confusion over different telescope models

[Mr TamiyaCowboy]

I am looking to upgrade from a small 3" scope to a bigger sky-watcher type.

i would like something that i can track with, so started looking at the sky-watcher 130 with an EQ2 mount, then i notice a 130P, and a 130PDS now i am getting a little confused, i pop to another site and they have a 130M.

each scope has a different focal length some are 650mm, some are 900, some at 1200. all roughly in the same price range but i am confused from all the different types etc etc.

i have around £250 GBP to spend on a new scope, and would like it to track (manual or powered). i found they tend to come on a eq2 mount so that is fine, but what focal length will i need ?.

would like to capture the things i cannot see without a scope like nebula and likes using webcam/DSLR but also use eyepieces.

thank you

Tami

[Nova]

Generally People who want to focus more on planetary and lunar observing will go for a longer focal lengths where as people who would like to observe more on deeps sky objects will go for shorter focal lengths thats not to say that if you went for a short fl you wouldnt be able to see planets or the moon but I believe a longer fl whould resolve planets better and give you a sharper image. If you were wanting to use a webcam or DSLR for deep sky then its reccomended that the minimum mount you will need is an EQ5 (a HEQ5 to be exact) as the EQ2 would not be stable enough. When you talk about tracking im not sure what you mean by manual or powered. You can obviously slew a mount by hand using the slow motion cables or just releasing the locks and turning it free hand which I suppose would be manual tracking but if you wanted to go auto then a GOTO mount or a mount with tracking motors would be required. You can always upgrade to auto tracking at a later stage

[jimmyjamjoejoe]

P = Parabolic mirror

PDS = Parabolic mirror with a dual speed focuser

M = Motor (usually only one axis, for auto tracking)

Generally a longer focal length will give you a narrow field of view with slightly higher contrast, so longer lengths are suited to planetary while shorter give wide views for DSOs.

[Pete Presland]

i think the pds's are fast f5 as well for astrophotography

[JamesM]

None of the scopes you list will be good enough to perform 'deep sky' imaging (galaxies/nebula) as the mounts they come with are not accurate enough to allow precise tracking of objects. This is essential in order to perform long exposures of these distant faint objects. As Steve said above, the minimum is a HEQ5 which costs a lot more than your budget. Using a webcam is an alternative imaging option which can be used on any scope that is focused on the moon or other planets. These objects are bright enough to be 'filmed' without the need for lengthy exposures and tracking and therefore an expensive mount. The best frames are stacked on top of each to make a composite image which can certainly reveal a lot of detail.

James

[onesmallstep]

Hi

If you can, contact your local astro group - there are several in your neck of the woods - and see if they are organising any public events that you can attend. This way you can try the various types of scopes and see which make / model is best suited for your own astro interests.

Type 'fedastro' into a search engine and click on the Societies link to find groups in Norfolk / Eastern Regions.

HTH!

[Mr TamiyaCowboy]

feel kind of let down, the advert says planets and deep sky objects. and then finding DSO is out of reach unless expensive mount used.

i can push towards a SW 150 (black) with an EQ3-2 mount, it is a bigger mirror at 6" and double the size of my desktop scope. and i could save up for a better mount. but it would still not be good enough for DSO as it sounds.

am looking to purchase one just after christmas, gives me enough time to research more on telescopes and mounts and what i really will be seeing as to what adverts say.

so this means i am really stuck to planets and likes

sadly i do not have transport to the astro clubs they are to far to walk to, so i tend to sit in the yard or shove the desktop scope on windowsill.

[onesmallstep]

Hi

One possible solution is to get the basic setup first just to get used to it and then add the upgraded mount at a later date to build on your experience. The Explorer 150 is a popular scope judging by SGL sigs and you always have the option of buying second hand when you have enough posts under your belt (50, I believe). Another option is a Dobsonian which is effectively the same telescope on a different mount. Again, you can upgrade to the EQ5/HEQ5 mount and tripod in the future and swap the tube over from the Dob base. Stick with it!

[Mr TamiyaCowboy]

i did look at the dobs and the desktop one is a dob to, but i did not know you can fit them to other mounts. so i could get bigger mirror dob like the desktop one and mount it to a better mount later.

only thing would be size and weight, there is only me to carry what i can by hand, laptop could be shoved into a backpack.

thank your for the advice it is much needed.

[jimmyjamjoejoe]

Many people move the 8" dob around by themselves fine.

Imaging is a tough and expensive hobby. You shouldn't feel too let down, you can still SEE planets and DSO's. It's just that DSO's require long exposures when imaging, as such they require a VERY steady mount, otherwise you get fuzzy images.

[Nova]

just to mimic what jimmy says. its only the imaging of dso's thats beyond the mounts ability. you will still get fine views of them and planets. I have the 150P and have recently started getting into planetary and lunar webcam imaging with the EQ3-2 mount with added tracking motors. I can certainly reccomend it as a great first scope

[Mr TamiyaCowboy]

i have decided to get myself a SW Skyliner 200 dob. and at a later date when pockets allow find a good mount and use the 200 tube.

i have one worry my hight, i am not very tall at 5ft. will i have any problems with a SL 200 mounted on a tripod ?

also i notice no choice in focal length will this hinder me later when trying DSO ?

thank you again for the advice.

[jimmyjamjoejoe]

You've made a good choice. According to this thread, your height with will be fine with the original mount, and since tripods are adjustable, you'l be fine with that too (EQ mounts can make you twist in some funny positions though).

The scope itself is an f5 (1000mm focal length / 200mm aperture) , which is nice and fast for imaging, certainly won't hinder you at all.

[Mr TamiyaCowboy]

You've made a good choice. According to this thread, your height with will be fine with the original mount, and since tripods are adjustable, you'l be fine with that too (EQ mounts can make you twist in some funny positions though).

The scope itself is an f5 (1000mm focal length / 200mm aperture) , which is nice and fast for imaging, certainly won't hinder you at all.

thank you Jimmy

feel more put to rest now. yes i like the dob style am getting a dab hand at manual tracking with eyepieces on the desktop scope.

i shall be only moving it about 20meters in and out of the house. but do have a few streetlights i am unable to hide away from. getting some filters for the tablescope so maybe they can be used with the new scope.

are there any other things i should be looking at before getting a larger scope, cleaning, tools etc etc ?

[onesmallstep]

Good choice of scope (see my sig). Height-wise you will be fine with a 200P/EQ5 setup. The F/5 focal length of this scope is perfect for DSOs so no worries there.

Good luck with your new acquisition.

[jimmyjamjoejoe]

are there any other things i should be looking at before getting a larger scope, cleaning, tools etc etc ?

A good Cheshire collimator, a good planisphere/sky atlas. Many people recommend the book "Turn left at Orion".

As far as cleaning - prevention is the best method here, you really don't want to clean mirrors unless absolutely positively 100% necessary. For cleaning eyepieces i think people recommend a drop of isopropyl alcohol and a very soft tissue.

[bcfcciderhead]

Good scope the 200p dob, i had the flex-tube version before i sold it for my EQ5 setup.

It will give you some nice views of the planet and nebula (the darker the sky the better they will be).

Orion will be great to start with, its about 2am at the moment but as the year goes on it will show at a more sociable time.

I have had some nice views of the dumbell and ring nebula with that scope, might be grey in colour but enough detail to see the shape.

[Mr TamiyaCowboy]

thank you everyone.

why are images grey or black and white may i ask ? and sorry for the stupid question.

can you make them in colour or is that where filters come in.

[onesmallstep]

Hi

The colours of nebulae and other DSOs come through on images but not with the dark adapted eye as night vision makes the human eye more sensitive to light, not colour. Another trick when observing is to use averted vision, that is when you look to one side of where you think the object is so that light falls on the corner of the eye (the part most sensitive to light) and not the centre. A realistic expectation when observing faint objects is pale grey/white smudges, the 'faint fuzzies' referred to by SGL members, e.g. the Ring Nebula will look like a smoke ring and the Andromeda Galaxy will appear as a pale grey oval with a brighter centre. All of the above will depend on filters (OIII or UHC for DSOs, colour filters for planets), sky quality, magnifications, eyepiece design, and your own eyesight.

HTH!

[onesmallstep]

Speak of the Devil! Just found this primer:

http://stargazerslounge.com/primers-tutorials/90030-primer-understanding-night-vision-averted-gaze-telescope-tapping.html