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johnturley

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Posts posted by johnturley

  1. 49 minutes ago, Rich1980 said:

    I contacted the retailer who told me "We checked this scope and it’s normal to have these small particles. You will not got one that is particle free. The OTA was checked by us and it passed our standards." 

    My Esprit 150 was virtually particle free.

    I've also read reports of Explore Scientific triplets suffering from similar problems, but both of those that I've owned were virtually, if not completely, dust free. 

    John 

    • Like 1
  2. 16 minutes ago, DaveGibbons said:

    Hi,

    I don't think that is acceptable even though a little dust makes no difference to optical performance it would bug the hell out of me! I don't think it is representtive of what to expect from a premium Skywatcher product from a state of the art optical manufacturing facility(so we are told).

    regards

    Dave

     

    There might have been a spec or two of dust with my Esprit 150, but nothing like this sort of amount.

    John 

    • Like 1
  3. 10 minutes ago, Susanm said:

    I purchased a Meade102mm scope that came with a barlow2x, a 9mm and 24mm eyepiece.  I am dissapointed that it really does not show much.  The best was the moons of Jupiter which were tiny images.  Was I expecting too much from this scope?

     

    Th moons of Jupiter will still be tiny images virtually no matter what you pay for a scope. 

    John

  4. 2 hours ago, dweller25 said:

     

    I had very specific reasons for buying the relatively light 100DZ, my expectation is that visually it will match the in focus views of the TSA - we shall see.......

     

    Hi David

    I wondered otherwise why you would want to get a 100 DZ when you already had a TSA 102.

    If I do decide to get a 100 DZ it will be mainly to provide a lightweight portable high quality scope.

    John 

  5. On 27/08/2020 at 17:51, dweller25 said:

    Thanks Chris,

    I had a very brief look through it last night but there was a lot of moisture and thin clouds in the sky. Looking forward to a night with better conditions.....

    David

    What other scopes do you have to compare your Tak FC100 DZ with.

    Several people people have posted on Cloudy Nights stating how marvellous the views through 100 DC and DZ are, in particular on the moon and planets, compared with larger non premium scopes such as Synta 120 ED's (such as Skywatcher ED 120, and Orion EON 10), and claiming that much higher magnifications can be used.

    I would be interested to know how one would compare with my ES 127 FCD 127 scope, I kept this scope after purchasing my Esprit 150, and mounted it on an AZ-EQ5 to give me a fairly portable refractor. Everything being equal, the FC 100 DZ would be much more portable, according to RVO's website being 595mm in length (enabling it to be carried on most commercial flights), and weighing just 3.8 kg, compared to the 7 kg of my ES 127. If the latter is the case then maybe it would be feasible to take it to Tenerife, and on future planned eclipse trips, replacing my fairly basic 80mm Opticstar Refractor. 

    John 

  6. My first attempt at photographing Mars with my Canon EOS 6D digital SLR  and processing with Registax, taken at approx 00.30 on 27.08.2020 when the CM longitude was approx 250. By coincidence the CM longitude was almost exactly the same, and with Syrtis Major just coming into view, as when I made a drawing using the same telescope 32 years ago back on 17.08.1988, when Mars was slightly closer to the earth, and the features appear to correspond remarkedly well. Unfortunately (perhaps) I am of that age, when planetary drawings and images were usually presented with south at the top, and that is the way I am used to viewing planets, in particular Mars, to me the features do not look right with north at the top.

    The attached photo was taken through my 14in Newtonian using eyepiece projection with a 12.4mm Plossl eyepiece, and a 1 minute movie with my EOS 6D, converted in PIPP, stacked and processed in Registax, and processed a bit further in Adobe Lightroom. I have only recently tried using Registax, but it looking at some other photos posted, it appears that I am not the only one who has a problem with Registax for some reason producing a bright ring around the following limb on Mars which was not there visually, and have not as yet figured out how to get rid of it. In addition I have not found a way of enlarging the saved image other than using a shorter focal length eyepiece, or adding a Barlow lens, and would welcome any suggestions, maybe I am missing something simple.  

     

    Mars Processed 27.08.20.jpg

    Mars 17.08.88.jpg

    • Like 11
  7. I'm finding that the surface markings on Mars are not standing out as clearly as usual this year, suspect some dust activity, but not a global dust storm at least not at present, however the south polar cap (now melting rapidly) has been standing out very clear. 

    John 

  8. 4 hours ago, maw lod qan said:

    This morning at 4am, I could make out a dark area a little off center of the planet with my 8"dob.

    But strangely, not the polar ice cap. It had me wondering if it shrinks noticeably during the summer season for that hemisphere. 

    It is good seeing Mars getting larger in the eyepiece.

    I'm surprised that you've not been able to make out the South Polar Cap, as its been quite obvious recently, although now shrinking rapidly, and I gather it can disappear completely towards the end of the Martian Southern Summer. I've read reports suggesting that it now shrinks more than it used to, suggesting that Mars may also be experiencing global warning, which in the case of Mars cannot be due to man made CO2 emissions.

    John 

  9. 7 minutes ago, John said:

    Why is it that dust storms seem to coincide with favourable oppositions I wonder :icon_scratch:

     

    I'm sure its no coincidence, they often happen around the time Mars is closest to the sun (Perihelion), and blanketed out the view of Mars around the times of the favourable oppositions of 1956, 1971, and 1973 (later stages), however 1988 and I think 2003 were not affected, at least not to the same extent. In 2018 there was a significant dust storm but it occurred (unusually) some time before perihelion. If perihelion occurs when Mars is distant from the earth, as during the aphelic opposition season, you wouldn't notice major dust storms from earth based telescopes.

    John 

    • Thanks 1
  10. I suspect that there is some dust storm activity at the moment, although not a blanket covering (at least not at present) as happens some years, as I'm finding that the dark markings are not standing out as clear as usual, but the south polar cap is quite clear.

    John 

    • Like 3
  11. 38 minutes ago, ebdons said:

    Hi, only decent barlow I have used are the tele-extenders from opticstar (same as meade 5000) i have the 2" x2 and the 1.25' x3 version and find them very good with nice clarity right to the edges, not used a powermate so not sure if these are that inferior? tony.  http://www.opticstar.com/Run/Astronomy/Astro-Accessories-Imagers-Opticstar.asp?p=0_10_5_0_3_66

    I suspect that they are made by the same company (JOC) as the Explore Scientific ones, their range of 82 degree eyepieces look identical to the ES 82 range.

    John

  12. 8 minutes ago, johninderby said:

    The Baader neodynium filter helps a lot and gives a natural grey looking moon. 

     

     

    I agree, the Contrast Booster filter which some observers prefer, gives objects a yellowish cast.

    John 

  13. 42 minutes ago, John said:

    On a practical note, how much inwards focuser travel do the ZWO and Altair ADC's eat up ?

    I've seen a figure of 57mm for the ZWO but that sounds a lot to me :icon_scratch:

    Thanks

    You can reduce this to about 45 mm by replacing the T thread to 1.25 in adaptor on the ZWO ADC by a T thread to 2 in adaptor, or fitting a Tele Vue 'In Travel' adaptor, as I have done on mine, assuming of course you have a 2 in focuser.

    John 

    • Thanks 1
  14. 46 minutes ago, paulastro said:

    Thanks John.  I've only just come across this thread.  I came in on page 6, and to be honest I was quite shocked  with some comments about how poor the views some people were currently getting of Saturn, Jupiter and even Mars.  Even to the extent of indicating it wasn't worth observing planets at all below certain altitudes. I was pleased to see your post.

    My latest observations of the above planets were made on the night of July 20th/21st and were very much like your own observing experiences.  In fact they were so good, despite not getting into bed until 4am, I couldn't sleep for a while as I was thinking about how great the night had been!, including nice views of the GRS transit, and alovely wiew of Mars with Syrtis Major well placed as well as other features, Saturn was just fabulous.

    As you suggested all sorts of things could account for peoples viewing experiences.  Local seeing conditions, using too large apertures for the conditions, the observers experience, the type and quality of the optics used, etc etc.

    I've never used an ADC, - from what people are saying it seems rather a hassle to me.  I think I'd rather use the time observing and making the most of any periods of good seeing.

    For the record, I was also using a SW 120ED as well, but other telescopes are available 😀.

     

    I think the benefits of ADC's show up mainly in apertures greater than 6 in, as I stated in my previous post, on the night of 20/21 July my ZWO ADC significantly improved the view through my 14 in Newtonian (as I stated I can't previously recall having seen so much detail on Jupiter when it was so low down), whereas the improvement through my Esprit  150 was only marginal, hence I would not expect an ADC to give a big improvement with a SW 120 ED.

    Local seeing conditions were also good for me on 20/21 July, ADC's will not do much to improve the view when seeing conditions are poor, which is probably another reason why some observers say they have found little benefit from using an ADC.

    As I also stated, I don't faff about for a long time trying to align the ADC with the horizontal horizon, it would be too much of a pain in the neck doing this every observing session. 

    John 

    • Like 3
  15. Comet has now definitely faded quite a bit from when I last photographed it on 11.07.20, but staying fairly bright for longer than predicted, I couldn't see it with the naked eye, but my wife with her superior eyesight could still make it out, although not the tail.

    I attach the best of the photos I took with my Canon 6D, 24-105mm lens at 105mm f5.6, 10 secs exposure at ISO 1,600, unfortunately slightly out of focus, it is difficult to achieve precise focus at night with a lot of modern camera lenses as autofocus doesn't work, and although you can manually focus the lens, there is no distance scale. In the past you simply set the distance scale to infinity. 

    John 

    Neowise 20.07.12.jpg

    • Like 4
  16. 12 minutes ago, John said:

    I ought not to but I do find a fuzzy field stop really annoying as well !

     

    I agree, the 17.5 mm Morpheus however does have a fairly sharp field stop, maybe the 12.5 is different.

    One reason I tend to prefer the Nager T6's to the ES 82's is the sharper and better defined field stop.

    John 

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