John

Looks like the one that I had and the one that @Stu had for testing are drawing admiring glances

I could not get to the show as planned so I'm sorry that I missed out. Hope all those attending had a good time though

Get back to the vendor and I'm sure they will put things right. The dew shields on ST80's do slide off quite easily though. They are just held in place by thin felt pads so you could add slightly thicker felt. I don't think there are special imaging solar filters but it should fit the scope that you specified it for.

Sometimes people use tube rings with these scopes so that they can rotate the tube so that the finder is in a more convenient position:

If you want to try a low / wide 2 inch eyepiece for a smallish outlay, this has just popped up in our classifieds and seems a decent deal:

Sorry you could not make it Dave and hope the back gets better soon. If it's any consolation I didn't make it either

It is an issue with equatorial mounts. I believe that having the eyepiece pointing at the ground when the scope and mount are pointing toward the pole star minimises the issue although it does not remove it completely. This may sound odd but I think it might help. Like Robin, as I don't image, I use alt-azimuth mounts for the vast majority of the time for this reason.

For astronomy I feel that the ones that are not fully corrected generally deliver better image quality (there are exceptions but they are very expensive). You just need to get used to the reversed left and right.

I have owned and used a Hyperion Aspheric 36mm. I was disappointed with it's correction to be honest with you, even in quite slow scopes such as my ED120 F/7.5. I didn't have the chance to compare it with the Aero ED 30 though but my guess would be that the Aero ED 30 is better corrected. I did not keep the Hyperion Aspheric 36mm for very long.

Does the prism diagonal give a correct image like the eye sees it or one where up and down are corrected but left and right are reversed ? Usually, the ones that give a fully corrected image have a flat top on the prism housing:

The edge distortions will depend on the spec of the scope that the eyepiece is used in. In an F/10 or slower scope, most eyepieces are sharp to the edge of the field of view. At F/4 most will show some distortion. Scopes also have some distortions of their own to add to the mix eg: coma with a newtonian and field curvature with refractors. I don't know what spec of scope Louis D's field photos were emulating. It would be interesting to know

The 30mm Aero ED's are better corrected at the field edges than the Panaview although they won't be perfect at F/6. They (the Aero ED's) can be found for £50 on the used market.

I would probably choose a Rigel Quickfinder to go on a refractor - it's "footprint" is much smaller than a Telrad. That said you can mount Telrads on such scopes: Some people put the finder base on the tube rings. Here they have modified the base and use a finder shoe to hold it to a tube ring:

Thats me in my avatar. Here is a larger version:

In pure optical terms the differences might be slight or non existent . Barlows can vignette the field of view of eyepieces with wide field stops and push the eye relief outwards a bit. Powermates and Telextenders don't have these effects. There are other telextender options which cost less than Tele Vue though. The Explore Scientific 2x Focal Extender is one that is very good.

With the F/6 focal ratio of the 200P dobsonian you don't really need Tele Vue quality to get great results. If you eventually move to something a little faster which typically you need to do to get larger aperture dobs / newtonians, the edge of field correction becomes more important. The Morphus reportedly is pretty good though, even in faster scopes. It was not around when I was building my eyepiece collection. Scopes tend to come and go but a good eyepiece set can stay with you for life !

My regular eyepieces are Tele Vue and Pentax but I've owned and used a few BST Starguiders and I think they are really pretty good eyepieces for their cost (£50 new, £30 or so on the used market). The BST's are a significant improvement over the stock eyepieces in my opinion. Going beyond them to, say, £100 - £200 apiece eyepieces and the peformance gains are much smaller. Your £200 would get you 4 focal lengths in the BST Starguider range, or 3 plus a barlow lens. The Baader zoom is pretty good as well but the field of view at the 24mm focal length is limited so you would need something like a 30mm NPL plossl to get those wider / low power views and also something shorter such as a 6mm for the higher powers that the scope is capable of. Budget blown a bit I suspect ! The Powermates are superb but one swallows up most of your budget and Powermating the stock eyepieces is not going to turn them into great eyepieces I fear.

I have one of the older Skywatcher steel tube tripods which has 1.5 inch diameter legs. The lower section is about 1 inch in diameter. It's quite sturdy - much better than the aluminum tripods. Its the one under the AZ-4 in this photo:

I don't recall the Bresser 127-L that I had producing any really objectionable CA Rob. A good 5 inch achromat I thought

I used a William Optics Minus Violet filter with a 150mm F/8 achromat refractor a few years back and compared the views of the moons limb with and without the filter. I found that the filter reduced the visible violet fringe by around 50%. The flip side was a pale lemon tint to the overall view. The CA was still visible but it was reduced.

The Baader Semi-Apo filters get decent reviews and seem work well: https://www.firstlightoptics.com/baader-filters/baader-semi-apo-filter.html The Baader Fringe Killer does a similar job: https://www.firstlightoptics.com/baader-filters/baader-fringe-killer-filter.html As does the Baader Contrast Booster: https://www.firstlightoptics.com/baader-filters/baader-contrast-booster-filter.html I believe the Semi-Apo produces the most natural tint to the view wheras the other two do introduce a slight hue to the image. Here is some further discussion on these:

I don't consider a scope really big until you can put a researcher in the secondary cage:

Big dobs are fun What could possible go wrong here ?

The largest I know of in Europe is this 42 inch: http://www.cruxis.com/scope/scope1070.htm Here is a link to the 30 inch at the Astronomy Centre, Todmorden: https://www.astronomycentre.org.uk/index.php/2-uncategorised/17-30-reflecting-telescope

I agree. Practially all my eyepieces have proved useful for observing DSO's of one type or another. Tiny planetery nebulae need a lot of magnification to differentiate them from stars. The Veil Nebula needs a field of view 6-7x as large as the moons disk to fit the whole thing in.