SCT or Mak for Lunar/Planetary Imaging?

[BlueAstra]

I have a choice between a Celestron C6 XLT SCT or a SW 150 pro Maksutov for lunar and planetary webcam imaging. The C6 is 150 mm aperture, 1500 mm focal length, F/10. The SW Maksutov is 150mm aperture, 1800mm focal length, F/11.8. Which do you think would be the best choice?

[Cornelius Varley]

Maks tend to give sharper images than SCTs but also tend to take longer to cool down (thicker corrector lens). The SW150 has an advantage over the C6 in that it should be easier to collimate, which shouldn't be very often.

[Mr Spock]

If you can manage the cool down time then the Mak will be better. With a smaller central obstruction it will give more contrast.

[Peter Drew]

I've always considered that the Mak is a better optical system than a SCT, however evidence shows that SCT's seem to be the first choice for lunar and planetary imagers. The pros and cons of the apertures you have specified suggest that there would be little between them and that either should give good results. Planetary imaging, however, is enhanced by increasing aperture, had the choice been between a 8" SCT and a 150mm Mak I would have plumped for the former.  

[johninderby]

The C6 OTA is nearly a kilo lighter than the mak which may be important or not. I did a head to head a few years ago and it was basicly a tie for sharpness of views. The C6 also keeps it's collimation very well compared to a bigger SCT. Collimation simply won't be a problem at all with the mak though. For purely lunar and planetary the longer fl of the mak would be a small advantage but not that much. The C6 has the advantage of faster cool down times.

My conclusions after the head to head was that  there wasn't much to choose between them. The mak is a good little mak but the SCT is a great little SCT. You can't go wrong with either of them.

BTW after the head to head ended up keeping the C6.

            John

[spaceman_spiff]

Well I have the 150 Mak and I am very happy with it. I use it for narrow field imaging (Solar, Lunar and planetary). With a good Barlow, this little scope is capable of resolving excellent detail. Cool down time can be an issue sometimes, before doing imaging, I leave it in the garage to cool down but it still needs an hour or so before it is at its best. I have never needed to collimate it and defocused stars are still nice and symmetrical in the centre of the field (meaning it is well collimated).

For video imaging I mount the Mak on an EQ5 pro, even with a Barlow this mount keeps things very nicely within the FoV.

I can't comment of the C6, but I'm sure it is also a good performer. It's been around for a long time so there should be lots of reviews of it.

HTH Dan.

[riklaunim]

For imaging there is in general no difference which design you pick. The key element is aperture - more is better. What the design may affect is the thermal stability, ease of collimation (and it stability) and alike. For 6" Mak is getting to big while SCT is almost big enough to be optimal I would pick SCT, but likely trying to find a 8" OTA.

[Chris]

Out of those two I'd say if you can store it outside go for the Mak, but if you are taking the the scope from inside to image definitely go for the faster cooling 6" SCT. I've owned a C6 and wish I hadn't sold it. I also briefly owneda 6" mak and just couldn't cool it properly in the time I had to observe. I don't think I would go above 5"in a Mak unless I kept it outside.

C8 would be better for planetary imaging as said.

[johninderby]

I too made the big mistake of selling my C6. Realy, really wish I had kept it. 

Like my little 127 mak as it is just the right size for a portable scope and cooldown isn't a problem but the 150 is a lot heaviier and takes a lot longer to cool-down. 

            John

[BlueAstra]

Thanks for the replies. I'm thinking of a Celestron Evolution 6 or the Evo base from FLO plus the SW 150 Mak. I can store the OTA outside. I also want it to be portable (car) for dark site use.

[nightfisher]

I have had 2 yes 2 150 pro skymax maksutov ota`s, they really are that good, i still openly feel the 150 Mak will trounce my 120ED on luna and planet viewing (but the 120ED is more all purpose scope), i have not looked through a C6, but feel for planetary and Luna imaging the 150 pro is the one to get 

[BlueAstra]

I think I'm going to go for the Evo 6 for a number of reasons. The Evo 6 is £1209. If I were to buy the Evo mount and say the SW 127 Mak it would cost £1156, roughly the same. However, the 127 Mak is less aperture than the C6, and the price of the Evo 6 package is £315 less than buying the Evo mount and C6 OTA separately. So effectively you are getting the C6 for half price in the Evo 6 package. The saving in the Evo 8 package (cost £1799) is only £95 less than the separate prices so not quite such a good deal. I had thought of the Evo mount plus the SW 150 Mak, which has similar aperture to the C6, but this would cost £1426 which is £217 more than the Evo 6 package. There seemed to be a view that the performance of the C6 and 150 Mak would be broadly similar, so the saving on the C6 OTA in the Evo 6 package is worth going for. I know aperture rules for planetary and lunar detail, but I wanted to keep the package reasonably small and light for portability. I could go for the Nexstar mounts, but the 6SE plus skyportal plus battery would be about £1000, but I think I like the Evo mount better.

[Chris]

1 hour ago, BlueAstra said:

I think I'm going to go for the Evo 6 for a number of reasons. The Evo 6 is £1209. If I were to buy the Evo mount and say the SW 127 Mak it would cost £1156, roughly the same. However, the 127 Mak is less aperture than the C6, and the price of the Evo 6 package is £315 less than buying the Evo mount and C6 OTA separately. So effectively you are getting the C6 for half price in the Evo 6 package. The saving in the Evo 8 package (cost £1799) is only £95 less than the separate prices so not quite such a good deal. I had thought of the Evo mount plus the SW 150 Mak, which has similar aperture to the C6, but this would cost £1426 which is £217 more than the Evo 6 package. There seemed to be a view that the performance of the C6 and 150 Mak would be broadly similar, so the saving on the C6 OTA in the Evo 6 package is worth going for. I know aperture rules for planetary and lunar detail, but I wanted to keep the package reasonably small and light for portability. I could go for the Nexstar mounts, but the 6SE plus skyportal plus battery would be about £1000, but I think I like the Evo mount better.

That makes sense to me mate. The Evo6 looks both portable and low hassle goto wise. I always use Skysafari on my phone to find stuff so why not use it for the goto setup as well, that's what I say  

The 6SCT will have slightly less contrast than the Mak for visual, but will cool a lot faster and will be quite a bit lighter. I bet you'll be able to carry the Evo6 in one go  

[nightfisher]

sounds a good plan, let us know how you get on with it, i am toying with going back to a mak, maybe a 127 on goto mount

[johninderby]

Have to agree seems like you've got it sorted. Looking forward to your opinions after you've got it.

 

I do,have a 127 mak and somewhere boxed up in the garage is a Sky Prodigy mount. Hmmmmm 

               John