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DevonSkies

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Posts posted by DevonSkies

  1. Thanks for all the comments in this thread. I think from what I've heard I can conclude that, although the Mak is a good little scope, the 100ED is worth the extra for the best planetary views. I think, deep down, I knew this all along.

    If I'm lucky I might find a used 100ED near me; otherwise I'll scrape together the cash for a new one. I don't want to plump for the mak and then wish I'd got the ED all along.

    • Like 1
  2. Plenty of food for thought.  I've also been considering the Altair 102mm f/11 achromat as an other option. It's a lot cheaper than the 100ED, but obviously will exhibit a certain amount of CA on bright targets. Whether the CA would be bad enough to justify spending the extra on ED glass is not clear to me. The longer tube of the f11 scope also makes mounting more of a problem. 

  3. 31 minutes ago, dweller25 said:

    Because the ED100 was easier to cool and could keep up with dropping temperatures through the night it gave sharper and more stable images quicker than the 127 Mak.

    The clear aperture of the 127 Mak is actually 120mm, which means the 46mm secondary gives a 38% obstruction - this reduces planetary contrast to about the same as a 2.9" refractor, so a 100ED will have more contrast - vital on the planets IMO.

    I have also compared the ED100 to my Takahashi TSA102. The ED100 gave embarrassingly close planetary views to the TSA102 !!!!

    In my opinion the ED100 is superb value for money.

    Thanks for that - I hear what you're saying about contrast. I agree the ED100 is great value for an ED refractor.

  4. 13 minutes ago, JG777 said:

    I also owned both and kept the 100 ED for its versatility and fast cool down times. As mentioned these ship with a focal reducer taking it from F9 to F7.65 so this adds useful functionality. I also use a Lunt wedge with it for solar which I recall has a limit of 4 inches so the 100 ED pro matches this really well. 

    Didn't use the Mak for for solar but for planets and lunar hardly any difference between the scopes in terms of quality of view its just the Frac releases them to you a lot quicker! The Frac will display minor flashes of CA which disappear as you snap into focus. The Mak is more portable though and easier to mount but I never quite took to it probably because I found it usually needed around 40 minutes before it properly settled down.

    So the 100ED pro won it for me mounted on Berlebach tripod it just felt more functional and ready to go.

    Thanks, that's really useful information.

    It's a tough choice. I can afford the Mak 127 right now, but I'd have to save a bit longer to buy the 100ED. I've also got a feeling I would eventually need to upgrade my mount for the 100ED, as the Porta II suffers from the wobbles at high magnifications, which will only get worse with a longer tube. On the other hand, cool-down is a concern with the Mak, as I tend to have limited opportunities to observe, except on those rare clear, still nights.

  5. 1 hour ago, Bobby1970 said:

    I had, until recently an ST102 and Mak 127. I have replaced 102 woth a 120 and 80 lol. 

    Anyway. I always found the combination of the two scopes very good. The Mak was excellent on the moon and planets. And certainly more portable than my old 8 inch dob. 

    My only complaint is when I use it on the goto mount, it just doesn't seem accurate enough for the narrow field of the scope. But maybe it's just me. 

    Aside from the goto issue, do you find the mount tracks well enough when it's aligned with the target?

  6. 1 hour ago, baggywrinkle said:

    I have the SW Mak 127 on the goto mount. It is an excellent wee scope, good views and great for exactly what you are looking for.

    Though the mount is a tad lightweight a mass placed in the EP tray make it more stable. It is easy to set up.

    The only downside are the poor quality ep's and star diagonal. Below two images (not the highest quality) taken with the Mak 127...

    post-29495-0-34332100-1453384828_thumb.jpost-29495-0-64223500-1453384850_thumb.j

    Thanks for that. The Mak appeals both for the price and because it should behave better on my Porta II mount than an f/9 refractor. I have some decent EPs already, so that shouldn't be a problem. 

    Does it take a 'normal' (i.e. push fit) 1.25" diagonal? 

  7. 16 minutes ago, John78 said:

    I saw this got reduced yesterday - I think its a decent price for a 100ED, I need to sort my mounting out before I pull the trigger on an OTA so I'll let this one pass...

    http://www.astrobuysell.com/uk/propview.php?view=108847

    What's a bit confusing is there's no difference in price in a 100ED compared to the 80ED as the former comes with the field flattener, and if you add one to the latter you end up at the same price as the former.

    Yes, I saw that one. Local collection only though, and Cambridgeshire is too far for me!

  8. I'm still on the lookout for a relatively lightweight scope for lunar, planetary and double star observations. I have a 10" Dob which will obviously wipe the floor with most small scopes, but I often can't be bothered with lugging it out to the garden for a quick look at the moon or Jupiter.

    It sounds like the SW Evostar 100ED would be a nice scope for this purpose. But at over £600 for the OTA it would be a major investment for me. So, I wonder whether the Skymax 127 Maksutov would be a worthy alternative,  given the much lower cost (around £350 including a goto mount).

    I understand the Mak will have a narrower field of view, but that's OK as I already have an ST102 for wide field. What I'm looking for is nice sharp, contrasty views of planets and the moon, as well as good performance on double stars.

    Any thoughts? How different will the view be between these two scopes?

    Thanks,

    Ed

  9. 31 minutes ago, Fozzie said:

    I thought this had been on the cards for a while now.. It's a real shame, I know a lot of people who I have upmost respect for on the forum rave about them, Mr Nightfisher for one spent a considerable amount of time in Ingleton last summer talking with great passion and enthusiasm about his..

    There are a few other options in the 100mm achro department.. the starwave 100 F11 is a gem (I have one and love it) more frequently skywatcher and bresser do a 100mm F9.8 I believe..

    Still though you can pick up an ED100 for circa £350 - £400 SH which is good value.. or you could pick up a 100mm F10 vixen skylight in candy apple red for a similar amount if my last browsing memory serves me well..

    Would love to get a TAL and pack it away in the loft for 20 years, wonder what it would be worth then, they are loved now, maybe they would be revered in the future.  (shame about being in the loft for 20 years but heyho, for the story it's a necessity!)

    Ta

    Fozzie

    Yes, the Starwave 102 f11 does look like a good alternative (maybe even better).

    I notice Astroboot have a TAL 125 Apo in their Bargain Zone at the moment - out of my price range though! Optical Vision (the importers) still list the 125 on their website, but maybe they are just clearing out remaining stock.

  10. I contacted a couple of dealers today (Rother Valley Optics and Harrison Telescopes) who recently listed the TAL 100RS on their websites. Both told me that the TAL is no longer being imported!

    Sounds like bad news for anyone looking for one of these highly-regarded achromats. Guess I'll have to save my pennies for a SW 100ED instead.

  11. 1 minute ago, Bobby1970 said:

    For a scope that is only 18mm more aperture i was initially surprised at how much bigger it was. I intend on taking it away on holiday to cornwall with me so it is still just as portable as the 102 was really. I have a padded carry bag which came with it and that makes things a little easier. The vixen porta II folds down to a reasonable size and then one eypeice case. All in all a fairly protable set up i would say. I am considering trying it on the Skywatcher Alt/Az goto mount but i think it will push it beyond the reccomended payload lol

    Thanks, that's good info. I have this padded bag for my ST102:

    http://www.rothervalleyoptics.co.uk/geoptik-padded-case-for-100mm-refractors-f750.html

    and it's actually oversized for the scope - in fact I'm sure an ST120 would fit. I'm wondering if I'm taking that bag on holiday anyway, I might as well fill it up and put an ST120 in it! :icon_biggrin:

    • Like 1
  12. 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?

  13. 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).

  14. 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!

     

  15. 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

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