Jump to content

740427863_Terminatorchallenge.jpg.2f4cb93182b2ce715fac5aa75b0503c8.jpg

JulianFR

Members
  • Posts

    322
  • Joined

  • Last visited

Posts posted by JulianFR

  1. Hi all ... I've been using an AZ4 mount for a while now with my SW Skytravel 120. Recently the altitude clutch has become quite ineffective... no matter how hard I tighten it with the clutch wheel, the telescope will tilt up and down... so it won't stay fixed on target. Even with no scope attached I can tilt the axis using the mount's handle.

    In retrospect I wonder if the 120 scope is actually too heavy for the AZ4...

    My question is, can the altitude clutch be fixed/adjusted to make it work effectively again? Is there anything I can do as a non-technical person to service the mount's clutch?

    Many thanks in advance, Julian

     

  2. Just an update ... I followed advice here and adjusted the secondary outwards/ away from the primary ( a lot!) and also checked and adjusted the vanes ... and at !last I got recent collimation ? I tried it last night and tonight and the results were good, with sharp views of Jupiter n particular.

    The the trickiest thing was managing the EQ4: it's the first equatorial mount I have owned and I (and the scope) were tying each other in knots. There must be a technique to this 

    !

  3. Thanks for the replies. I did use a pinhole collimation cap, as well as a Cheshire - and the offset was the same. I  removed the collimation cap for the photo to make the image clearer and easier to take.secondary mirror centred.jpg

    Re the f number, the scope is f5 and I know from Astro Baby's collimation guide that this means there will be an asymmetrical view. But my image seems quite extreme ... and Astro Baby used an image of her own scope, which is the same as mine, that appears to be well centred (attached).

    Because I'm appallingly cack-handed I would prefer not to remove the whole secondary assembly unless I have to ?

  4. Hi ... I've been away from astronomy (and Stargazers Lounge) for a couple of years for various reasons. I'm back now and have a problem with a Sky-Watcher 200p reflector on an EQ5 that I have acquired 2nd hand. And the problem is ... yes, collimation.

    The issue is, I think, with the secondary mirror. It seems to be misaligned because I can't seem to get anything on the scope collimated (I never was an expert collimator). Please see the attached image: following Astro Baby's advice I put (pink) coloured card in front of the primary mirror to highlight the position of the secondary. Looking down the focusing tube the secondary (pink circle) seems to be way off centre and appears to be nearly touching the outline of the focusing tube on the right-handed side. The shape of the secondary in the image seems to be pretty circular ... but it seems to be in the wrong position.

    I have tried adjusting the secondary's locking screw but that didn't change its off-centre position. I have also fiddled with the tiny Allen bolt adjustors ... but I don't want to fiddle anymore!

    So, any advice on how I can centralise the secondary as viewed through the focusing tube?

    Many thanks, Julian

    20160520_164105.jpg

  5. Charic ... Thanks for the comments. I'm one of those that likes the 15mm BST. Re the BST unscrewing , I've found that on the barrel end (the bit that goes into the focuser) rather than the eyecup end ... And it's happened when I've attempted to unscrew a tight filter. It's been no big deal. 

    Alan ... I'll look out for your review and will be interested to read what you think.

    Paul ... So at least it's not just me that has found it a difficult EP. But like you I will (as I said before) persevere with it. I WOULD like to enjoy it as much my 24 and 34mm MVs.

  6. Although the core of my eyepiece collection is BST/Starguiders I have two Maxvisions (24 and 34mm, the re-branded Meade models), which I really like. So for my birthday in June I thought I would buy a 16mm Maxvision, although as I already have a 15mm BST. But it's a Maxvision, I thought, so it is bound to be better and will replace the 15mm BST.

    Wrong. For me at least.

    I have been very disappointed with the MV 16mm sadly and I wondered if anyone else has this model. Maybe it's just me. 

    The fundamental problem is that I have to get my eye right up to the EP to get a half-decent view. In other words the eye-relief one't good. And then the field of view seems very constricted. It actually a bit like looking through a higher power Plossl. I've had one of those (another buying mistake!) and didn't like it. In fact the 15mm BST is much more comfortable to use... More comfortable eye-relief and the field of view just seems better. If the the MV is better optically that is well and truly hidden by its shortcomings... As I experience them at least.

    Build-wise it is like a mini-version of the 24 and 34mm MVs, but even so it feels lightweight, and less solid than the BST... Not the same as its quality-feel larger MV siblings. Also the end of the EP unscrews when I twist up the eyecup ... Something the BST is prone to as well, though not the larger MVs . 

    So, really a disappointment. 

    • Like 1
  7. Strange that if they had been where I would have expected them I would have recognised them as the Pleiades straight away but because they were just rising above the horizon I was confused.

    There is something dramatic about the horizon. I remember seeing the top half of Orion rising above the E horizon once and it seemed oddly spectacular (to me anyway).

  8. I'm embarrassed to ask this as I'm sure it will be obvious to everyone except me :-(

    I was out last night with the Dob (first time for ages... And a beautiful night it was too!) and around 2.15 I noticed a bright patch of stars rise above the treeline/horizon, roughly in the NE. I could not identify much else around this patch (ie the rest of a constellation).

    Through 10x50 binoculars this patch of light was a beautiful jewelled nest of bright stars ... And actually it looked better and more condensed through the 10x50s than through the wide 34mm and the Dob, which showed only a portion of this lovely conglonerayion.

    So what did I see? I don't have access at the mo to Stellarium to run back what this was. I've looked on star charts and my planisphere but, to my shame, I just can't work it out! Was it a bit of Pisces rising? Or Taurus (the Hyades)?

    I'll kick myself when someone tells me!

  9. That's very helpful both, thanks for the information. I see the Binocular Sky link mentions the Helios and the Strathspeys. And I can now certainly see the value of nitrogen purging.

    I'm leaning towards the Strathspeys... I like the idea of the individual focusing (I struggle a bit with centre-focus/dioptre arrangement). But does anyone know if there is much of a difference between the Waterproof and the more expensive Marine models, with astronomy in mind? They seem to have identical specs, although externally they look different.

×
×
  • 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.