Sky-Watcher Evostar 120 Achromat Overview.

[Chris]

16 hours ago, neil phillips said:

495 LONGPASS is also good. Neil English convinced me of this. And i have to agree its got some great strengths with achros. Nice post love it. 

Looks like I'll be adding the 495 Long pass to the list of things to try then  Thanks for the heads up Neil, cheers! 

[Chris]

11 minutes ago, Stu said:

Nice review Chris. I have a Celestron Omni 120XLT and have had some good views with it. I used it recently at an outreach event and it performed very well on the Moon.

It’s pretty handy for white light solar, you do get used to the green of a continuum filter after a while and it does sharpen up the views. Bit of a big boy next to the FC100DC though.

Lovely Stu! I wish you could still get hold of the OMNI range of scopes new, in which case I would have had real trouble choosing the EVo120 EQ5 over the OMNI 120mm CG4 package! 

I've just remembered I have some spare solar film, hopefully there's enough to make a filter for the Evo 

Edited February 13, 2022 by Chris

[Ian McCallum]

39 minutes ago, Chris said:

Lovely Stu! I wish you could still get hold of the OMNI range of scopes new, in which case I would have had real trouble choosing the EVo120 EQ5 over the OMNI 120mm CG4 package! 

I've just remembered I have some spare solar film, hopefully there's enough to make a filter for the Evo 

I got a freebie solar filter, when I bought my SW EV120 from a fellow member of SGL.  You can see the results below...  You can also see some CA on the edge of the lunar disk, there's also some of the solar disk (less noticeable).  I ended up buying a Wratten #8 filter from Auntie @FLO, as some of the other choices were quite expensive.  I see that the Baader 495 filters are still out-of-stock though.☹️

 

Edit: All of these images were captured using a Samsung A20e, attached to a smartphone holder clamped around the eyepiece.. 

Edited February 13, 2022 by Ian McCallum
Added info...

[Chris]

Very nice Ian, especially the last shot with the full solar disk - good Sun spot detail and you can even make out some faculae! 

[Ian McCallum]

2 minutes ago, Chris said:

Very nice Ian, especially the last shot with the full solar disk - good Sun spot detail and you can even make out some faculae! 

I had to Google that last word!😂  The granularity is noticeable, I guess my focusing was good.😉 

[Stu]

Cameras always show more CA than you see visually anyway, it was obvious on the Moon in the XLT but not overly distracting.

[Mark at Beaufort]

Very enjoyable video Chris.

I will be interested how you get on with this scope which is impressive only weighing just over 5 kgs.

For the money I quite fancy trying one but I only have a AZ5 mount with the stainless steel legs so I might get some wobbling at high mag.

[mikeDnight]

I talked a friend into buying a 100mm Helios way back in 1999 as I didn't have the courage to pay for a scope made in China. First light through that little achro, which I think cost my friend £245, settled my suspicions, as the stars were sharp and any CA was very well controlled.  There was no moon in the sky so we spent the evening checking out a few Messier objects and simply sweeping through star fields. I remember M1 revealing a N shaped tructure within its nebulous glow. The following day I ordered a 100mm for myself, but the day after I changed my mind and altered the order to a 120mm F8.3. The price for the 120mm Helios, which came with a beautiful EQ3, 90° mirror diagonal, 2X Barlow, and three lovely silver top plossl's, was a miniscule £275. First light was on a crescent Moon, and my first thought was "Where's the CA?"  There was CA of course, but it was nowhere near as bad as I'd expected. The 120mm Helios achromat was a joy to use.

Within a year or so I'd bought a 150mm F8 which was superb as a deep sky/comet seeker. Galaxies and nebulae drifted effortlessly into its field of view. Again, there was observable CA around the Moon and the brightest stars, but this was never made to be a lunar and planetary scope.  It's speciality lay in its ability to deliver wide, rich star fields, and the study of nebulae and star clusters. The 150mm was a perfect comet seeker!

The down side to these Chinese achromats became evident over time, as other observers bought their own Chinese achromats. The problem was never the CA. Such scopes will always show CA, its the nature of the beast. The real issue was spherical abberation, which was highly variable from one scope to another. Some were so bad they were unusable and had to be returned. However, when you got a good one it was an awesom beast!

On a side note, I never found any kind of filter to improve the view in terms of counteracting the chromatic abberation. I prefered the natural look. Of course a UHC or OIII can be very helpful on some fuzzies.

Edited February 13, 2022 by mikeDnight

[cajen2]

The Baader Semi-apo filter is available from FLO in 1-2 days.....

[Carl Au]

I have not owned an achromatic scope for over a decade now, but I did own a couple of fine examples of 4 inch achros. My first Vixen SP and a Tal 100R (and much later a 100 RS). Nothing wrong with a good achromat. Right scope, right place. 

[Chris]

On 13/02/2022 at 14:14, Mark at Beaufort said:

Very enjoyable video Chris.

I will be interested how you get on with this scope which is impressive only weighing just over 5 kgs.

For the money I quite fancy trying one but I only have a AZ5 mount with the stainless steel legs so I might get some wobbling at high mag.

Hey Mark thanks, glad you liked it  In the words of Mrs Doyle...go on go on go on go on 😜

 

Edited February 15, 2022 by Chris

[Chris]

On 13/02/2022 at 14:28, mikeDnight said:

I talked a friend into buying a 100mm Helios way back in 1999 as I didn't have the courage to pay for a scope made in China. First light through that little achro, which I think cost my friend £245, settled my suspicions, as the stars were sharp and any CA was very well controlled.  There was no moon in the sky so we spent the evening checking out a few Messier objects and simply sweeping through star fields. I remember M1 revealing a N shaped tructure within its nebulous glow. The following day I ordered a 100mm for myself, but the day after I changed my mind and altered the order to a 120mm F8.3. The price for the 120mm Helios, which came with a beautiful EQ3, 90° mirror diagonal, 2X Barlow, and three lovely silver top plossl's, was a miniscule £275. First light was on a crescent Moon, and my first thought was "Where's the CA?"  There was CA of course, but it was nowhere near as bad as I'd expected. The 120mm Helios achromat was a joy to use.

Within a year or so I'd bought a 150mm F8 which was superb as a deep sky/comet seeker. Galaxies and nebulae drifted effortlessly into its field of view. Again, there was observable CA around the Moon and the brightest stars, but this was never made to be a lunar and planetary scope.  It's speciality lay in its ability to deliver wide, rich star fields, and the study of nebulae and star clusters. The 150mm was a perfect comet seeker!

The down side to these Chinese achromats became evident over time, as other observers bought their own Chinese achromats. The problem was never the CA. Such scopes will always show CA, its the nature of the beast. The real issue was spherical abberation, which was highly variable from one scope to another. Some were so bad they were unusable and had to be returned. However, when you got a good one it was an awesom beast!

On a side note, I never found any kind of filter to improve the view in terms of counteracting the chromatic abberation. I prefered the natural look. Of course a UHC or OIII can be very helpful on some fuzzies.

Good to read your experience with these achro's Mike, and it echo's my experience so far.

I bought my first EVo120 in 2005 (old blue tube on a black EQ5 mount) and loved it, really sharp for an achro and the CA wasn't bad enough to be washing over bright objects like some of the larger F/5 Startravels. I reluctantly sold it when moving into a 1 bed flat but later picked up a second hand Evostar102 f/10 when we moved into our first house in 2010. This one wasn't quite so good with SA like you mention, it just lacked sharpness at higher powers. 

I agree that the CA is a known commodity, and there is even the infamous chromatic aberration chart that often appears! However the SA can be slightly pot-luck which may be expected for any mass produced affordable scope. 

I'm hoping for ok levels of SA, the FLO sticker on the box is sadly spitting the truth regarding the clouds so far so still no first light yet!