Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

sgl_imaging_challenge_banner_through_the-_eyepiece.thumb.jpg.cb85f690376dcb3053c747827de6bf9e.jpg

DevonSkies

Thoughts on the Startravel 102

Recommended Posts

I have been using a Skywatcher Startravel 102 for about a month now as a grab-and-go scope. I also intend to use it as a travel scope for holidays, but I've yet to try it in that capacity. So I thought I'd record some of my thoughts about this scope.

Initially I purchased the ST102 with an AZ3 alt-azimuth mount, but I quickly found I didn't get on with the AZ3. On the plus side, it is very compact and lightweight and would make an excellent travel mount. However, I found the friction bolt arrangement for setting the altitude tension to be unreliable, and the mount was difficult to use near zenith. So, I changed the mount to a Vixen Porta II, which is much more comfortable to use. The Porta II tripod does seem to vibrate a bit more than the AZ3 though (especially on concrete), so maybe I will change the legs for something more substantial one day.

Onto the telescope itself. The optical tube feels very solid and substantial. There is a large dew shield fitted, which is held on with a simple push fitting held in place by a felt band. Removing the dew shield reduces the OTA length significantly, but unfortunately the supplied lens cap won't fit over the front cell without the dew shield in place. This is a pity, as removing the dew shield would make the scope very compact for travel.

The 102mm doublet objective has a blueish-looking coating, that seems evenly applied. The OTA assembly is supplied with decent tube rings and a dovetail. If you buy the scope in a kit with the AZ3 mount it comes without a dovetail, and the tube rings bolt straight onto the mount.

The focuser felt quite smooth but a little tight straight out of the box. Initially there was no play in the focuser and the drawtube was well aligned. However, the focuser does prove to be a weak point on these scopes and I will return to this later.

Now on to the important bit - performance! The OTA came supplied with the usual 25mm and 10mm MA eyepieces. The 25mm is quite a good budget eyepiece, but the 10mm could be better. However, since I already have a set of reasonably good eyepieces I put the supplied EPs to one side. Also supplied with the OTA and AZ3 kits is a 45-degree erecting prism. This is useful for terrestrial observation, but not really of sufficient quality for astronomical work (although it is OK at low magnifications). I replaced this with the excellent Revelation 2" Quartz Dielectric diagonal.

This scope excels at wide-field views of open clusters and brighter DSOs. With a 25mm X-Cel LX eyepiece the whole of the Pleiades can fit in the field of view, which is a stunning sight. I also have a 32mm Panaview 2" eyepiece, which offers a whopping 4.4 degree field of view, framing the Pleiades beautifully within the surrounding sky. Under a dark sky the view is quite breathtaking. Other open clusters such as the Beehive also look superb with such a wide field. Best of all, this scope gives me the best view I've had of the Double Cluster in Perseus, with both parts of the cluster beautifully framed within the FOV.

Large DSOs are also a strong point for this scope. M31 (Andromeda) looks fantastic under a dark sky, and dust lanes are visible. Dimmer DSOs are quite within the reach of this instrument, with M1 (Crab Nebula), M33 and M51 all visible under dark skies. Globular clusters also make good targets, although perhaps a little more aperture would be useful here to see them at their best.

Working at high magnification, the ST102 is quite capable of splitting the "easier" double stars such as Castor and Sigma Orionis. A 5mm EP works well here, and a Barlow can help to increase the separation on brighter doubles. The dim companion to Rigel can just about be made out under good seeing conditions.

You may notice that I haven't mentioned CA (chromatic aberration) yet. That's because, for clusters, DSOs and most double stars it simply isn't an issue. For planets and lunar observation, however, it's a different matter. Yes, the dreaded purple haze is there, especially noticable on the limb of the moon and on bright planets such as Jupiter. In fact, the ST102 is quite capable for casual lunar and planetary observing, but if the solar system is a primary interest for you then you might look elsewhere. Although the optics are pretty sharp at high magnification, I really feel that the CA damages the contrast for planetary and lunar observation.

This is my first refractor (my other scope is a 10" Dob). I have to say I'm now a refractor fan! There's something about the ease of setup and the contrasty, pinpoint stars that appeals to me. I also like the short-tube concept from a portability point of view, and these scopes are very capable deep sky instruments. Yes, CA is a problem on bright objects at high magnification, so it's not an all-rounder like an APO, but for the price it's fantastic value for money.

I mentioned the focuser earlier. After some use, the focus tube developed some vertical play. There are two grub screws on the top of the focuser which are used to tension the drawtube. I needed to tighten the front (i.e. closest to the objective) screw to take up the slop, and also tighten the rear screw to remove any remaining image shift. After this adjustment the focuser worked fine again. I have now had to do this twice, so it seems that periodic adjustment is required. After the second adjustment cycle the focuser was very stiff, which I resolved by slackening off the screws that tension the spring in the focus pinion assembly. Now the focuser is nice and light and smooth, but I anticipate further adjustments will be necessary in future. We shall see! This is really a faff and the only real annoyance with this scope. There is a dual-speed Crayford focuser available which is a drop-in-replacement for the original R&P focuser, but at around £129 I'm not sure it's worth it on an OTA costing £169!

All in all, I really like this scope, apart from the cheap focuser. In fact, I like it so much I'm wondering what the 6-inch ST150 would be like on DSOs and clusters!

Ed

  • Like 6

Share this post


Link to post
Share on other sites

Great review and a great read. i have the 120mm Evostar which is a great scope and i absolutely love it. it has sligh Ca but i can handle that. all the best and enjoy. Scott

Share this post


Link to post
Share on other sites

Excellent review Ed - really brings out the charactistics of this scope very clearly :icon_biggrin:

I think the 150mm F/5 would show substantially more CA as that increases as the aperture increases. It would still be a very nice deep sky / rich field type scope though.

According to this table, your 102mm F/5 will be showing about as much CA as my 150mm F/8 shows:

 

CA-ratio-chart-achro.jpg

  • Like 1

Share this post


Link to post
Share on other sites
10 minutes ago, John said:

Excellent review Ed - really brings out the charactistics of this scope very clearly :icon_biggrin:

I think the 150mm F/5 would show substantially more CA as that increases as the aperture increases. It would still be a very nice deep sky / rich field type scope though.

According to this table, your 102mm F/5 will be showing about as much CA as my 150mm F/8 shows...

 

mmmm.... 150mm f/8... now there's a thought! Not sure I could justify it alongside the 10" Dob though!

 

Share this post


Link to post
Share on other sites

A good field review of these short tube refractors, they have a lot going for them.  Especially with our climate being so changeable, as you often have a short viewing window before the clouds roll in.  For really bright objects like Venus or the Moon, the inbuilt mask works well at reducing excessive glare.  What i did with my porta mount, was to cut a slit in some tennis balls, although it looks it bit odd, they did cut the vibrations down !

 

andrew

porta.jpg

  • Like 3

Share this post


Link to post
Share on other sites

Thats a nice review.

I had an 102 and was quite pleased with it. I did buy a fringe killer filter which helped on Lunar and planetary.

If you look at most Skywatcher reviews the 10mm stock EP always seems to be the one that gets criticised.

I mod'd the focuser on mine for a 10:1 type from Telescope Service in Germany. It worked well but I had to add an extra spacer as there was not quite enough backward focus with a DSLR.

 

Share this post


Link to post
Share on other sites
1 hour ago, andrew63 said:

A good field review of these short tube refractors, they have a lot going for them.  Especially with our climate being so changeable, as you often have a short viewing window before the clouds roll in.  For really bright objects like Venus or the Moon, the inbuilt mask works well at reducing excessive glare.  What i did with my porta mount, was to cut a slit in some tennis balls, although it looks it bit odd, they did cut the vibrations down !

 

Good idea, I might try something like that.

Also a good point about the aperture mask for moon and planets. I've found it virtually eliminates CA, but it does cause some loss of resolution.

I forgot to add that I have also tried the Baader Contrast Booster filter, which is supposed to be the most aggressive of the CA-reducing filters. Although it did noticeably reduce the CA, it left a yellow cast which I found unpleasant and also noticeably reduced the sharpness of the view at high magnification. In the end I decided I preferred the unfiltered view! At some point I will probably buy a dedicated grab-n-go for lunar/planetary work (maybe a Mak or an f/10-ish refractor).

Edited by DevonSkies
Typos

Share this post


Link to post
Share on other sites

Great review and sums up pretty much how i feel about my ST102. I have had it for a good number of years now and in fact use it on a Porta II mount myself.

However, it is going to be surplus to requirements shortly as i am waiting for............................an ST120 to arrive :-)

I use a semi-apo filter in my diagonal and it works quite well, it does impart a slightly yellow cast to the view though. But i can live with that.

  • Like 1

Share this post


Link to post
Share on other sites
49 minutes ago, Bobby1970 said:

Great review and sums up pretty much how i feel about my ST102. I have had it for a good number of years now and in fact use it on a Porta II mount myself.

However, it is going to be surplus to requirements shortly as i am waiting for............................an ST120 to arrive :-)

I use a semi-apo filter in my diagonal and it works quite well, it does impart a slightly yellow cast to the view though. But i can live with that.

I do wonder whether I actually should have got the ST120 in the first place. I was undecided between the two when I made the purchase, and decided on the 102 because I thought it would be more portable. But in the end the ST120 is only 10cm longer and 2cm wider, and for DSOs one needs all the aperture one can get!

I'd be interested to hear how you think it compares to the 102 when you get it. Will you have the chance to compare side by side?

Share this post


Link to post
Share on other sites
58 minutes ago, DevonSkies said:

I do wonder whether I actually should have got the ST120 in the first place. I was undecided between the two when I made the purchase, and decided on the 102 because I thought it would be more portable. But in the end the ST120 is only 10cm longer and 2cm wider, and for DSOs one needs all the aperture one can get!

I'd be interested to hear how you think it compares to the 102 when you get it. Will you have the chance to compare side by side?

Yes. I will. I am very much looking forward to comparing all aspects of the two scopes. I will let you know how it goes. 

  • Like 1

Share this post


Link to post
Share on other sites
55 minutes ago, Bobby1970 said:

Yes. I will. I am very much looking forward to comparing all aspects of the two scopes. I will let you know how it goes. 

Thanks. I'll look forward to hearing how you get on! 

Share this post


Link to post
Share on other sites
On 1/26/2016 at 05:00, andrew63 said:

A good field review of these short tube refractors, they have a lot going for them.  Especially with our climate being so changeable, as you often have a short viewing window before the clouds roll in.  For really bright objects like Venus or the Moon, the inbuilt mask works well at reducing excessive glare.  What i did with my porta mount, was to cut a slit in some tennis balls, although it looks it bit odd, they did cut the vibrations down !

 

andrew

porta.jpg

I put tennis balls on the bottom of my Celestron 127 SLT tripod and they do seem to help dampen vibrations. Another side benefit is that the tennis balls are visible in the dark so I don't trip on my own mount!

Share this post


Link to post
Share on other sites

Concur with all you've said about the 102. Great little scope although it does produce a little more CA than my evo 120 achro.

Share this post


Link to post
Share on other sites

Good little scopes these. I went for the 80mm as I wanted something really portable and have been pleased with it. It's poor on planets, but with the Baader semi apo filter the lunar views are actually quite good. 

Share this post


Link to post
Share on other sites

I've had a 102 for a couple of months now. Bought it to use for solar observing, but also use it for a grab and go option. I really like it. Lovely FOV for extended objects and really good for some doubles. CA is there, but I do not find it too obtrusive.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By Selborne
      Hi Guys/Girls
      I had a chance to get out in the garden last evening, had a go at capturing NGC 7023 - Iris Nebula, only managed to get 12 good shots, 240sec x 12, combined in Photoshop with Mean Stacking.  The dew was super heavy and currently I do not have any dew heaters (next purchase) so lost the battle after around 2 hours. 
      One interesting point is I captured these shots with the long exposure noise reduction switched on with the Sony A7Rii, so each shot took 8 mins to take and save, but as a result the noise levels were next to zero at 800 ISO, and at the end of the day the noise is always our enemy.  I need to try a real pro level 'cooled' astro camera just to see how much better it could be, as the Sony A7Rii is just stellar !
      I am very happy with the final shot, taken with my Skywatcher 100 ED Pro Esprit Scope on my NEQ6 mount, Skywatcher ED50 Guide Scope and Altair Astro ASI130mm camera, PHD2 of course.  The sky was nice and clear with low light pollution, as around 5 miles from major town.
      I do not take darks or flats or use Deep Sky Stacker, and I do not use filters, plus the camera has not been modified, so I am always delighted with the results I get from my set-up, as I have a deep level of respect for the hard work that most Astrophotographers go through to get the incredible images that we see here in Stargazers.
      I have read that some people believe that the Sony Alpha cameras have a tendency to 'eat the stars' and not show everything captured, to be honest, I always used a Canon 60Da for  many years for my astrophotography, until one day I though, what if my Sony A7Rii could be used, the first time I did this I released that it was time to sell the Canon 60Da, the 'Remote' (free) Sony software is almost as good as BackYardEOS, but the cameras are a decade apart in performance, the noise levels on the Sony are at least 4 maybe even 5 stops better than the Canon, that is the Sony A7Rii at 3200 iso equal to the Canon 60Da at 200 iso, so at 800 iso it is just so impressive.  As you can see from the picture only 12 frames, stacked in Photoshop (Mean). 
      Open to comments and welcome a discussion/debate,
      thanks
      Jamie

    • By Selborne
      Hi Guys,
      I thought I would share with you my first hand experience of the Skywatcher ED100 Pro Esprit Telescope, I have only had it a few months, but so far I am extremely happy with the results, it is so sharp and the contrast is very high.
      I live in a small town, Stowmarket, Suffolk, UK, where the light pollution is not to bad, but still I have to be cautious with the direction I choose to point the telescope.   All my astrophotography is done from the back garden on my patio.
      I have had a few different telescopes over the years, but I always found myself moving more and more into astrophotography, so after some research I selected the Skywatcher ED100 Pro Esprit, as many of the other users had commented on the sharpness and contrast.  As I wanted to focus on more wide field astrophotography the F5.5 speed giving 550mm seemed the right choice, I also use an ED50 Skywatcher Guide Scope with an Altair Astro ASI130mm camera for the guiding and of course PHD2 software, all mounted on my Skywatcher HEQ6 mount.
      Here is a shot of the Andromeda Galaxy, 20 x 30s stills at ISO 800 on my Sony A7Rii, no filters just RAW images processed with Photoshop, Stacked Mean option.  I used the Trevor Jones video on his BackyardAstro You Tube page for processing DSO's and it seems to work very well.  What you will see from the image is just how sharp it is, something that really surprised me when I processed the images.
      This has inspired me to spend more time outside in the garden to photograph more objects, plus I have recently purchased an Astronomic CLS Filter for my Sony A7Rii, so I am looking forward to using this to see if it improve the contrast.  I will keep you informed.
      Also I am looking forwarded to trying my Olympus EM1 MK2 camera, yes I know it does not have the capabilities of the Sony A7Rii for light gathering, but it does have a really clever mode where it can stack the images in camera to reduce noise, so I will also let you know how this went as well.
      Best Regards
      Jamie
       

    • By moise212
      I went this weekend to my girlfriend's parents and I took my Skywatcher 72ED with me and the smaller AZ-EQ5. Fortunately, the skies are dark there.
      So, on 11/12 August I put all the stuff on the mount and took 130+ 60s subs with the Canon 550D. The result is a crop, towards the edges the stars are not perfect yet, but they're a bit better than in the past. I put some additional spacers to the universal flattener and increased the backfocus distance. The comet doesn't fill the frame anyway.
      Unfortunately, the animation doesn't really play ball, I will upload it somehow else later. Neither on the processed image I did the best job, I need to improve somehow in removing the artifacts on the comet-only image.
      However, this is what I got:


    • By Owmuchonomy
      Thanks to FLO for my new ED150 DS Pro received on Wednesday. I was aware @John was down to test one so I delayed posting for a bit plus the delivery brought the clouds.  I will post my initial findings and thoughts and top up as I go. I own or have owned an ED80 and an ED 120 but I no longer have the latter to do an objective comparison.
      The first feedback applies to the outer packaging.  As discovered by others it is inadequate for the item. In my case the outer packaging was ruptured at the pressure points under the narrow white plastic wrap bands. I imagine the bands are used along the supply chain to manoeuvre the package. The gross weight is 26kg so it’s difficult to manhandle for an individual. Fortunately, the flight case was in perfect condition and hopefully has protected the contents. SW could learn from Lunt and double box their items.
      The flight case itself is typical SW and has considerable strength and weight. There is a lot of unused space though, with cut outs ready for a significant number of accessories which I can only assume is for another market. My version has the OTA, an M48 Canon EOS adapter (why?) and a threaded adaptor to allow connection to the draw tube. that’s it, no diagonal, EP, finder etc like other Pro offerings.
      The OTA weighs just over 9kg which is the same as my SCT 9.25 but unlike the latter is much easier to handle as it’s a lot narrower. So attaching it to my AZ EQ 6 is a doddle. I have to be sure to carry it level because like every other SW I have owned the objective end cap is loose so tilt the OTA and it falls off. I usually add a bit more felt to solve the issue.
      i was lucky to have about an hour of clear dark sky last night so was keen to do a star test for obvious reasons if you have read @John ‘s thread. The eagle eyed among you will have seen that the focuser is essentially fixed and has no provision for easy rotation during a session so one needs to rely on rotating the diagonal. My Moonlite which can be switched between the 80 and 120 does not fit the 150 so I eagerly await the adaptor 😉.
      I used my ES 82’ 4.7mm EP on Altair to run an initial star test. The CA profile has been well covered by @John and my experience is almost identical including the slight hexagonal appearance in some situations. In my case the in focus and in and out focus transitions revealed absolutely perfect collimation. A big sigh of relief there. Interestingly I had placed the scope outside for about an hour at roughly 21 degrees but the initial star test was too unsteady but 20 minutes later it was very steady.
      Using in addition to the 4.7 my ES 14 and 20mm eps i moved on to look quickly at some targets such As Iota Cass which was clearly defined as a triple with distinctive colour ranges, M27 which had a typical grainy appearance very similar to the view in the SCT and M81 and M82. Considering it was not astronomical darkness the dark centre of M82 was very well defined. The best view though was of M57. The detail in the ring was dramatic and high mag was easily tolerated. I must have stared at it for 15 minutes. I tried the Blinking PN in Cygnus and although a small target even with the 4.7 the brightness was remarkable and the structures defined.
      By now I was tired but tonight and tomorrow look good so I will try and post more findings from a visual perspective. Just to say that the mount had no trouble at all in swinging this beast around and I didn’t even need to do a new alignment from the last session with all targets centred in the EP when using the Synscan database.
      i must say I’m quite chuffed and a big thanks to FLO for excellent communication on this item.

    • By CarolandDom
      Hi,
      I have a Sky-Watcher Skyliner 300P FlexTube GOTO which I am enjoying however after a period of no use the base has become very stiff. My fault, as it became wet not realising that the cover I had bought for it was not waterproof.
      Looking through the threads in here I found one which I followed to try to strip down the base however I have become stuck at the point of trying to remove the motor housing from the base after removing the 4 machine screws. I suspect that it is a combination of corrosion and the base material swelling which is preventing me from removing the motor from the base. When I release the worm gear from the static gear using the release lever the motor turns easily which is what is fuelling my suspicion.
      Any advice or suggestions would be useful as I've come to a halt in my investigation for the moment. It looks to me like I'm going to need a new base which may be a better bet anyway as the original supplied is heavy and definitely not good in the damp.
      Dom
×

Important Information

By using this site, you agree to our Terms of Use.