Got 102 mm mak, worth getting 130 mm newt? or 127 mm mak?

[happy-kat]

The app you would use is exactly the same as the azgti the only difference is the WiFi dongle is external on the star discovery and internal WiFi on the azgti. But only the azgti can use the pro flavour of app in eq mode which gives eq or altaz option on use (mount with firmware update). Both apps work but you won't get eq mode doing eq tracking.

Edited June 23, 2019 by happy-kat

[happy-kat]

Why not download and have a play, if you search you'll find a post sharing how to use in emulator mode ie with no telescope yet.

You could always use a sturdier tripod legs for the azgti and put a wanted add out to see if anyone has a star discovery 150P flavour tube to sell. However I would check that the circumference of the OTA isn't too big for the mount. There are members who have tried all sorts on the mount why not search the site and see if you can find any user experience.

[Cosmic Geoff]

Beware of trying to cut corners with mounts - in my experience a lot of them are annoyingly wobbly even with the recommended OTA atop them. 

Wobbly: EQ-2,  Celestron SLT.

Celestron SE 6/8 - not great but okay for visual with a short 5.5 Kg OTA.

Not wobbly: AZ-4, EQ-5,  CPC800 mount & tripod.  

I bought a vintage 70mm refractor for a modest price and then found that owing to its length and weight the minimum mount was an AZ-4 or EQ-5 , either one costing far more than the scope did. 

[pellgarlic2]

19 hours ago, happy-kat said:

The app you would use is exactly the same as the azgti the only difference is the WiFi dongle is external on the star discovery and internal WiFi on the azgti. But only the azgti can use the pro flavour of app in eq mode which gives eq or altaz option on use (mount with firmware update). Both apps work but you won't get eq mode doing eq tracking.

That's good to note, thanks. I'd prefer to have the option of eq mode if possible, but I'd say it's not a deal breaker for me, and the other things this package have going for it make up for it. But it's good to be fully informed about its capabilities.

11 hours ago, Cosmic Geoff said:

Beware of trying to cut corners with mounts - in my experience a lot of them are annoyingly wobbly even with the recommended OTA atop them. 

Indeed, I'm getting that it's best to "under-task" the mount, not push it to the limit of its specification. 

The only query that remains in my mind about this package is that although I'll primarily be a visual observer, I know I'll want to try hooking up my DSLR to grab some snaps of the Moon, Jupiter and Saturn when the opportunity arises. However, I came across this video which says a significant modification is needed to be able to attach a DSLR. Can anyone advise if they've been able to connect a DSLR to this scope? Or I wonder if it's possible to just replace the focuser with an after-market one? Or am I opening a can of worms there?... 😬

 

[Cosmic Geoff]

The message of the video is pretty clear. ☹️

Also, did you notice how much the scope bounces around on its mount when he touches it toward the end of the video? 

[pellgarlic2]

I might just shelf my astrophotography aspirations (or at least resign myself to using the afocal method) for a few months, and add this to my Christmas list:

https://www.firstlightoptics.com/skywatcher-focusers/dual-speed-crayford-1252-inch-focuser-for-skywatcher-explorer.html

Description says: "This is the same focuser that is now supplied with the Explorer-PDS models.", and given that the aperture and focal length of the Explorer 150P-DS are the same as the Star Discovery 150i (aperture: 150 mm, focal length: 750 mm (f/5)), it seems safe to assume that the focuser I linked allows a DSLR to be positioned closer to the tube, and therefore be able to achieve prime focus.

This would require drilling new holes into the OTA, so it would still void my warranty, but I've read a few reviews indicating that the focuser is the weak point on the 150i, and that it's worth upgrading it anyway. 

[Ricochet]

27 minutes ago, pellgarlic2 said:

it seems safe to assume that the focuser I linked allows a DSLR to be positioned closer to the tube, and therefore be able to achieve prime focus.

Not at all safe. The properties of the mirror (aperture and focal ratio) do not tell you anything about the diameter of the tube and the distance between the primary and secondary mirrors, or the distance of the focal plane above the surface of the tube. Without this information you cannot say whether any particular focuser will or will not work. Based solely on the linked image of the focuser, I would suggest that it looks taller than the focus position shown in the previous video and would not work. 

[happy-kat]

The focuser you mention will not gain you what you think on a star discovery 150P tube. The PDS range have their primary mirror further up the tube pushing the focal pane further along meaning a DSLR can be brought to focus, but this means with an eyepiece these tubes need to use an extension tube in front of the eyepiece.

Th star discovery with a hacked focuser tube and a mirrorless DSLR might reach focus. You'll still need a very low profile t ring and t mount

 

Edited June 24, 2019 by happy-kat

[pellgarlic2]

2 hours ago, Ricochet said:

The properties of the mirror (aperture and focal ratio) do not tell you anything about the diameter of the tube and the distance between the primary and secondary mirrors, or the distance of the focal plane above the surface of the tube. 

27 minutes ago, happy-kat said:

The PDS range have their primary mirror further up the tube pushing the focal pane further along meaning a DSLR can be brought to focus, but this means with an eyepiece these tubes need to use an extension tube in front of the eyepiece.

Yikes! I knew there was a reason I'm on this forum asking for advice from you more knowledgeable chaps, so I don't make a stupid noob mistake 🤪  (and I do very much appreciate you all sharing your knowledge).

I had thought that focal length indicated the distance between the primary and secondary mirrors, and that therefore the two OTAs were in that sense equivalent, but I guess it's more complicated than that...

I'll keep a mental note of that Youtube video for if and when I'm ever feeling brave enough to start hacking bits of the telescope  

[Mr niall]

as @Ricochet and @happy-kat say; this is where your focal point is:

So the focal length is around the same length as the tube usually, but this is just a coincidence! 

But, on another more sober note, if hacking a telescope to bits and voiding warranties is an action you are seriously contemplating to make this work... then you still may not have found the right scope... 

Edited June 24, 2019 by Mr niall

[happy-kat]

Found what I was looking for re mirror less camera. Link to post here but I've neither got this telescope or camera to replicate the finding.

[pellgarlic2]

3 hours ago, Mr niall said:

... the focal length is around the same length as the tube usually, but this is just a coincidence! 

But, on another more sober note, if hacking a telescope to bits and voiding warranties is an action you are seriously contemplating to make this work... then you still may not have found the right scope... 

Thanks for the diagram - that makes it a lot clearer 😁

Regarding having not found the right scope, yeah - I am indeed embarking on further searching on the forums here and other websites regarding telescopes suited to/designed for astrophotography. 🤓

The 150i package has come very close to ticket all the boxes so far, but realising I wouldn't have the option to easily attach my DSLR has made me realise how important that actually is to me, and that I need to keep looking. It may be that I still end up going for that option if I can't find a better option though.

[pellgarlic2]

And so far, I've seen a lot of recommendations along the lines of:

"Read 'Making Every Photon Count' before buying anything, as it's a complicated business, and it's easy to make expensive mistakes" 😬

However, as I have a bit of an imminent deadline before I have to "put in my order" with my significant other, I hope it's a short book 🥵

Edited June 24, 2019 by pellgarlic2

[Mr niall]

11 minutes ago, pellgarlic2 said:

Thanks for the diagram - that makes it a lot clearer 😁

Regarding having not found the right scope, yeah - I am indeed embarking on further searching on the forums here and other websites regarding telescopes suited to/designed for astrophotography. 🤓

The 150i package has come very close to ticket all the boxes so far, but realising I wouldn't have the option to easily attach my DSLR has made me realise how important that actually is to me, and that I need to keep looking. It may be that I still end up going for that option if I can't find a better option though.

Ahhh… well if astrophotography is important to you I'd stop your search now.

There is no way you'll find what you are looking for at that price range if astrophotography is at all of any interest to you. Astrophotography gets exponentially more challenging and expensive for every mm of focal length you add. To achieve astrophotography worth doing with what you are looking at you'd would have to invest in at least a 150pds, HEQ5 mount, and guiding package. And software. You wouldn't get much change from £1500.

Astrophotography on its own is achievable with your budget but, assuming you already have a DSLR of some sort, you'd want to spend all of your budget on a skywatcher star adventurer mount and 100 or 200mm low f ration lens. Astrophotography is usually tackled with short focal length refractors too for simplicity and mounting considerations.

Visual and Astrophotography are very very different things.

Edited June 24, 2019 by Mr niall

[pellgarlic2]

Ok, perhaps I've been naive in expecting to be able to do too many things with one setup. It was my understanding that because a large aperture newtonian reflector is a good choice for DSO viewing, that it would therefore also be the best choice for photographing said DSO objects (as well as the Moon and planets). I imagine they can be used very successfully for that purpose, but with more expense than a lighter/smaller refractor of similar focal length?

I can see how what you're saying about the "expense per mm of focal length" chimes with what's been said in previous comments about the size and weight of an OTA requiring a suitable mount, and that for astrophotography it would all have to be even more stable than is required for successful visual observing. I do have a DSLR already, which I've had attached to my SkyMax 102 a couple of times, with not very good results (just attempts at shots of the Moon, shots were always blurry - either poor focus, or vibration from the mirror), but it's clear now that I'd have to spend more to get satisfactory results from an astrophotography setup than I would for a purely visual setup.

This discussion has been really helpful for me to come to some realisations about what's feasible and realistic, and now I need to get a clearer idea in my head of what direction I want to go in with this, and not try to find a £400 setup that will do everything that a £2000 setup could do 😆 

[happy-kat]

From a choice perspective the az-gti from reading and seeing various threads also can be guided but has goto that the star adenturer doesn't have. There are plenty there to read on the differences between them.

Simply visual you benefit from a light bucket but imaging effectively uses exposure length to see what the eye doesn't. You might find you need to compromise somewhere to balance what boxes you want to tick and what will keep your enthusiasm lit.

[Cosmic Geoff]

And as a footnote, a setup optimised for planetary imaging would be radically different and just as expensive.  Bought new, my CPC800 (C8 SCT + heavy duty fork mount), ASI224MC planetary video camera, and ADC would cost over £2000.   One doesn't have to use a CPC800, as a SCT on a substantial equatorial mount is usually preferred, but that is no cheaper.

[Mr niall]

 

12 minutes ago, pellgarlic2 said:

It was my understanding that because a large aperture newtonian reflector is a good choice for DSO viewing, that it would therefore also be the best choice for photographing said DSO objects (as well as the Moon and planets). I imagine they can be used very successfully for that purpose, but with more expense than a lighter/smaller refractor of similar focal length?

Not really... I mean sort of technically they can but you wouldn't bother. You can get better results with much smaller scopes for a whole host of reasons (not least of all the cost of mounting something that size), and the results wouldn't be any better. The focal length is actually your enemy here, as it means a much narrower field of view that misses most of the wider nice stuff you'd want to photograph.

 

17 minutes ago, pellgarlic2 said:

which I've had attached to my SkyMax 102 a couple of times, with not very good results (just attempts at shots of the Moon, shots were always blurry - either poor focus, or vibration from the mirror), but it's clear now that I'd have to spend more to get satisfactory results from an astrophotography setup than I would for a purely visual setup.

Your Mak has a focal length of about 1.3metres which means, using the 500 rule, you can get photos of about 1/3 of a second before stars start to smear across the frame. However the moon is achievable; if you set the self timer to 10 secs then it gives everything a chance to settle down before it takes the shot.

[pellgarlic2]

Ok, having realised that I was entirely unprepared for a discussion about realistic astrophotography expectations, I decided that rather than keep pestering you good folks for what are likely common AP questions, I would spend some time reading through threads on the astrophotography section here, and absorbing info from various other websites and youtube videos (and I will be getting a copy of "Making Every Photo Count" too). I can see now that the demands on the equipment for astrophotography are a lot higher than, and significantly different to the demands of visual observing, and that my best option is to put my astrophotography aspirations on hold until I have a better idea of equipment requirements, and maybe save up a bit of cash to go towards some suitable equipment.

From a basic perspective, I can see how the mount really needs to take priority (it needs to be very stable), and that the OTA should be light enough that it doesn't challenge the mount too much. Stability is paramount (da-dum, tsh!). Accurate tracking is highly important. Aperture comes third, or fourth, or fifth... So the requirements don't mesh with the requirements for a good visual observing setup (although there is of course some overlap). I'll likely be back at some point making a nuisance of myself on the AP sub-forum. 

In the short-term, for immediate viewing pleasure, I'm back to considering the AZ GTi to attach to my SkyMax 102. I believe it should be suitable, as it comes bundled with this OTA, as well as the bigger/heavier 127. The only potential hitch that I'm aware of (although experience has told me there may be some I'm not aware of ) is that the OTA in the AZ GTi bundle comes with a dovetail mounted on the side, whereas my one has a non-dovetail ("square") block on the bottom. I'm currently investigating to try to determine whether it's possible to easily replace that with something that would be compatible with the AZ GTi (and I'd also have to deal with the finder being in a weird orientation 🤔 possibly not too much of an issue given that it's a Go-To mount). 

I was also thinking I might see if it would be productive (no expectations) to attach my DSLR directly to the AZ GTi (which I believe should be possible?) for some wide-field astrophotography, in lieu of the "full shebang" AP setup.
 

[happy-kat]

I expect rings with a dove tail could be added to your mak102. Check with who going to buy mount from.

There are some fab images with dslr and lens using az-gti there is a huge thread on cloudy nights and they added guiding (it guides using both axis looking at graphs) which gave even longer subs. I think you might quite a lot of mileage from the mount.

If you are apple and not android be aware you'd need two devices if wanting to connect using sky safari.

Could look out second hand for sturdier tripod legs as future tweak.

Edited June 27, 2019 by happy-kat

[happy-kat]

A long read so a link to show what one person is doing with the az-gti, there is a thread or two on here but from memory have more of a visual angle as to which telescopes are being used.

link here

[pellgarlic2]

57 minutes ago, happy-kat said:

I expect rings with a dove tail could be added to your mak102. Check with who going to buy mount from.

Ah, good suggestion - will check that out, thanks. 😃

And thanks for the link to that Cloudy Nights thread - great to see that people are getting on well with the AZ GTi, and able to squeeze so much out of it 🤩

[happy-kat]

Why not share a picture of your mak and what it currently uses to mount to a tripod.

Edited June 27, 2019 by happy-kat

[Mr niall]

2 hours ago, pellgarlic2 said:

Ah, good suggestion - will check that out, thanks. 😃

And thanks for the link to that Cloudy Nights thread - great to see that people are getting on well with the AZ GTi, and able to squeeze so much out of it 🤩

You don't need tube rings as the diagonal on the Mak can be spun round to any position. What you would need is somewhere else to mount a finder. You could either drill holes for another finder base - or more easily pick up a Rigel Quikfinder or Telrad (telrad might be a bit overkill).

[pellgarlic2]

13 hours ago, happy-kat said:

Why not share a picture of your mak and what it currently uses to mount to a tripod.

I've attached a photo showing as best I can the shape of the saddle as well as the connector 🤨 - it's a 1/4" standard tripod fitting in the middle, the two holes either side are the fixings.

I haven't been able to find suitable rings under £100 😲 which is about the cost of the OTA, so too much.

I have found this "Astro Essentials Dovetail Bar" for £15, which would appear to do the job, but as it says it's for "cameras and other accessories", I'm not sure it would be able to hold the heavier mak (1.93 kg according to Sky-Watcher's website) in place with rotating on the screw. I could maybe replace one or both of the screws that currently hold my saddle on to the OTA with longer ones through both the dovetail bar and the saddle into the OTA, to make it more secure. But adding this bar "below" the saddle would also move the OTA's centre of gravity further away from the mount, which would decrease the stability.

https://www.firstlightoptics.com/dovetails-saddles-clamps/astro-essentials-vixen-type-photo-dovetail-bar.html