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AndresEsteban

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About AndresEsteban

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    Astronomy, Electronics, Languages, Trekking, Mathematics and Physics.
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    Rio de Janeiro

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  1. The BCO 10mm is an amazing eyepiece! Every time I tested it over DSO fields it suprised me by showing very dim stars not visible with other eyepieces! Don't know if this is due to the low number of glass elements along the optical path, or the special Baader HT coatings. It doesn't matter though, performance is outstanding!!! I also particularly like to use the 10mm BCO with the original Baader Q 2.25x Barlow! It turns into a superb 4.44 mm eyepiece with excelent eyerelief! I prefer the views with this barlowed 10mm rather than using the 6mm BCO alone. This eyepiece is a must in any eps
  2. The Q2.25 Barlow is a very fine one only beated by TeleVue Powermates. It also gives the flexibility of a 1.3x barlow when the lens is attached to an eyepiece without the whole lens body. Indeed one of the best barlow for its price in the market!
  3. Ok, my Meade Series 4000 32mm arrived so now I have 3 32mm plössls to compare. This is important because 32mm eps (with 50º-52º AFoV) have the maximum fieldstop diameter for a 1.25" eyepiece (about 27mm), therefore they are the eps that will give the maximum TFoV for your scope (Field stop x 57.3 / scope focal length). The plössls are: Celestron Omni 32 mm Meade Series 4000 32mm GSO Superplössl 32mm The winner is the Celestron Omni eyepiece without any doubt! Sharp an bright! The Meade came closer to the Celestron, coatings seem to have same type and coloration. Meade ep focal length seems to
  4. Technically, I agree with you John! 1) On my 200 f/5 reflector the Meade 40mm gives: 40mm/5 = 8mm exit pupil and 32mm ep gives 32/5 = 6.4mm . I'm 54 and certainly my pupils when fully dilated have not 8mm! So yes, technically it's a waste. 2) But with the 76.2mm f/16 refractor the 40mm ep gives 40/16.4 = 2.4mm and the 32mm, 32/16.4= 1.95mm. Although the field is narrower with the 40mm ep there's a gain in exit pupil than is perceptible in this slow scope (from 1.95 to 2.4mm). Well, what about the f/5 reflector and my actual pupil size when dilated? Being 54 years old I don't have 8mm for sure!
  5. Update folks! 32mm 1.25" plössls!!! I finally get my Meade Series 4000 32mm plössl. Now I have three 32mm plössls that I can compare: Meade Series 4000 32mm plössl - FMC, blackened lens edges. (Series 4000 typical body design -straight black cilinder) Celestron OMNI 32mm plössl - FMC, blackened lens edges. (Celestron and GSO share the same ep. body) GSO Superplössl 32mm - FMC, blackened lens edges. (Celestron and GSO share the same ep. body) Tested the bunch a few days ago. Object tested: Beehive Cluster, also known as Praesepe or M44. Telescopes used: a 200mm f/5 reflector (hand made with ex
  6. But is a trend for some manufacturers. Just checked Ricoh Imagining site for the Pentax XW series eyepieces (70º). Original Pentax MC on all air-to-air surfaces and special proprietary coating on cemented surfaces: PENTAX-Original Multi-Layer Coating for Outstanding Light Transmission Efficiency"All lens surfaces that come in contact with air are treated with the original multi-layer coating, while all laminated surfaces are treated with the innovative partial coating, to offer the light transmission efficiency of more than 90 percent (an astonishing 96 percent at 550nm) over the visible ligh
  7. Hi John! I didn't mention air-to-air surfaces specifically. In all we have 6 interfaces in a plössl: 4 air-to-air as can be ssen in the picture you posted and 2 internals, cemented. Don't know if all individual lenses have coatings prior to cementation or if they put the coatings after it, thus leaving only air-to-air surfaces to get the coating process as common manufacture method. But, as you've mentioned I've heard some manufacturers are coatming all surfaces, but I sincerely don't know which brands are doing this and if in fact it has advantages over uncoated cemented surfaces. But for th
  8. Coatings have an important role in the qualty of the image delivered, because they are responsible for optimizing light transmission through the optic sysem. As the number of optic surfaces the light path must travel increases, the qualty of the coatings turns out to be a major qualty factor. In FMC plössls we have 6 surfaces, 3 for each doublet. Celestron OMNI series and Meade S4000 have IMHO better coatings than GSO. Thus images are brighter. On the other hand we must consider the qualty of the glass used, and the manufactury process qualty variation. GSO seems to have pretty good glass in g
  9. Although we live in an OEM world with few manufacturers and several brands, some facts are clear: even with external barrel being the same, not all 32mm plössl are the same. Right now I have two and I'm waiting for a third. A Gso Super Plössl Fullu Multicoated 32mm 1.25" anbd a Celestron OMNI 32mm also FMC. Waioting for the Meade Series4000 32mm to finally choose the best from the group. So far results using my vintage OKKK 76.2mm f/16.4 refractor (39x), are: Celestron OMNI 32mm: Superb coating and brighter images than the GSO. Also seems to have a lower focal distance than the GSO, perhaps
  10. I have this 1.25" 32mm plössl eyepiece in two brands: Celestron Omni and GSO. They are not exactly the same eyepiece although mechanically they are the same. Both have multi-layer coatings and blackened lens edges but... I think the Celestron Omni series has a really superb coating, far much better than the GSO, as a result, the Celestron seems to get fainter details and daylight images, for example, seem much brighter (20% max?). On the other hand it seems they have not exactly the same focal length. The Celestron seems to have more than 32mm and just a little less field than the GSO. Convers
  11. Some videos of th Moon and planets to show the views given by Classic Refractors... The Moon http://youtu.be/oXeZvBRR_vQ?list=UUwMN3FPhdY041Y-7t_Wf8KQ http://youtu.be/pATzwlHz4M8?list=UUwMN3FPhdY041Y-7t_Wf8KQ Jupiter http://youtu.be/ZZBL6Ex1Vu8?list=UUwMN3FPhdY041Y-7t_Wf8KQ Mars http://youtu.be/su20U3-39W8?list=UUwMN3FPhdY041Y-7t_Wf8KQ http://youtu.be/OrPttYoSws8?list=UUwMN3FPhdY041Y-7t_Wf8KQ Saturn http://youtu.be/44egQ2DpO7k?list=UUwMN3FPhdY041Y-7t_Wf8KQ Castor (alfa Geminorum) http://youtu.be/YxRq9laU9XQ?list=UUwMN3FPhdY041Y-7t_Wf8KQ
  12. One important thing to get better contrast is telescope flocking. I've found that velvet glued over a cardboard sheet gives an excellent light absorbing surface. Moon and planet views show better contrast! Objective end flocking Focuser end flocking Focuser flocking
  13. Some experiments trying to take some images of double stars... Certainly this is almost impossible without a motorized EQ. However some positive results may be obtained... Castor (Alfa Geminorum)
  14. Moon viewa are excellent, with no visible CA of course. But using wide field eyepieces in afocal method may introduce some bluish line on the moon disc thta's not present in the visual mode. Also, the full moon disc centered on wide fild eyepieces brings the moon's disc over the border of the eyepice, thus being prone to produce some CA in this border zone. (Skywatcher wiled angle 66° eyepieces). Despite all these. I believe these are amaziong images for so simple settings.
  15. Mars and Saturn. Again all images are the final output of Registax program applied to 640x480 videos (30fps). Hope these pics give you an idea of how these vintage refractors perform. I don't doubt that despite of their long focus, these refractors are able to give beautiful DSO pictures (using Deep Sky Stacker for example) if a motorized EQ is available for long expsures anlomng a decent DSLR. the idea would be to put one of these OTAs on a modern EQ mount and see how performs. The same thing recording HD videos on planets with a DSLR, certainly more frames and sharpness will give better pics
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