Esprit 120 first light review

[codemonkey]

I managed to get a brief first light with the new Skywatcher Esprit 120 last night. As I learn more, I'll update this thread.

The Focuser
First things first, the focuser. The focuser is a really big deal on an imaging scope, and it's almost always neglected. This usually results in the purchase of expensive aftermarket focusers. Honestly I don't understand why manufacturers do this; either ship it with a usable focuser, or reduce the price and ship it without one at all.

Skywatcher claim that the focuser fitted to these as standard will handle payloads of 5kg while focusing, and 10kg locked.

My imaging train consists of a SX Trius 674 CCD, Orion Nautilus electronic filter wheel (with LRGB, OIII and Ha filters) and a focal extender. I think I weighed it all at about 2.5kg once, either way, well under the 5kg limit.

On unpacking one of the first things I did was stuck my ccd/efw on the back of the focuser and see if it would hold it without any tension applied. It did not; it immediately began slipping. Adjusting the tension/locking lever enabled me to halt the slipping.

Speaking of the tension/locking lever, it's quite awkward. I've never used a focuser with this type of locking mechanism and I'm not sure why they did it. On the bright side, it does seem to (without significant scrutiny) enable locking without shift.

In the field I was able to focus the CCD using the coarse-grained focus knobs, however inward adjustment with fine-focus knob didn't seem to work very well due to insufficient tension. You could say that's user error. I found that adjusting inwards with the coarse-grained control, then backing it out with the fine-grained enabled me to reach focus, even if it was a bit fiddly.

Another review I've seen mentioned the focuser having a series of tension screws that can be adjusted to enable smooth focusing with heavier loads. I'll be looking into making this adjustment and I'll report back.

Now something happened with the subs that I took last night, and I'm not sure what it is so it'll need further investigation before I can reach a conclusion on the focuser. After a few subs the stars got noticeably bigger, the images softer and the FWHM went up significantly. This could have been focus slip, or it could have been caused by user/guiding error: I forgot to turn the power up on the dew heater on the guide scope which caused some guiding issues. The dew heater on the Esprit was turned up well enough and was dew free. So it's possible there was significant focus slip during the subs, even with the focuser fully locked. I'll report back on this after the next clear night.

At this point I think I'll be able to adjust the focuser so that I don't have to look into a Moonlite/Feathertouch, but I'm uncertain. As I said, I'll try to adjust it and report back.

The Optics
In the past I've owned a Saxon ED100 doublet, Skywatcher ED80 doublet, William Optics GT-81 triplet, and a GSO RC8. I've not owned any premium refractors and barely used the GT-81 which is the only other triplet that I've owned.

I currently use SGP for imaging and have been using their statistics module to aid in focusing lately. SGP provides you with a Half Flux Radius (HFR) of stars across the frame. I've assumed this to be an average, but I'm not sure if that's the case. Anyway, we can basically say that a smaller HFR = sharper image.

With the ED100 the smallest HFR I saw was 1.47px. Last night, with the Esprit 120, I saw a HFR of 0.89. Now there's multiple variables at play here so we can't say that all of this is due to the optics, but I think it's safe to say that a significant amount is.

Now of course this is a totally unfair comparison. The ED100 is a doublet costing less than 1/3 of the price of the Esprit 120. The thing is though, it's this difference that I was looking for, it was this that would justify the price to me. How would this compare to a Takahashi? Who's to say.

One thing to note is that this analysis was done with a 11mm diagonal CCD chip and no flattener. And as you will see in the attached mosaic generated by PixInsight's AberrationInspector, the stars look pretty good across the entire field. Of course if you put this on a full frame sensor or even an APS-C sized sensor I wouldn't expect results as good as this. Note that this was generated from a single 430s frame, which was obviously subject to guiding/tracking fluctuations.

Speaking of the flattener, mine was missing from the box. According to my retailer, this has been known to happen with some of the Esprits because the flattener was packaged separately in some cases. I believe that info came from the local Skywatcher rep.

I have seen complaints in the UK that the Esprit were no longer shipping with the flattener, but apparently they should still ship with it over here. Mine is supposed to be mailed out to me shortly.

Everything else
The lens hood is retractable, which may help with transport but probably nothing else. It does have a locking screw (I think two actually, but my memory's terrible so don't quote me on that) which means it'll always stay up. That's a nice touch; my older GT-81 doesn't have one and relies on the tube rings being pushed flushed to the back of the hood to keep it up.

The lens hood does move awkwardly and doesn't feel very professional when compared to the smooth movement of the GT-81. But eh, it does the job and will stay up so I suppose that's what matters.

The scope comes with nice CNC tube rings and a Losmandy-D style dovetail, both of which are a big step up from the lower-end scopes and very welcome additions.

The scope also comes with a nice road case, complete with two wheels on one end, although I'm not sure how they'll go on typical terrain.

Also included is a diagonal, eyepiece and right-angle finder. As I don't do visual at all, these accessories will stay in their original packaging, never to see the light of day. Given the target market for this series of scope is mostly imagers, I question the inclusion of these accessories; they could be sold as optional extras as I imagine lots of imagers, like myself, would eschew finders in favour of platesolving, and probably never stick an eyepiece to it.

Conclusion
So far I'm happy with my purchase. I think going from a doublet to a triplet was a worthwhile investment, but if I were not into imaging I may not have been able to justify the cost.

I expect to be able to adjust the focuser so that it's realistically usable. A shame it didn't come like that out of the factory. If I'm unable to do so I'll report back.

Overall the mechanics of the scope (lens hood, focusing tension lever) feel a bit awkward and I'd hoped for better, but it's not really unexpected.

[casstony]

I just disassembled and tuned up an old WO 4" Crayford which was slipping in two places. The drawtube was slipping past the pinion - there's a tension screw over the pinion to apply extra pressure. After that the drawtube would still roll out until I added tension to the micro focuser - there's a nut that can be tightened to apply more pressure to the micro focuser bearing. The focuser now holds a 2" diagonal and the heaviest eyepieces.

[Slawomir]

Hi Lee,

Thank you for taking time to share your first impressions with your new telescope.

I am glad that you found optics to be very good, and it looks like you can successfully image with your camera without a flattener (although using one will probably make all stars in the corners perfectly round.).

I hope you will be able to adjust the focuser so it will work reliably. I actually expected that focuser might be potentially the weakest part of this scope, but as you said, it is still too early to say that with certainty.

I will be looking forward to your new, sharper, showing more faint detail and thus more beautiful images :)

[codemonkey]

Cheers Tony. Mine will definitely need tweaking, but at this point I've found no diagrams / documentation on the process.



Cheers S :-)

I went up to the "obs" this afternoon to collect my larger battery for charging and thought I'd have a little look at the focuser while I was there. What I saw didn't leave me all that happy.

Turns out there's space for four bolts under the focuser, some or all of which presumably play a part in tensioning the focuser. While I have four holes, I only have three bolts in there. And while playing with the fine-focus control with the scope parallel to the ground I noted that it did not adjust the focus at all. So, whatever I thought I saw in the dark last night was either my imagination, or slippage. I did notice last night that inward travel wasn't working with fine-focus, but I thought outward was and had assumed this was just insufficient tension. Must have been insufficient tension causing focus to slip :p

The question is, how did this pass QA? That's a pretty large oversight.

[casstony]

The good news is that the focuser can almost certainly be made serviceable with adjustments similar to those I described above - most crayfords (excepting FT) have a somewhat similar construction and operate on the same principles. If you can get some info/pictures about how to adjust that particular focuser that's great, otherwise I'd suggest getting permission from the retailer to disassemble and adjust the focuser yourself - once it's apart you can see which screws do what. Failing that send the focuser only in to the retailer or Skywatcher for adjustment and ask them to adjust it to suit a heavy load - no need to ship the whole scope.

[Camelopardalis]

Nice one Lee. My Esprit has been giving me nice round stars with no halos, which is what I was looking for in an imaging apo.

Lee, what was happening with the ambient temperature while your subs were getting softer / going out of focus?

I've noticed that I need to refocus regularly during the first half of the night at AstroFest, and I suspected thermals. After midnight when the temperature became more stable I didnt need to touch it much. If the tube is contracting with dropping temperature, it surely can't be unique to this scope.

The focus lock is a bit quirky, but as you say there's no shift. My focused doesn't slip, but then my DSLR only weighs about 500g.

[codemonkey]

Cheers Tony :-) I've hit up Skywatcher to see if they'll provide some details. I think all other crayfords that I've seen diagrams of usually have one clear grub screw that you adjust for tension, but these ones only have four symmetrically-placed bolts underneath so without opening it up fully or being provided with documentation, I'm not sure what to do.



Cheers Dunk :-)

Not sure about ambient temps, I wasn't measuring them. They were presumably dropping due to it being early evening, but I don't know by how much.

It's possible it was temperature related, but I have never seen such a shift on any one of my scopes, and I doubt the temperature shift was that much different. Given the other issues with the focuser, I think that's the likely culprit.

The main thing with buying a triplet for me is once you use parfocal LRGB filters with a doublet and a bhatinov mask, you'll see how out of focus the blue (probably, I guess that depends on your scope) light is. From there you think about how it's a spectrum rather than a discrete block and a significant amount of light in the spectrum isn't being brought to focus every time you're shooting L. This of course could cause colour halos, but I imagine other things could cause those.

[Camelopardalis]

The main reason I threw the temperature thing out there is because I'd spoken to a few others at AF who were using temperature-sensing motorised focusers to solve exactly the same problem...and mine was the only Esprit on the field ;)

Yeah looks like the blue is usually sacrificed on a doublet, probably not the greatest if you want to capture some OIII :question:

[Somnium]

thanks for your first impressions, i look forward to more details. i am not sure how big the focussing issues were, but is it possible this is due to changes in temperature. I am not sure how much this affects refractors but it may be a component of the issue. when you get a chance i would love to see a colour image to see how well the CA is corrected. congratulations again on your new scope, you have to be very happy with the results.

[codemonkey]

Yeah, I'm not sure. I have been imaging for a couple of years now from this location and I've never seen any measurable focus shift on any other scope due to temperature. I've been able to image for hours on end, always starting from the early evening, with the FWHM fluctuating but ultimately maintaining a horizontal trend.

Now it's possible that triplets are different in this regard, I've only ever used my other triplet once for real imaging, but I do use my GT-81 triplet as a guide scope and I've not noticed significant focus shift with that in the same conditions.

The other option is that this is a big beast, and maybe it hadn't fully cooled. I'm not sure if that would affect focus, but maybe? I would also expect the non-insulated aluminium composite panel box that I like to call an "observatory" probably doesn't have great insulative properties so I would expect the scope to be pretty close to ambient to begin with. I've never validated that theory with measurements though.

Anyway, probably seems like I'm saying with certainty that it wasn't temperature related, but I'm not actually ruling it out, I'm just leaning towards other causes based off previous experience (with different scopes!). I could be wrong, and time will tell :-)

I've contacted both SkyWatcher in the US and Tasco in Australia regarding my focuser issues and hopefully I'll have some helpful advice soon.

[Camelopardalis]

I guess the thermal behaviour depends on the construction, and carbon fibre tubes are featured in some other scopes to get around this. Also, I'm not saying with any certainty, but I noticed this last week and it was most noticeable in the evening when the temperature gradient was largest.

Keep us posted on the focuser issue, as this will no doubt be useful to those of us seemingly blazing the trail with these scopes :D

[gregbradley]

Carbon fibre may not be suitable for an APO scope. Aluminium tubes shrink and triplets will shorten their focal length as they get colder so to some degree theymatch each other and minimise focus shift. If it were carbon fibre unlike on a compound telescope which keeps everything the same at different temps it might actually make the scopes thermal behaviour worse.

This is from Roland Christen. I see Officina Stellare sell some carbon fibre APOs. I wonder how they perform in this regard.

If it makes you feel any better the FSQ106ED has a focus lock lever and it causes focus to shift if you don't partially engage then lock it all the way. Also there have been in the past numerous focuser flexure issues with it. I am not sure if this is still the case but it as for a while. So even Tak doesn't get it right when it comes to focuser every time.

The best focusers I have used have been AstroPhysics ones. Built like a tank and about US$600.
Then feathertouch (a bit lighter wieght though)
Greg.

[LewisM]

All the info i have read online points to CF tubes being NOT suggested for refractor. Open tube designs, yes, refractors definitely not. That came from Roland and Yuri plus I believe the guy that makes the objectives for CFF scopes.

[codemonkey]

Yeah, fair enough, it certainly does sound like a likely culprit.

Focuser issue is sorted! Well, the one with the fine-focus control. Focuser itself could use a tension adjustment, but I can work with that.

Attached shows the grub screw that, when tightened, enabled fine-focus control.

[LewisM]

Imitation really is the sincerest form of flattery - not far from an FSQ-106ED clone :)

Skywatcher did originally make these as quads, but had coillimation woes, so redesigned them as triplets with seperate flattener. A few quads escaped into circulation and are collector's items now (though plagued with issues).

Do watch for diffraction spikes in the images - the split rubber rings SW use for the lens cells have been shown on occasion to impinge into the light path and create diffraction spikes (smallish). A company in Germany offers to fix the issue for a small cost, IF you have the issue: http://interferometrie.blogspot.com.au/2014/08/esprit-tuning-how-we-finetune-esprit80.html

[codemonkey]

Cheers Lewis:-) Fortunately in my brief experiments I've not noticed this so I think I'm safe there.

Once I get my OAG and can balance my gear again properly I should be good to go and give this thing a decent run.

[casstony]

So it's not a standard Crayford like the first Esprit scopes - it's more a rack and pinion. Provided the distance between the bearings on top of the drawtube is sufficient relative to the diameter of the drawtube, it should be a very good focuser once properly adjusted.

[codemonkey]

Looks like it, Tony, that sure doesn't look like the smooth axle you'd expect on a Crayford. They never refer to the focuser as either a crayford or a R&P and instead refer to it as a "linear power focuser", whatever that means.

[Camelopardalis]

Great stuff Lee, thanks for sharing :thumbsup:

[Shiraz]

Nice report. Looks like your system resolution is seeing-limited for your site - that's as good as it gets. definitely a keeper.

Maybe there could be just a very slight amount of image plane tilt? (left hand sharpness looks just a tad under that in the centre and right panes). If there is some, you can easily adjust it out with the camera.

Suggest that an add-on stepper drive for the very tidy looking focuser might be worthwhile - aluminium wanders about like nothing else when the temperature changes.

[codemonkey]

Cheers Ray :-)

I think you're right regarding the tilt. I hadn't noticed it, but now that I look more critically I can see it. This could be because of the dodgy focal extender I have in the mix. Hopefully once I have my OAG and flattener I can get rid of that.

I'll definitely be looking for a stepper when I have the funds. I've gone on another shopping spree though, buying this scope, a new OAG, upgraded counter-weight shaft for the EQ6 as well as a belt mod kit, so I've pretty much exhausted all spare funds I had, so it'll have to wait a few months I think.

[codemonkey]

Ok, I have an update on this.

Kevin Legore of Skywatcher US has been a great help, providing me with the attached diagram.

Kevin also provided the warning The pads on the Esprit focuser can be adjusted but be careful when backing the screws off as the pads are only kept in place my pressure of the screws and the draw tube. I have attached a picture to show this.

Now it was a bit tricky adjusting it, I had to make multiple adjustments to the two sets of grub screws (there's another set on the other side of the focuser), as well as the grub screw I posted earlier. At one point I went too far and there was a distinct thud when the focuser reached a certain point. But after much tweaking I think I've finally got it sorted.

Tasco Australia still haven't responded to me regarding my issues with the focuser, nor regarding the missing flattener, but at least a rep in the US with no obligation to help came to the rescue regarding the focuser.

The documentation that came with the Esprit doesn't seem to quite match the bits and pieces that came with it, but I did piece together something pretty cool. With the extender and adapter that comes with it I'm able to set up my entire (for the moment) imaging train without a single one of those crappy brass-ring compression things. The entire lot is threaded and very secure, which I think is pretty damned cool.

[Camelopardalis]

Good stuff Lee!

One of the things that appealed to me about these were the screw threads, being able to avoid compression rings and their sag potential! Maybe unfounded of course :shrug:

[Slawomir]

It's great that you are refining your imaging train and that all is coming together nicely.

[casstony]

How hard would it be to include a pamphlet with each scope detailing the construction and adjustments for the focuser - would save the retailers/manufacturer a lot of emails I would think.

[LewisM]

Skywatcher USA is now standing behind the Esprits performance obligation:

http://www.cloudynights.com/topic/504065-stellarvue-svq100-tele-vue-np101is-takahashi-svq-106edx-iii/?p=6662726

[codemonkey]

Yeah, I think it's great. A definite improvement over what I had before.



Cheers S :-)



I know, right? Especially when it seems like such a common issue.



Good to see, thanks Lewis!

[Octane]

Are there any aftermarket focusers available (Starlight Instruments or Moonlite) that would fit the 120 or the 150 for imaging/autofocusing?

Congratulations, on your purchase!

H

[codemonkey]

You can definitely get a Feathertouch for them (120 and 150 have the same focuser), but I'm not sure about a Moonlite.

[Camelopardalis]

The 100 and 120 both have an M74x1 male thread at the end of the focuser tube, although this itself looks like it can be unscrewed from the focuser barrel :shrug:

[Slawomir]

I am sure Ron Newman from Moonlite will have or can custom make a flange for your scope. It would be best to email them and ask.

2.5" Motorised focuser + motorised rotator from Moonlite is a pretty awesome combo IMO.

[codemonkey]

That'd be very nice indeed... also very pricey!

I did another brief test last night, I think I'll definitely need motorised focusing with the Esprit. Not sure what the difference is between this and every other scope I've owned that necessitates it, but it is what it is. I also discovered that even after my adjustment, trying to focus near zenith is impossible with the focuser. I'll have to try it again, although I'm not sure I'm going to be able to reach a balance that will enable me to focus at all positions without it becoming so tight that I won't be able to motorise it.

I'll be trying to build my own motorised solution, which should cost < $100. I had planned on buying one, but it looks like it should be achievable to DIY and that beats paying $630 to land a Sharpsky.

Also going to be short on funds again as my EQ6 is up the creek... getting huge, image-ruining spikes in RA now, as well as worsening DEC backlash, so I'm requesting a refund and planning to upgrade to the AZ-EQ6.

[Octane]

Will you be able to automate your motorised solution?

The beauty of a RoboFocus or SharpSky is that it's all ASCOM compliant and can be controled via automation software. :)

These scopes seriously look tempting. I'd love to see some deep images taken with a full frame camera. I'm torn between spending on one of these or a Paramount!

H

[codemonkey]

Sure can... some guys over in the UK have done the hard work writing ASCOM drivers and even documenting what components they use, so it should mostly be a matter of putting the pieces together (easier said than done, of course).

[Octane]

Hope you don't mind documenting what you do on here, Lee! Would love to see your build.

H

[LewisM]

One word: FSQ-130ED

Nuff said. It'll ride the Losmandy just fine.

[Octane]

One word: divorce.

:P

H

[codemonkey]

PM Sent

[Octane]

Cheers, mate!

H

[LewisM]

You want a Paramount mount.... all of them are more expensive than the Tak FSQ-130ED, EXCEPT the MyT - and the MyT might be more by the time you add in everything.

I'd go with the FSQ130 on the G11...

[AlexN]

H. Do you need a paramount for your FSQ really? Your scope and camera weigh all of what 7kg? Hahaha. The g11 Gemini would carry the Esprit 120 and the FSQ side by side. Use the 120 for lum and the FSQ with colour stl11k and you will be set.

[Octane]

Oh, I meant that I want a Paramount, and, if I purchase one (which the dear wife has given me permission to) then I wouldn't be able to justify an FSQ-130ED. How much is one, anyway? Claudio has removed pricing from his site.

H

[Octane]

By the way, the camera and STL-FW8 filter wheel is quite heavy. The FSQ-106N is quite heavy, too. And, with an FS-60CB on top, it starts to add up.

H

[LewisM]

Just get the FSQ-130ED... forget the Paramount. Put the scope on your G11. Bliss.

I believe the US price for the 130 is circa $13K.... so, I guess it is more than the ME+... just.

[Octane]

So, about $20K Australian, after having to buy all the adapters and focuser. :P

I'll pass.

H

[AlexN]

H.. The dear wife allowed a paramount??!! Lucky man. I call dibs on the g11 if it is to be sold!

[LewisM]

See H, if you let me keep the N when I worked on it, you would need to buy an Esprit after all.... there is some weird logic in there somewhere :)

If you sell the N, let me know - 2 N's on one mount is like something in a dirty movie :P :) :) :P

[codemonkey]

Just an update on this: almost three weeks and no response from Tasco regarding either the focuser issues, nor the missing flattener. Very underwhelming support.

[LewisM]

I gave up on Tasco a long while ago. Once, you would get almost instantaneous replies from Rob at Tasco. Now you get NO replies from ANYBODY, let alone service of ANY nature. Terrible really, and it is for that very reason ANYTHING I need that Tasco supplies I get from Teleskop Express instead (AND save money!).

They are only losing customers doing this tactic of non-support. I am positive they would rather your dealer handle it, but sometimes they even give dealers the brush off as I found out. By the time Tasco had answered my dealer about a replacement MC board, I had ordered and had DELIVERED a replacement from Germany, and $75 cheaper too.

Tasco needs to WAKE UP!

[Camelopardalis]

Just a silly question...have you tried calling them?

[codemonkey]

They certainly do need to wake up. When people spend the amount of money that these things cost, they expect decent support.

My dealer has also told me that he'd chase them up, but having heard nothing back from him (he's usually very good), I'm guessing they're giving him the run-around too.

And this was after the rep told my dealer that some of them accidentally shipped without the flattener... kinda seems like something they could have checked, given they already knew it was a common issue?

[codemonkey]

Fair call. No, I haven't. Seems reasonable to expect a response from an email address that they publish on their website.

[codemonkey]

This morning I sent an email to Barry Smith direct (QLD rep), and just now, mere minutes after posting my last response, I finally heard back.

Apparently an order was raised for my flattener but "for some reason it wasn't shipped" but it will ship directly to me today.

Apparently their scope technician will be in contact to work through the focuser issues.

[Camelopardalis]

Given the prevalence of email in modern society I partly agree, but at the same time email is notorious for going awry in pretty much any global corporate scenario...

When high-tech don't work, revert to the old fashioned methods.

The reason I raised it was that when I was looking for "real" info about the Esprit before I bought mine, I contacted them by phone and was put through to a knowledgeable chap who was very helpful. Maybe I got lucky :D

[codemonkey]

That's interesting. I'm a software developer by trade, and for me email is basically a more official SMS; something that usually gets a response in minutes, or hours, not days, and certainly not weeks.

[Camelopardalis]

I feel your pain, and don't take this the wrong way, but for many businesses who don't specialise in IT, email is a secondary form of communication ;)

[codemonkey]

Yeah, fair enough. I guess my perspective may be somewhat outside the norm. Geeks gonna geek! :-)

[codemonkey]

After getting it touch with Tasco's telescope technician (very helpful, nice guy!), I've been provided with some more information on adjusting these focusers and I think I've now got it about as smooth and even as I'm going to get it.

The down side is, I carried the scope ~300m back to the house to do the adjustment, only to find the locking lever had fallen off somewhere along the way. Something to be said for build quality...

I've now asked Tasco for a replacement lever; given I'd never done anything to the lever besides use it for its intended purpose, that seems reasonable.

Tasco also told me the flattener would be sent last Friday and I should receive it early this past week. I contacted them yesterday and was told that the sales manager believed it had been sent yesterday because "the guys have been very busy".

[RobC]

Lee - How did the focus lock fall out ? You are not having much luck.

Rob

[LewisM]

Grab a metal detector and go search for it! I would!

These are hex screw retained aren't they? Loctite in your replacement when you get it!

[codemonkey]

I can only guess that it was retained as well as the missing bolt on the focuser, or adjusted as well as the pads on the focuser. All I know is that it was there the last night I used the scope, and it was not there when I got it back to the house, and I'd not touched it in between.



I'm not sure exactly how that mechanism works to be honest. There's a hex screw on the block that the lever goes into, I'm not sure if that holds it here or adjusts it. It's in the instructions that Tasco forwarded on to me but I don't have those on this computer so I'm not sure.

Alas, I don't have a metal detector. Hopefully Tasco will send me a replacement, in the meantime I can just stick an allen key in the hole where the lever's meant to go in order to lock/unlock it.

[codemonkey]

Ok, I finally have the flattener. Now if I can just get a replacement for that lever...

Hopefully soon I'll start gathering real data with this!

[codemonkey]

I just wanted to add to this to say that I've heard back about the lever; the tech guy at Tasco really is great to deal with so they're not all bad. As has been pointed out though, it might be an idea to use the phone as first method of contact with Tasco.

[Camelopardalis]

Glad to hear your experience is improving Lee :thumbsup:

[Avoman1]

Hi lee I recently purchased both the 80&120 Espirt scopes ( very happy with them) there was a flattener and some fittings missing from the 80 case. The owner of Sirius Optics where I purchased from rang the rep while I was in the shop ........ No problem was the reply and 10 days later I have the missing gear. Who knows why the flattener was missing to start with but its all good now. Not bad customer service.
Hope yours works out mate.

[codemonkey]

Glad to hear you've had a somewhat better experience, Darryl!

I've been pretty happy since the tech guy took over most of the comms; he keeps me up to date and has been very helpful.

I'm still waiting on a replacement lever and a replacement for the bolt that was missing in the beginning, but I know Tasco are trying to source it from the factory and are chasing them up trying to get an ETA.

Tonight's looking clear so I'll be back to testing this out, along with the new pier. I have the flattener now but I need to sort out spacing so still not quite there yet.... sooon.

[AlexN]

I'm out testing temp compensation of my focuser tonight. Seems to be working. I haven't refocused in over 2.5hrs with a 4 degree temperature drop and still have fwhm measurements in the mid 2's

[codemonkey]

Awesome! I'm still waiting on shaft couplers from the UK before I start work on mine. They're sending replacements now (they offered a week ago, but I thought it nice but a bit premature), so hopefully that won't be too far away.

Doing a SNR experiment at the moment, which is good, because I'm getting a FWHM of about 4.5, same as last night... good times.

[codemonkey]

I caved and bought another Moonlite tonight, to fit to the Esprit. Getting tired of issues with the focuser and I know a Moonlite will just work, having had two of them in the past.

SWMBO doesn't know yet... I like living dangerously.

[AlexN]

Man oh man. If I went and bought a Moonlite without authorisation there would be no discussion. I'd just be dead. I'd be out with my scope, enjoying the focuser. Then.. Out of nowhere, a kitchen knife at 99.99* speed of light.

Dead.

You are a brave man.. :)

I've been imaging up a storm here. Been out 2 nights in a row now. Light pollution kills me with the 300mm focal length I'm working at.. There seems to be no way around it. And my flats are causing me dramas too. But I'm having fun nonetheless

[codemonkey]

LOL! Brave, or stupid? A fine line, maybe. I think she knew it was coming anyway, she knows me well enough by now. And I just got a pay rise anyway.

Good to hear you've been having some luck. Keen to see your results! Past two nights have been shockers for me.

Last night I was imaging from 7pm through to 1am. Over the time I lost hours of data due to bad focus, and focus slip.

I lost over an hour because I used an inverter for the first time and had different power saving settings when the computer was plugged in, so it went to sleep a few minutes after I left it.

I couldn't get the filter wheel to connect for a while after that. Finally rebooted and that fixed it. Did a meridian flip, got everything set up again, left it running, came back at 1am to shut everything down, went to turn the cooling off on the CCD............. it wasn't on. Sharpest subs I've ever had, but totally useless with the amount of noise in them.

Tonight is the night, I'm certain... although I've said that the past two nights. On the bright side, I've got a week off so I can stay up late to try and get more imaging time.

[Slawomir]

I am sorry Lee that in the end the focuser turned out to be inferior and that it needed replacing. It really puzzles me that some manufacturers of astronomical gear dedicated to imaging sell products that need upgrading right away, if you are serious about astrophotography.

On the other hand, Moonlite will surely transform your fine telescope into a reliable, very capable and thus fun to use triplet :thumbsup:

[codemonkey]

Honestly I could probably fix it up if I just tweaked it a bit more. Problem is I'm getting sick of tweaking it it "just a bit more" and thinking "it'll be right this time". I've been spoilt with Moonlites in the past though and they're one of the things in this hobby that I know "just work" so that's hard to pass up.

[Camelopardalis]

Sounds like impatience is an expensive hobby :P

Sympathise with your issues, any setup can suffer with gremlins and star parties like AstroFest are a good demonstration of what can happen will happen, especially when in a remote-ish location.

I'd recommend looking for a 12v driven power supply for your laptops as they are less thirsty than inverters.

Btw, what sort of fwhm were you getting in your images, out of curiosity?

[codemonkey]

haha, yeah, I'm not known for my patience. I think sticking with refractors was a good choice ;-)

FWHM when things started going well was 1.9" - 2.1". That's uncorrected as well, as I don't have the correct spacing for the flattener... probably need to order something from precise parts which is going to cost an arm and a leg, but I need a rather obscure adapter to go form the Celestron OAG direct to the flattener.

Is there a particular power supply that you would recommend? I've not looked into this at all before, I assumed the only way to power these was using an inverter. I use macs as well, which may make a difference here. To be honest the inverter thing doesn't really bother me. I can use the 45w adapter on my 15", using an 80% efficient inverter and only chew through about 4.5Ah, which is no probs at all on my 105Ah battery. Planning to hook it up to a solar panel soon as well.

[Camelopardalis]

Yeah I guess we've just got to hope our refractors don't ever need collimating :lol:

If measured at the centre, then I'd say that's decent seeing compared to what I've seen here recently :sadeyes: maybe not the best in the country, but we've got to roll with what we get. The flattener spacing should only change the stars away from the centre.

For your laptop, have a look on Amazon or eBay using "car charger" and your Mac model, as the power connectors and draw are different for different models. In reality though, it sounds like you've got enough juice to keep your laptop going off the inverter for the night, so why worry :shrug:

[codemonkey]

Thanks mate :-)

Interestingly enough, I seem to be getting pretty round stars in the edges now, even without the corrector in place. I did an eccentricity map initially which showed elongation around the edges that wasn't in the center... I'm now wondering whether my polar alignment was good enough, maybe that initial run had some field rotation.

Thanks for the tip re the power! God knows lugging around that 105Ah beast is a pain, so anything I can do to reduce that until I fork out for solar is a big help.

[NeilW]

Hi Lee,

Can I just confirm something? In this thread it appears that your Esprit came with a Crayford style focuser, but on Andrews' site they say it comes with a "High grade 2.7" rack & pinion 10:1 dual-speed microfocuser". Was the one you're having so much trouble with an R&P?

Cheers,

[codemonkey]

Hi Neil,

This one is a rack and pinion. Other people seem to have no problem with theirs, so it could just be that I got a bad one... and I didn't want to send it back (too far to drive, didn't want to wait), so kinda my own fault.

Cheers,
Lee

[NeilW]

Are you still going to replace it? You mentioned Moonlight, but Baader have recently released their new Diamond Steeltrack. Initial reviews seem positive, and somewhat cheaper than the Moonlight, so it might be worth a look.

[codemonkey]

Thanks for the heads up! I am replacing mine, but I've already got a 2.5" Moonlite on order, due to arrive tomorrow.

The original steeltracks seemed to get good reviews from what I recall, so those could be a good option. As far as I can see the new ones at least only come in 2" though?

[brian nordstrom]

:thumbsup: If you want to sell the original , I will buy it off you .
Brian.

[codemonkey]

PM sent.

[codemonkey]

The Esprit is now fitted with its new focuser. Took about 2mins to fit, and is as buttery smooth as one can always expect from a Moonlite.

Have to say, I kinda prefer the look of the stock one, but meh.

[Atmos]

That focuser kinda reminds me for a miniature Darlek ;)

[LewisM]

Steampunk...

[RobC]

Lee - Where is the flattener ? If you move to a bigger sized camera sensor then you will need the flattener. If you incorporate the flattener in your optical train will you be able to achieve the correct back focus.

Also does the moonlight have a motorised focuser ?

Cheers

Rob

[codemonkey]

Hey Rob,

The flattener's not there as I don't have an adapter that will give me the spacing I need. I won't have any issues with backfocus here: the stock focuser was within a couple of mm of being fully extended without the flattener in place.

Initial tests showed some increased eccentricity in the the frames around the edges which I had assumed was slight curvature requiring the flattener to fix, but I've had other subs since that didn't exhibit this, so I'm not sure whether I'm going to outlay for an adapter at this point.

The Moonlite isn't motorised. I'll see how this goes in terms of focus shift over the evening as I'm still not sure whether that was the OTA or the focuser. I've got (most of) the parts to motorise it (DIY route) if need be.

Cheers,
Lee

[Camelopardalis]

Yeah I'm with you Lee, I think I prefer the look of the original.

But who cares how it looks in the dark :shrug: if it eliminates the slip and can be easily motorised then that's a win IMO.

[codemonkey]

I can now confirm that it was temperature all along. Not really a surprise to most I suspect, but honestly was for me because I've never had an issue with any scope I've owned before.

So now to get motorised/automated focusing built...

[Slawomir]

I told you... ;) :lol:


But more seriously, the telescope and all "attachments" look great - once you get it motorised and automatically compensated for focus shift with temperature change - I am certain this gear will put a big smile on your face each time you will aim the telescope at the skies and let it do "its thing".

[codemonkey]

haha, yeah, everybody did, but I always have to learn the hard way ;-)

I've just ordered some new shaft couplers since the Moonlite has a different size shaft and hopefully I can get the automated focusing sorted out shortly.

I think I'll skip temperature compensation at least initially, and just refocus between every sub... my longest ever sub were 40min narrowband and I've been manually refocusing about every 30-60mins so I think that should do ok to begin with at least.