Peter Drew

If you are using a white full tubed Newtonian it is worth applying externally a patch of flocking opposite the eye not in use.

Went outside at midnight, very bright silvery-white Moon with Saturn sharing the scene, sometimes naked eye is all you need. My "good" eye, following my recent cataract operation provided a really crisp view, I have just received notification that my other eye will be done on October 10 so binoviewing should be up to full strength this coming season. 🙂

To remove the corrector plate, just undo the screws round the ring that holds the corrector in place and the corrector can be pulled out. As most have said, before doing anything mark the position of the corrector so that it can be replaced exactly as before. When replacing the retaining ring screws just use finger tight action so as not to distort the glass. Good luck. 🙂

Could be a 6" Seben "Big Boss" Bird-Jones. What does it say on the sticker near the bottom end of the tube? 🙂

Subscribed. 🙂

The good news is that things can only get better! Most of us have gone through these issues to some extent in the beginning and the advice is to not invest further money towards this telescope. With practise, using the telescope will become a little easier, it will never be a satisfying experience though it will stand you in good stead eventually with a better one. Almost any Dobsonian mounted model will alleviate most of your frustrations. Keep at it, it will be worth the effort. 🙂

I agree. My advice was on the grounds of "if all else fails". The OP is in Canada and may not wish to send his telescope abroad.

The collimation of a triplet does not necessarily mean tipping of the lens stack as with a doublet. Radial displacement of a component of a triplet, particularly the central lens can produce the problem mentioned, I have corrected a few triplets based on the procedure I described and offered the advice if there was no alternative other than DIY.

Yes, there is a set of three collimation screws for each lens element. The fact that your laser image is centred further points towards collimation of the objective being slightly out. as commented by Phil, if you are happy enough with your images perhaps best leave well alone. 🙂

Just had a look at the spec of the GT81 and noted that it is a triplet. The centre component is very sensitive to alignment, if you have to attempt collimation I would suggest trying this component first. Very small adjustments would be needed as the apparent collimation is not too far off. Back off an adjustment screw a fraction to start, tightening in the first instance could chip the edge of the lens. 🙂

If this is what you are seeing visually at image "C" then that definitely shows alignment error due either objective collimation, focuser alignment or image train sag. My money would be on the objective. No sign of pinched optics. Try a laser in the eyepiece holder and see if the beam exits centrally through the objective, this will confirm or eliminate focuser problems. 🙂

Usually age related and one of the annoying things you have to put up with. There are medical interventions to mitigate the problem but these are not pleasant apparently. Using binoviewers seems to reduce the impact, if there is one particularly bad one in the centre of your fov, looking to the side and then quickly looking forward again can displace the floater for a couple of seconds before it floats back. 🙂

It could be that the singlet component has different external curves even if they look the same, might be worthwhile swapping them round if you haven't already tried this. 🙂

It's funny how the date affects telescopes. In 2024 a Bird-Jones telescope is often derided but if you could time travel that telescope back to the Galileo era it would be hailed as the World's finest telescope. 🙂

The 127EQ is one of the Bird-Jones design, it has a correcting lens fitted to the focuser tube. It is likely that this lens has been skewed due to the fall and this would probably affect the image regardless of how good the collimation has been done. Welcome to SGL. 🙂

A brief half hour last night, thin cloud in very wide streaks. Saw one Perseid below Ursa Major. A very bright flare from a satellite passing under Cassiopeia travelling North at 11.50pm. Saw five Perseids the previous night during a similar time period. 🙂

I would be wary of purchasing anything from Coronado until their trading future is settled. Coronado was taken over by Meade and Meade has apparently ceased trading. Neither your Mak or SCT are really suitable for Ha solar viewing although this is possible, however you stop the apertures down you will still be subject to the native focal length which will result in very high focal ratios. The cheapest option to get into Ha solar observation would appear to be a Lunt 40 telescope, 40mm is perfectly adequate to see the main Ha features and will not require any modification or compromises that could arise with a mix and match approach. 🙂

Had a quick look out before hopping into bed and caught the bright Perseid that Paul mentioned.

If the mirror is really dusty just give it a clean in the first instance, lots of advice on how to do this elsewhere on this forum. After cleaning, hold the mirror in front of a bright light and see if it shows through. In general, if you can see your face clearly in the mirror it's still serviceable. 🙂

Plus part of the parhelial arc above the right sun dog. 🙂

www.astronomycentre.org.uk

What a disappointing attitude to display a fine looking telescope. I have a similar one less the pair of stabilisers, Patrick was right about the mount! These telescopes were often assembled from parts offered by small outlets of the period so may not have a makers inscription.

A large portion of my star map usage over the years. Sad to lose him but what a legacy! I think anyone who leaves such a worthwhile legacy must rest in peace.

Using a sharpening stone or something similar produce a bevel on the chipped edge similar to the one on the mirror. Use strokes at 45 degrees downwards away from the mirror surface and use plenty of water. 🙂

I have often asked an audience how many stars can be seen with the naked eye on a clear dark night. The truth is none. They are so far away that only the light from them can be seen. An analogy is being able to see the light from a torch several miles away but you can't see the torch. So what you see is just where the stars are. Or are they? They will have changed position since the light started off. 🙂