Jules Tohpipi

11 minutes ago, Richard N said:

Curiously I have never found the need to level my dob. And indeed that’s what I perceive as one of its advantages. Each to his/her own I guess. 

Quite handy if you have a Goto dob or using an inclinometer😀

Thanks and congratulations for a very interesting and useful write up @AstralFields  Out of curiosity which inclinometer are you using - do you have a photo or link possibly?

Our early teens daughter visited last month on a school trip and had a great time. She's the type who usually comes back underwhelmed with school trips.

Do you use cordless power tools at all? I've been experimenting recently with using my Makita LXT batteries as a power source for my AZ-GTi and Goto Dob. I say recently but the bad weather means the very limited testing has been spread well over a year now. This is the first time I've talked about the experiments in any depth.

The Makita LXT batteries are 18V and I've been using a third-party 12V converter that's specifically designed to mechanically clip onto said battery i.e. no cable from battery to converter. Have also been trialing a standalone 12V step-down converter (requires a cable between battery and converter) which has more current capacity for driving the Dob and looks more reassuringly built.

Let me say from the outset that these experiments are not a good area of technical knowledge for me. I'm pursuing faith in the very high quality of the Makita batteries and their proven track record in the professional building industry (the same could be said of Dewalt etc) and putting blind faith in the unknown quality of the 12V converters I've purchased.

There have been several  incentives for giving this a go. The Makita batteries are compact and don't deteriorate as quickly over the years as the general-use, no-brand power packs on Amazon. My five-year-old Makita batteries are still going strong on both high and low-power tools (for occasional DIY use). The initial results for astro have been promising and the cheap option for me because I already have multiple batteries. Another standout point is these batteries don't start misbehaving until they are very, very low on charge. Yet I can recharge to full again in 20 mins for a 3Ah one (and longer for 5Ah). And I'm assuming - perhaps incorrectly - that being 18V converted down to 12V, then the scopes will still get a steady 12V even when the 18V battery is starting to drop from its nominal voltage. Nominal in the sense I measure them at just over 19V when fully charged.

So it's an initial recommendation with caveats - and I'd be welcome to comments if I'm barking up the wrong tree on this.  

All this talk of Planet X, I can remember when we used to call it Planet Twitter. 

Just in case, have you tried watching the video below? This got me up and running really quickly when I first started getting more ambitious with my AZ-GTi. Albeit I was doing it all on Windows 10.

For a complete beginner looking for fast results and interactive features for a child your best bet would be a telescope from the Celestron StarSense range. 

You need know next to nothing about the sky above you. You attach your mobile phone with the supplied holder and it works everything out for you - and tells you precisely where to manually aim your telescope using guide arrows on phone screen. It may sound gimmicky but it really works. Then you look through the telescope using your eye and the phone will tell you about what you’re looking at. 

https://www.firstlightoptics.com/celestron-starsense-explorer-series.html

On 25/01/2024 at 18:15, Orange Smartie said:

This is a bit of a complicated one, but I might be given up to about £400 to spend on a telescope. I can probably supplement that slightly, but I think my absolute top budget would be around £550. I've been thinking about a compact go-to system to complement my existing equipment (10" and 6" dobs) and I was thinking about possibly getting a Skywatcher 102 or 127 Mak with go-to function for doubles, planets and lunar.

So:

102 vs 127?

Az-Go2 vs AZ Gti (I understand the latter has Freedom Find, but the former doesn't - is this a problem?)?

Would I be massively disappointed by the Mak after using a 10" dob? Before anyone suggests the second hand route, that is not an option - the equipment must be purchased new from a proper dealer!

There's potential a few points to consider here, in terms of weighing it all up

What will you see?
The SkyWatcher 127 Mak has, as near as dammit, the same field of view and magnification (for any given eyepiece) as your 10" Dob. So, the planets will look the same size in both scopes. Obviously, the Mak will have less resolution due to its smaller mirror size. Overall, planets and lunar will be a near identical type of experience to the 10" but not quite the same resolution - but seeing conditions might constrain that sometimes anyway.

What would be the benefits?
The kit would be much lighter to carry than the 10" and stow to a much smaller size (especially if going the AZ-GTi route). You would gain Goto and Tracking. The tracking being more relevant for planets and lunar observing where you avoid nudging and instead have the target in centre-view constantly and avoid negative edge-of-field effects - both of which helps eek out more detail.  If none of these sound like major plus points vs your current 10" Dob experience then the money might be better spent on an alternative plan.

Other negative points
Set up time will be longer than manual Dobs. Not a huge hassle but for the AZ-GTi you'll need to: level the tripod, add the extension pillar, add the mount and scope then do an alignment for the Goto to work. For the AZ-GTi (not sure about the other mount you mentioned) if you're observing something you can find yourself, then the Goto alignment process is no longer required and you can just hit the 'Point and Track' button once you have the object manually centred in view - which really helps speed things up for simple object tracking.

Due to my bad back the 10" Dob rarely comes out now and the SkyWatcher Mak on AZ-GTi has been a saviour - and no I'm not disappointed when looking at Jupiter, Saturn or the Moon. If I were a younger and stronger man then, overall, I probably would not have bought the Mak/AZ-GTi just for the portability and  planet tracking benefit vs a manual Dob.

On 10/01/2024 at 14:52, Zermelo said:

Thanks for this discussion, it led to me buying this one:

 

Wow, that looks remarkable value at only £39.99 in the sale. Especially considering it's a roller case. Excellent spot!

Not 100% sure if I’m understanding your connections properly (because I’m not au fait with the ASIAir). But I would often get Wi-Fi disconnects from my AZ-GTi in the early days. It became much more reliable after I swapped the Wi-Fi to a different channel. Presumably because there was too much nearby traffic on that channel. 

Excellent - glad that helped! It took quite a while to track down a goldilocks case that would house the ST102 and AZ-GTi bits at the right size and price.

I have the MAX465H220 Trifibre for my Sky-Watcher 127 Mak. As Laurence mentioned it’s very heavy (for its size) and not cheap (plus the foam is an extra-cost option). But it is very rugged and high quality. I sense it could be thrown down the stairs ten times and the stairs and walls would look the more worse for wear than the box! Overall, I might have been equally happy with a cheaper and lighter case - like the one I use for the StarTravel 102 - because I mainly use the cases for quick and easy access to my gear when at home, rather than fiddling around with multiple cardboard boxes and packing. 
https://www.trifibre.co.uk/product/max465h220/

But if you’re after something that could withstand rough handling for a century or two then the Trifibre MAX cases are very good value. 
 

I went for the smaller 465mm version as I keep my shared RACI and diagonals in my eyepieces case. 
 

On 02/01/2024 at 19:42, Beardy30 said:

Yes please - that would be class! 
 

Sorry for the delay but have taken the photos now. 
 

FYI, this case has four foam layers supplied. The top layer is the egg-crate foam attached to the underside of the lid. Next there’s two separate layers of thick foam (the pick and pluck variety) and finally a thin bottom layer. For the OTA and AZ-GTi I plucked only the upper layer of thick foam, but plucked both layers to house the Sky-Watcher extension pillar vertically (located top left). One of the photos shows my Bahtinov mask slid down the back (top centre left). 
 

As you can see more would fit in there. But I keep a shared (between two scopes) RACI, diagonal and eyepieces in a separate box. But I’ve got two AZ-GTis that I keep one-a-piece with my refractor and Mak. 
 

13 hours ago, Lung said:

I don't think the Astro Fi (or Synscan) will fit on that steel tripod as it has the flat topped connection with 3/8 bolt.

There’s two versions of the excellent Sky-Watcher tripod with 1.75” Stainless Steel legs. The first just has a standard 3/8” at the top and is suitable for anything accepting that e.g. the AZ-GTi and general photography equipment. The other version has an azimuth pin and is suitable for the EQ-5 and the like. But I’m not au fait with the requirements for the Astro-Fi. 
 

Below are links for the two versions. Albeit, as FLO says, the image for the azimuth pin version is not the correct image. 
 

https://www.firstlightoptics.com/skywatcher-star-adventurer/sky-watcher-stainless-steel-175-tripod-with-38-thread.html
 

https://www.firstlightoptics.com/sky-watcher-mount-accessories/sky-watcher-stainless-steel-175-tripod-for-heq5-eq5.html

19 hours ago, Beardy30 said:

Just while we debate padded bags - does anyone have a storage option for the the Startravel 102 other than this option Oklop Padded Bag for 102/1000 Refractors | First Light Optics

I have a case with plucked-foam for my StarTravel 102 (link below). There’s room for the OTA, AZ-GTi, the Sky-Watcher extension pillar and more. Later I can take some photos of it with the kit in place if you’re interested in ordering. 
 

https://www.cases-and-enclosures.co.uk/hard-cases-protective-storage/flight-cases/large-protective-flight-case-l585-x-w365-x-h250mm-with-cubed-foam

On 21/12/2023 at 19:16, Telescope40 said:

Hello. Just the one pressie for my Canon IS 10x30 binos. 
Original case just not cut it so from the the large river in S America site a Aproca hard case. Looks the business and the binos are happy in their new home. 
 

John 

Well, your lovely new case has certainly caught my eye because I'm equally unimpressed by the Canon 10x30 bag. After Googling, I assume that's the case labelled for the 12x36? If so I'll start ordering

Out of curiosity, what covers are you using for the objectives in the photo?

51 minutes ago, Chandra said:

The mount that has already been mentioned AZGTi is very interesting at a very reasonable price, but you should keep in mind that when you use it manually it does not have slow motion controls, which can make it difficult to use in that mode.

Without detriment to the many excellent points in your post, I'd just like to highlight one feature of the AZ-GTi which is something of a hidden gem - rendering slow-motion controls unnecessary. That's its 'Point and Track' feature. You manually push the scope to your target, select 'Point and Track' in the app, and finally tell the app which target you have pushed it to, then the AZ-GTi  will track it. The killer feature here of 'Point and Track' is that no pre-alignment is necessary, no star choosing, no point north and level first, nothing. It's especially great for quick grab and go observing of planets with tracking.   

Just to add support to the above recommendation, the small field-of-view 'issue' for Celestron/Sky-Watcher Maks is often greatly overstated and repeated with little thought. I say that in the specific context of half the world being happy to recommend manual 8" f/6 dobsonians to complete beginners - yet it's a telescope whose FOV is barely wider than the Maks in question. As the yellow and red rings in the chart below shows.

35 minutes ago, Lung said:

I don't have any experience to base that decision on. I might be fine with a purely manual mount, or I might find I really want something more techy but I simply don't know at this point. I do lean more techy in general, and have been looking at whether I could control a mount from my PC and stream my phone as a webcam at the same time to let my kids use it from indoors when it's too late for them to be outside, but I'm also very happy to learn the basics the old fashioned way and develop into computerised viewing later.

If you lean towards techy and want to control the mount wirelessly from a PC then the Sky-Watcher AZ-GTi mount with a 127 Mak is certainly designed to do exactly that. There's a learning curve for the initial installation and set-up of getting the two talking to each other - but a PC literate person with the patience to look at a couple of YouTube videos should cope easily. The AZ-GTi mount would also allow quick switching to a second telescope for wider views (if the hobby bites), for example an entry-level refractor such as the Sky-Watcher 102T. Plus the latter telescope also makes for an excellent first step on the EAA (aka EEVA) ladder for observing galaxies and the like in real time (have a look at the 'EEVA Reports' sub-forum here for what's possible - with multiple members posting their EAA images). 

https://www.firstlightoptics.com/sky-watcher-az-gti-wifi/sky-watcher-skymax-127-az-gti.html

https://www.firstlightoptics.com/startravel/skywatcher-startravel-102t-ota.html

There’s two types of personalities that recommend telescopes. The first ask questions and weigh-up the requirements  and constraints the buyer might have. The second type forsake all that and say buy ‘X’ because the glove fits for them. Fortunately the two are easy to tell apart. 

12 minutes ago, Elp said:

But no lights on the edges of each wing which would trail across the whole image? And it's must be incredibly low (as in very very low) to capture it so magnified.

The engine pylons only just fit into the frame, let alone the wingtips...

It's definitely the underside of an aircraft. In otherwise complete darkness, a very brief-duration flash to the area would freeze its motion - regardless of the exposure time. 

20 hours ago, Second Time Around said:

I think the main reason why people lose interest is that they find it hard to find objects. This is especially so in towns and cities where there are few stars to see with the naked eye to guide you to objects.

Therefore I'd very much recommend that you look at Celestron Starsense scopes. These make it very easy to find objects with a free smartphone app - indeed my 8 year old grandson picked up how to use it in minutes.

Go to https://www.firstlightoptics.com/celestron-starsense-explorer-series.html?gclid=Cj0KCQiA35urBhDCARIsAOU7Qwnbi6bN7TTF30Xxg8ALXRvQWIoxQcdIdhMIofHouUaaA4qQKzz4AKcaAiaJEALw_wcB

By the way, the 70mm one you linked to is the model I bought for my grandkids.

First Light Optics has the next model up on special offer.  However, although it has a larger aperture it's on the same mount and is likely to be a little more wobbly due to the increased weight and tube length.  It'll also have a smaller field of view and so show less of the sky at once.  So my choice would still be the 70mm.

Finally, one of the other advantages of Starsense Explorer telescopes is that they'd be very easy to sell secondhand and for a good price.

Absolutely this. Nowt kills the hobby faster than being new and not being able to find nowt. 
 

Slipstream in using a mobile phone with a 12-year-old to give informed guided tours of the sky, and the job’s done - as a first dip into the wonder of it all. 

1 hour ago, lee g said:

So after reading all these helpful replies I think I’ve figured out what went wrong.

just before the primary mirror fogged up I had used a hairdryer to clear the corrector plate and I probably inadvertently warmed the inside of the tube up thus resulting in warmer air inside. Does this sound feasible in your opinions.

If the tube is truly sealed then no that's not the reason. Same physical principles as why sealed double-glazing doesn't form dew/fog in the air gap [actually usually some inert gas but..] of the two panes when it's cold outside but warm inside. But does fog internally if the seal is broken.

If outside air can get into your OTA, then the act of heating your corrector plate would mean the heated air inside becomes capable of holding more moisture - and that extra moisture is supplied courtesy of the cold (but very humid) air entering from outside - on that particularly humid night. This hotter air then has to dump part of that extra moisture again when it drops below the dew point hitting your very cold primary mirror. 

21 hours ago, lee g said:

So my sct lives outside in a well ventilated shed. Last night I set up 2 hours before sunset when I went out to observe i turned on my dew strip heater on the secondary mirror, but within half an hour for the first time ever the primary mirror had fogged over. This ended the session there and then. How is this possible since the mirror sits in a sealed tube and how can I prevent it in the future.

 

Last couple of nights in East of England the relative humidity has been at 100% (unless you're on the coast). This is somewhat unusual and probably the key factor. Caused by a combination of rain earlier in the day, followed by freezing cold temperatures in the evening (air less able to hold water vapour at lower temps).  At 100% humidity and below-freezing temperatures, the air is fully saturated, no longer able to hold any further water,  and will dump water vapour onto whatever cold surfaces it encounters. 

Conclusion is that the sealed tube might not be so sealed. Alternatively, there's a very small amount of outside air getting in.

The only solution in such extreme 100% relative humidity conditions is to get the relevant surfaces heated up.