Jump to content

1564402927_Comet2021Banner.jpg.a8d9e102cd65f969b635e8061096d211.jpg

Ricochet

Members
  • Posts

    2,637
  • Joined

  • Last visited

Everything posted by Ricochet

  1. With an f5 dob you're not really missing out on having a 30-40mm eyepiece as the exit pupil (6-8mm) is too large unless you are at a really dark location. What you are missing out on though is a wider field of view. With your scope the eyepieces I would be looking at are the 21mm TV Ethos and the significantly cheaper option of the 20mm APM HDC, assuming that you don't need glasses to observe and can get your eye close enough to the lens. Another option would be an 82° eyepiece at around the 25mm mark.
  2. I tried it and they were a bit too big for me, or rather my nose is too big to fit in the gap with the eye cups raised. What I have thought about since is that the m43 thread could be used to fit Morpheus eyecups and extensions instead, which may give that little bit more room.
  3. Yes, on axis at least. I didn't test off axis to check what happens at the edge.
  4. I was just able to have a quick look at Jupiter through gaps in the cloud. There is no bloat as far as I can see, but I may have overstated the visible detail as I couldn't see any banding tonight, just a bright disk and four moons.
  5. There are two designs of lens cell for the generic Chinese barlows, with and without filter threads. Brands can order the same barlows with and without the threads, and can even change their choice for different batches. Just because there is a picture of one without threads doesn't mean all of them are unthreaded. I've got two ae barlows and both of them have the cell with filter threads.
  6. When screwed to an eyepiece. Extending the light path increases the magnification and my drift time measurements gave a magnification of 2.1x when screwed to the binoviewer nose piece. I expected higher but that's what the timings say. Mine look identical to the photos for the WO barlow, which I assume is specified as 2x when attached to the nose of a binoviewer.
  7. I use an AE555 I picked up from Astroboot, which gives 2.1X and the nose from the barlow that FLO sell as the Astro Essentials Barlow, which gives 3.1X, but this does generate some reflections off an element inside the binoviewer when the moon (or some of it) is drifting out of the field of view. It wouldn't surprise me if the WO linked above is the same as the AE I have so that would be my choice if I was buying a binoviewer barlow now.
  8. I don't think you need a barlow with your telescope, it's already got one permanently fixed in the focuser and the zoom will probably go to as high a magnification as your scope can handle by itself. With regards to the zoom, generally speaking the cheap 8-24mm zooms are considered better performers than the 7-21mm zooms, although the 7-21 might be fine in your scope as it has a reasonably slow focal ratio (f8.77). If you can increase your budget there is a 7.2-21.6mm zoom which is quite highly regarded. The zooms have a relatively low field of view at their low power settings, and your telescope has a reasonably long focal length so a low power/finder eyepiece would be my priority. A 32mm plossl will maximise the field of view that your scope can give without breaking the bank so my suggestion would be that you buy a zoom and a 32mm plossl. I would not buy the plossl set as I don't think the barlow or 6mm are going to be useful to you, leaving only the 12 and 25, and really you want a 32 instead of the 25.
  9. The XW eyecup has a similar shape but it is a lot bigger than the Starguider. In addition rather than just the top section of the outer part of the eyepiece rotating upwards, the whole outer part rotates up as one piece. In the XL/Starguider comparison photo below, the part on the XL which rotates is everything above and including the silver "ring" about half way down. With the XWs (but not older XLs), the very top part of the eyecup does unscrew, but instead of rotating up/down to help with eye placement, this piece unscrews completely to reveal an M43 thread, as shown in the second picture.
  10. I don't recall any but at only 16x they're not particularly suited for the task and so I don't tend to use them for it. Jupiter shows a couple of bands and moons, Saturn shows a disk and "single" ring if I recall correctly. If I remember I'll have a look with them the next time it is clear and get back to you. Personally, if I was to buy a bigger binocular it would be one with interchangeable 90° angled eyepieces. It's a lot more money to do that though. 70mm is as big as I'd like to go on a monopod so anything bigger would need an more substantial mount, which takes more time to set up and warrants a longer session than I tend to use the HRs for.
  11. I've got the 16x70s. I think they're very well made and optically very, very good. Correction isn't perfect across the whole field of view but it is good enough for an instrument of this type and I'd have to specifically go out and test them to describe which aberrations are present at the edges of the field. Coatings are excellent as far as I can tell, transmission seems high and scatter is low. I think if you put the full moon just outside of the field of view you can get some reflection off the inside walls. I've just had a look down through the objectives and discovered that only the first 3-4 inches past the objectives are blackened, with the rest of the walls being grey, although there are ridges/micro baffles the whole way down. However, looking right next to the moon isn't something you usually do and during general use there are no issues with reflections. Part of the reason I went for these over the cheaper options is the lighter weight, but as far as I am concerned they are still not something you would want to hand hold and so you would still need to mount them on your monopod. I have been sufficiently impressed by the quality of these binoculars that I've Manfrotto fluid foot monopod to mount them on and have an ebay saved search so that I can consider any 10x50s that might appear on the used market. I don't feel like I would ever need to upgrade from these to another ~15x70 binocular.
  12. I don't have a binobandit to knock the focus between sessions, but I don't remember having to focus my lightquests aside from the first time I used them. I've got some field optics eye shields on the eye cups at the correct angle for my focus settings and I just flick them up and down as needed. Field optics eyeshield
  13. Quite a few reviews saying that it isn't up to the normal manfrotto standard and it looks like the ball head can't be removed and breaks easily. You'd probably be better off going for one of the Newer/Zomei/etc clones such as the one below, which is the same price as the Manfrotto you linked. Zomei Q555
  14. The Stellalyra is out of stock until next year, therefore the Skywatcher Skyliner 200p is the telescope to go for if it is to be a Christmas present.
  15. Jupiter is quite low so you will have to look through a lot of atmosphere which reduces the quality of the view. You should try to: Observe Jupiter when it is at its highest in the sky Try to observe Jupiter when it is over nature, not man made objects (roads, houses). Even observing when it is between two houses can show a substantial improvement. Get your scope out to cool at least an hour before high power viewing. Only use the 25 and 12mm eyepieces. The 6mm and barlow are too much for your scope. Sit at the scope for a long time and watch for the moments of best seeing. You won't get the best views from a 2 second look.
  16. It looks really plasticky and flimsy. I suspect it would be a waste of money. What budget do you have for a tripod? EBay usually has a large selection of second hand photographic tripods if it doesn't have to be new.
  17. Yes, orthos would work well, but personally I prefer the extra comfort given by Vixen SLVs at that field size.
  18. I had a look through a BHZ in a Skywatcher 1145p (f4.4) last night to see how it performed. It actually did better than I expected, but astigmatism across the field made finding the correct focus more difficult than with better corrected eyepieces. It was more apparent on brighter stars so with a larger scope I would expect it to be more obvious. In the centre of the field it was slight, but the addition of field curvature made it more apparent towards the edge, but nothing compared to an eyepiece you would traditionally think of as having astigmatism. I should also point out that I do have astigmatism (~0.25-0.5D) in my eye which would have been contributing so a user with a lower value may see better star images. As a quick grab and go option I thought it was ok, and would use it again, but given the new cost you may expect more from it. I also used my Vixen SLVs (4, 6, 9) and I thought they coped very well at f4.4 and would be a good "budget" choice if the 50° field is acceptable to you. The 24mm Panoptic was stunning in the scope from centre to edge and would be an excellent choice if you can afford it, but will likely make you want to upgrade all your existing eyepieces.
  19. I would go for the 200p as it is a full size dob and not a tabletop dob. With the 150p I suspect one of the first things you will want to change will be to swap the tabletop mount to something tripod based. Not true. The larger aperture will perform better than the smaller scope under all sky conditions. The only time the smaller scope wins is when it is small enough to be transported to a darker site and the larger scope isn't.
  20. To be honest, I'm not sure. It's been years since I used it without the fan and I tend to get it out in advance to cool anyway. Low power views are fine straight away but high power planetary views are maybe half an hour with the fan, an hour without. If the air temperature drops rapidly a fan helps the mirror keep up, otherwise the mirror may never actually acclimatise. The battery I use is like the one linked below, but I think it is a lower mAh, cheaper version. 12v battery The fan is an 80mm coolink fan. I also fitted a generic pc speed controller into the telescope base but it isn't needed, running the fan on full speed is fine if it is sufficiently isolated to prevent vibrations being passed to the scope. You will need to do some diy to change connectors so that everything ends up being compatible. I replaced the screws that hold the mirror cell to the tube with longer ones so that I could attach the fan via hair ties. There is also a baffle to ensure air passing through the fan enters the scope. The baffle has a length of p-strip around the circumference which presses against a second length of p-strip around the opening in the rear of the scope. The hair bands and p-strip are both used for vibration suppression.
  21. "Shading" is vignetting, not coma. I'm not sure if you would notice any vignetting visually even with a "normal" 2" focuser when used visually as you need to lose half the light to notice. It is a very strong focuser, with no flex at all at any extension so the weight of the eyepiece will never affect the collimation. The Stellalyra is probably a bit smoother to turn because it is a Crayford but I don't know how it handles heavy loads. If you want the best of both worlds there is a Feathertouch replacement available for the Bresser but it costs more than the scope. Another thing I like about the Hexafoc is that you can rotate it 45° so that the focuser wheels are always in a convenient position.
  22. As someone who owns both XWs and a BHZ, I disagree with both of these points. Where the BHZ excels is when you want a quick grab and go session with only a couple of eyepieces in your pocket. If you're going out for an extended session with a case full of eyepieces the premium fixed focal lengths are superior, revealing more detail and having a higher optimum magnification than the BHZ.
  23. I agree with this. Definitely. Most people concentrate on image correction when comparing eyepieces and internal baffling, light scatter and reflections are ignored. The SLVs are significantly better than the Starguiders in this regard. Space will be blacker, the object you are looking at will be sharper and there will be no reflections of the object floating around the view (although you may still see reflections and scatter from the binoviewer).
  24. Jupiter and Saturn are now getting lower in the sky so I think you would be better off considering more DSO observation over the winter with planetary coming back into play next summer. Your choice of Celestron X-Cel LX eyepieces is a good choice, so long as you stick to the 12mm and shorter focal lengths. The 18 and 25mm will have quite noticeable aberrations in an f6 scope and you can make better use of your money elsewhere. I have the Bresser 8" and in my opinion no 1.25" eyepiece has a wide enough for your lowest power eyepiece. My lowest power eyepiece is the 28mm Nirvana and I think this eyepiece fills the role very well. You can buy the current version of this eyepiece from Telescope Express, and possibly some other brands that I am not aware of, for a very reasonable price: TS-Optics 28mm Ultra Wide. Going back to the Celestron X-Cel LX range, you definitely want the 12mm as this will give you an exit pupil of 2mm, which is ideal for extended objects (12 / f6 = 2) and for DSO observations you could stick with just these two eyepieces. The 9 and to a lesser extent the 7 will also be useful for DSOs (where they fit into the field of view), and for planetary I always found the 7mm to be a goldilocks focal length under UK skies, although the 5mm should be the optimum choice when sky conditions allow it. Of the two scopes under consideration the altitude bearings, mirror cell and focuser are reasons why I would buy the Bresser again if I was making the choice again. I purchased the 1:10 dual speed upgrade for the focuser (as well as 1.25" and 2" Baader clicklocks) and bought a 12V computer fan and battery quite cheaply to cool the primary mirror.
  25. Given the current state of affairs this is a good plan unless you find yourself particularly drawn to one of the brands over the other. Personally, as an owner of an 8" Bresser, I would buy another over the Skywatcher or Stellalyra (GSO) offerings based on the larger altitude bearings, the mirror cell and the focuser. I can carry my 8" Bresser from the shed into the garden in one piece (base + OTA) because the two holes on the sides of the rocker box make nice handles to lift the whole setup. The Stellalyra only has a single handle on the front of the base, which is fine for carrying the base by itself. If you add a pair of handles to the sides of the base I am sure it could be lifted as one piece like the Bresser. If you have any stairs or quite uneven ground to traverse you will probably want to carry the OTA and base separately even though the weight is manageable (for me at least). In this case, again the Bresser is easier to carry out of the box as you can use the altitude bearings as handles, although a central handle over the centre of gravity would probably be easier for both scopes.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.