Bored of "First Telescope" Threads yet?

[DhamR]

Long story short, the first one was damaged.  The mount had a crack in the wooden mount through where the alt axis is.  Wasn't sure if it was just the paint/veneer or through to wood but FLO were great and swapped it out.

Replacement has arrived, and I got a quick go with it yesterday evening until, very quickly, my view fogged up.  I thought this was dew, or my breath on the secondary.  But nope, nothing.  Then I looked up... clouds...

Notes:

- Collimation is surprisingly easy. Instructions were reasonably clear, but once I understood what I was trying to do it was quite straightforward getting the primary lined up.

- Speaking of instructions: the line telling you to align the telescope with North when you switch it on is not made clear enough in the instructions... I spent ages wondering why 1-star alignment was sending the scope off miles away from Jupiter: now I know.

- Being something of a photographer, I thought I'd find focusing quite easy, but it's not.

- The focuser really is both stiff and sloppy.  PTFE tape is on its way down from the river.

- I think I need an eyepatch to stop my non-dominant right eye from getting tired from squinting (yes, being left eye dominant as a photographer is a nightmare)

Edited December 8, 2021 by DhamR

[Concordia000]

3 hours ago, DhamR said:

Long story short, the first one was damaged.  The mount had a crack in the wooden mount through where the alt axis is.  Wasn't sure if it was just the paint/veneer or through to wood but FLO were great and swapped it out.

Replacement has arrived, and I got a quick go with it yesterday evening until, very quickly, my view fogged up.  I thought this was dew, or my breath on the secondary.  But nope, nothing.  Then I looked up... clouds...

Notes:

- Collimation is surprisingly easy. Instructions were reasonably clear, but once I understood what I was trying to do it was quite straightforward getting the primary lined up.

- Speaking of instructions: the line telling you to align the telescope with North when you switch it on is not made clear enough in the instructions... I spent ages wondering why 1-star alignment was sending the scope off miles away from Jupiter: now I know.

- Being something of a photographer, I thought I'd find focusing quite easy, but it's not.

- The focuser really is both stiff and sloppy.  PTFE tape is on its way down from the river.

- I think I need an eyepatch to stop my non-dominant right eye from getting tired from squinting (yes, being left eye dominant as a photographer is a nightmare)

Several things I’d like to comment on:

- I am also a photographer with a dominant left eye. It used to be worse when my right eye was nearsighted but my left eye was far-sighted, but now that my left eye also deteriorated (thanks work) it got a bit better. 
- What I want to say is that it’s not as bad as it seems, at least when it comes to telescopes. You can adjust the focus to fit either your right eye *or* your left eye, and there’s no need to cover either once you are used to it. If you have to, use your hand and that’s usually enough. You do not need to touch the scope to see through it.

- I am unsure how the helical focuser works on the Heritage, but as far as I understand it’s not a true helical focuser like a camera lens’, but a big plastic screw with the eyepiece on it. Temperature and weight of the eyepiece might influence how tight it is; I suspect it’s on the tight side because it needs to prevent slipping. (like every helical focuser, even ones costing as much as an entire Heritage on its own!)

- Did you tighten the eyepiece enough? Sometimes that’s where the slop comes from. 
- The other potential issue is the vibration in the assembly. Anything not tightened down fully (for example, the clutch on the mount) will lead to vibes when focusing, and it happens to every setup.

[DhamR]

You're right about the focuser, it's actually loose, but because the thread is fairly poorly machined, turning it to focus is rough which is why I said it felt tight, because it's actually loose. Because of the slop, you think you're in focus and then let go of the focuser only for it to come to rest in a new position. 

Have just had it out for the third time, I've got the focus bang on for the 24mm EP now, and ptfe tape holds it sturdy, then when I use the 10mm I have to secure it partially removed from the focuser to get an image at all (I assume this is normal?), I have just been using that motion to focus, rather than the helical focuser, and then I lock it down when happy. Makes switching back to the 24mm much easier than unscrewing the thread all the way... 

Also I definitely need to close my right eye to see anything, possibly due to local light etc, I think an eye patch might be a good idea. 

I've had some further issues with the mount, but it turns out they were fairly simply resolved:

* the clutches HAVE to be fully locked down for powered movement to work properly. This was messing up my alignment. 

* alignment requires you to finish on an up and a right movement for some reason, this baffled me for ages with the select/confirm button being greyed out otherwise with no error. This is just poor UI design tbh. 

Last time out observing I bounced between the moon and the Pleiades, there was also a cool orange and blue double I stumbled upon almost at the zenith. 

Tonight I had some great views of the terminator of the moon, albeit with some cloud dancing in front. And I got my first view of the orion nebula. This was brief and not particularly detailed, but this is the first time it's been within reach and I'm very happy to have seen it.

I had to collimate again on both outings, I suspect putting the scope back with its bum resting on the foam it arrived on is the issue here, so I've left it supported by the dovetail tonight.

I might need some storage advice from elsewhere on the forum too, it's having to stay out of sight at the moment so the little one doesn't see it, but when she can, I'm wondering whether it's OK staying in the garage or should come indoors. 

Pros: fairly secure, closer to outside temp (garage is detached), not going to get knocked as it might in the house 

Cons: garage door is noisy at night, I might need to be careful about damp. 

Edited December 15, 2021 by DhamR

[Starwatcher2001]

6 hours ago, DhamR said:

* alignment requires you to finish on an up and a right movement for some reason, this baffled me for ages with the select/confirm button being greyed out otherwise with no error. This is just poor UI design tbh. 

This is because all gears have some slop in them, also known as backlash. When they are moved in one direction they mesh and take up any slack. If you then move them in the other direction the motor will need to run for a short while (depending on the quality and design of the gears) to take up the slack in the other direction before the telescope itself actually moves. By forcing you to be consistent in the direction of the last movement you make, it ensures consistency in your positioning.

On my C925 scope using high-power eyepieces (and therefore a slow motor speed) it can take 20 seconds before I see movement through the eyepiece. The backlash is pretty poor. But once you know that "one weird trick" of always ending alignment in the same way, it makes alignment more accurate.

[DhamR]

How does that work if it chooses to turn left to find the first target? Does it know the amount of backlash and account for it? 

[Starwatcher2001]

If you watch carefully when it does its goto, in one direction it will travel past the target slightly, then back up a bit. That backing up takes up the backlash to ensure accuracy.

This becomes more obvious if you connect the mount to an app like SkySafari. The app will show a map of the sky with cross-hairs showing where the scope is pointing. During slewing the cross-hairs will move on the screen, and they'll sometimes go past the target then back. (That's the scope using that "one weird trick" itself).

Depending on the handset that comes with the goto, there's sometimes a "backlash setting" for both alt and az directions. Here you can set the backlash values for both movements. The scope can then use a faster motor speed to take up the slack.

For example, suppose I'm using high magnification to look at a feature on the moon. I'll set the motor speed to 1 or 2, so as I move the scope with the controller it only moves slowly. (Don't want it whipping off the moon entirely!) I press the button to move slightly to the right and the scope responds instantly. It does the same every time I move right. I now press left and I hear the motor running but it takes 20 seconds before the telescope tube actually moves (which is annoying). Next time I press left it will respond instantly as it's already taken up the slack. Every time I change direction I have to wait for the slack to be taken up again.

Now suppose I tell the telescope just how much backlash there is (the manual should tell you how, but it's basically trial and error). I adjust the backlash accordingly and do the same experiment with that lunar feature. This time when I change direction with the buttons, the scope knows how much backlash there is and can use a higher speed to take up the slack, before dropping back to the speed I asked it to move. So it doesn't prevent backlash, the scope just takes it up quicker to give a faster response when you change directions. You can hear the motor change note when it does this.  It may well take it into account when slewing to a different object, but I'm not sure.

If you don't set the backlash the scope still works and is just as accurate, you just may get that annoying pause when changing direction, particularly when using higher magnifications. So it's not something to worry about when you're starting out. Indeed I suspect many people don't bother, or have too little backlash to make the effort worth while.

Note, as I understand it, the scope knowing the backlash doesn't save you from having to use that "one weird direction trick" when aligning.

 

 

 

Edited December 15, 2021 by Starwatcher2001
Added a bit to clarify something

[DhamR]

Thanks for excellent description, that makes sense.

I guess in that case the up and the right final movement should be complete, i.e. passed any backlash, rather than just a tap of the button at a low speed.

I'm using the synscan pro app at the moment, and am playing with the free versions of the other apps to see if there's one I particularly want to splash some google bucks on.

Edited December 15, 2021 by DhamR

[Starwatcher2001]

Yes, go past the target if necessary and then use the correct direction buttons to creep back up on it and stop when you get there. If you overshoot, you're supposed to go back again and then creep back up to it again.  You can decide for yourself if the faff is worth it. My view is that as long as "goto" gets the object somewhere in a low power eyepiece, I'm happy. I'm not that bothered if it's not slap in the middle.

On my setup I always moved* the object to the top right quadrant of the eyepiece before the final alignment movements.  That ensured I was going in the right direction. Your actual direction might be different depending on diagonal type, and maybe other settings in the handset. In the NexStar handset you can reverse the directions that the buttons work - which is handy, but confuses matters even further!  

I like SkySafari myself, but there's quite a few app about. Stellarium is also well regarded.

 

(*I now use StarSense which automatically aligns everything while I bring out the rest of my kit and get a coffee etc.)

[DhamR]

Yeah I read the lengthy app thread and now have 6 or 7 installed on my phone (although not all offer integration with Synscan - and I've tried none of them).

I'm being particularly fussy about alignment because I don't yet know what I expect to see when I'm looking for things.  Once I find my way and get a bit better with names it won't matter so much.

Was pleased I managed to find the Orion Nebula myself though (I know it's only a short hop downwards from the central star in the belt - it felt like an achievement).

Can Starsense be used on a Virtuoso GTi do you know?

Edited December 15, 2021 by DhamR

[Starwatcher2001]

Sorry, I don't know. I did manage to find a thread here that might be useful:
https://stargazerslounge.com/topic/318998-starsense-on-az-gti/

Do be aware that StarSense isn't cheap and has it's own setup issues.

Well done on finding Orion. Star hopping is a skill that comes with practice and is well worth developing, even with a goto telescope. I have a Dob without any electronics and still enjoy hunting down objects by hopping.

 

[DhamR]

Ahh I thought I saw that name associated with a phone mount that sat on some entry level celestron refractors and used the phone camera to help guide your movement. Might be something else.

[johninderby]

Celestron uses the Starsense name for two completely different systems. One is for the entry level scopes using a smartphone and the other is for the add on system for GOTO mounts but is a much more sophisticated system using an inbuilt camera and used to automatically do the scope alignment. 

Edited December 16, 2021 by johninderby

[DhamR]

At least I wasn't wrong!

[DhamR]

I've managed a cheeky couple of hours out in the cold tonight (you do not feel the cold until you come in...)

Ticked off a few of the most obvious sights even though the sky was pretty misty and the moon was being a pest:

- Pleiades

- Beehive Cluster

- Double Cluster

- Orion Nebula, including the Trapezium this time.

- Merope Cluster

And a few other clusters.

I got in the right locations for a look at a few nebulae too, but other than being able to see the sky brighter in their vicinity, that was all I got to see.  I'm wondering if I need a wider eyepiece than my 24mm for some of them?

- I split my first double, can't remember which though  it was doable at 30x but looked even better at 75x  

I also bought a cheap m42 to 1.25in adapter this week (I already have an M42 to Canon adaptor for use with old lenses) to see what my 60D would see of the moon.  I don't think I nailed the focus, the sky was misty, and the mirror slap was causing a slight shake (I can switch that off, but was just getting a quick snap).  I was surprised how steady the scope sat with it attached, and might be a useful tool to show my daughter what I'm looking at through the scope when the time eventually comes!

 

[DhamR]

I've been having a further play with the collimation, and I'm finding that to get the secondary even close to centred and circular in the focuser, I have to have it right at the end of its thread, which doesn't feel right to be honest, so I've emailed FLO (and added a picture here).

I've also got the top truss thumb screw clashing with the red dot when the scope is collapsed which seems like a poor design decision...

Other than that I can get collimation pretty spot on. 

I've had a few partially cloudy nights and realised when this is the case, aligning the Virtuoso is not worth bothering with. By the time I've started, the stars I was going to align with are gone behind clouds (it is doable with the moon though). Its also incredibly difficult star hoping when you can't see full constellations for reference (is that a bright star? Or just the only star I can see). Beggars can't be choosers with the weather like this I suppose. 

Saw Jupiter as a big white ball with four smaller stars coming off it last night. Just before it dipped below horizon. 

Andromeda still evaded me though. 

And on a few other nights I showed my wife and mother in law that the Plieades is visible with the naked eye. Although neither of them could get a view through binoculars... Not sure what they were doing wrong. 

I'm heading to a Bortle 4 area for new year so will be taking the scope. Any advice on transport would be great. I don't like the idea of leaving the scope attached to the mount by the dovetail as I do when storing, was thinking of just wrapping the OTA in a duvet or coats. But I would like a more permanent solution. 

Edited December 30, 2021 by DhamR

[happy-kat]

I find checking a photo of the collimation line up with Al's collimation aid app quite helpful. I've the 130p flavour heritage, these are f5 telescopes so you don't get all the inner circles concentric as there is an offset from it being f5. Sorry I'm on the phone soon don't have a photo to hand until tomorrow.

[DhamR]

Sorry which circle should be offset? 

Not quite sure I understand why the focal ratio would make any difference but I'm probably being dim. 

[wulfrun]

On 30/12/2021 at 08:07, DhamR said:

I've also got the top truss thumb screw clashing with the red dot when the scope is collapsed which seems like a poor design decision...

I found this too, on a non-Virtuoso version. I've changed the finder since but I found you could just about move the finder forwards on its fixing far enough to avoid the locking thumbscrew.

[happy-kat]

This is a good guide and often referred to on here

https://www.astro-baby.com/astrobaby/help/collimation-guide-newtonian-reflector/

[Spile]

I can’t see the sight tube in your image. Does this help? https://astro.catshill.com/collimation-guide/

[DhamR]

Site tube is in this one. I was following that guide already tbh. Its that that makes me think the mirror should extent further to be directly underneath and circular. 

[Pixies]

Hi @DhamR,

What sort of sight-tube are you using? If it a long one like the FLO Pro Cheshire, try inserting it a bit further, so the outer circle is much closer to the secondary. Also, from your picture, that outer circular edge doesn't look very circular. Not sure why - perhaps it's just a shadow of some kind?

Anyway:

 

To me, your secondary looks twisted. The top (in the picture) need to be slightly rotated towards you. It's also a little to far down the tube. Once that is sorted, you can adjust the tilt.

The Yellow ellipse is how the outer edge of the secondary appears to me. It should be circular and aligned with the red reticles above.

Having the open design of the Heritage makes it a lot easier to see what's going on!

 

[Spile]

This is my interpretation of the rotation/tilt alignment error...

 

 

Edited January 3, 2022 by Spile

[Spile]

[DhamR]

23 hours ago, Pixies said:

Hi @DhamR,

What sort of sight-tube are you using? If it a long one like the FLO Pro Cheshire, try inserting it a bit further, so the outer circle is much closer to the secondary. Also, from your picture, that outer circular edge doesn't look very circular. Not sure why - perhaps it's just a shadow of some kind?

Anyway:

 

To me, your secondary looks twisted. The top (in the picture) need to be slightly rotated towards you. It's also a little to far down the tube. Once that is sorted, you can adjust the tilt.

The Yellow ellipse is how the outer edge of the secondary appears to me. It should be circular and aligned with the red reticles above.

Having the open design of the Heritage makes it a lot easier to see what's going on!

 

I'm not in possession of a Cheshire yet. These were taken through the focuser. I've ordered one from svbony but they told me it was a "banned item" and they can't ship it to the UK. When questioned they said "because lasers" despite it being a laser-free pure sight tube... So I'll need to look elsewhere. 

The secondary definitely isn't that far into the field of view when looking down the focuser, and the lack of circularness is part of the problem, if I tilt it to lose the oval shape, I lose the reflection of the primary off the right hand edge. 

I think the reason the focuser looks oval is perspective, in the wide angle view I can't be confident the camera was looking directly down the tube. 

Edited January 3, 2022 by DhamR