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Ricochet

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About Ricochet

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    Hertfordshire
  1. Ricochet

    Eyepiece Deleema v.2

    They are a very similar design, I believe their 18 and 25 also have issues in faster scopes. I used to have a 7mm and preferred it a bit to my 8mm Starguider but the rest of the range may not be better than the equivalent Starguiders.
  2. Ricochet

    Eyepiece Deleema v.2

    You will probably have to spend more. There is an 18mm Baader Classic Ortho if you don't mind the 50° field, a 16mm Nirvana-ES or something from the Explore Scientific 68° range. You can also look at the Ultra flat eyepieces, it depends which suppliers you can use.
  3. Ricochet

    Eyepiece Deleema v.2

    25mm + 3X barlow = 8.3mm 18mm + 3X barlow = 6mm In any case, the 25 and 18mm Starguiders are unsuitable for an f6 scope in my opinion. The shorter ones are fine, but not those two.
  4. All stars and planets are so far away that if one is in focus, the rest will be too. In fact in some conditions it is easiest to focus on a nearby star when you want to look at a planet. When focusing on a star turn the focuser knobs so that the star becomes a point of light. This will tell you that you are in focus. If some eyepieces will focus then it is unlikely that you have a problem with extension tubes (and I don't think your scope has them anyway).
  5. Ricochet

    Eyepiece Deleema v.2

    I started with 8mm and 12mm Starguiders with my 8" dob, and was very pleased with them. At longer focal lengths I prefer the Explore Scientific 68° series (also sold as Maxvision and Meade SWA with a different eyecup design). The 24mm 68° (same FoV as a 32mm Plossl) wasn't quite wide enough in my opinion so I agree with @vlaiv that the 28mm is the better option. I now use a 28mm (82°) Nirvana but this may be harder to find.
  6. I find it easiest to remember that Exit Pupil = Eyepiece Focal Length / Focal Ratio Therefore with your 6mm eyepiece and f6 telescope you have 6mm / 6 = 1mm If you add a 2x barlow you not only double the focal length, but the focal ratio, so now you have 6mm / 12 = 0.5mm.
  7. Yes and no. You won't go wrong by buying something from Televue and if you bought second hand you wouldn't lose a lot if you were to change your mind. However, at the other end of the scale, the barlow sold by FLO under their astro essentials brand is actually very good optically. Where a premium barlow betters it is more in the mechanical side, better materials for the body, a compression ring instead of a simple thumb screw to hold the eyepiece. There are probably differences in the quality of the coatings but you might be hard pressed to notice. As with all things you're probably best off looking for reviews of any specific barlows that you are looking at, rather than assuming that more expensive is better. You might also want to consider getting a telecentric focal extender rather than a standard barlow. These will not vignette longer focal length eyepieces and maintain the original eye relief of the eyepiece as well as being more accurate with regards to the magnification factor. The Televue Powermate and Explore Scientific Focal Extender are your options here and either brand should serve you well. (I use an old Meade branded one which is the predecessor of the Explore Scientific.)
  8. You can push higher on Saturn but only when the conditions allow, so I think you would often find the higher power unusable. That is ok when you have a lot of options but not if it is your only eyepiece.
  9. Ricochet

    Help please

    As it is new you will be covered by the initial (2 year?) warranty but you should also register it on the Bresser website to have it extended to ten years.
  10. I think that you are aiming for too much magnification. An 8mm Starguider with a 2x barlow would be a much more useful combination I feel.
  11. Ricochet

    Optolong Filter

    If FoV is the issue perhaps you need to consider wider AFoV eyepieces. My 14mm XW has about the same FoV as a zoom on the 24mm setting.
  12. Ricochet

    Optolong Filter

    For an f5 telescope would have thought that the optimum would be at a shorter focal length than that, perhaps around 15mm. What focal length setting do you use for unfiltered views?
  13. The first thing that I would do would be to remove any extension tubes and reducers from the focuser, and then reinsert them, making sure that they are square. Any tilt in one of those or between the eyepiece clamp and your laser could produce this issue. Once you have done that check if the issue persists. If it does then it suggests either: There is slop in the focuser or it is not running true, which you can probably fettle out (hopefully someone with the same focuser can advise). The tube itself is flexing simply under the moment of the focuser being slightly further out from the tube. If you can tell that this is the issue I think you would be entitled to a replacement as I do not think this is normal. With regards to the dents I doubt that any of these tubes have perfectly circular cross sections, so if the deviation is consistent the entire length of the tube that might be considered "normal" although yours would appear to be an extreme example. The fact that tightening the tube rings can flex the tube doesn't sound right. With an eq-mounted reflector you would be loosening and tightening the rings several times in a session if you are using it visually and you can't stop to recollimate each time. If there is a local astronomy group I suggest you contact them and see if there is anyone who would be prepared to have a look at it and give a second opinion.
  14. The height difference is only 3mm. The paper will be fine.
  15. You would not measure to centre the secondary under the focuser. You should put your cheshire/sight tube in the focuser and adjust the focuser position so that the circle formed by the bottom of the sight tube is only a tiny bit larger than the size that the secondary appears. You can now easily see when the mirror is at the correct height and orientation. No, they didn't. A flat mirror would not focus light to a point. They may have had less obvious curves but they still have them. You still mark the centres in the same way and the curve of the mirror should not be a problem.
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