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michaelmorris

SW 80ED vs SW Esprit 100 ED?

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I'm currently looking at my medium range plans for my telescopes.  My main deep sky imaging scope is a SW 80ED.  It continues to give me good service, but the operation of the focuser continues to give me grief.  To be honest, the basic  underlying problem is that the focusser could do with being replaced with a mechanically superior piece of kit.  This has got me thinking, do I spend £300 on a Baader Steeltrack focuser + adaptor or do I just bite the bullet and take the opportunity to buy a whole new scope?  The scope that seems to fit the bill would be a SW Esprit 100 ED.  It would give me more or less the same field of view as the SW 80ED with more aperture.  The Esprit + field flattener would be around £1,650 (around £1,350 net after selling the 80D + Focal reducer).

So here are my questions.  Would an Esprit 100 ED give noticeably better images than the SE 80ED?  In your opinion, in terms of image quality and ease of use, is the Esprit really worth the extra £1,000  it would cost me when compared to the SW 80ED + Baader Steeltrack focuser?

astronomy_tools_fov (2).png

Thanks

Edited by michaelmorris

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I don't think it will.

There will certainly be improvement in image "depth" for same imaging time, but we have to think about term "noticeable" here, and what it would mean.

100mm scope will gather about x1.56 more light, and if you match focal lengths perfectly, this translates into x1.25 increase in SNR under ideal conditions. However, conditions are not ideal - there is LP noise (from LP signal which increases with aperture), read noise, dark current noise - these don't change (except LP noise) - so overall SNR gain will be less than x1.25.

Question is, if you have two images with faint detail, one having SNR of 5 in faintest regions and other having SNR of 6.25 - would you be able to tell the difference? I think one would, but barely so. So in the best of circumstances you would be barely able to tell the difference.

If you are having issues with optical quality of 80ED - like stars not being perfectly round, or slight violet fringing or things like that - I think you will be able to tell the difference in that regard more easily than in SNR boost from aperture increase.

I think that visible increase in SNR would come from x1.5 factor and above. That means 120+ mm refractors if you can keep the same focal length (not easy thing to do, but 120 F/6 scope + x0.75 FF/FR would get you pretty close - but I'm not aware of any particular 120 F/6 apo triplet that will match price of 100 Esprit).

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hi in the same dilema,but sourcing a esprit 100ed in this country has come up blank,like you i have a ed80 which gives me good detail but i want somethink to reduce my imaging times,heard nothing but good about the esprit but how much better is the million to 1 dollar question,just a shame you cant borrow one😁

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2 hours ago, michaelmorris said:

do I spend £300 on a Baader Steeltrack focuser

I had just the same problem with the stock focus unit on my ED80DS-Pro and bought a Diamond Steeltrack and it transformed things for me. Personally I think it improved the image quality because with the original unit I am convinced the focus would change during an imaging session.

HTH

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I’ve just bought an Esprit 100. Is it worth the money? Probably not when I’ve seen some cracking images on this forum from ED80 owners and money is the sole part of the equation . But I do know I’ll have it for life, I can spend all the time in the world getting more and more out of the scope and not feel the need to upgrade again. (Probably..) 

Jarvo. 

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3 hours ago, michaelmorris said:

I'm currently looking at my medium range plans for my telescopes.  My main deep sky imaging scope is a SW 80ED.  It continues to give me good service, but the operation of the focuser continues to give me grief.  To be honest, the basic  underlying problem is that the focusser could do with being replaced with a mechanically superior piece of kit.  This has got me thinking, do I spend £300 on a Baader Steeltrack focuser + adaptor or do I just bite the bullet and take the opportunity to buy a whole new scope?  The scope that seems to fit the bill would be a SW Esprit 100 ED.  It would give me more or less the same field of view as the SW 80ED with more aperture.  The Esprit + field flattener would be around £1,650 (around £1,350 net after selling the 80D + Focal reducer).

So here are my questions.  Would an Esprit 100 ED give noticeably better images than the SE 80ED?  In your opinion, in terms of image quality and ease of use, is the Esprit really worth the extra £1,000  it would cost me when compared to the SW 80ED + Baader Steeltrack focuser?

astronomy_tools_fov (2).png

Thanks

I think that you will notice the difference in terms of CA and star shape from a triplet. You will also have a marginal improvement in signal to noise ratio in the same time integration time. I have been spending 16hours imaging a target recently a 1.25x improvement does not sound much but that would save me 3 hours in a 16 hour integration and could mean another night on the same target. 

Now the question is...is it worth the money.....No probably purely in terms of optical performance not but a SW ED80 is not a scope that I would be keeping for a lifetime of imaging, your user experience with the Esprit 100 will be vastly better and that accumulates over the years. 

Adam

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3 hours ago, michaelmorris said:

Would an Esprit 100 ED give noticeably better images than the SE 80ED?  In your opinion, in terms of image quality and ease of use, is the Esprit really worth the extra £1,000  it would cost me when compared to the SW 80ED + Baader Steeltrack focuser?

Probably the most significant difference (when comparing a good APO triplet with a good ED doublet) is the reduction in blue bloat around bright stars. 

As for whether the Esprit is worth the increased cost... If you are objective (not many of us are) and consider only performance-per-£ then, no. It isn't. A SteelTrak focuser on your 80ED makes more sense. But if you want it enough and accept the law of diminishing returns (dictates you must pay considerably more to improve on your Evostar 80ED) then the Esprit 100 wins. (Don't forget there is also an Esprit 80). 

HTH, 

Steve 

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22 minutes ago, Adam J said:

Now the question is...is it worth the money.....No probably purely in terms of optical performance not but a SW ED80 is not a scope that I would be keeping for a lifetime of imaging, your user experience with the Esprit 100 will be vastly better and that accumulates over the years. 

I think AdamJ and I were posting at the same time. His response is more eloquent 🙂

Steve

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Having had an ED80 I upgraded to a Moonlite focuser and still wasn't pleased with the image, I managed to find an Esprit 80 and a 100 at exceptionally good prices second hand and the difference is like chalk and cheese, I'd never go back to an ED80, IMHO it just isn't in the same league, the Esprits just have greater contrast and clarity and the focuser are a hundred times better

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Would a second-hand Equinox 80 be worth looking at? Decent focuser, though not Moonlight/ Steeltrack quality and faster than the ED80 at f6:25.

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As Steve FLO says, I think you'd get very significantly tighter blue stars and tighter stars generally.

It would also be genuinely faster because you have a similar FOV and yet more aperture. (5027 square mm versus 7854 square mm.) 

Olly

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I don't think the colour correction will be that significant if you're shooting mono and refocusing on filter changes?

What you're playing for is a larger corrected image circle, so if you had a full frame camera then the esprit would be significantly ahead.

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19 hours ago, Adreneline said:

I had just the same problem with the stock focus unit on my ED80DS-Pro and bought a Diamond Steeltrack and it transformed things for me. Personally I think it improved the image quality because with the original unit I am convinced the focus would change during an imaging session.

HTH

Hi

The steeltrack certainly looks like a nice piece of kit, but I have some queries

1 - Does it provide as much (preferably more) inward focus than the SW focuser?

2 - Will a SW focal reducer thread onto the end of the draw tube?

3 - Can one easily attach a shoe for a finderscope to it?

4 - Is it rotatable?

Thanks

 

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4 hours ago, SamAndrew said:

I don't think the colour correction will be that significant if you're shooting mono and refocusing on filter changes?

What you're playing for is a larger corrected image circle, so if you had a full frame camera then the esprit would be significantly ahead.

When I've processed ED80 data I've found that the stars were somewhat larger than premium triplet or quadruplet stars and the blue ones did bloat. The blue bloat arises from the lens failing to bring the shortest blue and violet wavelengths to the same focus as the rest of the blues so refocus won't solve the problem. Don't get me wrong, I think the ED80 is a wonder-scope for the money but it doesn't have the best blue control. This affects pretty well all refractors to some extent. Although TEC insist that their field flattener does not affect the colour correction of the 140, most of their customers, myself included, think that it does. Without the flattener my 140 certainly showed some blue bloat and the flattener has reduced this to insignificance. Another scope prone to blue bloat is the Tak FS60 and my early TeleVue Genesis (never designed for imaging) was a devil for it.

Only when you shoot in narrowband will the problem be stopped entirely and, for this reason, NB imaging is a great leveler of optics.

Olly

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1 hour ago, michaelmorris said:

Hi

The steeltrack certainly looks like a nice piece of kit, but I have some queries

1 - Does it provide as much (preferably more) inward focus than the SW focuser?

Not sure I know the answer to that question and I no longer have the SW focus unit to make a comparison.

2 - Will a SW focal reducer thread onto the end of the draw tube?

I use the SW FR/FF via a Baader ClickLock - as far as I know the threads are the same.

3 - Can one easily attach a shoe for a finderscope to it?

I believe there is a separately available shoe.

4 - Is it rotatable?

No - I use the click lock to rotate as and when I need to, which is rare as I tend to always image with the sensor sides orthogonal to the OTA axis.

Thanks

I've attached photos of mine so you can see the arrangement I use; I find this to be very satisfactory whether used with the ZWO filter wheel and Atik428ex or with my Canon 70D.

HTH

Adrian

IMG_8495.thumb.JPG.f31bff4a1c98a685afbb1e6e08b08f44.JPGIMG_8496.thumb.JPG.050953af642e3ac81275f7f73b955c2c.JPGIMG_8497.thumb.JPG.da5f0550e5bcf6c6e54f2e59a7773b81.JPG

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Coming from a ts 80 triplet to an esprit 100 it is a real improvement. The stars are round in all the corners of the 1600mm. For me the esprit 100 is a keeper. Also the focuser is way better. No tilt anymore when using the locking mechanism. Then some argue the tak is better but for an aps size sensor and 4 times the price (with accs) it is another story.

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