John

Interesting Sky & Telescope piece on "test" double stars and pushing the limits of your scope here: https://skyandtelescope.org/observing/pushing-limits-a-spring-sky-double-star-romp/

A 1 degree true field of view is large enough to see both M81 and M82 with a little bit of room left around them. The combination that gets a 1 degree true field varies depending on the scope and eyepiece used. As an example, a 102mm F/10 scope with used with a 20mm focal length plossl eyepiece shows a 1 degree true field of view and 50x magnification - enough to fit both galaxies in the view at the same time. Larger apertures show the galaxies more clearly but they are visible in quite small scopes. This sketch was made by Michael Vlasiv using an 205mm aperture newtonian, under a dark sky, and a 25mm eyepiece giving a 1.25 degree true field of view. As you can see, both galaxies fit comfortably within that:

I think I've reached that point as well. Probably a while back really but I've had the occasional lapse since I have used quite a lot of orthos and they are very good in pure optical performance terms. I do prefer longer eye relief, wider field of view and a larger eye lens these days so I don't find myself reaching for my remaining ortho very much. I think viewing comfort as a lot to be said for it, particularly using undriven, alt-az mounted scopes as I do.

M81 and M82 can be seen with very small and low cost scopes. They were the 1st galaxies that I ever saw through a scope - a cheap and old 60mm refractor. I was so thrilled to see them, I kept staring at them for hours ! You can pick them up with 10x50 binoculars but they are defined better as a galaxy pair with a scope at around 25x magnification.

From my back yard, where I have some light pollution though it's not too bad, I find that I get better results using a slightly higher magnification even if that is at the expense of true field of view breadth. On the largest objects (eg: the Veil Nebula) it is nice to have the largest field you can get but most targets fit comfortably within a smaller field.

The Panaviews are a popular choice of first 2 inch eyepiece and work pretty well with the 200mm F/6 dobsonians. They are not perfectly corrected all the way to the edge of the field but are not bad at all for their price. The 1.25 inch size eyepieces of similar focal length simply can't show as wide a field as those in a 2 inch fitting because the inside diameter of the eyepiece barrel is what determines how wide the field can be. A 32mm 2 inch eyepiece can show 40% more sky than a 32mm 1.25 inch. The Aero ED eyepieces are more expensive but are a bit better corrected than the Panaviews as John says above. I currently have the 30mm and 40mm in that range. Of course, when you are thinking about filters, the question of 1.25 inch vs 2 inch comes up when you have a 2 inch eyepiece

Sounds like you have got a good range now. Paying more would certainly take you into the realm of diminishing returns. Its getting a taste for very wide field views that costs the money

The Skywatcher HEQ5 has a touch more capacity than the Celestron AVX. The NEQ6 is better still but my goodness they are heavy !

I guess you will know of this Italian website ?: https://www.stelledoppie.it/index2.php?section=1

Can you split the "double double" Epsilon Lyra with your 8 inch OOUK scope ? Those pairs are 2.3 and 2.4 arc seconds apart respectively and should be a straightforward split for your scope at around 120x magnification. If you can't split them then either the seeing is poor or the collimation needs adjusting. Another good "test" double that is better placed right now is Porrima - Gamma Virginis. That pair has a separation of around 2.5 arc seconds.

Actually, since then I have done that comparison on a few targets. The image of, say a tight double star, looks pretty much identical through the 12 inch dobsonian stopped down using an off axis cardboard mask with a 10cm aperture. The aperture can be positioned so that it avoids both the secondary vanes and the secondary support so it is an unobstructed 100mm scope. I would expect the mirror system to transmit a bit less light than the objective lens of the eyepiece - perhaps 90% rather than the refractors 98% so the performance on DSOs might be a little less with the stopped down newtonian.

Will you tell him on CN Don, or shall I ? I have the Baader T2-Zeiss prism, an Astro Physics Maxbright and a couple of TV Everbrites and I honestly can't tell the difference between them. Some folks apparently can though

It does work but I've had a couple of glasses of decent wine so I can't attempt to explain the optics behind it. But it does work !

Hi and welcome to the forum. I've edited the title of your post to add the bit about observing the Sun with your Skywatcher 114. You should get more advice with a more specific title

The Contrast Booster and CLS filter are quite different to the UHC and O-III filters. The CB and CLS are broadband filters. The UHC is a narrowband and the O-III is a line filter. More on these classes of filters here: https://www.prairieastronomyclub.org/useful-filters-for-viewing-deep-sky-objects/

You have to spend quite a bit more to get much in the way of better optical performance than the mid focal length BST Starguiders

I used to think that but I feel that diagonal choice does matter a bit more now: https://www.cloudynights.com/articles/cat/articles/mirror-vs-dielectric-vs-prism-diagonal-comparison-r2877

The UHC type work better with smaller scopes than the O-III type. The CLS type barely have any effect in my experience. These things only work with nebulae (ie: not galaxies or clusters) and the improvements are subtle rather than startling but the contrast in the nebulosity is improved to some extent.

Great haul of lovely targets ! Time just slips by when you get into the "zone" deep sky hunting

I did have a Lunt 50 h-alpha scope for a while a year or so back but for me, my interest in observing the Sun did not really take off (probably the quiet Sun didn't help either) so I decided that I had too much tied up in that piece of equipment and sold it. I now have a much less expensive Lunt Herschel Wedge which gives me nice white light views when I want them using the scopes that I use for nighttime use. I guess if you get the h-alpha bug then the money will seem like a good investment as the solar activity gradually increases.

A good session despite that missing SN Mark. Sorry that you did not quite get that but you did spy some other nice targets

Thanks for that Geoff It strikes me that comet observing is a bit like following the England football team in major tournaments. Lots of enthusiasm and initially optimistic predictions but, eventually, the inevitable sense of anti-climax

Great report ! Glad you have "found" the simple pleasures of observing again

Sounds like a good session Paul

I'll add tonights haul to last nights thread. 12 inch dobsonian again (3rd night in a row !). Got the Supernova SN2020ftl. Looked similar brightness to last night ~mag 14 ? New galaxies tonight were: Leo: NGC 3193, 3190 and 3185 which are 3 of the 4 Leo Quintet in the lions "neck" NGC 3605, 3607, 3608, 3626 and 3596 in the rear end of the lion. Virgo: NGC 4179 M 49 NGC 4526 and 4535 (the latter is known as "Copelands Lost Galaxy" and it's a faint surface brightness face on spiral) M 87 (no jet, alas) NGC 4478 and 4476 M 58, M 59 and M 60 NGC 4638 M89 and M90 NGC 4550 and 4564 And finally the "Siamese Twins" galaxies NGC 4567 and 4568 showing their "V" configuration quite nicely I thought at 122x (Ethos 13mm) as they interact together. Photo below by NASA. Another fine night and I decided to stop at those two constellations rather than venturing into Coma Berenices tonight. I found the larger scale map of the Virgo / Coma cluster in the Sky & Telescope Pocket Sky Atlas very useful for navigating around this multitude of fuzzies. Hope others have enjoyed these clear dark skies as well