The clouds are gathering...

[pakarinen]

Dew shield is retracted. A bit heavier than I expected, maybe more than my ST120. Need to weigh it. Mechanicals built like a tank. Metal dustcap. Might have to put the AZ5 on my Twilight-1 pod.

But now who goes buh-bye? 90mm Mak? ST120? Both? Don't want to sell my ST80 - it's just too easy to use /transport - but something's gotta go.

[Lady Fraktor]

Why would you need to get rid of one?

Congratulations on the new refractor, hopefully you will have it out gathering photons soon.

[pakarinen]

Why would you need to get rid of one?

Congratulations on the new refractor, hopefully you will have it out gathering photons soon.

Storage space mainly and trying to minimize clutter, thanks!

[davesellars]

Looks good! congrats on the new scope!

Keep the 120ST - it's very capable at deep sky and will have a reasonable light gathering advantage amount over the 102mm ED. I would have thought the mak would be the least useful since its small aperture and central obstruction would give it considerably less contrast and ability for lunar and planet observation - the 102 ED will be considerably better.

[Lady Fraktor]

I would agree with Dave

[pakarinen]

Yes, I think that's probably the best way to go. And I really am a fracaholic anyway.

[Bigzmey]

Congrats on the new glass, looks great! If you HAVE to get rid of one I would also vote for 90mm Mak.

ST80 has an advantage over 102ED in the max TFV, ST120 - in aperture. 90mm Mak will underperform compared to 102ED in any aspect other then size and weight. But then how much storage space 90mm Mak really takes?

[Unitron48]

Congrats on your new scope! Ditto here on getting rid of the Mak....if you must!

Dave

[turboscrew]

Nice scope! I'm sure we're all behind you whichever scope you'll decide to get rid of. :wink:

[25585]

I'm for keeping them all, so far.

[notFritzArgelander]

Keep all. While it’s true that the a Mak’s contrast will suffer on largish nebulous objects due to the central obstruction, that same obstruction enhances contrast on lunar and planetary and terrestrial objects. If you want I could post the link to the transfer function that quantifies this later. (I’m dawdling abed with only a fat finger and a phone at the moment.) But there’s a reason from optics why Maks are known for razor sharp contrast on small targets.

[notFritzArgelander]

Keep all. While it’s true that the a Mak’s contrast will suffer on largish nebulous objects due to the central obstruction, that same obstruction enhances contrast on lunar and planetary and terrestrial objects. If you want I could post the link to the transfer function that quantifies this later. (I’m dawdling abed with only a fat finger and a phone at the moment.) But there’s a reason from optics why Maks are known for razor sharp contrast on small targets.

The key graph is shown in Figures 104 and 105 at this link:

https://www.telescope-optics.net/obstruction.htm

However, the actual MTF graph (FIG. 104) indicates that the above formula is somewhat pessimistic in regard to the effect of CO. Obstructed aperture has significantly better contrast transfer - even better than that of a perfect aperture - in the right half of MTF frequency range (i.e. for details smaller than about 2 λF linear, or 2 λ/D in radians. Even in the left half of the graph (range of resolvable low contrast details), obstructed aperture has an edge.

[John Baars]

Great scope. Congratulations!
No need to get rid of one of your scopes.You don't have to you know:-)
I have too many scopes too. Two of them come down from the attic once a year--so much nostalgia attached to them.....Sooner or later, every amateur regrets getting rid of telescopes that took him to the next level. I know, because I have been there.
Moreover, your Mak fits in the glove-departement of a car, so easy to transport :-)

[pakarinen]

Moreover, your Mak fits in the glove-departement of a car, so easy to transport :-)

Well, yeah, there is that.

[messier 111]

nice setup , thx for the clouds lol .

[pakarinen]

nice setup , thx for the clouds lol .

Happy to share - anybody who wants 'em can have all of mine.

[OzEclipse]

nice setup , thx for the clouds lol .

Happy to share - anybody who wants 'em can have all of mine.

I have almost a whole week of clear skies predicted for next week.
AP Workshop participants coming up on Saturday 2 April for an overnight stay.

No thanks, you can keep 'em. I'll take care of the clear skies.
Thanks
Joe