Esprit 120 on the way!

[codemonkey]

Well, that all happened a lot more quickly than I expected. As per usual, Peter from Astro Petes hooked me up with a great price and I now have a Skywatcher Esprit 120 on the way, expected to arrived tomorrow or Friday.

The question is, will the lowly EQ6 handle the Esprit with the GT-81 I'm using as a guidescope. Poor GT-81, one day it'll get some serious use.

[Slawomir]

Great news!

I will look forward to your impressions with Esprit.

As for guidescope, why not use OAG? :)

[codemonkey]

Yeah I may end up going back to an OAG.

I've used a couple of OAGs. One was the Orion Deluxe, which was junk. The other was the TS 27 which was much better (but came with nothing, unlike the Orion which came with a bunch of spacers, making life much more simple).

When I was using OAG it was with the RC8, which was slow and had a decent focal length. I found it difficult to find stars sometimes. The other thing was that I found PHD seemed to guide better on round stars than on the misshapen ones you get with an OAG. Honestly don't know how much merit there was to that, but that's what it seemed like.

I only bought an OAG originally because I got the RC8 and everyone seemed to say that once you hit 1.5m of FL, OAG is the way to go, but below that a guidescope is easier. So when I went down to 900mm, a guidescope seemed like a good option, and I've had no problems since doing that.

[Somnium]

Great purchase! so we can blame the next 3 weeks of constant cloud cover over the east coast of Aus on you ? :cloudy:

[codemonkey]

haha, the forecast was already looking less than great before I ordered, honest!

[Slawomir]

The heavens "knew" about your decision before you ordered the scope!

But honestly, I am sure it will be a great scope.

[Atmos]

I was seriously looking at one of those about 2-4 weeks ago, ended up going with a 130 instead of the 120.

At F/7.5 and a 0.8x flattener, you'll have a real ball with that :)

[codemonkey]

Cheers Colin :-) I assume your 130 is the Sky Rover? Keen to see how you find it!

The Esprit is F7, 120mm so 840mm. I've seen no mention of the flattener also being a reducer, and I sure hope that's not the case because that would bring it down to 672mm and be useless for my intended purposes.

[Atmos]

It is indeed the Sky Rover. Picking it up tomorrow in fact :)

You'll have to double check but I have a feeling that most refractor flatteners tend to also be a 0.8x reducer.

[codemonkey]

Awesome! Hope it's everyone you want it to be :-)

Probably a bit too late for me now, it's already ordered. I'll be pretty unimpressed if it's also a 0.8x reducer since nowhere in any specification including advertisements or the product manual does it say anything about being a reducer. I guess we'll see!

[Atmos]

Hopefully I am completely wrong then!

[codemonkey]

I certainly hope so :-) The flattener on my GT-81 only reduces by about 5% and I'll accept a nominal reduction like that, but if it's actually a 20% reduction without any mention in the docs/ads I'll be most unhappy.

[AlexN]

Just as a note bud, I ran an eq6 with an 11" SCT and a 4" Williams Optics Apo for guiding. Handled it fine. Your 5" and 3" Apo setup won't even come close to the limits.

[rustigsmed]

Hi Lee,

Congrats on the purchase, they look like awesome refractors, looking forward to a review. As for a flattener how about:

http://www.teleskop-express.de/shop/product_info.php/info/p7941_Long-Perng-2--Adjustable-Field-Flattener-for-APO-refractors.html

hang on if you got the SW one you should be ok
http://www.teleskop-express.de/shop/product_info.php?products_id=6743#c s

this says it doesn't change the FL :thumbsup:

Russ

[codemonkey]

That's good to hear, thanks Alex :-) I figured with ~10kg for the Esprit, ~4kg for the GT-81, ~2kg for the imaging train I'd probably be getting to the point of it being too much, but if yours managed with an 11" SCT and a 4" WO APO, I don't think I need to lose any sleep over it lol.



Thanks Russ! That's a relief. I was pretty sure it wouldn't as that seems a big thing to omit from documentation, but you never know.

[Camelopardalis]

Lee, congrats on your new purchase, you're going to love it :thumbsup:

I recently bought a 100 and have been blown away by the quality of the images I've got from it so far.

Just be prepared...the 120 is quite a big scope...the friendly Tasco/Skywatcher chap at AstroFest had one on display. Substantially larger than the 100, and they come in well padded travel cases.

The flattener is just a flattener not a reducer.

[AlexN]

Dunk, I would love a chance to have a look at the 100 one time. I'm considering a fast apo for wide field work and specs wise, that Esprit 100 looks on paper like a fsq106 at half the price. Definitely interesting.

Lee posted pics of the 120 yesterday in another thread. Makes the gt81 look like a finder scope.

[Camelopardalis]

Ah yeah I noticed that, just catching up on IIS after AstroFest :lol:

Drop me a line when you're free and the weather looks like cooperating, Alex. I was surprised by the size of the 100! I've been using my WO Zenithstar 71 as a guidescope recently...

[codemonkey]

Cheers mate. How're you finding your 100? And yeah, the 120 is a beast! I wasn't expecting it to be so chunky.



Hey mate, just make sure you do your research on these. When I was looking around for info on the 120 I saw mention on some of the other forums that the 100 was known to have issues. I'm not sure what the issues were and how wide-spread. Obviously there's some good ones around, 'cause Dunk has one, but definitely worth checking it out I think.

[Camelopardalis]

The 100 shows great promise. I've just got back from AstroFest so once I get around to looking at some of my data we'll see how good it is ;)

The dew shield is HUGE...all the times I've used it so far it has not dewed over once. My Zenithstar that I was using as a guide scope was not so lucky :lol:

But hey, what are these issues with the 100? It'd be useful to check mine for these...:help:

[h0ughy]

saw this at astrofest

[codemonkey]

I didn't know specifically what the issues were, I just saw vague mention of them having "issues" when I was looking for info on the 120. I just did a quick search and found a post on CN where the Skywatcher rep said that they pulled the original 100 due to collimation issues; apparently that one is no longer available and there's no known issues with the 100's currently shipping.

Always worth doing your own research before buying though, things change, more info becomes available etc.

[Camelopardalis]

Yeah I had seen that one, apparently there were two versions of the 100, the f/5 version with integrated flattener and the f/5.5 for which the screw on flattener is supplied (here in Australia).

There's a chap who posts on CN who owns a 100 and a Tak FSQ106 and images with both ;)

[RobC]

Lee ,

I think you made a good decision to purchase the Esprit 120. I have imagined alongside Dunk with his Esprit 100 and it is very , very impressive.

You made some comments about the need to refocus. This is common to all the upmarket brands and you will need to motorise the focuser.

I have an Esprit 150 on order and hopefully it will turn up this week.

Cheers

Rob

[raymo]

Sorry Rob, but it is a little bit humorous, I was wondering what you
imagined when alongside Dunk.
raymo

[Camelopardalis]

That my humour was as sharp as yours raymo :lol:

[raymo]

I didn't realise how it sounded until I read your response. Whoops!
raymo

[RobC]

Bloody spell checkers. That's a secret Raymo, I cannot tell you. I do remember getting cranky because his Esprit 100 was performing ( imaging ) so well.

Cheers

Rob

[LewisM]

Houghy's photo could open up a caption contest... lots an idle mind could conjure up with hat image...

The original Esprit series were indeed pulled due to collimation issues with the quadruplet version. They could not correct it so instead redesigned it as a triplet with a separate flattener. You will also read a few reviews of extreme frustration over flattener spacing - Skywatcher's figures are apparently wrong - so you will need to experiment. This seems more prevalent with the 80 than the 100 and up.

The guy on CN doesn't own the FSQ - he borrws various other brands of scopes and does image comparisons of the SW against them - so far he's done the FSQ and an AP150 and I think there was a 120 from TEC of AP in there too.

The Esprit series is stacking up well. Very, VERY slight halation but otherwise pretty darned good!

[RobC]

Get over it Lewis and stop this nonsense. I don 't understand what your angle is with all your negative nonsense about the Esprits. Lets see you produce some better images than the Esprit 100.

Rob

[LewisM]

Negative??? What part of "The Esprit series is stacking up well" and "pretty darned good!" is negative???

Yes, the initial batch were flawed, but that was resolved. Then there is an issue with the correct flattener spacing - with the 80 mostly - as SW's figure is apparently wrong. So you need to experiment - happens with many scopes.

Negative? Really?

[LewisM]

If people would rather stick their head in the sand re ANY small niggles with scopes, then so be it.

Heck, the FSQ in the thread Dunk is referring to has a diffraction disturbance in the image (an intrusion somewhere) very similar to the same issue some Esprit 80's and 100's showed (depending on batch).

Would you have rather NOT read about Lee's issue with the focuser and other niggles?

[Camelopardalis]

According to the chap I spoke to at Skywatcher (take that for what it is!), there were originally 2 versions of the 100, the 3-element f/5.5 which is for sale and that I bought and a 5-element f/5 that didn't work, so they pulled it.

The back focus from the flattener varies by model and isn't particularly generous on the smaller models, but I get sharp stars corner to corner with my crop sensor and that's all that matters to me. If anyone wants to come play with it and their full frame DSLR then they're welcome to get in touch with me, I'd be keen to see how it fares. That might also highlight any spacing issues.

I'm not sure what to expect with regards to halation. I was interested in a triplet because I've suffered blue halos with my WO doublet (unsurprisingly) and even some other triplets I've seen. Any examples of clean and halated images would be great, so I know what I'm looking for. But this isn't my thread :lol:

IMO my judgement when I was looking for a new scope was that the Esprit are fairly new and most of the issues could be put down to a bumpy start, but it's always better going in eyes wide open. Obviously, TV, Tak, whoever have a head start, but who's to say they always get it perfect first time? The measure of a brand is how they stand by their product over time and how they handle any support issues.

[LewisM]

Kevin Legore of SW USA did once fully describe the collimation issue with the early batch (now all pulled). The spacer ring interference in the optical path is the reason why SW USA now fully test each Esprit before sending them to customers. It is uncertain if all the newer model have the one piece continuous spacer or not ex factory. They should be.

Regarding halation, it is VERY subtle. When the say SW vs AP images are compared, the Esprits show a very minor degree of halation. Very acceptable amount in fact. All Esprit images are also warmer toned.

All in all an excellent telescope series. I almost bought an Esprit 120 but went for an FSQ instead.

[Camelopardalis]

Thanks Lewis! Do you have an image from your Tak you could post so I can see how it should look?

[LewisM]

Actually, not really, since I did not nail focus on ANY of the images I took recently (still waiting on my Sharpsky system, so manually focussing for now - at f/5, the CFZ is SO minute it is rather difficult!). Note my CCD is not orthogonal either - need to adjust the bottom right corner.

BUT, here is a slightly OOF shot of NGC6188 with the FSQ-106ED...

WARNING - BIG image.

http://www.pbase.com/lewism/image/160890607

[codemonkey]

Cheers Rob :-) That 150 is going to be a beast, congrats!

I'm still not sold on the refocus thing yet. I'll do another run, this time without screwing up my guiding, and see how it goes. I've never had to do it on another scope, and yes, I've monitored FWHM over runs.

[AlexN]

I'm waiting with baited breath to see the 150!

[Slawomir]

And we all can say goodbye to clear skies here in SEQ... ;)

[Camelopardalis]

Interesting, thanks. Is that a single, unprocessed image?

Btw, focusing at f/5.5 with a a Bahtinov mask is a breeze, but irritating to do it with any frequency, it interrupts photon collection! What's this Sharp sky system?

[raymo]

I'd love to have a JPG as unsharp as that Lewis.
raymo

[Slawomir]

Hi Lee,

You could compare focus visually with a Bahtinov mask on a bright star at the beginning and at the end of imaging session on a night when temperature will change at least a few degrees, if you wanted to know for sure :)

[codemonkey]

Good thinking, thanks mate. I thought of this, as I usually do, after I'd already packed up and was on my way back to the house. I should also take note of the focuser position to reduce the likelihood of focus slip being the cause.