Ricochet

The solution to that is to buy the 2" Clicklock as well. 🙂 I think they're excellent, and would happily fit them to any scope.

If there's only one part of the scope that needs improving, the chipboard rocker box is the bit you want it to be. 🙂

To start with, you've got the telescope on the mount the wrong way around. The end with the eyepiece is the front and needs to be able to rotate upwards. Once you've done that the cap on what is the right hand end of your telescope in the photos above pulls off so that light can reach the primary mirror at the rear of the telescope. The manual should explain how to use the handset to control the mount. Once you've got that sorted, point the telescope at the furthest object you can see during the day time. Once that object is centred through the eyepiece, adjust the finder scope so that it is also pointing at that object. This should allow you to point your telescope at a celestial object accurately enough to start set up when you take it out at night.

Is the problem the rocker box itself or is the flex in the axis? If it is the former fitting some braces at the joints will probably stiffen things up. If the problem is the az axis I had a bit of play in the az axis on my bresser. The bearing is simply a bolt in the centre with three Teflon pads around the perimeter of the base board. The play between the bolt and the base board meant that the rocker box could slide a small amount as well as rotating. Adding a stack of Teflon disks around the central bolt both took the weight of the scope, making rotation smoother, and removed the side to side play and stiffened things up. If your issue is similar then perhaps the same method will work for you.

The closer an object is to you the further out the focuser has to be to focus. Needing to use the extension during daylight but not at night indicates that you set up your scope during that day using a target that was too close. As a result of this, there would have been significant parallax between the scope and finder, hence it not being aligned at night.

Why are you attempting to collimate a pair of Maxbright 2s? If there is a fault with then contact Baader and they will repair or replace them (the latter being subject to new stock).

Do you mean exit pupil? Exit pupil is related to magnification by the formula Magnification = Aperture / Exit pupil This means that for any given magnification both f7 and f11 100mm telescopes will have identical exit pupils. If you want to increase the exit pupil at a certain magnification it is the aperture rather than the focal length that you must increase. For example if you choose to set a magnification of 200X, all 100mm telescopes will have an exit pupil of 0.5mm, all 150mm telescopes will have an exit pupil of 0.75mm and all 200mm scopes will have an exit pupil of 1mm. If instead you mean eye relief, then this can be countered either by using an eyepiece range with consistent long eye relief or using a longer focal length eyepiece and barlow, although the 4mm planetary you mention fits into the former category. As Mike says, for planetary observing binoviewers are the way to go, providing you get a decent pair and can merge the images.

With the 76dcu, can you remove the smaller of the two OTA sections and screw the focuser directly to the longer front section? If this section can be removed and is the same as the one on the fs60 shown above, then removing the 127mm section of the OTA and adding a binoviewer with an optical path length of ~110mm should leave a telescope that focuses. Whether it is possible to balance the scope without the dovetail impeding the use of the focuser or whether the drawtube vignettes the image is another issue.

Is it coma you are seeing? Perhaps the focuser is sagging a bit under the weight of an eyepiece which would miscollimate the telescope and shift the coma free zone from the centre of the FoV. Coma appears to "point" towards the centre so moving a star around the FoV will reveal where it points to. If it is not the centre try comparing different weight/size eyepieces and see if the position changes according to eyepiece size. If the star image appears to be an oval one side of focus and a perpendicular oval the other side of focus then you could have astigmatism present. As the Heritage focuser rotates you will also need to loosen the eyepiece clamp and rotate the eyepiece to rule out it being inherent in the eyepiece you are testing, and rotate your head to check whether it is inside your eye (more likely at larger exit pupil, see the Televue chart below). If it is a function of your telescope mirrors check multiple times during a session, it could be induced only while the scope is still cooling. If the stars appear slightly triangular then you have pinched optics, and usually overtightened mirror clips on the primary are to blame. However, with just a collimation cap being used so far, I suspect the collimation needs to be looked at in the first instance with a decent cheshire or concenter.

The problem here is trying to compare eyepieces in "hazy" skies. The whole experiment is atmosphere limited and so no real comparison can be made. The field being brighter reveals that the SLV must have higher transmission, but why is the field bright? Because of light from the moon scattering in the atmosphere. Repeat the test in good clear skies and I am sure that the SLV will have a darker background sky with brighter objects because the coatings and baffling are far superior. Coma will be approximately the same in both eyepieces because it is primarily caused by the parabolic mirror of the telescope rather than the eyepiece. Astigmatism, field curvature and chromatic aberration are probably going to be the eyepiece aberrations to look for.

Have you got an outdoor area to observe from? Looking out of a window will degrade the views through the telescope and restrict the area of sky you can see. When you go to the mountain how will you get it there and how far will you need to carry it once you get there? Something from the Skywatcher AZ Pronto range is probably going to be the most suited for your scenario and budget.

Yes. In my experience/opinion you will want a wider field of view with an 8" dob than you can get from any 1.25" eyepiece. If you have a 1.25"-2" adaptor that is threaded for filters you can use a 2" filter with 1.25" and 2" filters. If you buy a 1.25" filter, you will end up also having to buy the 2" filter later. The 24mm ES68 is a nice eyepiece, but in line with my comment above, I would also look at the 28mm or 35mm in that range. With your skies the exit pupil with either should be ok. For comparison my widest field is a 28mm 82° eyepiece.

I've got the 8" dob so not quite the same, but from the same manufacturer and series so some parts are the same or a similar design. 1. All telescopes natively give an inverted image. Those with a diagonal may modify the inversion further, but for astronomical viewing it doesn't matter which way is up. 2. You can use the coordinates with a go to mount, but for manual mounts the dials are too small and too imprecise to be useful. Learning the constellations and star hopping is the way to find an object manually. 3. If you mean a nebula, then yes you will see this if you are looking in the right place, unless you are right in the centre of a city in which it could be possible to have enough light pollution for even Orion to be obscured. The 25mm eyepiece will be the correct one to use for this object. The nebula is actually visible as a naked eye object, and appears as the middle star in Orion's sword. If you have aligned your finder correctly this should make it fairly easy to find. If you mean the actual milky way then no, I can't see it from my home, but from dark sky locations it is visible to the naked eye. All stars (except the sun) are so far away that they will only ever be a point of light in any telescope you can buy. Ursa major is in the north east and Jupiter and Saturn are in the south west so I would think you will need to be on a rooftop balcony with a full view of the sky to be able to see both. The two planets are quite low now, and from my location Saturn is setting by about 18:30.

Remove this 2" clamp from the focuser. You will have to loosen the grub screw with a small hex key (2mm?, there should be one supplied) before you will be able to unscrew it from the focuser. Find this extension Screw the two together, then refit to telescope.

If you do the collimation/locking screws up tightly enough then it might be fine. In any event you can easily check once you get to your site using either the barlowed laser method or by shining a red light torch into the side of a cheshire. Once on site I would only ever adjust the primary.

No. After you have the secondary centred, you must adjust the tilt so that the cross hairs at the bottom of your cheshire intersect with the doughnut in the centre of the primary mirror. Once that is done, you can collimate the primary using a collimation cap. You adjust the primary so that the dark hole in the centre of the cap appears to be in the centre of the doughnut. No. It will make almost no difference aside from slightly modifying the diffraction spikes on bright stars. It is far more important to have the mirrors in the right place. The vane in question is the right hand horizontal one that appears thicker. If this is because the vane itself is twisted you can attempt to straighten it. If this is because you have a wire fixed to that vane for a secondary heater the only improvement would be a thinner wire.

Everything you have marked should be concentric. The only thing that is not concentric is the shadow of the secondary mirror, which is the dark shadow outside of the red circle, which will be offset towards the primary mirror. Try extending the focuser and/or pulling the cheshire out of the focuser until you can see the whole secondary, if it is one like the red FLO premium cheshire that can be clamped at any point along its length.

The secondary needs to move "down" in your picture. You want the gap between the edge of the focuser tube and the secondary mirror to be the same all the way around. If you have a sight tube (included in long cheshires) or concenter you can more easily see where the secondary needs to be using either the edge of the sight tube or a ring with the concenter.

I think the problem is that we need someone to test them side by side to determine if there is any difference in reality. The design of the lenses internally is the same but when the APM line was announced it was claimed that the lens coatings are better. Coatings and stray light control make a big difference in performance so if they are better it would be worth paying the extra in my opinion. Are they actually better in practice? I don't know. You should also note that the eyecup has been changed in the APM version, which may make the eyepiece more or less comfortable to use. However, for planetary viewing I personally prefer to use binoviewers. This necessitates using smaller eyepieces so that you can comfortably get both eyes positioned over the eye lenses. Usually you will need a barlow or gpc to be able to bring the focus point within the range of your focuser travel, which means that long focal length pairs of eyepieces that aren't necessarily well corrected at your telescope's focal ratio will actually be fine. Sticking with the APM brand, the UFF range (60°-65°) are often used for this.

That dob is the one where you have some adjustment on the balance point. What happens if you move the tube slightly "down" from the bearing (so the primary is further from the pivot)? What about at low elevations? Does the nose dive when you put an eyepiece in?

The eyepiece has to be a set distance away from the primary mirror. Because your adaptor adds length to the focuser, you will have to wind the focuser further inwards to "remove" this extra length. So long as your focuser has enough in travel for you to be able to focus your eyepieces, there will be no difference in how you use the focuser compared to using old 0.965" eyepieces.

Anyone who tries that will not see anything. The shape of the primary mirror determines the exact position the eyepiece must be at. If you do not extend the truss poles the eyepiece will be in the wrong position and the only thing you will see will be the inside of the telescope.

Yes, those would work, but you would probably also want a parfocalling ring so that you can set how far the stack slides into the focuser. However, with the cost of that set there is no real financial advantage in buying it over the M54 rings which will solve focusing with both 1.25" and 2" eyepieces.

This is what you need to do, but you may need more than 20mm to bring any 2" eyepieces to focus. FLO sell 8mm and 9mm extension rings. You'd need at least two, but you could email FLO and see if they are able to source any other sizes. The other option would be to see if you can fit a Baader UFC system between draw tube and 2" Clicklock, but this needs careful selection of parts so you end up with the right threads either side of the UFC.

I would get the BHZ, as I think the coatings are a bit better. I don't think you would get much use out of the zoom though, a low power eyepiece with a wider field would probably be a better choice.