Ricochet

Unfortunately, Lee's username showing as "guest" suggests he is no longer a member. However, the focuser in the photos looks like this focuser. You should pay careful attention to the dimensions given in order to work out if changing to that focuser will still allow you to focus.

If you think the focuser might be the issue have you tried: Applying some downward pressure/weight to the focuser while looking through the collimation cap to see if it throws the collimation off Applying some upward pressure to the focuser while star testing to counteract the eyepiece weight to see if the "sweet spot" moves to the centre? Without getting the collimation centred I don't think the shape of the diffraction rings can be investigated as eyepiece aberrations will be seen at he edge of the field of view.

I suspect it is down to the difference in equipment being used. The Vixen HR series has meticulous optical design, expensive glass types, a high level of polishing, top coatings, and excellent stray light control via internal blackening and baffles. The binoviewers and barlow have none of these things. In moments of exceptional seeing it could be that the BVs become the limiting factor, and this is why the HR mono view pulls ahead. My cheap BVs definitely could be better with regards to scattering and stray light control, and I would guess yours might be the same.

Taken in isolation, there is FC in every single XW, but how it presents itself will depend on the telescope it is paired with. There is also a difference in the "direction" of the FC between the short (3.5-10mm) and the long (14-40mm) XWs such that the short XWs will hide FC inherent in a telescope and the long ones will exacerbate it. In my dob, FC is noticable, but not not extreme, and with a touch of off-centre focusing, the field can be flattened if needed. In my spotting scope, which has an even flatter field than the dob, it appears flat to me in the centre 55-60°, with "acceptable" FC building up to about the 65° mark and then in the last 5° FC and astigmatism really kick in. In the dob, the other optical qualities of the 14XW are so good that the FC seems a small price to pay, remember that eyepiece design is a balancing act of distortions and aberrations and every design must have some issues. You could instead look at the similar 14 Morpheus, but we know that the alternative to FC is astigmatism, and in reports we see reports of reduced FC, but increased astigmatism. In your dob, you might find you have the same opinion as me, that the reports of FC are overstated, and the amount of FC is acceptable. However, this telescope has a radius of curvature of ~1200mm, which is quite flat, but you also have an ED doublet refractor that the eyepiece will be used with. This has a much smaller radius of curvature, somewhere in the region of ~265mm, and hence a much more curved field of its own. The combination of this type of scope and a long XW is exactly where you are going to see objectionable FC and so you are probably better off looking at other options. If I was to upgrade my 14XW for astronomical use I think I would be looking at a 14 Delos. Unfortunately, I don't know enough about the 12.5mm APM to hazard a guess as to how it would perform in comparison.

Where does it "bend"? I can't imagine that any individual part is bending, but there could be some flex in the joints. Are you sure that all the connections between different parts are sufficiently tightened? For instance there is a bolt that passes up through the underside of the tripod into the mount head that should be fully tightened. Perhaps a photo showing this bending would help diagnose the problem.

Great idea. The heritage 130p would be a massive improvement even if your telescope had been in perfect condition. Sending the current one back is the right call, it sounds like there must be something seriously wrong with it.

It is definitely worth trying your dad's telescope, even if it is just to confirm what it is that you don't want in your telescope. Even if everything is "wrong" with your dad's telescope, say you don't like the eq mount, setting up the goto, the weight or diffraction spikes on stars, at least you know and we can find you a telescope without those things. Edit. I see I'm a bit late. Have fun with your dad's scope

If you are seeing something like the first image then you are defocusing way too far and not doing a star test. The amount of defocus you need is probably measured in micrometres and will produce a set of rings hopefully like the second image. Having said that, if you've used a laser then this is likely the cause of your problem. If you use a laser for the primary it should be with the barlowed laser method or you will just be doubling any error from the secondary alignment.

Orthos are pretty small eyepieces. If you have a case with pluck foam you will probably find that a 2x2 hole is just about the perfect size to hold an ortho vertically. In the case that you don't have any caps I would get some camping mat foam and put a small square in your 2x2 hole to form the bottom of the hole, and then have a second piece to go on top of the eyepiece. I think that such a foam should be soft enough to protect the eyepiece but rigid enough so that the foam is not pressed into contact with any of the lenses, but a bit of testing would be required to check if this is true with the eye lens, depending on how much compression there is when the case lid is closed.

It looks like the supplied eyepiece has a 56° field so the 30mm UFF will have a slightly larger field, 1.75° vs 1.63°.

At that price I would buy a new one to get the 10 year warranty, which is worth way more than the price difference in my eyes.

So? There is no need for a new focuser to fit in the same way as the current focuser, all it has to do is fit and provide the correct amount of extension to allow you to focus. If all other focusers fit into the tube then you need to measure the inside diameter of the telescope tube and find a focuser that fits that diameter. Teleskop Service are probably your best bet in terms of the number of different focusers that they stock. However, focusers are reasonably expensive and if your telescope has a plastic focuser perhaps it has other parts that are of similar quality in which case it might be more worthwhile changing to one of the 102mm Bresser achromats, which are available from FLO for £219, if you have a mount that is suitable (and if a 102mm achromat is the type of telescope you want).

Some of the Bresser Messier line is sold in the US as Explore Scientific First Light. Unfortunately, there are only a few OTA-only options and looking at the images, it appears that which focuser you get depends on which mount you buy the telescope with. In fact, in the 102mm Refractor listing, even the telescope changes from the f10 to f6 version with one of the mounts.

I would still go back to TS with your issue and see if they can provide you with a better pair. I have a pair of generic, Starguider branded, binoviewers and they are collimated at all dioptre positions. The TS ones are supposed to have superior eyepiece collets, if you cannot adjust the dioptres then this advantage is lost.

You need to remove the mount head from the tripod by unscrewing it anticlockwise. Once you have done that the central bolt will be exposed. I believe that the tripod in question only has a 1/4" bolt so you will have to buy a 1/4" to 3/8" adaptor and then you will be able to screw the star adventurer to your tripod. Watch the following video for an idea on how the head is removed.

If Jupiter looked like an amoeba then I think it is likely you are not in focus. To focus you must turn the focuser to make the object as small as possible. Jupiter should appear as a small disk with a couple of stripes across it and up to four moons orbiting around it, each one looking like a small point of light.

Do you know if the FEs can be easily disassembled or are they sealed like the ES eyepieces? I've got the old Meade branded version of the 1.25" 2X FE and I solved the reflection issue by flocking between the two lens groups.

How far will you be carrying it? An 8" dob can be carried for a few metres over flat ground in one piece but any further, or uneven ground and you will probably want to split it. You will probably also want a second trip for a stool and your eyepieces.

You should attempt to get the secondary in position using the collimation screws on the secondary. If you follow the astrobaby guide there are two steps to secondary collimation. If you cannot get the two steps to coincide then you may need to adjust the spider veins, but we're talking maybe half a turn on the thumbscrews I would think.

This can be done with any barlow where the lens cell can be unscrewed from the body and screwed to the eyepiece threads. The actual multiplication factor depends on the distance between the barlow and eyepiece lenses so the actual amount will vary from eyepiece to eyepiece. I have both the AC555 and the AC666(?), which seems to be the AC555 with an additional body to make it a "2x" barlow. I use the AC555 with my (Starguider) binoviewers where it functions as a 2.1x barlow and requires ~30mm of in focus compared to monoviewing.

For observing from a balcony I would suggest only considering alt/az, not eq mounts. I would think that the way an eq mount changes the position of a telescope would be a bit of a nightmare on a balcony. I would also consider whether you can construct some sort of pier towards the front of the balcony rather than using a tripod, and fit an alt/az head to that. Moving the telescope forward those couple of feet could make quite a difference from a small balcony. Obviously, this won't work with a Newtonian where you need to stand at the front of the tube, but I think those have been discounted already.

I suppose if you have a particularly sloppy focuser it might be a problem, but in that case you could never collimate accurately. In my dob the results this way are indistinguishable from the result of using a star, and you can see the collimation while you make adjustments.

If you are doing it as in the picture above with the hole at the bottom of the focuser then I think you want it as precise as possible as you will be using the hole to centre the reflection. However, if you have a laser collimator with a 45° angled face there is no need for the cut out. Just angle the face so that you can see it from the primary end and the reflection will show on the face of the collimator, and you can centre on the hole in the centre of the face. This is shown in the image below. In the flesh the shadow is seen as an even circle, but for some reason it did not come out properly in the photo.

It basically turns the laser into a torch which illuminates a patch in the centre of the primary. So long as the secondary collimation is close enough that the doughnut is illuminated, you will see the shadow and be able to use it to collimate. I think because the beam is diverging, small changes in secondary collimation will not alter the angle of the rays hitting the centre of the primary and so the reflected image is the same.

For a standard 8" or 10" dob you need a space about two feet square and four feet high, which is actually less space than for a tripod mounted scope that is stored "assembled".