Mak vs Frac

[Smithfire]

Hi guys.

What would be better for planetary views, a f12 102mm Maksutov or a 102mm f12 achromatic refractor?

Just wondered if one would have edge with regards to colour etc?

Many thanks

[Cornelius Varley]

The Mak should be better (no CA) and easier to handle.

[JamesF]

I think it's hard to give a general answer, but given the central obstruction of the Mak I'd guess that the achro might give slightly more contrast, whilst the Mak shouldn't have any noticeable chromatic aberration (not that I'd expect to see much in an f/12 achro either).

The Mak would probably win in terms of portability and usability (a metre-plus achro is going to need a reasonable mount to be stable).

James

[Schorhr]

I never owned a 102mm f/12 refractor, but given the maks high obstruction I'd say the refractor may have an advantage as 150-200x is the max. useful magnification anyway. At f/12 chromatic aberration should be acceptable.

What refractor is this? I only know of 102/1100.

But for the price of the typical refractors either a larger newtonian (5"... 6"...) or the step up to the 5" mak may be an option?

[lunator]

For easy of use the Mak would win but I don't think the views would be hugely different. Either will work well but the refractor will be long...

Cheers

Ian

[Tonys]

Ditto. A 102mm frac would need a sturdier mount, which could probably add significantly to the cost. Regarding the CA, I have an F8 and it's only an issue for me with Jupiter and Venus, so an F12 should be okay.

[John]

I'd go with the refractor actually. If you had said a 127 mak I would have said very close but the mak might just steal it but a good 4" F/12 achromat (assuming you can find one !) would perform better on the planets, the moon and binary stars than a 102 Mak, in my opinion. The points about mounting practicalities of the long tube of an 102mm F/12 refractor are perfectly valid though and not to be overlooked.

[Smithfire]

I have a EQ5.

I Could be tempted by a 127 mak if it would edge it over a 102 refractor?

Clive

[Schorhr]

Hi,

why not a 6" newtonian?

The neq5 and a 102/1000mm refracor allready has a few issues (long leaver), I would guess a 1200mm refractor would make things worse, especially for imaging the shorter newtonians or Mak may be the better way to go.

[Alien 13]

I have a EQ5.

I Could be tempted by a 127 mak if it would edge it over a 102 refractor?

Clive

Me too, i do need a planet grabber that is super lightweight and doubles up as a telephoto lens..

[JamesF]

I have a EQ5.

I Could be tempted by a 127 mak if it would edge it over a 102 refractor?

Clive

The 127 Mak would have about 50% greater aperture area over the 102 even after allowing for the central obstruction and will have better resolution thanks to the larger diameter.  That's going to be hard to compete with.

James

[Schorhr]

As telephoto lens the 4" Mak is indeed a nice device, but at f/12.7 has it's limitations :-)

[hobsey]

Go for the 127 mak.

[Caldwell14]

I have never looked through a mak and though I must buy one, mushy views on the whole, often very mushy.

[John]

I have a EQ5.

I Could be tempted by a 127 mak if it would edge it over a 102 refractor?

Clive

You could put a 6" mak-cassegrain on the EQ5 and have a great planetary scope

You might want to think about drives for the mount if you don't already have them.

A lower cost alternative would be a 6" F/8 newtonian, which also give great planetary and lunar views. You can pick those up as optical tube for around £100.

[Mr Spock]

With a Mak you'll need to watch cool down times. They take ages if you go from warm air to cold air.

[twotter]

The answer is the mighty TAL100RS

[Smithfire]

Oooooh just checked the TAL100RS out online good credentials! Tell me more!

Clive

[nightfisher]

Oooooh just checked the TAL100RS out online good credentials! Tell me more!

Clive

The Tal100 IS a very, very good telescope, but now hard to find one and the 127 mak will be just as good, in a shorter package

[Ags]

I have a 102mm mak, it is great for planets! A long refractor would need a heavy duty mount by comparison, and simple leverage suggests it will wobble every time your eye brushes the lens. Also that long frac tube will make for some awkward viewing positions. And it will be heavy. Setup will be pain. Mak good. Frac bad. :-)

[Caldwell14]

A TAL100RS  on an AZ4 would make a very nice outfit indeed. It would be very difficult to find an unbiased voice against such an outfit, much in the same way some folks advocate the 200p SW Bostonian...a no brainer. 

[Caldwell14]

My predictive text is at it again, that should be dobsonian.

[Stardust]

127 Maks are suberb scopes, I kept one over a OMC 140 1/6th wave. I had them side by side and so wanted the OMC to win but It wasn't really worth the extra money. They've both gone now but I wont part with the TAL 100RS  

[Dude_with_the_tube]

my new toy Celestron/Vixen 90mm f14.4 (F=1300mm ) refractor is stunning performer planetary wise.Literally no false colour at all on moon and gives superb crisp views on it.tried it on Pleiades and was gobsmacked.nice pin sharp stars and lovely pitch black background.

Scope will be undergoing "surgery" in january when new focuser arrives so the scope can accept 2" eye pieces as at the moment only 1.25" can be used,but with Ethos its  breathtakingly good.Small plastic surgery will be done in a few days time to lift up the visual looks of the scope

so if back to topic frac or mak,its frac for me any time. Maks are great,but cooling time isnt.Frac takes only a few mins if any and its ready to go.And there is something magically magnetic to these nice old looooong focal length fracs.every on wants one,not every one has one and who has one,wants another one

[Smithfire]

Thanks for all the replies everyone. A second hand 127 mak does seem to tick all the boxes, and like I said it would only be for planetary viewing and maybe a bit of webcam work later on.

Clive