Thank you everyone for the detailed explanation.
No, it is not difficult to track a celestial object on an alt-az mount... it's actually very easy. Every minute or so, you do a simple nudge up/down and left/right. Easy.
Technically, with an equatorial mount that has been aligned to Polaris (with Earth's axis of rotation), every minute or so, you would do a simple nudge in one axis only (right ascension) instead of two. So, slightly easier. But you have to do a good polar alignment for this to be the case and inexpensive EQ mounts generally don't come with polar scopes to make it easy to do an accurate polar alignment. So you'll likely have to do nudges in both axes every minute or so anyway. And, when switching targets, you may have to frequently do meridian flips -- swinging the telescope around so that it is on the correct side of the meridian -- a hassle in my mind and not intuitive.
In my opinion, an EQ mount can make objects easier to track once found. However, a beginner may find it harder to operate and find objects with an EQ mount. Furthermore, for this benefit to be achieved, the EQ mount should be of high enough quality and stable enough to allow steady tracking.
Yes, I think a good EQ mount makes tracking easier than a good manually driven Alt-Az mount. However, the difference is really only relevant at high magnifications (say, 200X and above), which none of these telescopes will support.
The learning curve for an EQ mount is quite a bit steeper. And a low-quality EQ mount can truly make life miserable.
(...)
I would prefer a 640-mm focal length to a 900-mm focal length for an 80-mm refractor. The difference in length and convenience is quite substantial, and shorter scope also provides a significantly wider true field of view.
The first one !!!
The first one for 4 different reasons:
1. It has an alt-azimuth mount, which is MUCH better for a newcomer – the movements are natural (up is up, right is right and so on), no matter in which geographical direction you aim. With an equatorial mount the movements are often counter intuitive:
2. Its focal length (640mm) is the shortest from all 3 telescopes, so the field of view (FOV) with the longer eyepiece (25mm) will be the biggest (around 2 degrees). This is the second most important thing for a newcomer.
3. The focal length of 640mm is still “long enough”, so with the shorter eyepiece (10mm) the magnification will be 64x – good enough to clearly see the rings of Saturn, the bands oof Jupiter, lots of details on the Moon and all 4 stars of the Trapezium in the heart of the Orion Nebula
There's abundance of experience and knowledge here.
I was inclined towards the Option#2 and Option#3 while writing the original post, and added Option#1 as more of a back up option.
But now I'm clear that AZ mounts are the best at this point of time and that's the right way to go. And I think ES 80/640 should be the one.
And I did a bit of search and found a place where a 3x Barlow would be provided with the Option #1 - ES 80/640 telescope 
Alongside that I came across the following Bresser telescope
4. BRESSER MESSIER AR 80/640 AZ Nano Refractor Telescope (Link)
Price : 235 $ (INR 20000)
Eyepiece : 1 (Super Plossl 26mm)
No Barlow included
Mount : Bresser Nano AZ mount
The thing that caught my attention was that the optics is 'MgF2-coated optics'.
How much of a difference does it make if the ES option #1 (80/640) doesn't have a coating? Quoting a part of a review on the official ES 80/640 product page - "Checking the 80mm objective lens first, it was obvious the lens is not coated--not multi-coated, not even single coated!"
Would there be a significant difference with and without the coating?
Also adding a link of a 90/720 AZ Bresser NASA telescope if it makes sense.
5. Bresser NASA AR90/720 AZ Refractor Telescope - But this would come with Kellner 10mm and 20mm eyepieces as against the Plossl in ES, and 3x Barlow with JWT-25 Altazimuth mount.
Please share your thoughts. Thanks
Edited by wandering_comet, 28 March 2025 - 11:52 PM.
