Ruud

Bird-Jones (at the bottom of this page)

Note that the Bird-Jones spot diagrams for 30mm off axis are swollen up to such an extent that they do not fit in the diagrams.

Other correctors, in particular Houghton derived designs, work much better (Buchsroeder-Houghton for photographic use and Houghton for visual use).
 

from: Rutten and van Venrooij, Telescope Optics, a Comprehensive Manual for Amateur Astronomers

I this thread by @fwm891 you can see what you get with and without a field flattener:

4 minutes ago, GlenM said:

Looking at the 17.5mm first for widefield.

That's the best. Beats everything in my F/5 refractor.

Edited version:

Even if made of good quality components. Bird Jones Newtonians are difficult to collimate. There are Youtube videos showing how to go about this. We never recommend these telescopes. A simple parabolic Newtonian is a better choice.

200p? Good plan. Clear skies to you.

Hello Asghar

A shower cap would make a good dust cap.

Knobs on flex cables aren't important. (I like them for a refractor, where you sit at the back of the telescope.)

I suspect the mount and tripod may struggle with the task of carrying such a big scope.

How much will it cost you?

See here:  https://agenaastro.com/agena-rubber-o-ring-for-50mm-finders.html

O, that's for a 50mm finder. 

Thanks Charl, cool images.

It would be bad if the magic smoke escaped. That is vital to a mount.

The WO Z73 is a visual refractor, it has excellent colour correction but no built in field flattener. You need to buy one separately if you want to optimise it for photography.

The Omegon is an astrograph and looks like it might be better suited to your purpose. I don't know much about it though. I think it may be a re-branded SharpStar 71SDQ Quadruplet.

Atlas and Hercules are high on my list of favourite craters. Thanks for a wonderful sketch!

Wow, may details. Great work Mike! 

Excellent image, Avani.

I assume the north pole points to the right. If so, the northern hemisphere must really be brighter than the southern. That is pretty obvious from your image.

The albedo features in the southern hemisphere seem to be an artefact from the processing because they do not show in your second, less processed version. I would expect to see at least some of these features shine through.

Still, if I tonemap your second version to the extreme, I get this

which makes it difficult to decide either way.

Thanks for the image. It is wonderful as always.

Phenomenal images with marvellous colours!

Skywatcher Nirvana 16mm 82° is well within your budget. It is almost Nagler-good and will provide a true fov of slightly under 2.4° at 34x magnification in a 550mm focal length telescope. The exit pupil will be 2.9 mm.

Also, it Barlows well.

Edit: I see Flo has this eyepiece in the WO UWAN version. It's the same eyepiece, bit looks like it might be a bit more expensive? (Skywatcher Nirvana is around €120)  

Wow, you had the sky clearing up on you and made good use of it.

Wonderful sketch. Thanks!

Gorgeous galaxies! 

Oh, that is wonderful!

Who doesn't like the Iris nebula?

Excellent image!

Difficult to say which version I like better, but if the second had just a few less red stars it would be my favourite for sure. Anyway, both versions are excellent!

Ooh that texture! This nebulosity is beyond compare.

Amazing!

Brian, it is a magnificent image!

What a lovely quaint chart! I had some trouble identifying everything in it, so using Stellarium I went to London in 1869.

It looks like the old chart is off by a few hours, and the brightness of the stars is quite arbitrary at times. Delphinus is missing entirely and I couldn't trace the left arm of Hercules even though I think it is there.

In order to get a level horizon in the Stellarium screenshot I had to place it halfway the screen, which made a very wide view necessary, so that the screenshot too is distorted. I zipped the full size view: stellarium-000.zip It is a magnitude 5 chart.

It may have its flaws, but the 150 years old chart easily beats the Stellarium chart when it comes to charm and beauty.

I get that when I don't have an image open.