A review of my Sky Watcher Esprit 150

A review of my Sky Watcher Esprit 150

by Jeff Marsten (CN member Jeffmar)

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I have done visual astronomy for over 20 years and imaging for nearly 10 years. I live in Salt Lake City, Utah. My neighborhood is as bright as a super max prison at night and I almost always travel someplace darker to do my astronomy. At present I own 4 Celestron SCT's and 5 apochromatic refractors of various brands. I have three working mounts; a Celestron CGX and a CGX-L, and a Losmandy G11T. 

Did I really need this scope? The answer is probably no because I had an Explore Scientific 127 carbon fiber apo and an Istar Phantom 140 apo. They both are good scopes with Phantom being a bit better as far as sharpness goes. When I read the lists of apochromatic scopes a lot of guys on Cloudy Nights had I would shake my head and wonder how they could go so far down the rabbit hole. I guess you could say I get it now. 

Why I bought this scope:

Last spring I was looking through my buddy James' Esprit 120 at the Coat Hanger asterism at a star party. I was very impressed by how incredibly sharp the view was with pinpoint stars and lots of contrast. About a month later another friend of mine, Lester, brought his new Esprit 150 to one of our favorite dark sites to try it out for the first time. I was so impressed with his scope I ordered one the next day. I haven't used my other two large refractors since. 

Comparisons with my other refractors:

Focusers:

The Explore Scientific 127 has a decent focuser, but it has only had 2 inches of travel. The company compensates for the lack of travel by providing two 2 inch spacers that are a real pain to deal with in the dark. I replaced the stock focuser on the ES 127 with a Feathertouch focuser. What a difference that made with a lot more travel, and it is as smooth as silk! The Istar phantom had a focuser than was rough and inconsistent. I had to go through all the moving parts, do some lubricating and working the focuser back and forth until it smoothed out. So the Esprit gets a B+, the Explore Scientific gets a C for the stock focuser and the Phantom gets a B- (after I fixed all the issues). I probably would have given the Esprit an A if I hadn't experienced how good a starlight focuser is.

Optics:

Last fall I did a comparison of the optics with my three large refractors. I used a 2x2 inch sudoku puzzle I had filled in with various ink colors and put it a hundred feet away. I used my best Sony full frame camera to take multiple photos of the puzzle with each scope while making sure my focus was a good as possible. I am not knowledgeable enough about star tests to say anything intelligent about scope optics, but I can tell when one photo is sharper than another if I stare at it long enough. The result of the optical evaluation was the Esprit had the best optics so let's call that an A. The Phantom was not quite as good so let's say it's an A-. The Explore Scientific was a bit lower on the scale so it gets a B. 

Fit and finish:

My Explore Scientific 127 was actually a bit better than my Esprit 150 only because of the dew shield. The dew shield on my Esprit is loose and floppy, but it will mostly stay in place once I tighten up the two screws. Coming in third was the Istar Phantom 140. When I got the Phantom the focuser was very rough as I mentioned before. There was a loose screw rattling around in the tube I had to put it back where it belonged. The screw that held the focuser in place seemed like it was bent, so every 360 degrees it would get very hard to turn. The scope rings would slip so the tube would slide back and I couldn't seem to tighten the rings enough to keep that from happening. I am giving the Explore Scientific 127 an A, the Esprit 150 an A-, and the Istar Phantom a D. Quality control should have been a lot better with the Phantom.

Using it for visual:

I will admit I don't use it for visual as much as my C14. The reason is that my C14 does a much better job on anything faint. It also usually does better on planets, the moon, and even double stars. It's just hard to beat a scope with 14 inches of aperture and good optics. I can say my Esprit usually beats my C8 because of the superior contrast that comes with a good apo. I use the Esprit mostly for imaging, but I always take advantage of the dark skies where I image to look at targets. At a Bortle 2 area my Esprit can show almost as much as my C14 I use for our club star parties which are closer to the lights of the city.

A comparison with a Stellarvue 180:

Last fall I went out to my favorite imaging site during a full moon to do some visual with my two imaging buddies. My friend, Lester, had just taken delivery of a Stellarvue 180 triplet and he wanted to spend some time doing some visual on Jupiter, Saturn, and the moon. Seeing was really good and the views of both gas giants were pretty spectacular. My two friends and I spent hours going back and forth between my Esprit 150 and Lester's Stellarvue 180. Yes, there was a difference between the two scopes, but it wasn't a big difference. The Esprit almost kept up. The views were spectacular through both scopes. We could see some of the lessor storms on Jupiter and a lot of cloud turbulence through both scopes. The rings of Saturn looked razor blade sharp on both scopes and the Cassini division was a black and defined ring. The difference was a slight increase in contrast through the Stellarvue. The moon was pretty impressive also. Since the moon was full, we didn't get the contrast of shadows the terminator brings, but the detail was still there if a bit more subdued. It was harder to see a difference between the Esprit and Stellarvue while looking at the moon. I would love a chance to get out with both scopes again to do visual. They were both very good with Lester's Stellarvue edging out my Esprit. 

Imaging:

I have used all three of these scopes for imaging and have been pretty happy with them. I used the Explore Scientific 127 for a few years for imaging and noticed some weird looking inverted spikes around the brighter stars. I called Explore Scientific, and they suggested that I back off the extra screw they use to hold the objective lens in place. I did it and it helped but I still got remnants of spikes, but it was better. I didn't have any of those issues with either the Phantom or the Esprit. I would say that the Esprit is just a little bit better than the Phantom for imaging as far as resolution and detail goes but that could be a result of an extra 10mm of aperture. Both the Phantom and the Esprit seem to be better than the Explore Scientific for imaging. 

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All of these images were done using my Esprit 150. I use this scope for two-thirds of the images I take. It seems to be a very versatile size and focal length. I am not into wall to wall cosmic clouds as much as some other people are, but occasionally I use my Astro-Tech 80 triplet for those wide nebulae. My Esprit 150 is large enough to get anything from a lot of nebulae to most galaxies. For me it is a sweet spot scope. 

I use either my Celestron CGX-L or my Losmandy G11T with my Esprit 150. Both of those mounts seem to work just fine for good auto guiding with my 150. 

Conclusion:

My Esprit 150 is a phenomenal scope. It is definitely the best scope I own as far as sharpness and versatility. I haven't used my other large refractors since I got my Esprit, and I haven't really missed them. I used to think that if I could only have one scope it would be a C14, but because of the how good my Esprit 150 is at so many things I might have to change my mind. It certainly is a lot easier to image with than my C14. I bought my Esprit on sale for 7000 dollars. It is still a chunk of change, but when I compare it to my friend's Stellarvue 180 costing 19000 dollars it seems like a bargain. The only downside is how heavy my Esprit is. My carbon fiber Explore Scientific 127 is so much lighter it's a breeze to handle compared to my Esprit.