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1st scope help please


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Hello

I am searching for my first telescope. I'm aware astrophotography and visual astronomy require different set ups, however, I also know some scopes can offer a little of both... Please can you all offer some suggestions on a good all round option for :

Budget- £400-£800

Area :I live in the country in a dark skies neighbourhood and will be viewing from acres of open fields. 

Priority:

Visual quality highest possible of moon, planets and like the ability to capture that, but also offer some deep sky abilities and some basic deep image capturing to further the interest. 

Portability. Able to set up and move with realitive ease. 

So far, looking at :

Skywatcher Star Discovery P150i 6''.

Skywatcher Skymax 127AZ GTi 5''.

Skywatcher Explorer 200P EQ5

But there are so many I'm now so confused to know which one to get. 

Thanks all. Any ideas or advice welcome. 

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None of those telescopes are really suited for astrophotography. The 200P on a EQ5 is ,but not without additional motors being fitted to allow the mount to track the targets being photographed. There are so many variables to consider. Firstly how serious are you in this astrophotography journey?. Do you just want to snap a few pictures of the planets and the moon etc?, or are you wanting to take serious quality astro photos?. You will have to learn your way around the night sky, unless you go down the Go to computerized mount road 

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I second the query, more serious AP will require more investment especially towards the cost of the mount. The more substantial the mount the less the portability. Need more details.

Maybe a 70-80mm apochromatic refractor may be the all around scope for you? There are plenty of forum threads on SGL regarding first scopes if you search.

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Thank you for responding. 

Maybe I'm totally mistaken. The Goto mounts on these I listed, do they not track but just take you to the subject via the smart phone app? 

Will they not track the subject in the night sky? 

In response to questions. Let's put complex astrophotography off the table for now. Yes I do want to pursue, but very aware I could not take great images with this kit and if I enjoy it (being a beginner) I can always change kit in the future specifically for astrophotography. That being said. As a beginner it would still be nice to capture some first images along with the visual of the planets and perhaps some deeper space should a scope allow. Some do list this on their descriptions, especially the ones listed. Out of those I listed are any of them good for visual observations and to snap some basic dslr imagery? Or perhaps you can suggest another go to computerised scope up to £800?

Thanks

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Altaz mounts do track but in tiny left right up down movement which follows the target object but not the rotation of the object. The longer the image exposure the more rotation of the object that occurs, so with an altaz mount at some point (can be in seconds depending on size of telescope) the target becomes smeared, the image edges are hit first but the whole image eventually.

Altaz image taking is possible but you have to work within the limitation of such tracking. It's about what your expectations are on what you want to achieve on DSO. Planets/Moon less impacted as short videos of very fast frames are used. The star discovery does not come to focus with a DSLR. The virtuoso v2 with a 150P flavour in theory would as the truss could be left not fully extended.

If your viewing is from a nearby field you may want to consider what equipment is practical in size and weight for you to use, this also includes storage location to using location. Portability is very personal to individual situations.

Edited by happy-kat
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I suggest that you take a hard look at where you are prepared to compromise, to keep within your budget.

If you can do without a powered mount (no tracking, no GoTo) you could get a fair sized Dobsonian mounted Newtonian within your budget.

If you want GoTo, you can get a smallish telesccope on a lightweight and rather wobbly mount.

If you want a non-wobbly GoTo mount that will take sundry small and medium-sized scopes, that can be used for some entry level imaging of whatever you like, you want at minimum an Eq5 Synscan at about £700, and a HEQ5 (about £1000) or EQ6 (wellover £1000) would not be overkill.

If you want to image planets, the bigger the scope the better, but I have found one can get a result with an alt-azimuth GoTo, even a wobbly one. Alternatively, use an equatorial mount that tracks.

BTW, ALL GoTo mounts include tracking in their functions.

Note also that non-wobbly mounts can be decidedly heavy, and some setups can take quite some time to assemble and get working every time you take them out.  One of my setups is configured so that I can carry it outside and get it going in a few minutes without having to align the GoTo myself,, but if you want one exactly like it you will need to spend nearly £2000 at current prices.

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The 150PDS on an EQ5 PRO would probably do most of the things you want, but be 200 pounds over budget. I dont know what i would choose were i in your shoes, since i understand the appeal of doing a bit of everything. But try not to undermount whatever scope you get, it will be frustrating to use and you might end up hating it.

I also would mention what @Cosmic Geoff wrote about the setup time. My 200mm newtonian and full astrophotography setup takes somewhere around 30-60 minutes to setup to a point where imaging starts after placing the tripod on the ground. Could be as long as 2 hours if the scope has to cool down first.

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I'll give recommendation based on what I've read so far on your interests.

This scope:

https://www.firstlightoptics.com/stellalyra-telescopes/stellalyra-6-f12-m-crf-classical-cassegrain-telescope-ota.html

This mount:

https://www.firstlightoptics.com/equatorial-astronomy-mounts/skywatcher-eq5-deluxe.html

and tracking motor for that mount.

This scope will provide you with very good views of planets and the Moon. It does not require expensive eyepieces. It will show you deep sky objects as well. It's only "weakness" visually is rather narrow field of view, but even that is not as bad as you might think. With 56mm Astro Essentials plossl - it will be capable of 1.6° view at x32 magnification. Not quite wide field, but not bad either.

With simple addition of planetary type camera - you'll be able to do some serious planetary and lunar astrophotography.

Mounting just DSLR and lens on mount with tracking motor will give you chance to start doing some wide field astrophotography and as far as telescope goes - you'll be able to mount camera onto telescope and start doing some astrophotography there as well - but due to focal length of telescope - you'll have to do some special steps in processing (binning your data) - and images that you create will be sort of small - enough to fit smaller galaxies and planetary type nebulae - but not wide enough for M31 andromeda or M45 pleiades or similar (for that you can use DSLR and lens).

If you can - get GOTO mount, but if not - you can take either single motor upgrade, or possibly dual motor with guide port. That is looking into future (but adds to required budget). If you get dedicated planetary camera - you'll be able to use it later as guide camera for more serious deep sky imaging with said scope.

 

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As a fellow beginner, I'd suggest getting the best scope for visual that you can afford first. There are mobile phone holders to go over the eyepiece that can produce excellent photos of the moon and planets to assuage your need to start astro. After you have some experience and do a lot of reading on here about astro, I'm sure you'll have a much clearer ideas as to whether you want to take it further with a dedicated setup.

Just my opinion - I don't do astro! 🤭

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1 hour ago, vlaiv said:

Astro Essentials plossl - it will be capable of 1.6° view at x32 magnification. Not quite wide field, but not bad either.

I don’t know what I’m doing wrong but I was looking at this scope a while back and checked the FOV. I worked it out at 1.31 degree. This was me using the 56mm eyepiece with its largest possible AFOV of 43 degrees. I of course used the FL etc of the scope. What am I doing wrong?

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22 minutes ago, bosun21 said:

This was me using the 56mm eyepiece with its largest possible AFOV of 43 degrees.

Eyepiece can be either 1.25" or 2" in diameter, and respective max field stops are ~27mm or ~47mm.

If you take 1.25" eyepiece in say 32, 40mm and 45mm focal lengths - AFOVs that you get will be 48°, 39° and 34° (this is zero angular magnification distortion case).

Usually 32mm and 40mm plossl eyepieces are quoted to have 52° and 40° as they have some AMD and are between zero AMD and zero rectilinear distortion.

With 56mm eyepiece in 1.25" format - max AFOV would be ~28° not 43°.

Look here for fomulae used to calculate AFOV - two extreme cases no AMD and no RD : https://www.televue.com/engine/TV3b_page.asp?id=113

For TFOV it is even easier - you don't need to know AFOV - you only need to know focal length of the scope and field stop of eyepiece.

Formula is arctan ( field_stop / 2 * focal_length) * 2

In case of 6" CC scope above, FL is 1836mm (give or take) and if we take 47mm field stop we get arctan(23.5 / 1836) * 2 = ~1.46 degrees

So it is 1.46° rather than ~1.6° calculated by astronomy.tools FOV:

image.png.bf8b68a1385efe1b1f36883d2e09eaef.png

(it is probably slightly off because it is not using field stop data but rather AFOV data - which can often be different than quoted by manufacturers).

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25 minutes ago, vlaiv said:

Eyepiece can be either 1.25" or 2" in diameter, and respective max field stops are ~27mm or ~47mm.

If you take 1.25" eyepiece in say 32, 40mm and 45mm focal lengths - AFOVs that you get will be 48°, 39° and 34° (this is zero angular magnification distortion case).

Usually 32mm and 40mm plossl eyepieces are quoted to have 52° and 40° as they have some AMD and are between zero AMD and zero rectilinear distortion.

With 56mm eyepiece in 1.25" format - max AFOV would be ~28° not 43°.

Look here for fomulae used to calculate AFOV - two extreme cases no AMD and no RD : https://www.televue.com/engine/TV3b_page.asp?id=113

For TFOV it is even easier - you don't need to know AFOV - you only need to know focal length of the scope and field stop of eyepiece.

Formula is arctan ( field_stop / 2 * focal_length) * 2

In case of 6" CC scope above, FL is 1836mm (give or take) and if we take 47mm field stop we get arctan(23.5 / 1836) * 2 = ~1.46 degrees

So it is 1.46° rather than ~1.6° calculated by astronomy.tools FOV:

image.png.bf8b68a1385efe1b1f36883d2e09eaef.png

(it is probably slightly off because it is not using field stop data but rather AFOV data - which can often be different than quoted by manufacturers).

Thanks for the detailed breakdown of how the FOV is properly calculated. I used the same tool as shown in your post. I was told that the AFOV for both the 32 and 40mm 1.25” was 43 degrees maximum, and the only benefit for using a 40 over a 32mm (1.25”) eyepiece was the larger Exit pupil if FOV was your reason for selection in the first place.

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2 minutes ago, bosun21 said:

I was told that the AFOV for both the 32 and 40mm 1.25” was 43 degrees maximum, and the only benefit for using a 40 over a 32mm (1.25”) eyepiece was the larger Exit pupil if FOV was your reason for selection in the first place.

There has probably been some mix up with that statement.

Correct statement for 1.25" 32mm and 40mm plossls would be: They will show you same true field of view (not AFOV) - because they both have same field stop diameter - max for 1.25" format, and yes, 40mm will have larger exit pupil, but AFOVs will not be the same. 32mm will give about 50° max AFOV and 40mm will give about 40° max AFOV in 1.25" format.

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2 minutes ago, vlaiv said:

There has probably been some mix up with that statement.

Correct statement for 1.25" 32mm and 40mm plossls would be: They will show you same true field of view (not AFOV) - because they both have same field stop diameter - max for 1.25" format, and yes, 40mm will have larger exit pupil, but AFOVs will not be the same. 32mm will give about 50° max AFOV and 40mm will give about 40° max AFOV in 1.25" format.

Thanks again, and that’s where I have gone wrong. I was mixing up the TFOV with the AFOV. I now know for future reference. Much appreciated 👍

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  • 2 weeks later...

Reverting to your original question, FLO do the Skywatcher Explorer 150p on an EQ-3 Pro Go-To for £719. I've never had an EQ-3 (Pro or otherwise) so it's possible it might be undermounted - no doubt the more experienced on here can tell you.

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  • 1 month later...

Go for the StarDiscovery 150p Newton WiFi and add a SV305 (CMOS IMX290) astrocamera. And enter the realm of EAA first before you you go into full-fledged astrophotography.
The mount is able for up to 15 seconds unguided exposures. That's a lot compared with Stellina or eVscope which cost 4.000 EUR but offer mostly shorter exposures and less aperture.

https://agenaastro.com/articles/guides/miscellaneous/agena-beginners-guide-to-choosing-equipment-for-deep-sky-eaa.html

Also a good read is "Astrophotography on the Go" for getting a feeling what could be achieved.
https://www.amazon.com/Astrophotography-Go-Exposures-Practical-Astronomy/dp/3319098306

Best,
Peter

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