I would like to acquire a small equatorial mounted scope as a grab scope

[overlord (Charles)]

I have never used an equatorial mount before. what are the suggestions. Hope it's ok to post here on a newby topic, but i'm not really a newbe, well maybe actually i am when it comes to equatorial mounts.

Basically I need heavy mag to see the planets during nice seeing. My Dobby cannot do that. 300x and ZOOOOM!

[overlord (Charles)]

Also i am wondering how much it costs to attach a simple traditional 'clock drive' to one of these things. i don't really want this fancy goto stuff. see, i am a hunter and the sky is my prey

[Screwdriverone (Chris)]

Hi Chucky,

I am a bit intrigued when you say your dob cant do high mag?? most dobs have a focal length over 1000mm, generally 1200mm or 1500mm. Now with a refractor, the focal length is usually 900mm or lower, so in both cases, you will only get about 300x mag on a planet with say a 10mm eyepiece and a 3x barlow.....

As for a relatively simple EQ mount with clock drive, take a look at say Andrews comms for an EQ2 or EQ3 with RA motor as this will be enough for basic tracking...my Eq2 is quite portable, but still heavy with the counterweights. Pop a refractor on that or a short tube reflector (parabolic mirror only) and you have a niceish grab and go.

Refractors are more expensive per mm of aperture so if its details on planets you want, aperture rules and price per mm, dobs cant be beaten. What size is your dob? If it is 200mm or more, you should be able to get in close around 300x depending on the seeing for details on Mars, Jupiter and Saturn, but only get discs looking at Venus, Neptune and Uranus due to the cloud tops on these ones.

Cheers

Chris

[Fox]

Chucky, just my 2 cents, but I'd go into Bintel and take good look at those Skywatcher class scopes. An EQ3 class eq mount (can have drive built in) plus any semi apo ED small refractor, around 80mm or so. That will suit your bill of eq mounted, good enough for a quickie on planets, and genuinely small/compact enough to be as 'grab and go' as you can get. Getting a scope any bigger than that, then I'd say you'd need a CG5 class eq mount for decent stability (the choice is yours...). Fox

[toc (Tim)]

I would stick with the dob, and get a tracking platform - a small refractor on a EQ mount is not going to come close to a 6-8 inch newtonian when it comes to planetary detail.

[danielsun]

Chucky, getting a small refractor will be a step backwards compared to your dob. If you say you are struggling to see the planets with your dob then something is wrong, maybe it needs some major collimation.
You won't get better planetary detail than with your dob.

Cheers Daniel.

[Fox]

Sorry chuck, my mistake I didn't read you wanted to go up to 300x for planets. Yeah, a small refractor will not do, but perhaps a 6 to 8 inch newt - I've always wondered what those Meade Schmidt newts are like... Fox

[Barrykgerdes]

Originally Posted by overlord

I have never used an equatorial mount before. what are the suggestions. Hope it's ok to post here on a newby topic, but i'm not really a newbe, well maybe actually i am when it comes to equatorial mounts.

Basically I need heavy mag to see the planets during nice seeing. My Dobby cannot do that. 300x and ZOOOOM!

That would be a handy device to have if it was possible. However such a device does not exist. If you want an equatorial mount to hold a telescope big enough to do what you want it won't be grab and go.

To improve on the planetary views over what you already have will be a larger aperture with a long focal length. That would need at least an EQ6 size mount and a 12" SCT.

If your current telescope is an 8" or 10" DOB, stick with it and get it working properly. These can be quite "grab and go". When the conditions are suitable excellent views of the planets can be seen at 300x mag.

Barry

[Fox]

Chuck, what aperture is your current dob? From your original post, I assume you want more grab n' go portability (correct?). You do realize that you'll probably need to compromise aperture for size/portability, so under good seeing, planetary views are unlikely to be as good as your existing larger dob. Can you be a bit more specific as to what you want & expect... ? Fox

[jenchris (Jennifer)]

I'm a bit intrigued as to why an EQ is needed if you're not doing AP?
My meade lx90 will come under the heading of portable without too much trouble - but not quite grab and go.

But an alt az mount with goto will give you huge potential and stability - you don't need an eq mount unless you're photobound.

Let's face it, you can stick a LX90 on a table without the tripod if you want!

[casstony]

The biggest contribution to grab and go that I've figured out is an EQ5 mount left permanently on the back verandah. All I have to do is carry the ota out and I'm ready to go. One of my favourite scopes for grab and go is an Celestron 6" schmidt cassegrain ota - presently on special for $499 at Andrews. - 6" aperture with great optics in a very small package and well suited to a set of WO binoviewers.

[overlord (Charles)]

Originally Posted by Screwdriverone

Hi Chucky,

I am a bit intrigued when you say your dob cant do high mag?? most dobs have a focal length over 1000mm, generally 1200mm or 1500mm. Now with a refractor, the focal length is usually 900mm or lower, so in both cases, you will only get about 300x mag on a planet with say a 10mm eyepiece and a 3x barlow.....

As for a relatively simple EQ mount with clock drive, take a look at say Andrews comms for an EQ2 or EQ3 with RA motor as this will be enough for basic tracking...my Eq2 is quite portable, but still heavy with the counterweights. Pop a refractor on that or a short tube reflector (parabolic mirror only) and you have a niceish grab and go.

Refractors are more expensive per mm of aperture so if its details on planets you want, aperture rules and price per mm, dobs cant be beaten. What size is your dob? If it is 200mm or more, you should be able to get in close around 300x depending on the seeing for details on Mars, Jupiter and Saturn, but only get discs looking at Venus, Neptune and Uranus due to the cloud tops on these ones.

Cheers

Chris

Hi! My dobby is f/5, 8" so yeah, not really a planetary machine but i can see the cassini division around the edges now that its well collimated. I am very interested in the planets and would like to do some huge magnifications. I like to draw what i see and it's annoying to do what when i have to move the scope lol. The planets are so dynamic and changing every day ever so slightly whereas the much larger heavens move slower so I want something planetary and good. i have an idea what i have in mind but telescope selection is one of life's dilemmas. I just bought a planetary eyepiece as well, 6.3mm, before i never went above 100x except with a shocking barlow through which I saw apparitions of the Virgin Mary.

I have seen some detail on Venus stopping it down to 2" a few mornings ago. I believe they correspond to Lowell's spoke arrangement on that planet, but they looked slightly curved as well so they might have been clouds. I also believe I can see in ultraviolet or some wavelength which does not register on cameras so well as I see these wierd features in the Saturn hemisphere pointing towards us currently and others say nay.

[overlord (Charles)]

Originally Posted by toc

I would stick with the dob, and get a tracking platform - a small refractor on a EQ mount is not going to come close to a 6-8 inch newtonian when it comes to planetary detail.

Ah thank you, tracking mount huh! I didn't know they were available! That sounds like an awesome idea! I will do that.

I see.

[overlord (Charles)]

Originally Posted by Fox

Sorry chuck, my mistake I didn't read you wanted to go up to 300x for planets. Yeah, a small refractor will not do, but perhaps a 6 to 8 inch newt - I've always wondered what those Meade Schmidt newts are like... Fox

Yep. Thanks. I'll stick with the Dob then and do the tracking mount thing.

[Fox]

Originally Posted by overlord

Hi! My dobby is f/5, 8" so yeah, not really a planetary machine but i can see the cassini division around the edges now that its well collimated. I am very interested in the planets and would like to do some huge magnifications.....

Ahh, working on the principle of 30x to 40x per inch of aperture on good nights, perhaps up to 50x on those rare exceptional nights - then there's no getting away that bigger scopes are going to work more comfortably to reach 300x+ mag (and all other considerations aside wrt portability, weight, cool down etc.). I'd agree with all above, a 10 to 12inch+ scope, either dob (tracking idea is great) or tracking SCT is your best bet.

On exceptional nights, the NP127 from 230 to 270x is wonderful on Jupiter, and even Uranus/Neptune are pretty (but tiny). I can really understand your desire for more grunt to get beyond 300x+. Whether a large tracking dob and/or SCT is grab n' go depends on your perspective, but for me, I peter out with an OTA beyond my TV NP127 ie. ~7kg. OK, I'm a wimp. Fox

[PlanetMan]

Hi Chucky,

I have skimmed this thread and discussion seems to have shifted from your original sentiment of a portable refractor to getting the most out of your dob. In principle - aperture rules and the advice you are getting in principle is correct. Before going any further I will state that I am a refractor-oholic.

With these two points stated - dobs are good provided you have the lifestyle and time for them. If you want something hassle free, quick to jump outside have a look around for an hour and then back inside, that will retain 80% its value should you want to sell, and is genuinely portable then a "top" quality refractor is pretty hard to beat.

Ultimately, it depends on your level of interest in astronomy. I have found that initially a lot of folks buy dobs or big reflectors of one type or another but as time goes by the set-up and cool-down gradually becomes more and more of an excuse to not go outside at all and ultimately they leave the hobby of switch to something smaller.

The old expression is that the best telescope is the one you use the most. I am still looking at the stars with my Tak while quite a few of my friends with Dobs, SCTS and Newts are all fine ornaments in their houses or garages.

[Fox]

Originally Posted by PlanetMan

Hi Chucky,

I have skimmed this thread and discussion seems to have shifted from your original sentiment of a portable refractor to getting the most out of your dob. In principle - aperture rules and the advice you are getting in principle is correct. Before going any further I will state that I am a refractor-oholic.

With these two points stated - dobs are good provided you have the lifestyle and time for them. If you want something hassle free, quick to jump outside have a look around for an hour and then back inside, that will retain 80% its value should you want to sell, and is genuinely portable then a "top" quality refractor is pretty hard to beat.

Ultimately, it depends on your level of interest in astronomy. I have found that initially a lot of folks buy dobs or big reflectors of one type or another but as time goes by the set-up and cool-down gradually becomes more and more of an excuse to not go outside at all and ultimately they leave the hobby of switch to something smaller.

The old expression is that the best telescope is the one you use the most. I am still looking at the stars with my Tak while quite a few of my friends with Dobs, SCTS and Newts are all fine ornaments in their houses or garages.

Planetman, the suggestion of a small refractor was mine, but due to me not understanding Chucky's desire of wanting 300x+ mag for planets in particular, so a small refractor ain't gonna cut it. Having said that, I myself have travelled the path of Newt, to 8inch SCT, to refractor - and I have similarly become a dedicated refractor nut like yourself. In keeping with Chucky's original intent, IMHO you would something close to a 6 inch refractor. Such a scope would need to be semi-apo at least, to be practical, and we are talking big bucks here (like an NP127).

[PlanetMan]

Basically I agree - with a few proviso's however. Firstly, my views are not reflective of price. I would offer the argument that some of the high priced refractors eg NP127 TSA120 are in fact better value for money in the context that folks tend to use them more (overall actual time behind the EP) than their 14" SCT etc and thus from their overall usage they are arguably better value. I would love to take a look through a TV127 as I suspect the view would be pretty good.

However, one claim from Tak which I initially thought was pure b#$%*$@# was that their fluorite refractors can achieve 100x magnification per inch on bright objects. This claim appears in the manuals and also can be found on astronomics site

http://www.astronomics.com/main/prod...roduct_id/FS60

Anyhow, I tried my FS-60 on Saturn and was dumbfounded/shocked at what 60mm of Tak 100% flourite (not flourite particle lens) could achieve - I took it up to 200x and could see plenty (bands, belts etc).

[Kal (Andrew)]

flour is what makes bread

fluorite is what is used in lenses

[toc (Tim)]

All this talk about magnification is all so dependant on seeing anyway - 300x about the limit from my backyard for the 90% of the time.