90mm refractor vs 90mm mak. which is better

[kuro]

As title suggests, which scope is better

[jgs001]

I think that's more dependant on what you want to look at or achieve, as to which is better. both have the same light gather ability (aperture) and resolution. The Mak has a central obstruction which reduces contrast, the frac will have much better contrast. The tube of the Mak is shorter, for a longer focal length, so can have benefits for mounting. A cheap frac will probably suffer from chromatic aberation, which the Mak won't.

Do you have a specific pair of scopes in mind ?

[E621Keith]

Depends on which 90mm refractor and which Mak and what you use them for.

A 90mm Questar 3.5 mak will probably beat most mass produced refractors on moon and planets, but premium Apo, such as Tak Sky 90, will turn the table.

Refractor will be better for widefield.

On the more budget end of the scale, I think a WO Mergez 90 will perform better than a Skymax 90.

What scope are you considering?

[GeorgeB]

It depends on what 90mm refractor you are thinking of. A refractor doesn't have a central obstruction, so has greater light gathering. On the other hand a Mak would be optically of higher quality than an equivalent cheap achromat refractor and would be better value for money than a top end refractor that is optically equivalent. If you were more into getting good crisp views of the Moon and planets then the Mak 90 might be preferable. On the other hand, if you wanted wide field views of faint fuzzies then a good quality short focal length 90 mm refractor might be better.

[kuro]

I have a celestron 90eq but have been looking at a skywatcher mak for portability

[LukeSkywatcher]

I've just been cuddling my 200mm SCT again. I forgot just how light it is.

[Alma]

Depends also on the type of mount. If you have a GOTO mount then I would say a Mak over a cheap'ish refractor every time, however the high focal ratio (typically f/12) of Maks makes it quite difficult to find anything without GOTO. In that case I think a low focal ratio refractor of around f/6 to f/7 would be better, but try and get an ED or APO quality scope if possible as chromatic aberration becomes much more noticeable in short focal length refractors.

[E621Keith]

If you have an Celestron Astromaster 90 EQ then a Skymax 90 should be better. The Mak should have less chromatic abberation and will be finished to a higher quality standard.

The Astromaster is F11, the Mak is F13, neither are widefield instrument.

[kuro]

Well I bought the scope anyway so I now have two. I will compare them and keep the one I feel more comfortable with.

My refractor is the Celestron firstscope 90eq which I bought because of favourable reviews and seems well put together although I have not had the chance to use it yet.

Paid £80 for the Skymax 90 which was hardly used, has a few extras and also a custom made case. Does this sound like a good deal? Ive seen a few of these go for well in excess of £100

[mdstuart]

Sounds a great deal to me!

Mark

[kuro]

Oh No! Just saw on the ebay listing that a question was posted and it turns out that its an 80mm version which i guess will be inferior to the Skymax 90 and therefore my 90mm refractor.

Is it possible to back out of the deal as this was not clear on the main listing. I won it in the last few seconds so it will make no real difference to the seller.

If I have to go through with the deal is this a poor scope?

[RikM]

I would say you got a good deal. The Skymax 90 is a lovely little thing.

[kuro]

Yes, but Ive bought an 80mm thinking it was a 90mm

[RikM]

Too slow typing.

I am afraid I don't know, never looked through an 80mm Mak. I have a 127 and an observing buddy has the 90. They are both good for small scopes and no CA, which is nice. I would expect the 80mm to be quite similar. If you now have both, compare them side by side and move on the one you like least.

[E621Keith]

First time I've heard of a 80mm mak but I Googled this photo of a Skymax 80. I don't think SW make this any more.

The central obstruction looks huge for a Mak. 30+% obstruction in a large CAT may not be a problem, but it may cause some problem on a 80mm.

Skywatcher 80mm Mak Cass F13 | Flickr - Photo Sharing!

Ebay is a dangerous place. While there are some good deal, it also easy to get burned by bad one.

[kuro]

I found a review that said it was quite a good little scope. at the end of the day i will still have my 90mm refractor to fall back on and if this proves. no good i will sell it on.

i don't think the listing was deliberatly misleading as the seller was listing on behalf of a friend and only put in what he was told.