catburglar

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I’ve had my scope permanently mounted on a pier outside for almost 2 years protected by a Telegizmos 365 cover without any issues. The only bit that comes inside is the hand controller because that becomes unresponsive if it gets very cold which means I can’t switch on at the start of the session.

If the scope gets covered in dew during an observing session I’ll wipe it down before putting the cover on, and in winter I’ll sometimes uncover it on a bright day to let the air circulate a bit. 
 

About twice per year I apply a bit of wax to the OTA, a bit of WD40 to the electrical contacts and leave it at that…

3 hours ago, Gary M33 said:

Does anyone know of a telescope repair service in the Lincolnshire area that might be able to help?

I’m not sure where you are in Lincolnshire but Rother Valley Optics (based in Sheffield) might be able to sort this out for you….and they may be only an hour or two away from you…

I’m just starting on this path too…I have a 10inch SCT, 90mm Mak and (arrived this week) a TV-60…Not had a chance to use it in anger yet, but the prospect of wide field and high(ish) mag lunar and double stars, in a package that can be carried in one hand and do double duty for bird/wildlife spotting pushed me over the edge.

but,I probably wouldn’t have gone for anything smaller than 60mm.

I had great views of the entire Veil nebula and the North America nebula with an ST120, 30mm 80 deg AFoV eyepiece and OIII filter. 
 

The slightly shorter focal length of the ST102 means that you could get similar FoV with a 25mm 68deg AFoV eyepiece.

It’s true that at exit pupils larger than 5-6mm lead to bright background sky, but with filters this is reduced and and contrast is enhanced, and a 30mm 70-80deg AFoV eyepiece will give a bit more area around these large objects that can make it easier to determine where they start and end…

I’d be tempted to give it a go TBH…

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.

39 minutes ago, Paz said:

I am not sure why they call it a Maksutov though, it looks more like a classical cassigrain i.e it has spider vanes holding the secondary rather than a meniscus lense.

I think it’s because they have a sub-aperture meniscus between the primary and secondary that serves the same purpose as the usual maksutov corrector whereas a classical casegrain doesn’t. Having it in this location means it’s smaller hence lighter than a traditional mak of the same aperture and allows for an open tube, so it cools quicker than a traditional mak too…The trade off is that you get spider vanes and diffraction spikes…

Is anybody still eager /intrigued to find out how this turned out? Or is it just me😁?

I’m not sure what you’re seeing, but can’t see the airy pattern…if I look at the bright star towards the bottom and just left of centre in your cropped view then I think it shows a ring artefact - probably as a result of sharpening or deconvolution algorithm. Are you looking at something else?

@vlaiv has probably hit the nail on the head in terms of what’s the ‘fastest’ option - an 8inch SCT or RC, with a suitable reducer and combined with pixel binning will be hard to beat if you can get by with the narrow FoV and lower effective pixel count…But if you’re going to do mosaic’s to make up the FoV then you’ll be negating the benefit… 
PS There’s an 8” Edge HD in the classifieds if you’re interested 😁 (no connection to the seller)

3 minutes ago, Lee_P said:

Thanks for the input! My mount is on a pier and I do often have an RMS around 0.6.

But that’s with a 70mm refractor, not a sail disguised as an 8inch Newtonian…I think the 6inch mak newt should be nice quality and no issues with spacing/back focus. 

I guess the point I was making was that If you want to image at higher resolution and not be any ‘slower’ than you currently are you’ll need both aperture and focal length and good guiding. It may be difficult to get all three because of your mount. An 8inch newt is a pretty big thing to put on a HEQ5class mount and expect 0.5”-0.6” rms guiding. What’s your current guiding performance like?

If you can achieve the required guiding accuracy then one of the Orion AG scopes might be a good bet- a step up from the Skywatcher/Stellalyra. I think the MN190 might be a step too far- it’s both heavy and long…But you might fancy the explore scientific MN152- FL=750,  a bit easier on the mount in both weight and length might give your guiding system less aggravation.

2 minutes ago, Lee_P said:

I'm not fully clued up on binning... could you explain a bit more? If it only affects the length of my subexposures, then that's no problem. I currently shoot 2-minute subs, it would be easy to switch to 3-minutes.

You can work out a measure of the “speed” of your current system- it’s aperture squared multiplied by image scale squared. In your case 71^2x1.9^2=18,200…if you do the same calculation for your new options then you’ll get an estimate of how much faster or slower it’s going to be…So a 6inch newt at approx 1.2arcsec 150^2x1.2^2=32,400…So about 1.8x faster than your current set up…if you bin pixels that will change your working resolution, but provided you use the correct resolution for your bin factor I think this calculation should still give you a good guide.

The OP states that his specific aim was to get “closer in” to his targets…So this means imaging at a more higher image scale. Currently he’s at approx1.9 arcsec per pixel and with good guiding on a HEQ5he may be able to get to somewhere around 1.2 arcsec per pixel (this will require a guiding accuracy of around 0.6 arcsec RMS). 1.2arcsec per pixel requires a focal length of around 650mm with the 2600camera- so the 107PHQ is a bit longer than you need, but if you regularly get guiding errors lower than 0.6 RMS then you may be able to make use of the extra FL. I’d expect an 8inch newt on the HEQ5 might be pushing it a bit on all but the very best (and calmest) of nights. A 6inch F5 with coma corrector may be the sweet spot.

Whilst brightness variations may affect the perception of colour, to me this seems like it could represent evidence of a real colour change.

Irrespective of brightness, Mars, Jupiter and Saturn all appear very different colours to my unaided eye, so the comparison that Betelgeuse was similar to Saturn seems unlikely to arise simply because of poor perception of colour on behalf of the observers- although I accept that stranger observations have been recorded throughout the history of astronomy…

I had a pair of 10x30’s for over 15 years and no problems with the stabilisation…They were always kept clean and in their case when not in use, but the rubber coating did develop a bit of stickiness…I chose to replace them without a second thought- they’re great for terrestrial uses and very handy for a bit of astro- much better than their 10x30 spec would suggest…I could easily see as much with them as with a pair of handheld 10x50’s without stabilisation.

Just now, catburglar said:

I think the eVScope offers a bit more than this for some users. The ‘Citizen Science’ angle allows relatively easy entry into asteroid occultations, rotation light curves and exoplanet transits. 
 These things might be interesting projects for some and there was talk of allowing users to do some analysis of their own data rather than simply contributing data to the ‘professionals’ for analysis…Don’t know if that’s come to pass yet.

But I’d agree the price is a bit steep, and if you’re prepared to do a bit of the legwork yourself there’s nothing here that couldn’t be achieved in a more hands on/interactive way.

I may be coming across as a bit of a Fanboy😁 Perhaps I’ll have to get one to try it out…

5 hours ago, Robindonne said:

More like “ watch the lunar eclipse on youtube vs see it live/real”

I think the eVScope offers a bit more than this for some users. The ‘Citizen Science’ angle allows relatively easy entry into asteroid occultations, rotation light curves and exoplanet transits. 
 These things might be interesting projects for some and there was talk of allowing users to do some analysis of their own data rather than simply contributing data to the ‘professionals’ for analysis…Don’t know if that’s come to pass yet.

But I’d agree the price is a bit steep, and if you’re prepared to do a bit of the legwork yourself there’s nothing here that couldn’t be achieved in a more hands on/interactive way.

The first version of the evScope had a digital eyepiece but used an IMX224 detector so was limited to approx 1.3Mpixels. Then they released an ‘equinox’ version which kept the same detector but ditched the eyepiece. And now this evScope2 - chip is IMX437 with approx 4Mpixels but eyepiece gives 7.7Mpixels- so I guess they’re doing some ‘drizzle’ing but not seen an explanation online. 
 

All versions have option for phone/tablet image display with up to 10users at a time.

Personally, I think the evScope beats Stellina as a tool for different user types because of the Citizen Science angle- although that only adds value once the clouds clear.

If I was in your position I think I would definitely go down the dedicated astro cam route- it’s the right tool for the job not a tool that’s being coerced into being something it’s not…

Set point cooling makes calibration easier, the chip is likely to be smaller so flats and tilt are easier to deal with and QE is likely to be higher and noise lower than a DSLR so you get more SNR in any  given set of exposures, and then there’s the whole mono vs colour time advantage…

Processing (relatively) poor quality data from a DSLR may not be the best training for processing good quality data from a dedicated astro cam. Whereas time spent learning and perfecting focus, guiding, image calibration etc is always going to be useful.

+1 for the telegizmos 365.

I’ve had my AltAz SCT permanently mounted on a pier with a TG365 for almost 2 years. I’ll wipe the scope down after each observing session to remove the worst of any dew before covering it up and occasionally in the winter I remove the cover every few weeks on a clear/crisp day just to make sure that it gets a good airing for a couple of hours.

No problems so far.

A meteor storm for me- I saw comet Hale Bopp and Hyakutake and they were great, but worsening light pollution in the intervening years means that even ‘great comets’ may not be that great anymore….Similarly a daylight visible supernova will still just be a really bright star (can’t really believe I just typed that)….so I think the meteor storm is likely to be the most striking, albeit transient, visual spectacle.

The OP referred to an AZ-EQ5GT which in altaz mode has a weight limit of 15kg per side. The 10inch SCT should come in a little under 15kg- according to the spec on FLO the C11 OTA is 12kg.

I have used a 10kg mak newt on an AZ-EQ5 in altaz with just 2 counter weights and it handled the weight fine although the longish OTA and some free play in az that some examples of this mount seem to show made it a bit irritating for me, although goto and tracking were fine. I didn’t try in EQ mode.

7 hours ago, PeterC65 said:

The zenith height of the eyepiece from the ground is 1500mm. Comparing this with Dobsonians, the Skyliner 300P is about the same but the Skyliner 250P is shorter at 1250mm so I'm thinking that the 12" may be a better height (and of course a bigger aperture).

Just one comment on observing comfort…The eyepiece height on a 10 or 12 inch dob will vary with altitude much more than it will with your 150- a longer tube and balance point closer to the mirror will almost guarantee it… I suspect you’d need to swap between standing/seated observing as you move between objects…In my experience a mak/SCT or short focus refractor is most likely to give you observing comfort across a broad swath of sky.. 

You could stick a 10inch SCT on an AZ-Eq5 if your budget would allow…or the Evolution9.25… and both would give you an beefier mount for your other scopes if you wanted it.

9 hours ago, Mike JW said:

classified as IB(s)m pec. (s) = transition to a ring, Im = irregular magellanic  type, B = not sure what this refers to? a bar?

Mike- the description of type IB(s)m from https://ned.ipac.caltech.edu/level5/March14/Buta/Buta3.html suggests that you’re correct see the specific quote below.

A special hallmark of the VRHS is the recognition of the Magellanic Clouds as extreme late-type barred spirals of the type SB(s)m that show a characteristic one-armed asymmetry and offset bar (de Vaucouleurs & Freeman 1972). Magellanic irregulars form the last major stage along the VRHS, and are often barred (i.e., classified as type IBm or IB(s)m, implying a subtle spiral variety)