Cosmic Geoff

You shouldn't believe everything you read online. 🙂 Cutting the IR with visual pass filter and then adding a IR pass (and visual cut) filter is going to mean you don't pass much of anything. The only reason I can think of for using two filters together is to suppress an unwanted pass-band.

Definitely, yes. I found that with an ASI224MC camera, using an IR-pass filter gave sharper images on Saturn, but with an ASI462MC it fails to do so.

I doubt that it matters much which IR pass filter you use unless you have some advanced project in mind, rather than wanting to see what difference it makes. I use the IR pass filter from ZWO (850nm) that costs about £25. The longer wavelength pass filters may give greater suppression of atmospheric disturbance. Using an IR-pass filter should render the ADC much less necessary (or unnecessary), but if you are using a UV-IR cut filter and an IR pass filter in turn, leaving the ADC in place saves you the bother of removing kit and refocusing. In my case I just rotate the filter wheel.

I meant make your own elevated stand e.g with concrete blocks and put the Dob mount on top of it. Like a table-top Dob but on a larger scale. The 8" Newtonian is not 'far too big and heavy for a tripod'. You just have to buy a suitable mount and tripod (not cheap, alas), de-mount the Dob, fit it with tube rings and put it on the mount. In practice it would be less bother to sell the Dob on and buy another Newt with the suitable mount as a package. It's up to you to decide whether you want to do this and set up a heavy mount and tripod + tube assembly every time you use it, and pay out for a suitable mount (the most likely off the shelf solution would be a HEQ5 GoTo at around £1000) Or did you mean the 8" OTA is too big and heavy for you to lift to shoulder height? At the 8" size another option is to buy an 8" SCT with tripod mount (normally GoTo). In terms of weight, size etc this would be much more user-friendly than a Newtonian or Dob. Not cheap though.

A Maksutov would make a good planetary scope, if you are looking for something fairly small and manageable. You should be able to pick one with a mount that is within your budget. A 150mm PL Newtonian and mount might be within your budget, offering more aperture for the money but more bulky. None of these are likely to give you planetary views as good as you'd get with your 200mm Dob (and an elevated stand).

It might prove challenging, given the small field of view. But why would you want to platesolve, other than for imaging (small) deep space objects? I found that when imaging planetary nebulae etc with an 8" SCT and f6.3 focal reducer, the 'Precise GoTo' available on Celestron mounts was usually enough to get the object into the camera FOV.

Early morning session with CPC800, ASI462MC, filter wheel, ADC, visual pass, UV and methane filters. Jupiter & Saturn: 5000 frame video, processed with Autostakkert & Registax, Moon 500 frame video (infrared), methane single shot of 556ms. The Saturn image is similar to that from 20 July, while the Jupiter image is my best for this season. The Jupiter image taken with the CH4 (methane) filter is interesting. It shows the GRS, a bright belt and two moons.

Only if your expectations are low. A good scope for planetary viewing (or imaging) bears little resemblance to a good scope for beginner DSO imaging. You could try DSO imaging with the 114/500 if you put it on a serious mount. If you are limiting yourself to one scope, then you should decide what sort of thing you want to image (ultrawide, e.g. the Orion ring), wide field (M31 and companions), narrowfield (small distant galaxies or planetary nebulae), or planetary, and buy accordingly. Trying to make one scope or camera do everything is unlikely to end well. There are tools that can show you what field you get with a particular scope and camera.

The C925 will not be balanced once you move it away from the horizontal, unless there is a balance weight not visible in the photos. Also note that the Celestron OTA is designed to be mounted via a dovetail bar on the side. My 8" Celestron SCT is mounted that way.

What objects do you want to see? Faint extended objects will be invisible or very hard to see in Bortle 7, while planets and double stars will be observable. EAA would help to some extent.

I'd need convincing that it is worth trying to upgrade the mount, given that it is already GoTo and has plain bearings. If its existing performance does not match your ambitions and the APO scope, I'd say you need to invest in a better mount. I use an EQ-5 Synscan for EEVA imaging with a 102mm achro. The mount has a bigger weight capacity than the EQ-3-2 and has roller bearings. Ambitious imagers recommend an EQ-6.

SCTs with their typical f10 focal ratio, are not demanding of eyepieces, so no desperate need to buy exotic eyepieces. I use Plossls for the lower powers. An 8mm eyepiece is the highest power you are likely to need. I have a 5mm Celestron X-cel LX I acquired as part of a bundle, but have only used it once or twice in my SCT.

Have you looked on FLO or other sites, to see what kind of mount is bundled with Celestron's C925 when sold with a mount? You will see that they are all GoTo mounts. Celestron don't offer a non-GoTo or manual alternative. See also the CPC925 which is integrated with a fork mount. I have the same tripod that's used for the CPC925. It's quite a heavy item and very rigid. I fitted a second dovetail bar on the OTA of my C8 SCT to mount accessories and to give something to hold on to while mounting the scope.

A case where a camera will reveal far more than the eye. From my Bortle 6 location I have secured many images with a 4" refractor that show spiral arms in galaxies.

It's an adequate planetary camera. But there are later models with smaller pixels that match better with typical planetary scopes, e.g. no Barlow needed with a SCT or Mak. With a ASI224MC and a f5 scope you'd want to use a Barlow lens of around x3.

Check out AWR: AWR Technology (Astronomy - Electronics, Motors, GOTO drives, Sidereal Clocks, Display Units) who may be able to do something for you.

Revelations of driver trouble here: New ASI120MM Mini Drivers Not Working - Beginning Deep Sky Imaging - Cloudy Nights

Premium batteries should work, but I have found that the cheap "8 for £1" batteries are useless. Try a proper power supply if you can. I have not encountered a case where refreshing the firmware restored an apparently dead handset to life. I assume you are plugging the handset into the socket marked "Hand Control". But if you want to try it (which entails buying cable, adaptor and downloading various bits of software) you might at least get an idea of how dead the unit is. Does anything happen if you press the R/L/up/down buttons in the middle of the handset? You could also dismantle the mount base to see if anything is unplugged in there.

The problem could be anything from bad connections to a faulty handset. Since you got it from an estate sale, there is no guarantee that someone hasn't opened it before you and fiddled with the insides. Are you using an adequate +12v PSU? You can buy replacement handsets, but i suspect this could cost more than you paid for the whole thing.

I have never used heaters with my SCT. You can make your own dew shield out of foam mat or cardboard if you want. I'd rate a dew shield as an essential #1 accessory. If you have plenty cash, the new aluminium dewshield looks very good and is compatible with the Celestron heater ring. Planets can be a disappointment if viewed visually, looking small and over-bright. It's best to use a lot of magnification, which makes them look bigger and dimmer. They may look blurry at high magnification, but at least you can see some detail. I tried 5 and 7mm eyepieces on Mars once or twice when the seeing was good, but that's an extreme. Generally a 8 or 10mm eyepiece would give enough power for your scope. You could get a zoom eyepiece, which will either suit you or indicate which fixed eyepieces you need to buy. Also check the collimation of your scope - if it is not spot on, performance will suffer. It should be OK on a new scope but you never know...

I dragged myself out of bed on the morning of the 20th, for what the forecast claimed would be a clear night. There was cloud around, which gradually got worse, but I secured my first Jupiter and Saturn images of the season. CPC800, ASI462MC, ZWO filter wheel with UV/IR cut filter, ZWO ADC, videos of 5000 frames, gain 350.

I've seen an observatory mounted 16" LX200, which had a non-adjustable wedge, probably the norm for this class of instrument.

I have taken a large number of DSO pictures with an ASI224MC, basically because I had one already and did not want to spend loadsamoney on a more suitable DSO camera.

The reason for such guides is to match the pixel size to the resolution of that aperture of scope. The focal ratio here includes the effect of any Barlow lens etc. For example, a 2.9um pixel size used with a f7 scope and x2 barlow would be about right. For planetary use the FOV will normally be restricted to keep the resultant video to a manageable size. A large sensor is not entirely wasted as it is useful for finding the planet and centering it. It will also be advantageous if you also want to use the camera for deep-space imaging.

The GoTo is more to keep the planet in the FOV when you have narrowed the region-of-interest for taking a video. It drifts off quicker with solar system align than with 2-star align, which suggests that tracking with a poorly aligned equatorial or a manual mount will not be much fun. Also useful for finding Neptune. 🙂