Infrequent Observer - Grab & Go scope to reboot my enthusiasm?

[Geoff Lister]

John,

I have just done some measurements. The Tasco OTA is 690mm long, to rear of the primary mirror adjustment screws. I tried it in the Skymax mount, and the OTA just catches the tripod leg with ALT at 75 degrees. You could go a little higher between the legs.

Below is a composite photo showing (top left) Tasco touching tripod leg at 75 degrees, (top right) the Skymax 127mm MCT on mount with ALT 90 degrees, just clearing the tripod leg, (bottom left) Virtuoso 90mm MCT on Skymax mount, with plenty of clearance, and (bottom right) Virtuoso MCT at 90 degrees on Virtuoso mount, again with plenty of clearance over the AZ axis clutch release knob.

Below is a composite showing (left) Skywatcher Skymax Synscan mount, (mid) Celestron Skyprodigy mount with built-in Starsense camera, and (right) Celestron Cosmos 90 WiFi mount that uses Sky Safari / Sky Portal App on a tablet in place of the wired handset. These are essentially the same basic design with different plastics and user interfaces.

I hope this helps.

Geoff

 

 

[johnha]

Thanks Geoff, those are really helpful. My Tasco is longer (about 100cm) & wider so it would max out earlier. I hadn't fully appreciated where the SkyMax eyepiece would end up with the scope vertical.

John.

[Geoff Lister]

John,

Just back from a short break in Rome, so sorry for the delay in responding.

The mount offset does (just) allow the 127's diagonal to clear the tripod head, providing the OTA's dovetail plate is positioned correctly in the mount's clamp.

Not quite shown in the photo above, I substituted the original straight-through finder for a right-angle equivalent. This avoids the pain-in-the-neck, (in both senses of the phrase), when aligning on objects above about 60 degrees altitude. With the Virtuoso's 90mm MCT, there is plenty of clearance to 90 degrees, but the red-dot finder is almost impossible to use, above about 60 degrees Alt., because the table or mount prevents you from looking along the OTA's barrel, even from a kneeling position.

Geoff

 

[johnha]

Thanks for all the replies and comments - they have all been really helpful.

In the end I've bought a Celestron NexStar 4se (102mm Mak on an AZ GOTO), the reasoning being:

1) The mount offers more alignment options, includes a basic wedge and supports EQ alignment.

2) It was available locally (important as my ability to receive large boxes is limited) although I had underestimated the size of the box such a 'small' scope requires.

3) Although the SkyMax offers a larger aperture - I reasoned that the actual difference would be limited (given the longer focal length of the SkyMax).

Apart from a minor hiccup (requiring a firmware update for the hand controller), so far I'm really pleased with the package - the GOTO (and it's various fine tuning options) is really interesting.

 

Thanks again,

John.

[Geoff Lister]

John,

Looks like you are sorted. Now all we need is some clear skies.

Geoff