Astronomist

Have you actually measured the angle of the spider vanes? There may be a manufacturing flaw, although the quality of the JOC dobsonians is generally very good. as long as there are no issues when collimating I would think that this would be no big deal anyway. clear skies Harry

Thanks for your replies, I have not had any clear sky yet to test the insulation, great scope by the way AstroKeith, like the gold foil, very space age! lol I saw a thread something like that once in the refractors forum on CN. clear skies Harry

yeah that definitely sounds like pollen to me.

pollen does sound like a likely explanation, you may not have noticed it until it caught the light at an angle.

Hi all ( if this is the wrong forum I do apologize ) I am considering wrapping my 10" Dob in some silver foil insulation material that I have left over from a DIY project. As I understand it this should stop dew formation on the tube, improve thermal stability, and make the tube less cold to the touch on those chilly winter nights. Is this a good idea? are there any disadvantages that I haven't thought of ? thanks in advance, Harry (astronomist)

It could be dirt deposited in condensation, but that wouldn't explain the ring shape. What colour was the ring?? kind regards Harry

if you can afford to go larger the Opticron Oregon 20x80 is within budget and gets good reviews. The astronomical views at 80mm are great, but hand holding is not really an option. ( I do not have this exact model, I have the Bresser spezial astro 20x80 which is broadly similar ) https://www.firstlightoptics.com/all-binoculars/opticron-oregon-observation-20x80-binoculars.html

I am also from Wiltshire ( Salisbury specifically ) so am quite close to Cranborne chase- its Bortle 4 according to cleardarksky.com. unfortunately it does seem to always be cloudy on new moon ( and every other phase of the moon ). kind regards Harry

in either version of the SW 150 the BST starguiders should be fine, I had the 5mm, 12mm, and 25mm in my 10" F5 before I upgraded. they are good eyepieces but ,as Wulfrun says, I found the 25 showed a little aberration in the outer 20% or so of the field . I also have an SR 4mm similar to the ones that come with the firstscope. I get it out sometimes to make me appreciate my current eyepieces more.

nice work! where did you get the motor/gearbox assembly or is that 3D printed also?

I just received a new telrad base. I broke the old one in a 'DIY accident'.

Update: having disassembled my scope and measured the cell it is apparent that the disappearing clip is caused by the fact that the mirror has 1-1.5mm lateral movement space around it to avoid pinching the optics- the mirror settles into whichever side of the scope faces down, causing the upper mirror clip to overlap the mirror by less. I certainatly don't find it causes problems with collimation. I hope this is helpful

oops , sorry if those photos are too big.

I have the 10" version and have noted the same thing, on closer inspection it seems that the invisible mirror clip overhangs the mirror by slightly less than the other 2 . I will try to upload a photo but I am new to the forum. . . . the second photo should show the invisible clip.

would it still do the astrophotography mode thing if it was attached to a telescope? incredible image by the way, a cut above my feeble attempts at imaging using my Nokia held up to the eyepiece.

Don't know about 12" Dobs but I found my 10" was not all that much different to my friend's 8" F6 in a side by side comparison. obviously the DSO views where a little brighter and the planets maybe a tiny bit more detailed, but in my area the seeing is usually the limiting factor anyway. If you are looking for a significant improvement 12" is probably the way to go, although never having used one I don't really know how much less portable it is regards Harry (stargazer_3000)

incredible! all the more impressive considering the lack of tracking! thanks for posting

If by 'infra-red' you mean night vision then these might be what you're looking for- but you will need a very substantial budget. https://www.nightvisionstore.co.uk/pvs7-gen-3-night-vision-goggles-c2x14702529 maybe I have misunderstood???

Thanks for your advice, looks like I'll be buying the 28 UWA when funds allow. . . . . unless I can budget for a 31mm Nagler 🤣 🤣🤣 regards, Harry (Astronomist)

Hi everyone, long time lurker here but this is my first post, so if I have done anything wrong please do tell me. Wondering if anyone here has experience with the Omegon redlines in shorter F ratio scopes, I was considering the 32mm for my 10" F5 dob but have read mixed impressions of them over on CN, maybe better to spend a little more and get a 28mm nirvana clone. https://www.astroshop.eu/eyepieces/tecnosky-eyepiece-uwa-82d-28mm/p,76428 https://www.astroshop.eu/eyepieces/omegon-redline-sw-32mm-eyepiece-2-/p,33240 thanks in advance, Astronomist