important, but fast optics tend to show more aberrations than slower ones. Some eyepieces don't work well in fast scopes, for example, and the ones that do tend to be more expensive. For Newts and refractors, fast optics mean a shorter tube. With a slow scope it can be hard to get wide-angle views since eyepieces have an upper limit to their own focal length imposed by their barrel diameter, too long and the field of view is restricted giving no benefit. (The exact maximum depends on eyepiece apparent field as well as barrel diameter, but it's 32mm for a 1.25" format Plossl for example.)

The f number is simply the focal length divided by the aperture. f/10 is slow compared to Dobsonians in particular, but it's similar to a lot of refractors and faster than some Schmidt/Mak-Cassegrains.

I concur they could give people the wrong idea, but I'm not sure what's best to do about it. The magazine won't stop putting the images in, not least because they'd disappoint the regular readership. Astronomy Now does have a regular section on sketching, and I think S@N does too, but maybe give more prominence to it? I wonder if accompanying telescope reviews with either sketches or as-the-eye-sees images would be useful.

Unfortunately my family will complain if I make the fridge light red. It gets me most nights when I pop in to make a cuppa, I never remember to close my eyes before getting the milk.

I just went to Poundland and picked up a rear bike light.

Would I be right in thinking that a smaller Newt is likely to have a proportionately-larger obstruction, other factors being equal?

LOL. I knew I'd muck things up when I decided to switch the units to inches from mm! And this forum preserves my mistake forever, no eternal edit here.

I'm looking at a similar choice regarding my first scope, though at a smaller scale with a lower budget. Depending on exactly how much I have to spend, it could be 2.8" frac vs 4" mm dob (the Orion Skyscanner), or 3.5" frac vs 5" dob (the Skywatcher Heritage Flextube). I figure LP is going to spoil DSO views so I want a scope good for planets; does the extra aperture on a dob outweigh the "suitability" of a long-tube refractor for planetary targets?