SCT or MAK

[Neil H]

Hi hope your all well , I have a question I do enjoy looking at the moon and planets  some times I do fit my small 224 mc camera but my acromatic refractor puts a purple tinge to the edge of the target so was thinking of getting a SCT or MAK I am leaning more towards the SCT but are they worth the extra cost over the MAK

I do 99% visual  

 

[vlaiv]

I'd say - decide based on aperture.

Up to say 5" go with Mak - above that go with SCT, of maybe consider classical Cassegrain

[Neil H]

Sorry classic cassegrain can you link one please , found a thread by John in derby so now I know what a classic cassegrain is ,  the 8 inch stellalyra looks a nice tool 

Edited July 31, 2022 by Neil H
Up to date info

[vlaiv]

1 hour ago, Neil H said:

Sorry classic cassegrain can you link one please , found a thread by John in derby so now I know what a classic cassegrain is ,  the 8 inch stellalyra looks a nice tool 

Yep, there are 6", 8" and 10" versions

 

[Greymouser]

I would also suggest the possibility of a very long focal length achromatic refractor, such as: https://www.astroshop.eu/telescopes/bresser-telescope-ac-102-1350-messier-hexafoc-ota/p,54409

I have one and initial trials suggest there is no CA at all. It has a good focuser and only weighs about 5 KG. It is long however, but my Skytee easily handles it. As does my AZEQ5. On the moon it is very sharp and I look forward to trying it on Jupiter et al soon. 

[Neil H]

I do have the besser 127/1200 which is nice and has a sharp image till you pop a camera on  then it's not so good 

This is part why I want a different telescope  . I have the HEQ5 pro which should not have a weight problem with a cassegrain 

[CraigT82]

Didn’t you have a 200p newt Neil or have I made that up? 
 

I think any of the CATs will do well for you so it comes down to personal preference. I’ve never had a classical cass so can’t comment on those but I did have a skymax 150 and I absolutely loved it, hits a real sweet spot of size/portability and capability (both visual and imaging).  Downsides is that you will most definitely need some kind of dew management. 
 

 

[catburglar]

I’ve had both a skymax 150 and C6 SCT so had an opportunity to do a side by side test on a few occasions…there wasn’t much between them visually, although the image in the max generally seemed to have a bit more sharpness at focus whereas the SCT was a bit ‘mushier’- in reality there were very few occasions where I was convinced that I could see more in one than the other, but the Mak was usually the more pleasing view.

I’ve also owned a 7inch Mak, and this too was optically very sharp, but at this aperture the cool-down did seem to be much more prolonged than the 6 inch - so it needed well over an hour on some nights before the tube currents disappeared…I’ve subsequently seen members use a insulating jacket  to ease this but never tried it with that OTA. I’ve used it with a 10inch SCT and it does seem to help…so that might go in favour of the Mak…But if you want to go bigger than 8 inches of aperture I think the classical cassegrain or SCT are the better choices.

[Greymouser]

5 hours ago, Neil H said:

I do have the besser 127/1200 which is nice and has a sharp image till you pop a camera on  then it's not so good 

This is part why I want a different telescope  . I have the HEQ5 pro which should not have a weight problem with a cassegrain 

Forgive me, I have not been very clear and you have perhaps misunderstood me. I have used a 127L alongside the F13.2 Bresser, at the same time and the CA in 127L was visible to my eye, in the 127L, not at all in the longer focal length Bresser. The F13.2 was sharper and easier to get good focus too. Don't get me wrong, the127L is a great scope, but for the moon, the F13.2 beat it easily. To put it simply, the higher the F number, the better the performance on the moon and planets, it would seem in my experience. That said, my experience with the Skywatcher ED80, tells me exotic glass can have a significant part to play. My best view of Jupiter recently, was with that.

I will also add that I have two SCT and one CC. My C5 is just so wonderfully grab and go, but at F10, less sharp than the refractors. ( Careful here, no intent to start an argument! ) My C9.25 has shown me some wonderful stuff, mainly at F6.3, but again seems sort of fuzzy on the planets. My CC6 I have not used enough to come to a judgement, but I rarely use it, so I guess it has to go.

I think the advice above from vlaiv, is good though, if you must have a SCT or Mak. I would suggest though, that you consider the Bresser 127 Mak, which at F15 has less of a central obstruction. I have often been tempted, but so far have not got one, because the F13.2 refractor, could well do all I need.

Hope that clarifies and helps a little. I myself will know more when I test the F13.2 on the planets this summer, if all goes well.

I guess that unfortunately, the only way to know for sure, is to try them all out, which for me is all too tempting.

 

Edited August 1, 2022 by Greymouser
spelling.

[SthBohemia]

Let's settle the question once and for all, simple solution regarding the proposed purchase...

A SEVEN INCH QUESTAR 🙂

[Neil H]

Hi yes do still have the 200/1200 Orion optics love it but can't do anything over head or it hits the tripod leg even when doing goto you can't be to sure which ways it's going to go and some times hits the leg 

The bresser sounds great but may be to long the 127/1200 fits in my car just nice a longer one will be a pain 

[Greymouser]

10 minutes ago, Neil H said:

Hi yes do still have the 200/1200 Orion optics love it but can't do anything over head or it hits the tripod leg even when doing goto you can't be to sure which ways it's going to go and some times hits the leg 

The bresser sounds great but may be to long the 127/1200 fits in my car just nice a longer one will be a pain 

Well, firstly, if you like the OO 8", but are having troubles with it hitting the tripod when near the zenith, why not just get the extension for the tripod? https://www.firstlightoptics.com/sky-watcher-mount-accessories/skywatcher-eq5heq5-extension-tube.html  I have one for my Skytee and the long refractors, it works well.

As for the extra length of the F13.2, why not just try a similar length of wood in your car? Soon see then if it is doable. It is only 15 cm longer or so...

It is hard to not want to try new stuff though, I know this only too well. I am forever chasing that better scope, but so far have not reached the end of that journey. Perhaps I need to find Tak money?

If you ned a more compact scope, a SCT or a Mak are just the job, however, they come with compromises. I love my SCT scopes, doubt I will willingly sell them, but they are just not the best visually on the planets. imo. If you have the money to consider a CC 8", perhaps consider a Starfield 102mm f/7 ED Doublet Refractor? I had one for a short while, but it was marginally too heavy for what I wanted it for. It was however a truly excellent scope, with no trace of CA anywhere. I would have kept it if I didn't have the F13.2, but they did similar jobs. https://www.firstlightoptics.com/starfield-telescopes/starfield-102mm-f7-ed-doublet-refractor.html

[Neil H]

Hi I do have an extension tube but if you use it with the Newtonian the eyepiece is about 7 feet up so makes it way to high  , I was thinking of getting another one and cutting it down some thing to look into later on 

My mate just said to me that as I have a really good Newtonian I will not gain by getting a sct of mak other than it's compact , he also said get a big refractor ??

Edited August 1, 2022 by Neil H

[Trentend]

I picked up a C11 last year. It is a bit of a beast but by far the best lunar and planetary visual views compared to all of my other current and previous scopes (FC100, Mak127, 18” dob). Covered mine in B and Q radiator foil and always found it usable straight out the box with minimal cool-down. Having said all that the scope I use the most is a humble skywatcher 127mak. Pin sharp on solar system, no collimation, light as a feather and view much brighter (which I prefer) to my frac.

Have though always hankered after a Mak180 “planet killer”…

Edited August 1, 2022 by Trentend

[JeremyS]

18 minutes ago, Trentend said:

I picked up a C11 last year. It is a bit of a beast but by far the best lunar and planetary visual views compared to all of my other current and previous scopes (FC100, Mak127, 18” dob). Covered mine in B and Q radiator foil and always found it usable straight out the box with minimal cool-down. Having said all that the scope I use the most is a humble skywatcher 127mak. Pin sharp on solar system, no collimation, light as a feather and view much brighter (which I prefer) to my frac.

Have though always hankered after a Mak180 “planet killer”…

Is there a particular reason your Tak is installed upside down?

[Greymouser]

52 minutes ago, Neil H said:

Hi I do have an extension tube but if you use it with the Newtonian the eyepiece is about 7 feet up so makes it way to high  , I was thinking of getting another one and cutting it down some thing to look into later on 

My mate just said to me that as I have a really good Newtonian I will not gain by getting a sct of mak other than it's compact , he also said get a big refractor ??

Have you thought about a smaller tripod then? https://www.firstlightoptics.com/tripods/sightron-japan-carbon-fiber-tripod.html

The lazy geek loaded it up with a mount and a C9.25. If I could afford one, I would for my AZEQ 5. ( Might do anyway, after all who needs to heat the house this winter? )

Your friend is right too, you will gain little with a Mak or SCT, but could gain a lot with a very long focal length refractor. @F15Rules, is right.

[Trentend]

8 minutes ago, JeremyS said:

Is there a particular reason your Tak is installed upside down?

The Taks fine it’s everything else out…

[Louis D]

The only SCT I've looked through that inch for inch rivaled a Newtonian with a hand figured mirror and undersized secondary for planetary views was a Celestron Edge HD (8" in particular).  With a 10mm Delos, Jupiter was sharp, false color free, and showing lots of fine belt details.  It was stunningly better than the multitude of standard SCTs around the observing field that night.  I think it's down to the optics putting all the light bundles where they're supposed to be:

[nfotis]

A HEQ5 mount can handle a Skymax 180 (that's a 7" Maksutov), if you can add an electronic focuser.  The view is quite contrasty and sharp. You may need to use a Reflectix dress of the OTA if your local temperatures are swinging too fast, in order to control internal air currents.

At 2700+ mm focal distance, trying to focus manually is a bit irritating (too sensitive to vibrations with the standard tripod). It's quite more manageable than a C9.25 on that mount, weight-wise (yes, I tried one on my HEQ5 mount).

Of course, a C9.25 is an even better tool for shooting planetary, because at f/20 with a 2x Barlow, you get nearly 4700mm focal distance. It requires some more effort, though, with the mount.

N.F.

 

 

[Gonariu]

Still using your Bresser 127/1200, the solutions could be:
1) diaphragm the objective to 10 cm or 9 cm, thus increasing the f / d ratio but decreasing the resolving power;
2) decompose the photograph into the three red, yellow, blue channels and discard the blue image;
3) use a special filter to reduce chromatic aberration.