Ricochet

I suspect it would be too heavy. Manufacturers have a habit of overloading their mounts and the biggest AZGti combination uses a special lightweight 130ps, which indicates that they couldn't fit a standard 130p on it.

I suspect you might be seeing coma. What happens if you move the position of the star around then field of view? Does the direction of the spike change? For a properly collimated scope there should be no tail when the star is precisely centered, with the tail pointing away from the center when the star is not centered. If you find that the tail directions all point away from a star position that is not in the centre of the field of view you need to recollimate your scope.

So long as you have enough room start the hole with a good sds drill and short drill bit, you can then drop longer drill bits into the hole, connect the drill and continue drilling. However, with the cramped conditions the drilling will be difficult. Your builders will probably have to take it in turns drilling.

This sounds way too thin. How deep does the existing pier foundation go? If deep enough I would be more inclined to drill down into the existing foundation and epoxy long rods into it to bolt a steel pier to.

I would consider the SLVs as "optically better" than the Starguiders. They're sharper, with less scatter and no reflections (except some old ones, apparently). The only thing the Starguiders have over the SLVs is the extra 10° field of view, so it depends how much stock you place on that feature. Personally, 50° isn't wide enough for my taste (except for solar, where I use SLVs), so I see where you're coming from in that regard. In terms of image presentation, my SLVs, Delites and XWs all feel very similar, just with different fields of view.

No, the ST120 is too big for the AZGti For Astrophotography the HEQ5 is the minimum recommended mount. The EQ3 might just about be ok for visual but I've not used one to know. Refractors can also require collimation. Newtonians tend to require it more often but I suspect most people don't do the collimation screws up tightly enough. The ST120 is a fast achromat. This means it will have lots of chromatic aberration and be suitable for low power, wide field views but not lunar/planetary or astrophotography. Visually, on those low power views the ST120 might be better than the 130PDS. If you want a Skywatcher refractor for lunar/planetary or astrophotography then take a look at the ED Pro range.

One of the standard beginner's astrophotography setups is the 13PDS on the HEQ5 mount so that would be a good choice if you want to progress onto astrophotography. However, be aware that it isn't just quickly swapping an eyepiece for a camera and snapping whatever you're looking at. A single image can be comprised of exposures taken over a whole session or even multiple sessions. The goto eq mounts required for astrophotography are also quite big and heavy so you may prefer a second smaller set up for visual. If goto is a requirement for visual too perhaps look at the AZGti options, or without goto you could mount a 130PDS on an AZ4.

Centralisation isn't strictly necessary. If it clamps squarely and repeatedly in the same position then you can just make sure to always put the clicklock in the 2" clamp at the same angle and use collimate to that point. If it isn't repeatable or it is tilting the laser and/or eyepieces then I would try a different 1.25"-2" adaptor and if confirmed as the issue talk to Baader about getting it replaced.

I would start by looking at a 6" f8 dob. FLO sell several versions: Stellalyra Skywatcher Bresser

Exactly. As the optical axis and the mechanical axis of the telescope don't need to coincide, all you have to do is to be able to get the secondary mirror under the focuser and then collimate from there. However, the squarer that the focuser is, the easier it is to collimate the secondary, which is why I shimmed mine a bit.

I'm not entirely sure what you're talking about here but I suspect that you may be trying to do something you've seen in the video that isn't possible with the Bresser focuser. If you can wind the focuser though the full range of travel with it always pointing at the same spot then as far as I know there aren't any grub screws you should be touching. I've shimmed mine with washers because there are no "squaring collimation" screws. The small grub screw (hole) that you can see in the side of the focuser base plate on the left of the photo just holds the focuser to the plate as far as I can tell and the grub screw further up the focuser to the right of the photo controls how the drawtube runs in the focuser. No, I just drew a cross on the side with a pencil. I may have even drawn it on some masking tape that I later removed as squaring the focuser only ever needs to be done once. If there is only a slight error you don't ever have to do it as you can just shift the secondary a bit. So long as the secondary is under the focuser that's all that matters.

What part of it was it that caused you the most trouble? Was it the OTA itself or the EQ mount and tripod? I would be inclined to look at alt/az mount options that use a 3/8" threaded mount so that you can pack a much smaller photographic tripod. The Skywatcher Pronto, AZ5 and AZGti ranges all fit the bill.

There is no such thing as a filter for general observing. A CLS might have been an option ten years ago but with the move to LED lighting they are less effective. Your choice of filter depends on the type of object you are observing. As a quick summary I would say: Moon and planets: Neodymium, the Baader one if you can afford it. Star clusters (open and globular): More magnification, so long as you keep the exit pupil at 1mm or higher, and the cluster fits in your field of view. Galaxies: Sometimes a CLS seems to help a little, but really you need to get to darker skies. Emission Nebulae: UHC and OIII filters. From a dark site UHC performs better on a larger number of objects, but with increasing light pollution the tighter filtering of an OIII becomes more valuable. Filters are the one item where going for a top end product 9e.g. Astronomik) really pays off IMO.

Just sit the mirror in a bowl of water and it will loosen. Mine loosened and moved the first time I washed my mirror and had to be replaced.

Loosen the clicklock slightly so that you can rotate the laser in the clicklock. Rotate the laser and watch the dot. If it stays on the same spot the laser is ok, if it draws a circle the laser needs collimating. If the laser is OK move on to the clicklock. Loosen the 2" clamp a touch and rotate the clicklock. If the dot stays on the same point the clicklock is OK, if it draws a circle the clicklock clamping mechanism is tilting the laser. Also try unclamping the clicklock to check for repeatability. You should find that the laser always hits the same spot when clamped, If the clicklock is OK, move on to your 2" clamp. You won't be able to check for rotation here but you can check repeatability. If you have a clamp with more than one thumbscrew try different screws and see what happens. If you've got the standard Bresser Hexafoc 2" clamp this is one of the places where your problem lies. The inner profile of the clamp is 2mm fixed - 8mm compression ring - 2mm fixed. That lower 2mm fixed section will always coincide with the location of an undercut, such as the one on the clicklock, so that the top fixed part of the clamp inner barrel becomes a pivot against which the compression ring tilts anything with an undercut. The solution here is either to change the 2" clamp or to change your 1.25"-2" adaptor to one that is smooth sided and never use any 2" eyepieces with undercuts. My OTA is also slightly oval and to compensate I have added a couple of washers under two of the focuser faceplate fixing screws to get the focuser pointing closer to the correct point and then tweaked the secondary position by simultaneously shortening and lengthening the up/down spider vanes to get the secondary perfectly under the focuser. Having the secondary perfectly centred in the OTA is just a starting point, and not required for collimation.

If you want grab and go I think you need to go with a 102 option, or even a smaller ED scope, that can be stored set up on the tripod and carried out in one go. I don't think that a 120 frac will be any more grab and go than your 150 dob. Edit: in fact, why are you storing the dob base in the shed and the OTA indoors? If you store the OTA on the base in the shed you can just carry the whole scope out as one piece and there's your grab and go scope. That's what I do with my 8" and set up time is less than a minute.

In your Skymax either will probably be ok, but if you ever buy a faster telescope the ES68 will be significantly better, so long as you don't need to wear glasses when observing. As far as I am concerned the options you should be looking at are the ES68, the TV Panoptic and the APM UFF.

Using an OAG for astrophotography requires careful choice of spacers to ensure that the main camera and guide camera are both in focus at the same time. When observing visually, different eyepieces have different focus points and you would be unable to use the telescope focuser to focus the eyepiece without changing the focus of the guide camera. The only option would be to fit a helical focuser to the diagonal and use that to focus the eyepieces instead of the focuser. As far as I am aware, these types of focusers tend to have limited travel and so you would be limited to eyepiece ranges that claim to be parfocal, and would be unable to use items like barlows and binoviewers that can change the focus position significantly. The way to get around this issue would be to use a separate guide scope instead of an OAG, which is basically what Starsense is. If you want to try to save yourself the cost of buying a Starsense unit I would be inclined to try just manually running through the alignment procedure when using the scope visually as you don't need the ultra precise guidance that you do whilst taking long exposure photographs.

There may be companies that will insure that amount for loss, but when you dig into the terms and conditions every single delivery company excludes anything containing glass from damage insurance. When posting a scope the only insurance against damage is the quality of packaging that you provide. Double boxing and decent "fillers" inside the inner box are a must.

F6. From what I recall, only the central 1/3 was useable.

Yes, that's the one.

As far as I know they are the old 66° gold line eyepieces in a nicer housing. I had a 15mm gold line thrown in with a second hand scope and it was the worst eyepiece I've ever looked through. Apparently the other lengths are better though.

Correction wise, they should do pretty well. Essentially they are all something like a 20mm Plossl with a barlow in the nose so if you've got a 10mm Planetary then it's like a 20mm Plossl and 2X barlow. If you put that into a fast f5 scope then so far as the "Plossl" part of the eyepiece is concerned it is in an f10 scope, which is still quite slow. As you go shorter it get's more extreme, with a 5mm Planetary "seeing" an f5 scope as f20. This is the same design method in similar eyepieces like the BST Starguider and Celestron X-Cel LX. Where the Planetaries fall down is the same as with other cheap eyepieces; transmission, scatter and stray light control, which will impact the image in all scopes irrespective of speed.

Start with a 24mm Explore Scientific 68 to max out the field of view, then 12mm and shorter BST Starguiders or ES82s.

If you want to see deep sky objects then aperture is king and this pushes you towards the 8" over the 6". There are three "standard" dobsonians generally available, the 6" f8, 8" f6 and 10" f5. All three of these have the same focal length, so they are the same height, and have approximately the same size rocker box so they all take up the same amount of space in storage (assuming stored vertically in one piece), all can be transported with the OTA across the back seats of a car with the rocker box in the boot, and all are best used with an adjustable height observing seat. As you increase in size, there is an increase in cost, but also an increase in weight. If you store your dob in a shed or similar location and only have to carry it over flat ground then the 6" is a 1 part carry, the 8" might be a 1 part carry depending on your stature (it is for me) and the 10" should definitely be carried in two parts. I am sure people will respond that they can lift their 10" in one piece, and I know if I had gone for a 10" I would be tempted to too, but you really shouldn't. If you will need to carry the telescope up and down stairs then all of them become two part carries and fitting decent handles to the OTA should be looked at. The smaller and lighter the telescope is, the more likely you are to use it and this isn't taken into account often enough. With regards to the view through the telescope, when viewing planets, resolution and optimum magnification scale with aperture (diameter of the mirror) so the 8" is a bit better than the 6". However, the 6" being f8 over the 8"'s f6 means that it has a proportionally smaller secondary so there is less diffraction from the secondary and this will mask the difference between the apertures so in practice you would probably find that the difference in planetary performance is not that great. However, when it comes to deep sky objects we are interested in the light gathering capacity of the telescope, which scales with the square of the aperture. In this case, going for the larger telescope will allow you to see dimmer stars that are invisible in the smaller telescope and it will also allow you to view extended objects at a higher magnification with the same image brightness, which makes them easier to see. In this case what you really want to do is go for the biggest aperture that you can easily get out/put away as this will be the scope that you get the most use out of. For me the 8" fits the bill perfectly. If it looks like it might be clear that evening I can get it out to cool on the off chance as it is no hassle to put it away again if it clouds over. Similarly, if it is unexpectedly clear and there is a half an hour window to observe in I can get the telescope out and be observing within a couple of minutes.