Cosmic Geoff

Your money would be better spent on an EQ5 Synscan (used) or on upgrading a used manual EQ5.

The SCTs are lighter and more compact. And if the SCT and the Newtonian are mounted on GoTo mounts of equivalent performance, the argument that the Newtonian is cheaper loses much of its force. I have owned both types, and there is no way I would want to revert to a Newtonian. I have reently acquired a f6.3 focal reducer BTW.

It depends on the seeing. I soon realised that I could get better views of the planets by imaging than visually. And I realised after a while that even with an 8" SCT the results were variable, apparently dependent on the seeing. I read that the most fanatic planetary imagers take their big SCTs to the Carribean, where the seeing is better than in the UK. And if you want to "dabble in deep sky" a much smaller scope would do to start with. Many deep sky imagers use small refractors rather than big Newtonians.

Many astro cameras eg. the ASI224MC require an IR-cut filter to achieve the correct colour balance with an OSC colour image. I do not see that any other lind of filter will be any use for EAA of galaxies.

I bought a used EQ5, added a single axis drive and manual Dec slow motion via a knob or long rod, and later converted it to Synscan. I was not aware that there were two possible positions for a Dec motor - you can see where I put mine if you look at any pics of a Synscan EQ5 mount. I think you can dispense with the manual slow motion knobs. My RA drive had a clutch that disengaged the motor but it was too fiddly to use and I never used it. For fine adjustment you can use the electrics and for coarse movement disengage the mount clutches.

Short answer: because you do... your scope was not specificically designed for attaching a ASI183MC camera - it was designed for use with a diagonal and an eyepiece. If your experiments so far don't indicate what size of extender you need to get within the focuser's range, you could buy a set of T2 estenders, eg this one: https://www.svbony.com/svbony-extension-tube-M42/ I bought a set of Svbony extenders which may not have been this exact one. One of these extenders or a combination of them should get you sorted. I assume your camera has a T2 thread if you unscrew the nosepiece (if it has a nosepiece).

A picture of your intended setup would be useful. I have a Startravel ST102 and find a planetary camera will come into focus with a diagonal or an extender. To focus a DSLR, a T2 extender about 2" long is needed.

That is curious behavior, but quite possible for a switch-mode device which boosts the voltage up to a constant level. (There is an indication elsewhere that these mounts develop a higher voltage internally to drive the motors.) At one point in my career I was designing (not too successfully) a switch-mode power supply that boosted a battery voltage up to a constant level. I found that the lower the input voltage, the greater the input current (as above) and that a nasty feedback loop was liable to develop which dragged the input down...

In that case you should start saving up for a mount and tripod suited for imaging. As an absolute mimimum, I'd suggest an EQ5 Synscan with 1 3/4" steel tripod, unles you want to settle for a DSLR + telephoto lens + tracker mount. You can put other small telescopes on your SLT mount up to its weight limit, and even try some short exposure imaging. What do you think the Star Adventurer Pro will do that the SLT won't? EDIT: I did not know the Star Adventurer Pro was a star tracker...

is this good for it? Depends what you want to do with the mount. The weight and load capacity of the tripod (given in the link) clearly indicate it is intended for use as a portable visual mount, rather than for imaging. For about £30 more you could buy a much more substantial Sky-watcher tripod with a flat top and IIRC a 3/8 screw. The tripod in the link will be as wobbly as your SLT tripod.

I have done some EAA (EEVA) with an alt-azimuth mount. I did not use a DSLR (and some DSLRs may prove entirely unsuitable for EEVA). I use a ZWO ASI224MC for my EEVA (mainly because I already had one I bought for planetary imaging). I use Sharpcap 4, which also supports plate-solving. A check you could do is to put your 25mm Plossl kit eyepiece, that you probably got with the scope, in the focuser, focus it on a star, and then check that you can wind the focuser inwards by 5 to 6 mm. If you can't, you may not be able to bring an ASI224MC to focus, and if you can't focus that, you may not be able to focus any other camera either.

I don't think a recommendation as such is necessary - any machine that runs Windows and isn't ancient should be adequate. Ebay is awash with ex-business laptops running Windows 10, refurbished and sold on by dealers, going for low prices. And don't put all your childhood pictures on a laptop or any other machine unless you have a backup. The #1 problem with slimline laptops is the hinges - they get stiff and rip the screws out of the slim plastic mouldings. I use a Dell Vostro 5468 which is several years old.

Electrolytic capacitors do age and fail with swollen tops, so you should definitely replace the two capacitors as suggested above. You say that the mount works OK with the handset, which indicates that the fault lies with the other stuff. We used WiFi to connect laptops in a lab where I once worked, but had to take it out because the other gear in the lab interfered with the wifi, making it useless.

Don't assume that accessories that some people have fitted to their telescopes will be needed on yours. I have had a CPC800 for several years, used it for visual, planetary imaging and some deep-sky imaging, and so far have not been troubled by mirror flop or felt the need to invest in a Crayford or an electronic focuser.

The most effective way to find focus is to focus visually on a small bright object e.g. Venus, Jupiter or a first magnitude star using the stock 25mm Skywatcher eyepiece. Pull the eyepiece out by 5 to 6mm and refocus. Now remove the eyepiece and fit the camera with its 1.25" nosepiece. The camera will not be in focus but shoud be close enough so that you can now see a blur circle (or blur donut) on which you can focus if you have a roughly suitable gain and exposure time (try gain =300 and exposure time of 10 to 100ms). The in-focus exposure time for Jupiter is only 2 to 4 ms, as the camera is sensitive. Apologies for stating the obvious, but you should remove the fisheye lens from the camera, and if you want to attain the correct colour balance in your images, you should buy and fit the ZWO IR-cut filter to the nosepiece. If your focuser has insufficient in-travel you may not be able to get focus for the camera without using a Barlow lens etc. I recall that when I had a 203mm Newtonian, the planetary camera I had only focused with the focuser at the inner limit of travel.

An EQ5 Synscan not behaving well? What else is new. 🙁 I assume this is referring to the alignment routine. I'll refer to my experience with the mount, which I still have not totally mastered after nearly two years since upgranding it. The initial movement from the home position often fails to accurately locate the first star, or the second. As for a three star alignment, I have given up on that - it's hard enough to figure out where the alignment stars are with a two star alignment. Give me a Nexstar alignment procedure any night of the week. I have found that if one does a good polar align followed by a two-star align, using two alignment stars on the same side of the meridian, the mount will then perform on that side of the meridian with gratifying accuracy. However if you want to GoTo an object on the other half of the sky, then tough, you are back to using the finder or a Platesolve & resync, unless you want to go through the alignment process again with a fresh pair of stars. I have found the mount works well in conjunction with an imaging scope and Platesolve & Resync. If I was using it with a narrow field visual scope I would probably have concluded by now that it was a waste of space in my storage facilty.

I assume we are discussing the hardware Starsense camera and handset here, not the smartphone app? My suggestion is to get the system working without the wifi etc and then add the wifi and ipad. You might have to temporarily refit your finder (without unplugging or powering down the camera) if the alignment is a way off.

There is sure to be a pair of screw positions somewhere on the back rim to which you can fix the finder once you have bolted on your dovetail bar. Whether it will be in the ideal position is another matter. There may not even be an ideal position, given the positions an equatorial mount gets into.. However if I were you, I would consider selling the complete CPC800 on and buying another OTA. This would give you the option of buying another C8 OTA (possibly making some money) or going for an Edge HD or one of the new Classic Cassegrains.

Seeing the rooftop inverted strongly implies that you are not using the star diagonal. You should use it to avoid pointless neck-ache when observing the night sky. Fitting the diagonal will give you an erect image (but reversed L-R) and require a significant refocusing. We have seen a number of newbies complain of this, particularly when using a low-power eyepiece. Needless to say, I have never had this problem with my telescopes, and avoiding it is probably a matter of getting used to using a telescope.

You should not need a 40mm eyepiece for that purpose. With the Nexstars (including the Celestron equivalent of your scope) I have found that the Goto alignment if properly done will place objects within the field of a 25mm eyepiece. If you are not getting that degree of accuracy with your Az GTi, some attention to the mount or alignment procedure may be required. BTW you might as well have a 32mm 1.25" Plossl, as the actual FOV will be the same as with a 40mm 1.25" Plossl.

It should not be dificult to get the 8 SE into focus if pointed at a suitable target. "White" suggests you are trying this in daylight. You need to find a high-contrast target such as distant tree branches against the sky, and then wind the focuser till it comes into focus. If you focus on a distant point of light at night and the focus is not too far out, you will see a bright disc or donut, which makes things much easier as you wind the focus knob in the direction which makes the disc smaller.

If finding objects quickly is part of your requirements, I suggest a C6 SE or C8 SE GoTo SCT. The C8 has the aperture to show lots of galaxies and other DSOs from a dark site, and is compact enough to be easily transported by car and light enough to be carried a modest distance. Not cheap though, at today's prices, unless you can pick up a used one. I have taken mine down to rural Devon a couple of times.

When I looked for one a few weeks ago I saw several on ebay and eventually got one via astrobuysell.com/uk/

In my experience with the same mount, a bad power cable connection will definitely cause malfunctions. You can splay the split centre pin slightly with a craft knife, and attach a cable tie to stop the cable shifting around at the inlet. You can also get a bad connection where the handset plugs into the mount arm. If the handset cannot get a response from the mount, an Error 16 or Error 17 will result. The cause can be scrambled firmware (had that), or a failed internal connection ( not had that) or a general failure caused by something like water in the connectors (had that). It is not a simple matter to refresh the firmware even if you have a working mount and handset and power. See nexstarsite.com for guidance. How far do you get before encountering an issue?

Any error codes? Have you checked that the power cable is making proper contact, and/or the battery is charged? Has any water got into it? Did it find the mount previously? Various things have to work for the firmware update to succeed. I imagine Celestron can supply a replacement board as a last resort, as this is a current model.