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Ricochet

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Everything posted by Ricochet

  1. An Astronomik CLS might show a tiny bit of improvement, any cheaper light pollution filters will definitely be a waste of money. If you can locate M13 as a faint patch of light then the best filter you can use from home is to increase the magnification, up to the point where the exit pupil is ~1mm. The best light pollution filter is to put your dob in the car and drive away from the light to a dark site, when/if possible. Edit: I should point out that the 1mm exit pupil limit advice is solely for open and globular clusters in which the stars can be resolved as points of light. For extended objects (eg galaxies) the limit is an exit pupil of ~2mm. For nebulae you can use UHC and OIII filters, which require even larger exit pupils and will probably only be of use on the brightest nebulae under your skies.
  2. The main advantage of the collapsible dob is if you have a storage space in which the collapsible dob will fit but the solid tube won't. Similarly it may be possible that you have a vehicle into which you can fit the collapsed dob on its base rather than putting the OTA and base in separately. The advantage of the solid tube version is that it is actually lighter (and so easier to carry) than the collapsible version and will probably hold collimation better. Personally, at 10" I wouldn't even consider the collapsible version.
  3. I would call the missing piece the eyepiece clamp. If the telescope is new I would return it for replacement, if it is second hand your best bet is probably to try contacting whoever you bought it from to see if they can find the missing piece. Unfortunately, I suspect buying a replacement will be very difficult unless you get lucky with someone selling off a damaged Astromaster for spares. Failing that, you might have to buy an entire focuser of approximately the same size as the one on the telescope and fit that.
  4. The best thing to do while using an 8-10" dob is to observe whilst seated. I find that an adjustable drummers stool (the type that spin up and down) is the perfect height for observations at all altitudes. I'm 5'10" so you might find it a little bit more difficult if trying to observe something right down by the horizon but generally that isn't something you do as the atmosphere degrades the image significantly in that scenario.
  5. I found that in my 8" f6 dob the maximum field of view from a 1.25" isn't quite wide enough so I think that rather than spending £70 on an eyepiece that turns out to be slightly too narrow, you should save up for a good eyepiece with a wider field. Personally, I would be looking for something at least as wide as a 28mm 68° eyepiece. If you're in no rush then taking your time also gives you the opportunity to see if anything suitable turns up on the second hand market, which could also help in terms of the budget.
  6. It certainly is. The mount itself is really quite good so being able to put the mount on top of a tripod is an ideal upgrade.
  7. Only the smaller 100p base has a thread for tripod mounting. Fitting the larger bases to a tripod requires some modification.
  8. From previous posts the current telescope is a standard 76/700 reflector so there is definite merit in an upgrade. Given that you've mentioned both deep sky and planets I don't think you can go far wrong with the standard suggestion of an 8" f6 dobsonian, providing that you live in a house with a garden and can store it downstairs or in a shed or garage. If you will have to carry your telescope up/down stairs then something smaller is needed. In this case a 6" f5 Newtonian on an alt/az mount (carried in two parts) is probably the limit. You will also need to budget for additional eyepieces as the ones supplied with your existing scope aren't worth keeping.
  9. I have one of these for my solar scope and wouldn't have considered it for a Heritage 150, I would have thought that it would be a bit too prone to vibration at high power. An AZ5 on the Horizon (assuming the head unscrews) would be my guess for the best reasonably priced option, or for £30 more the heavier but more stable AZ4/steel tripod package.
  10. Brightness of a point source is related to aperture so the 8" should be brighter than the 6". Brightness of extended objects is related to the exit pupil so these should appear to be a touch brighter in the f5 scope than the f6. Additionally, the pds scopes have larger secondaries so that the fully illuminated field is larger. This could result in brighter off axis performance but secondaries are usually sized at the point where people won't notice the drop in brightness at the edge.
  11. I've read somewhere that the optimum is actually 2.4mm but so long as you have something in the ball park you'll do fine. What you need to remember is that this is for observing unfiltered extended objects only. For anything using a filter you need to increase the exit pupil and for objects that resolve as point sources (open and globular star clusters) you can go down to about 1mm. Personally, I think it is much more important to choose your eyepieces based on exit pupil rather than magnification for DSO observation. Choosing steps based on doubling or halving the image brightness works very well. Choosing eyepiece focal lengths based on this is easily done by starting with an existing eyepiece and either multiplying or diving the focal length by 1.4. Using this method both your 13-8 and 8-5 jumps are too big. If I were in your position my choice would be to sell the 8 and 6.7 and replace them with 10 and 7mm XWs, if you are happy with the narrower field of view.
  12. Providing that you have some sort of raised platform on which you could place the Heritage 130p, that is the one that I would choose. The Explorer 130 has no "p" designation, which suggests it has a spherical mirror and I would think that a parabolic f5 mirror would outperform a spherical f7 mirror. Additionally, the mini dob base supplied with the heritage is a good stable mount whilst the EQ2 is on the wobbly side. Given that the two most important things to look for in a telescope are probably a) optical quality and b) mount stability, the option that wins on both seems to be the sensible choice.
  13. You don't "need" one, but you would very much want one as you will certainly get better star shapes in the outer field with one. With regards to collimation, there is only one way in which it could alter the ability for you to reach focus, and that is if you have significantly changed the distance between the primary and secondary mirrors. You could have done this by moving the secondary down towards the primary and/or moving the primary up towards the secondary. The first step of collimation is to centre the secondary mirror under the focuser. This must be done with a cheshire/sight tube or concenter, and cannot be done with a laser. As you have only mentioned using a laser the secondary could easily be in the wrong position. However, the most common cause of not being able to focus a telescope which has previously been focused with no issue is forgetting which combination of extension tubes are required to do so.
  14. This isn't a good test as I believe with the 2" adaptor removed from the focuser the remaining hole is larger than 2" so even an oversized eyepiece barrel will still fit. Careful measurement of both the 2" adaptor and eyepiece barrel is probably the best way to determine which is at fault.
  15. Can you post a picture of the damage here? Depending on how bad it is your best option might be to mask the damaged area rather than replace the mirror. With regards to a replacement have a look in the used telescope section on eBay. There was someone a while ago who was selling parts from telescopes individually, including astromasters, so perhaps there is one there. You could try contacting Celestron directly and see if they are able to supply a replacement, but I've not dealt with them to know how likely this option is. Generally speaking any 130mm f5 synta mirror should fit so perhaps you can find one in the second hand market, but I don't think it is very likely as one telescope tends to have one mirror and they don't usually get separated. Unfortunately, the cheapest option might be to buy an entire telescope.
  16. The thread that I can see has links to the sponsor of this forum, FLO, which is a UK supplier who will deliver to Europe. Of the two barlows suggested in that thread one is a generic barlow sold under the astro essentials brand. If you search on eBay for a 2x barlow you will find many listings for the exact same barlow shipped directly from China to whichever country you live in. The second suggested barlow is sold by Baader. Searching for Baader products on the websites of more local European suppliers should allow you to find it. With regards to eyepieces it is possible that almost any eyepiece would be an improvement. The cheapest option would be a decent Plossl eyepiece, but at 10mm the eye relief will be getting a bit tight so the slightly more expensive generic eyepieces sold as "Planetary" eyepieces would be better. Beyond this, it depends how much you are willing/able to spend on an upgrade. My suggestions for an upgrade would be one of: 8/12mm BST Starguider (sold under different names outside of the UK) 10mm Baader Classic Ortho 9mm Vixen SLV 8.8mm Explore Scientific 82° 9mm Baader Morpheus Routinely changing the extension of the telescope during a session will become tiresome quite quickly. My choice would be to find a barlow that comes to focus without the need to change the extension of the telescope.
  17. This will be your problem, they are quite different heights I think. You need to put the 2" extension in the focuser and then put the self centring adaptor into that. If you put the self centring adaptor straight into the slightly larger than 2" hole at the top of the draw tube your eyepiece will be too close to focus.
  18. The Skysense app and phone cradle are supposed to be good and there are a few people here who have bought one of these sets just to get the app and cradle so that they can reuse it on a different telescope. The LT 114 telescope however, is definitely one to avoid. It has a cheap barlow lens built into the focuser to try to reduce the aberrations from the fast spherical primary mirror. Reviews of this type of telescope typically use the word "blurry". The DX 130 in the same range is probably a much better telescope to observe with and additionally, the DX mount is probably a bit nicer to use than the LT mount. Other telescopes are available, but with a relatively low budget you have to choose between spending the money on the telescope and spending the money on electronic aids to find things. The usual recommended starter binoculars to learn the sky are 10x50, and if you decide to buy some of these the ones I would go for are the Opticron Adventurer T, but looking at the light pollution map for your listed location, I think they might be a bit of a disappointment. What I think you need is a telescope with a large aperture to gather the light from faint stars so that you can then observe star clusters at relatively high magnification to dim the background sky. This time last year the Skywatcher Skyliner 150p would have been ideal for about £200, but covid supply issues have pushed prices up and availability of all telescopes is very patchy. If you are prepared to wait until covid is "over" then maybe the price will come down again, but in the meantime I would definitely keep an eye on the second hand market.
  19. I think this advice may have been misunderstood. The advice in this post is that as the Heritage 130p is a collapsible dobsonian. the telescope itself can be shortened by about 1cm when the barlow is going to be used. Sorry, Neil, but it is actually you who is missing the point. The eyepieces focus when placed directly into the focuser. Putting an extension tube between eyepiece and focuser is completely unnecessary and will do nothing but push the eyepieces out too far so that they cannot be focused. @Lotinsh: What you need to do is to send this barlow back as it does not work with your telescope and look for one in which the upper section is physically shorter as this should mean that the lenses in the nose don't have to be pushed as far beneath the focal plane, or as advised earlier, get advice from other owners of this telescope about barlows which definitely work with it. However, given that you only have the starter eyepieces supplied with the telescope, my first upgrade choice would be to replace those (or at least the 10mm) with something better first.
  20. Yes, I think so. Obviously, it is not as stable as a top end tripod as you are still providing some support but what the monopod does do is to take the weight of the binocular so that you can easily hold them and observe even high altitude targets without (much) strain. Additionally, with only one leg coming down to the ground, you can easily pan around without the risk of tripping over the splayed legs of a tripod. The disadvantages are that you won't be able to share the views with someone else as you can't pass the binocular to someone else without loosing the target, or stop to consult a map half way through a star hop. That particular head is a trigger grip ball head that has an almost unique design that means that the trigger grip doesn't get in the way (of your face) when you mount binoculars on top of it. It has been available for years under a variety of brands but currently the only place I know you can get it is bundled with the Amazon basics video tripod. The trigger grip ball head design allows you to squeeze the trigger to move the head and then locks in position when you release the trigger. With a standard ball head or monopod mount you will find that for any single tension setting you have something that is either too tight for smooth movement or is unable to support the binocular at high altitudes.
  21. I think the best combination for this size binocular is the head from the Amazon basics video tripod and a good monopod that extends high enough to hold the binoculars above your head.
  22. There should not be any grit on the lens by the time you use the "pen" end. The pad is for removal of oils after any solids have been removed.
  23. In practice you probably wouldn't really notice the difference between exit pupils of 4.5mm and 5mm and either is fine. I think that really you want an eyepiece that will maximise the field of view so it is a case of choosing between: 20mm 100° 30mm 82° 40mm 68° In my 8" f6 dob my mono view set is 28mm, 14mm, 10mm and then a 2x telextender to give me 7 and 5. The "missing" 20mm (or 28mm) is the one you can probably skip, the rest I get regular use from. You might find a zoom or more closely spaced fix eyepieces are useful for the higher magnifications where you are hitting atmospheric limits.
  24. Given that the problem appears to be finding objects and a RACI finder is wanted for the new scope to help find objects, I would suggest just buying a RACI finder and shoe for the current scope. This will give you the ability to determine whether the RACI helps or whether a go-to system is required before spending hundreds of pounds on a new set up. Additionally, I would suggest getting an eyepiece around the 18mm mark for observing DSOs that you do find as there is a big gap between the 9 and 32mm eyepieces already owned.
  25. I don't think there is something that is "too advanced", but the problem I think you will most likely encounter is that the telescope is too big. Binoculars are the most grab and go instrument that you can have. If you have the urge to go out, you just pick up the binoculars, go outside and start observing. On the other hand, an 11" SCT requires significant planning before a session. The mount must be carried out and set up, then the OTA must be taken out and put on the mount. Given the weight and bulk of the OTA, lifting it on to the mount is potentially a two person job. Once set up the telescope will need to acclimatise for perhaps a couple of hours before use. An SCT will also require active dew control to prevent the front corrector dewing over. Ideally, an 11" SCT would be permanently mounted in an observatory rather than set up and packed away each time. It is possible that this telescope is your wife's dream scope, but I think that this would have to be something that you discuss with your wife, rather than something that appears to be a surprise gift. Assuming that your wife's interest does lie with the moon and planets, rather than deep space, then I would be more inclined to look at a 5"/127mm Maksutov as a first telescope. The Skywatcher Skymax 127 AZGTi bundle would probably be my personal choice, although the current worldwide stock situation means that you need to find out which telescopes are currently available and adjust your selection accordingly.
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