Cosmic Geoff

I used the "economy" style drive on a EQ-2 clone mount some years ago. It was awful.

After seeing your image I had a go last night imaging Saturn in visual and infrared with CPC800, ASI224MC, ADC, ZWO IR-pass filter.

3000 frames, processed in registax6.

I then took off the ADC and imaged in infrared with the ZWO IR-pass filter. This gave the sharpest result - possibly my sharpest image ever of the major ring division.

The seeing was bad. Not conclusive, but interesting.

A Celestron SCT or Celestron Edge HD SCT seems to be the preferred tool for planetary imaging, so no worries...

You could get a C9.25 instead of the C8 Edge HD?

I assume you are just buying the OTA?

Lots of detail on those rings. With IR pass filter and Powermate, what was the frame rate/exposure time like?

I would not worry about whether the setting circles work properly or not, as they are of little practical use in any case. They are simply too small to be of use for finding anything with the main telescope. GoTo has made these things obsolete, and the circles that were of practical use were from 6" up to 2 feet in diameter.

4 hours ago, MarsG76 said:

I was wondering about the C8S and C8A designation.. both a StarBright XLT and are sold as brand new...

Dovetail bar width? There seem to be two options.

This may help: https://www.scopereviews.com/C8History.html

C8 SCTs have been manufactured for nearly 50 years, and some people are still using the older ones.   Recently we had a thread from the owner of a 30 year old example who took it apart and cleaned the mirror (to the horror of some respondents). Reportedly the SCT was fine afterwards...

My own C8 (with Starbright XLT coating) could be at least 5 years old, and it's OK.  So I wouldn't worry about the mirror degrading if I were you.

On the other hand, it seems that vintage C8's from some years are of poor optical quality and best avoided - see the History and elsewhere.

I suggest just go with the 25mm eyepiece you've got, and then decide if it's worth spending out for another eyepiece. Since you have GoTo, you can centre the companion galaxies M32 and M110 - in a photo M31 extends out to these, but most likely not visually.

Visually the satisfaction lies mainly in finding a fuzzy blob representing the central part. 

Ioptron? Check their catalog - I'm sure they do something like that. It'll be a GoTo - any new mount that tracks is a GoTo these days.

21 minutes ago, Markinaboat said:

Rather than start a new topic, just wondered if anyone would know if this would power a 127SLT (considering buying used as a 2nd travel scope for my boat) for maybe 2/3 hours? Seems good for the price and of course safer than a life-po battery.

That link didn't work. There are 57 different ways of powering these mounts.🙂  Three that I have actually tried are:

a 12v 7Ah sealed lead-acid battery (cheap and runs mount for ages, far more than 2/3 hours).

10x 1.2v rechargeables in a battery holder - this worked but you'd need to find or make a suitable 12v charger.

Celestron LiFePo 86WH powertank - expensive but lightweight for the capacity and totally safe, supposed to last longer than lead-acid.  Again, this will run your mount for ages. Any bad news you may have read refers to poor quality stuff from China, or misuse.

If you want to mount a C8 for planetary imaging, the minimum requirement is not that severe.  For a whole season I used a C8 with the SE alt-az GoTo mount. It is not suitable for the purpose - it's wobbly, has backlash and for this exacting task tended to drift, but none of this affected the quality of the planetary images.  I also used a RA motor-driven EQ5 one night - that worked OK too.

An EQ-5, HEQ5 or AVX would do the job, but note that you don't need a EQ mount for planetary imaging - in fact it might be better to use an Alt-Az GoTo, since one expert points out that tipping a SCT upside down partway through the session might induce some mirror shift and put the collimation out.

I actually use a CPC800 at the moment- no polar aligning required!

I think that the seeing is the dominating factor. If you look at my recent posts where I include an unprocessed frame you can see that the typical blur was just awful and I suspect will swamp the effect of binning and barlows.

4 minutes ago, Davey-T said:

I see you're using a colour camera, what are the pros and cons of using colour versus mono ? I've got a filter wheel with a set of Baader LRGB filters in, was just using the L last night for testing

The colour camera gives a good enough image with far less work. I don't want to be bothered with filter wheels, 3x exposures and extra processing work. 

What field of view are you aiming for? To mimic the effect of a 25mm visual eyepiece you will need a camera with a chip with a size of the order of 25mm. The ASI 120MC and other planetary cameras have a chip size of 4.8mm or similar, which means that it is 25 times more difficult to get an object in field than with a low-power eyepiece.

Perhaps you should look at using a DSLR instead.  These have large sensors and may cost less than a large chip astro camera.

Were you using full frame? I crop to 320x240 for planets which vastly increases the frame rate. No need to record a lot of black sky.  Frame rate on Saturn can be slow especially if there is excess extinction.  Last session I got something like 60 fps IIRC with an ASI224MC and 8" SCT in clear conditions.

When you have the Moon in focus with the camera, mark the focus barrel with a pencil (etc) and use this mark to get a first focus on Jupiter.  Use your finder to acquire Jupiter - it will have to be accurately set up.

I have a Nexstar SLT 127mm Mak (5")  and based on my experience with this I suspect that the new 6 SLT is pushing the limits of the mount.  Is the SLT6 a WiFi? Do you really want that or would you prefer the more reliable option of a handset?  The 6" telescope is also available in the form of the 6SE, which is a more sturdy mount but also a lot more expensive. There is also the 6" Nexstar Evolution, which clearly costs more than you are prepared to pay but represents a proper mount for this scope.

The Star Discovery 150p is a 6" Newtonian, but it  is a lightweight budget version.  You get a GoTo mount, but AFAIK this is also a WiFi mount. (If one is being cynical, this saves the makers the cost of supplying a handset).

Neither of your provisional telescopes is awful, but also consider the 127mm Mak, which you can get with various mounts.  The Celestron SLT version has easy to use software and a handset.  I still like my Mak and get it out quite often, despite now having bigger telescopes.  If you get the Mak or one of the SCT designs like the 6 SLT, you have the option of putting it on different mounts at some later date.  With the Star Discovery it is more likely that you'd change the whole outfit IMHO.

I can understand why you don't get on with a large Newtonian on a German equatorial mount - this combination is notoriously user-unfriendly, and after a brief encounter with an 8" example I bought a C8 SE to replace it.

I bought a CPC800 to use for planetary imaging. I don't have figures, but the mount is really solid and tracks well. there is almost no backlash.  Like you, I wanted a stable mount that did not require polar aligning etc etc.  In this respect I am totally satisfied.  Setup time is longer than I hoped but is as indicated in the previous posts. (With a C8 SE one can just pick up the whole assembly and carry it outside, making setup time very low).  BTW you do not need to align the tripod N/S - that's a Skywatcher feature, not Celestron. 

On the downside, the fork/OTA assembly is disagreeably heavy, about44lbs/21Kg, and you have to be able-bodied to manhandle it.

Re wedge, the relevant wedge costs 400 pounds and I have not seen much positive written about the portable fork/wedge arrangement. A case of "should have kept the NEQ6"?

Re focal reducer, I have read that, far from being cheap, the Edge HD focal reducer is far more expensive than the C8 reducer and costs several hundred pounds.

Saturn on 14 July.  The main division is not as sharp as I would have liked, but the inner ring shows up very bright and one can see symmetrical shadows of the planet on the rings.  Altitude about 14 deg.

Imaged with CPC800, ASI224MC, ADC

14 July - Jupiter with Io (on left) Callisto (below ) and GRS.  Imaged with CPC800, ASI224MC, ADC. 

I never seem to get the detail pin-sharp, but see the raw frame included for comparison.

15 July - Jupiter imaged with C8, ASI224MC, ADC. The SE mount is awful, but does not affect the final image quality.  The other side of the planet, looking rather plain.  Looks like a disappearing GRS on right.

An EEVA-style image of Saturn's moons. 14 July, 22:07 UT, taken with CPC800, ASI224MC +ADC.

Exposure 5 secs. The faintest moon visible is Encelasus, mag. 11.7

Next night I looked visually with an 8" SCT and could not make out any moons at all.  Our Moon nearby was near full.

Saturn is severely overexposed in order to get the moons.

I am not familiar with the Meade or its spec but the Edge HD has a built-in field flattener which AFAIK is of more use to advanced astrophotographers than to those who want a scope for visual or for imaging Jupiter.  The Evolution mount is very nice and has wifi  and a built-in battery - alternatives are the cheaper mount of the SE (not bundled with Edge) and the very stable (and heavy) fork mount of the CPC800, to name just two. The basic C8 SE is a lot cheaper than the Meade.

The Starsense is a nice accessory (I have one) and saves some tiresome alignment when you set up. It also has some handy observing lists in the handset.  Worth considering especially if the bundle on offer is saving you some of the £300 price.  It has to be said that GPS (built into the CPC800) also halves the labour of setup, reducing it to just pointing the scope at a couple of objects and synchronizing.

I hope this helps.

I suggest that you find a camera to attach to the scope and run the output to a laptop., and see what you make of the performance and user-friendliness of this arrangement.

When I got my first GoTo scope, remote viewing was at the forefront of my mind, but in practice I have not pursued this and do not see it as a useful or desirable objective.

Large Newtonians on German equatorial mounts are notoriously user-unfriendly. If the size and user-unfriendliness of your scope and mount are the issue, have you considered changing to something easier to use? Like a SCT on an alt-azimuth mount?

If you have put a f9.8 102mm reftactor on a SLT mount that could be your problem.   The SLT mount is designed for short and lightweight OTAs and the pendulum effect of a long OTA (as distinct from its weight) is widely thought to make matters worse. 

The two scopes are as different as chalk and cheese.  Before buying either, you should take a sheet of A4 paper and write down for each scope:

What exactly you intend to observe with it. Which kind of objects?

Where you are going to store it.

How you intend to get it from store to observing site (in the extreme case you may need a pickup truck for the 16" Dob, for all I know).

How you are going to get it mounted up for each session.

(As an alternative to the above three, where are you going to site your observatory, what about security for it and what's your observatory budget?)

Are there targets you want to image? If so,  what kind of kit is used or recommended for these projects? Only the SCT is really suited for imaging anything, and it is best suited for planetary imaging.

Somebody mentioned EEVA. You should look into that before buying a BIG scope.  I made a couple of experiments and found to my shock that a small cheap telescope & EEVA gear would pick up galaxies just as well as an expensive telescope of twice the aperture without EEVA.