Skymax 90 MAK on an AZ3?

[lw24]

Hi,

I have recently purchased my first telescope (Startravel 120 on an AZ3 mount) and am enjoying it alot. I have gained a sudden intrest in observing the moon, and other planets, and after a few looks I have noticed that my telescope is not deisgned for this purpose (I knew this before I bought the telescope).

I was thinking of upgrading my current telescope to make it become better for planetary observations, but after a bit of adding up, it seems it may be cheaper to buy a whole new telescope OTA instead.

The telescope OTA in question is the Skywatcher Skymax 90 OTA. I have a few questions:

-Will it mount straight onto my AZ3 mount, or will I need to buy an adaptor? (Please specify what adaptor)

-Will the Skymax 90 be better at planetary observations than my Startravel 120?

-Would you reccommend buying a dew sheild? (I have looked around for one but can't seem to find one to fit this telescope)

Cheers!

Clear Skies!

[AndyH]

A dewshield is pretty much essential for any scope with glass 'up front'.

One of these dewshields should fit. I've got a couple of the AE 70mm ones and the quality is good. Fine price too !!

Anti-Dew - Astronomy Accessories - Warehouse Express

I've never used a very fast refractor(F5), so can't comment with authority on how good the views are when you ramp up the magnification on the 120. You should get nice views from the wee mak, but it is only 90mm, remember. Will it be better than the 120? I think I'll leave this answer up to others.

Looking at pics of the skymax 90, I think you'd need a short dovetail for it to fit on the AZ3? Again I've never used either items, so hopefully someone could confirm. A dealer could tell you for sure.

Andy.

ps: Just had a thought. Have you tried 'masking' the 120, down to say 80 or 90mm? This may give better views at higher power?

[JamesF]

I'm unconvinced that the Mak would be any better than the ST120 with the exception of not having the CA. Now I've got mounts sorted for both my ST102 and Mak 127 I'll see if I can compare them on Saturn when we next get some clear sky. I really didn't find CA a problem on Saturn last week when the seeing was pretty good, but it does seem to be more noticeable when it isn't so good.

On the moon I've only found CA an irritation near the limb and a moon filter killed off a lot of that (full moon without a filter through the 102 was borderline painful to look at, so a moon filter is pretty much mandatory for me anyhow).

I suspect that your ST120 actually gathers around 90% more light than the 90 Mak and the relative lack of light may limit the viable magnification.

Could be that a fringe-killer and/or moon filter might be a better bet than the Mak.

[lw24]

I totally understand where your coming from.

I already have a moon filter, but i've noticed some CA on stars and other bright objects.

Do you think the money would be better invested in a Baader Semi Apo or a Baader Fringe Killer?

If so, what one would you think is better?

Cheers!