10" dob.worth upgrading yet?

[mastodon]

i've managed to get some good veiwing over the last three nights with my skywatcher explorer 130PM,especially last night when i got a brilliant view of the moon and also saw saturn and its rings for the first time although it was quite faint.my question is before i sucumb to apperture fever could anyone tell what the significant benifits would be to upgrading to the skywatcher 10" dodsonian as these seem to be alot of telescope for not alot of money.would galaxies and nebulae be alot brighter?i have allready been advised on this forum to get a decent 32mm eyepiece so would i be better sticking with my existing scope and upgrading all the standard eyepieces?thanks for looking.

[mike-h]

i bought the skyliner 250px 3 weeks ago for £312. Amazingly big scope for the money. I havent had too many clear nights so far, but what I have seen is impressive (to me-i am new to this). The Moon under 480x mag was amazing. Saturn was a decent size bright disc with a clear thin horizontal line cutting thru it -the moons were also visible. I couldnt make out any surface details but the sky wasnt very dark. I need to take the scope to a darksky site and maybe try some filters (i need advise here-which colour and type would be best).

Do consider portability before you buy.The base weighs 12kg and the tube weighs 12kg too. 112cm tube fits across my back seat.

Also, collimation can be an issue on a large F5 reflector-took me lots of practice to get this spot on for the focuser + secondary (primary is then easy to do).

Fell free to ask any questions.

Mike

[mike-h]

Also, have a look at one of todays posts about how big does a planet look. It gives aterrific link to some photos of jupiter thru different sized scopes.

Mike

[mike-h]

Oh, the post is in the Observing section and was posted by Lightbucket

Mike

[mike-h]

Sorry, one last thing to consider b4 you buy a dobsonian: you may miss not having slow motion controls. If you want to look at the moon and saturn under high mag then the image moves fairly quickly and you have to nudge the scope every few seconds. When first ordering a scope in December I was adamant i wanted slow motion controls but now i'm not that bothered.

Now i had the 200p EQ5 for a few weeks in January (sent it back cos of faults) and then bought the 250px dobsonian to replace it. Here are some comparisons

PROS

1) the Dob is much quicker to set up (under 2 minutes)-no balancing or weights to fit. Easier to transport-only 2 pieces.

2) the dob is much easier to "strafe" across the sky-i.e. left, right, up, down is much simpler (for a newbie like me) than the equatorial's polar axes.

3) the dob has far less 'wobble' when toucning the focuser etc...

CONS

1) i didnt see this one coming but the low mount for the Dob means its not as high off the ground as the EQ5. if you have a high garden fence or other obstructions then you will lose some low down views. You may be surprised by how low it is.

2) the nudging is not as good as slow motion contols. Not a problem at all up to 100-200x mag. 300-500 take a little practice. At 500 x you only get a few seconds in FOV. You may need to make a few mods (milk carton washer !) to the azimuth movement to make it nudge easier and in small amounts.

It all needs to be taken on balance. To get the 250px on a HEQ5 mount more than doubles the cost. The counter weights and mount will be a heck of a lot heavier (double?) than the 12kg for the dob base. If you wont be transporting the scope and you have plenty of cash then an EQ mount will be better for tracking object under high mag.

Mike

[mastodon]

thanks for the info mike,very helpful.i had just about made my mind up about upgrading but have just noticed the price of the scope has shot up from £312 to £389 overnight.missed a right bargain.

[mdstuart]

Put a wanted on Astro Buy and sell and you may get one. I recently paid £195 and another forum user got one for £185...but then you do need to be sure you are getting one in good nick, particularly the main mirror...

Mark