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Louis D

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Everything posted by Louis D

  1. I generally go by exit pupil. I can tolerate exit pupils down to about 0.7mm with ease. Below that, floaters and viewing discomfort start to dominate.
  2. Generally, the 32mm Skywatcher SWA is too not well regarded. You can search for reviews of its predecessor, the 32mm Celestron Ultima LX. It's little better than an Erfle. Usually, the discussion is between the 32mm Panaview and the 30mm Aero ED SWA. The latter is regarded to be a bit better corrected in faster scopes. I have the 35mm Aero ED SWA, and it's pretty decent for its price. If you're willing to jump up in price, the 30mm APM Ultra Flat Field is phenomenal.
  3. Invite a few less people to pay for the mount. 😁 Sacrifices must be made.
  4. The dovetail bar would be attached to the tube rings rather than the tube itself. I would probably screw some flush fit grub screws into the old screw holes to keep out dust. Did you try putting Sorbothane pads under each foot of your tripod to dampen vibrations? Once I did that, I could live with the vibrations from manual focusing on my 127 Mak.
  5. Assuming your secondary is aligned properly (usually a set it once and forget it situation), I just do a quick check each night of the primary with a Rigel Aline that stays in the focuser like a plug during storage.
  6. Yep. I find those mid-range power most useful for what I view such as open star clusters and nebula. Even when viewing planets, dropping back in power often yields a better view. I mainly use very high power for resolving globular clusters and splitting doubles. I also like to push the magnification up on the moon sometimes, but I mostly resolve the bubbling of the atmosphere.
  7. I have a 1.25" or 2" laser, and can only get it to work in 2" mode because there's too much play in the 2" to 1.25" adapter, and it's a really nice one. If your laser is 1.25" only, I don't know what to tell you. If it can be used in 2" mode, use it in that mode to help minimize play. Make sure the focuser is retracted all the way as well. If you can get your secondary aimed at the center of the primary using the laser, put it away and switch to using an Aline collimation cap to align the primary back to the secondary.
  8. I don't know if I said this before, but I find that I use powers between 75x and 100x the most often, so plan your purchases accordingly. 22 years ago, I started out with a 38mm Rini 2", a 14mm Pentax XL, a 9mm Vixen LV, and a 5.2mm Pentax XL. I used the 14mm the most by far in my 8" Dob and only recently replaced it with 14mm Morpheus.
  9. Good to hear that. Sometimes it's the most basic things that need checked. I once put my 12mm Nagler T4 in the focuser and freaked out that I couldn't achieve focus on anything. I eventually pulled the eyepiece out of the focuser and noticed I hadn't removed the 1.25" barrel's translucent cap. I was using the 2" skirt with an extension that makes it impossible to see or even easily remove that cap. ☺️
  10. The annual Winter Star Party (WSP) is held at Camp Jackson Sawyer on Scout Key in far south Florida, USA. The viewing conditions are generally rated among the best anywhere. The laminar air flow off the Gulf of Mexico helps immensely.
  11. There's also the fork mount which pretty much only works for SCTs and Maks (see Meade and Celestron). The eyepiece can be difficult to get to if it ends up between the forks in a dual fork arrangement. There are newer single fork designs that would allow you to pivot the diagonal to the side where the missing fork would be. These single fork mounts tend to be visual only. Fork designs have the advantage of being lighter than GEMs (German Equatorial Mount, or EQ for short) because there's no counterbalance weights and there's no meridian flip to deal with. However, they're inappropriate for all but the shortest refractors and Newtonians, so they're limited to use with CATs (Catadioptric or folded designs). With an equatorial wedge, they can track with a single motor like a GEM. The newer designs track in alt-az mode with two motors under computer control like any other alt-az mount. Dobs require fairly level ground, though they will still work pretty well on a gentle slope. They're really the only solution for 10" and larger Newtonians for most folks. There's also the split ring mount for Newtonians that have been built by ATMs (Amateur Telescope Makers). I don't think I've ever seen this design commercialized. It allows large Newtonians to track in the same manner as they would on a traditional fork mount with an equatorial wedge, but with much more stability.
  12. I have the 9mm Morpheus and 10mm Delos, and they are very close. Both are very sharp and contrasty center to edge. The Morpheus is noticeably wider. Here's a comparison of images shot through my various 9mm/10mm eyepieces using my AstroTech 72ED refractor. The full view is shot with a lower resolution, wider field of view phone camera and resized upward to match resolution, so don't pay too much attention to it for sharpness. It's mostly there to give you a better idea of its apparent field of view.
  13. I would start with the RDF's mount and stalk. See if they are bent or loose. The foot may have loosened on the tube. It may be possible to loosen things up and shim the mounts until it can be aligned with the internal adjustments.
  14. @Bryan_D Keep us informed about how you get on with your new scope since lots of folks buy these as a first scope.
  15. I do find the image a bit bright with the original Baader solar film from ~20 years ago. I don't know if they've darkened it up a bit or not. I like to have an IR blocking filter in place to limit any unblocked IR from cooking my retina. Without it, after a while, I feel fatigue in my observing eye.
  16. Well, you could build your observatory on top of a tower like several amateur astronomers have done:
  17. I figured out mine by setting up my telescope indoors in the daytime with a yardstick at the other end of the house. I then imaged the width of the ruler shown in the eyepiece with my cellphone camera for each barlow/binoviewer combination and did the math to get the relative magnification factors after downloading the images and viewing them at full resolution. The key thing to make this work is to ensure that the field stop is clearly imaged, so keeping the phone parallel to the eye lens and at the eye relief distance is imperative. You can also do it simply by eyeballing it without a camera if you don't mind a couple of percent error. If there is significant vignetting, you have to make a judgement call about where exactly the field stop appears to be. If the edge fades completely to black, crop the center from both images by the same number of pixels and check the amount of ruler shown. For this to work, the exact same part of the central image has to be used to avoid eyepiece distortion coming into the calculation.
  18. Actually, many of them are older with presbyopia and can no longer accommodate field curvature. I used to be able to accommodate it, but no longer. That's why it's important to understand each observer's situation. Not only what telescope was the eyepiece used in, but what condition are the observer's eyes in (presbyopia, astigmatism, distance vision, etc.) and type of correction or lack of any.
  19. Only a $50 difference in the US. Perhaps more in the UK then. The 14mm and 20mm do have some, but if you're young, your eye may be able to accommodate the difference when gazing from the center to edge. I used the 14mm Pentax XL for years without noticing field curvature. Then during my mid-late 40s, presbyopia set in and I could clearly tell that center and edge focused at two different distances. Once refocused, the edge is pin sharp. I ended up replacing it with a 14mm Morpheus despite its edge astigmatism and slight field curvature. That larger apparent FOV is just so much more immersive than the XL's 65 degrees. The 7mm Pentax XW is nice, but it has some edge issues. The 3.5mm XW is pretty much flawless. I'd look into the 6.5mm and 9mm Morpheus as well. I have the latter, and it pretty much the equal of my 10mm Delos. The 6.5mm is supposed to be similar. For a 2", check out the 30mm APM Ultra Flat Field. I really like how immersive, flat of field, and well corrected to the edge it is. It also has really comfortable eye relief. I ended up retiring my venerable 27mm Panoptic in favor of it. For a mid-range, the 17.5mm Morpheus is supposed to be pretty nice. Personally, I really like the 17mm ES-92, but it is huge and heavy.
  20. Perhaps you're experiencing SCT mirror flop? Try running the focus far in each direction and come back slowly to focus from each side to see if that helps. That, and don't use the mirror to focus on either side of best focus once collimated. Instead, pull your DSLR partway out of the focuser, lock it down, get best focus with the mirror focus knob, recollimate, then loosen the DSLR and slide it in and out on either side of best focus to see if the same anomaly recurs. This would eliminate mirror flop as a cause. If you still see the issue with this method, I have no idea what is going on.
  21. @F15Rules Look for a used Meade 140 APO Series 4000 2x triplet Barlow. That's the nosepiece I've been using to reach focus since the included Arcturus 1.85x and 3.0x nose pieces are complete garbage. They produced really odd coma-like distortions in all scopes and with all eyepiece pairs. With the Meade, there is no indication anything extra is in the light path other than increased magnification of 3.0x. Slowing down my scopes to around f/18 also allows the 23mm aspheric 62° eyepieces to really shine as well-corrected 7.7mm eyepieces. I've picked up multiple copies of this Barlow for various uses for around $35 to $40 apiece. You could compare it to your Baader and WO nose pieces to see which works best for you.
  22. That's why I asked how the 34mm SVBony compares to it, since the Q70 sets a pretty low bar to compare against. It probably wouldn't be fair to compare it to a 35mm Panoptic, though if by some miracle it equalled it, that would be news.
  23. I'm curious how it performs in the outer 25% of the field. Does it maintain pinpoint stars to the edge? Do you have to refocus the edge for best focus (flat-field)? Do stars change from lateral to radial lines on either side of focus out near the edge (astigmatism)? Do stars smear into radial rainbows near the edge (chromatic aberration)? Even if there are some of these issues, are they pretty minor in comparison to your Q70? How's the eye relief? Can you see the entire field with eyeglasses (or can you pull back a ways and still see the entire field if you don't wear eyeglasses)? Not much has been reported on this intriguing eyepiece so far.
  24. My Meade 140 2x Barlow nosepiece yields 2.4x natively in the original housing, 1.6x screwed in to an eyepiece, and 3.0x screwed onto the nose of my Arcturus (Revelation) binoviewer. Your 1.6x nosepiece might be similar. On the nose of the binoviewer, I have plenty of focus travel left even in my Dob's low profile focuser. If you use your 30mm eyepieces, you'll get the equivalent of 10mm eyepieces, which is good for planetary and lunar observing in my experience.
  25. The cheap green ones can pump out well over 5mW in the infrared due to a lack of IR filtering. That, and many put out well over 5mW despite saying otherwise. I'm of the opinion laser pointers shouldn't be used for outreach because little kids are always trying to relieve presenters of them to play with as light sabers. It gets annoying having to keep reminding them to pay attention to what is being pointed out in the sky rather than the pointer itself. I blame failed parenting and kids' generally short attention spans. Laser pointers are fine when there are no kids around, but that's a rarity at outreach events. I never mount the laser sight at outreach events, either, because kids have a tendency to look down the front of everything on the field, including laser sights. So, that leaves using them alone in my backyard. I'm 35 miles north of the nearest airport, and the planes are landing every 10 or 15 minutes and approaching miles east of my narrow viewing window to the south. Since they're heading south, at worst, I'd hit their backsides if I somehow shot a beam through my trees at them. They don't seem to take off to the north, possibly because that's where all the landings are coming from, so hitting the cockpit would be next to impossible. We don't have much in the way of police, sheriff, or ambulance helicopters out my way either. However, they're super easy to hear coming compared to a high flying airliner.
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