Almost bought ES ED 102 APO but GSO 8" RC?

[codingquark]

Hello! Joined the forum only a day ago!

I am a beginner at using scopes. I grew up in times where my skies were so clear that I still remember feeling "hey dad! Look at that!  A bunch of stars not just one!" (which I now think to have been M13). The same skies have gone to be very polluted and now I only get to see constellations like bootes and Ursa Major. I still love observing these and following their paths over months.

Some years ago, I had the chance to look at moon, Saturn and other planetary objects through an 8 inch dob that a friend's friend had got. I was so amazed looking at Saturn, I spent the whole night there. Since then, I have not had any scope. I have had binoculars, but I use them while trekking. They're cheap, I would not buy them again. In last couple of years, I started capturing insects with my phone's camera (these phones can do amazing things!) and some Moon. Two months ago I was reading "Anathem" by Stephenson and that got me to think "man, I gotta stop looking at these stars with naked eyes and get me some scope!". This seems possible because my finances have improved, and I think I can fit the hobby nicely with my interests in trekking, spending solitary hours at night by myself and fiddling the crap out of computers (I am a writer of scripts! lisp anyone?).

A friend of mine got GSO 8inch dob last year, but he lives far away and I do not get to visit him only virtually. I asked him what I should do and his first answer was "get an 8 inch dob!". I started researching. I even captured some (terrible) Milky Way through my phone (no mount, no tracker nothing, but I could see many things) to get a feel of how astrophotography feels like. Over the period of a few weeks, I felt that I would rather go for a scope that I can use to learn techniques such as star hopping, identifying objects etc and use the same scope with much improved mount and capture Glorious Photos(TM). I narrowed down the choices to ES ED APO 102mm FCD100 with alt az mount to start with, or Redcat 51 with iOptron sky guider pro.

I had almost purchased the ES rig (FCD100, Bresser alt az mount, 30mm + 15mm + 4mm GSO Plossl, GSO 8x50 finder) for about US$2000-2500 equivalent in my currency. Before placing the order, I called up the friend, and explained my reasoning behind the choices. He suggested I should not try to combine visual with photography. I kept pushing, so he suggested I get Redcat but I was not willing to let go of the visual bliss. So he suggested I go with GSO 8inch RC with a GoTo mount. The GSO RC8 with accessories (EQ5 mount, eye pieces etc) is coming to approximately the same price.

I am very very confused. I want to have fun already! But I want to eat 2 pies at the same time with weight on photography eventually in 6 or 12 months. Should I get the APO? Or the RC? Or the dob for now and start building a whole different rig later on? I know I'm super into the hobby at least without any aid to the eyes, I'm sure I will love observing every now and then, and photography the skies all the time.

You guys gotta help me! I don't know what to do! 😆 Really, please help.

Thanks!

Some details about my geography:

1. Skies from backyard are about bortle 5
2. 50km drive is bortle 2 skies
3. I have enough cargo space in my car to carry large scope (not that I want to walk around carrying 30kg load like military troopers)
4. https://en.wikipedia.org/wiki/Köppen_climate_classification - BWh (https://en.wikipedia.org/wiki/Desert_climate#Hot_desert_climates)

Edited June 26, 2021 by codingquark
Added geography details

[Clarkey]

Hi Codingquark and welcome to SGL.

Quite a bit to cover so I will try to keep it short.

Firstly, visual and astrophotography are very different beasts with very different requirements. Generally for visual, aperture is your friend and for easy of use some form of alt-az mount is desirable. In this case the 8-10" dobs or newtonians are very good. You might want to consider a goto tracking mount, but again to avoid general contortion trying to get to the eyepiece alt-az is still the 'better' option.

For AP you are looking at a equatorial mount which needs to have good tracking to get longer exposures. Aperture is less important. AP is also a very expensive rabbit hole to go down. Ask anyone here! It is possible to do AP without an GEM, but you are making life difficult to start with.

I would strongly suggest getting a copy of Making Every Photon Count before looking at AP. It is a good guide to the type of set up you are likely to need.

Making Every Photon Count - Steve Richards | First Light Optics

In terms of your choices above the Redcat is a popular choice and a good starter for AP in terms of cost and ease of use. For the ES scope you will need at least an HEQ5 or similar to give good tracking accuracy. The RC8 is just too heavy and would really need a NEQ6 or similar by the time all the AP kit has been added. Also, the the refractors and RC would really need guiding due to the FL. RC's are really designed for AP and are not so good for visual. Also, at the long focal length they are not easy 'starter' scopes.

In general terms, I would suggest if you want to do visual and AP, the refractor and EQ mount would be the way to go. Personally I would keep the AP and visual separate otherwise you end up compromising on both.

Hope this helps.

[EntropyTango]

It's hard to do both visual and AP on a limited budget.

My personal opinion is that you should do some visual astronomy before you do imaging.

Dobs are great visually but limited in AP terms without some equatorial platform.

So if you have your heart set on AP and don't mind the travel and setup time

it's probably best to invest in a decent equatorial mount.

Then you can get a small refractor for your AP and something like and an 8" F4/5 newtonian for visual work. (good for AP too)

As Clarkey mentioned AP can be a rabbithole in terms of money, especially if you are a perfectionist

If you have a DSLR already this can be a great starting point before buying a dedicated astro-cam

That would leave more money for the mount and scope

Good luck and clear skies

 

(just a note about the RC8, they are great scopes but a pain to collimate and the long FL amplifies tracking errors,

I would suggest a decent quality small refractor instead)

Edited June 27, 2021 by EntropyTango

[codingquark]

Thanks Clarky and EntropyTango for replies!

 

1 hour ago, Clarkey said:

Firstly, visual and astrophotography are very different beasts with very different requirements.

 

1 hour ago, EntropyTango said:

My personal opinion is that you should do some visual astronomy before you do imaging.

This has been the theme from my friend as well. I should just keep them separate. Hmm... 🤔 Will I really be seeing so much more than, say, the RC8 or the apo refractor that I should keep a whole separate rig for visual? If I'm willing to go through the learning curve of RC's collimation, will it serve as "occasional visual 'scope" and excellent (as good as the es apo) 'scope for AP?

Again, I really appreciate the help guys. Like I said, I almost went for the ES because it felt like I could spend many many hours for years observing through eye pieces as well as DSLRs / CCDs - with 80% AP and 20% visual. But then the RC8 showed up which messed up all my equations. So far it seems to me that since I'm a beginner, the collimation will be too much for me to handle and hence I should go with a (preferably large FOV) refractor. If we assume I will get used to collimating the RC8 in a few months, what is the comparison?

I should clarify that I'm not super interested in redcat because 1) it is super wide FOV 2) there is no visual at all. I realise that I will probably have to buy many other telescopes to fit various objects in frames, but I would prefer not to start with something that won't let me see anything with eyes. To counter this, both of you have already said I should get a Newtonian specifically for visual, and redcat / ES for AP. This line of thinking depends on what you guys think of RC8 I believe.

Thanks!

[Clarkey]

The RC8 is a great scope - I have one which is one of my two imaging scopes - this and an ED80. The main 'issue' with the RC8 is that the long FL. At 1600mm is is pretty long and by the time you get all the astro gear on it you need more than an HEQ5 - mine is mounted on a AZ-EQ6 which is much more sturdy than the HEQ5. Additionally you will need a guide scope or ideally off axis guiding which adds more complication and cost. In terms of FOV it is very narrow which is good for small stuff like galaxies but not good for nebulae. You can always crop a widefield image - you cannot make a narrow one bigger (without mosaics). The other consideration is pixel scale. Depending on what camera you are using and what you are planning to photograph this needs to be considered. Typically you would want to aim for about 1"/pixel. With my RC8 at native FL and the asi1600mm I get around half this so I bin the data 2x2. You can only really do this with mono. If you are using OSC or a DSLR you don't get this option and will be oversampling. In general terms due to the seeing in the UK there is actually little benefit in going over a FL of about 800mm with modern CMOS cameras due to the seeing. You can just crop the image to make it 'bigger' in the frame.

I am not sure on your budget, but the most important thing is the mount. You can have the greatest telescope in the world, but with a poor mount it will be worthless. If you are serious about long FL astrophotography spend the money on a good heavy duty mount such as an NEQ6. This will then cover you for most 'standard' sized scopes. If you want to put an RC8 on it then great - but equally it will handle anything much smaller.

Have you considered a newtonian for imaging and AP? Something like a 200PDS is a good AP scope and is also good for visual. Even something like a 130PDS which will go on a lighter mount can give great images at 'sensible' cost. There is a great thread on this forum which shows what is possible.

At the end of the day it is down to budget and patience. There is nothing to stop you starting with a long FL RC8, but it is harder than starting with a widefield scope.

Edited June 27, 2021 by Clarkey

[Astro Noodles]

I think the advice give here is absolutely correct. AP and visual are two different animals, and require different equipment.

If you are looking in the $2000-$2500 range, it should be possible to get decent beginner level setup for both activities.

For visual astronomy, you could start out with one of these Sky-Watcher Classic 200P Dobsonian | First Light Optics for £400

For an entry level into AP, you will need a DSLR (second hand Canons can be had for less than £150). And then you would need a German equatorial mount, These start from about £500 for one of these Sky-Watcher Star Adventurer 2i WiFi Pro Pack | First Light Optics with a sturdy tripod, to about £1000 for one of these Sky-Watcher HEQ5 PRO Go-To Astronomy Mount | First Light Optics

Then you would need either a decent camera lens or a small apochromatic refractor, weight dependent on the mount you choose. These have a good reputation https://www.firstlightoptics.com/pro-series/skywatcher-evostar-80ed-ds-pro-ota.https://www.firstlightoptics.com/skywatcher-mounts/skywatcher-heq5-pro-synscan.html. With a flattener/reducer £700 but would be too heavy for the sky-guider.

Then you might need several hundred/Thousand Euros/Pounds/Dollars for accessories/connectors/dew heater/laptop/viewing chair/eyepieces/filter etc - you see, the difficulty is not just knowing where to start as being able to stop once you have started.

By the way, you could start out with visual and then move onto AP. You don't have to buy it all at once. 🙂

 

[codingquark]

Okay, the clear consensus is to keep the rigs different. Alright then.

The only question I've left is if it will be wise to do the following:

Buy RC8, mount it on EQ5 GoTo mount and use it for visual. Save for NEQ6 + imaging train and start AP.

If this does not make sense, I will get 10inch GSO / SW with Plossl EP collection (40, 25, 6, 2x Barlow) since it will all easily fit in my budget. I can even get the collapsible dob from SW.

 

PS: In saying "RC8", I am aware I'll be going for narrow FOV, hence keeping ES102 FCD100 option open just in case. Mount shall remain the same - EQ5 right now and NEQ6 later.

[Astro Noodles]

If you budget will accommodate it it, then yes it seems like a good way to go.

A word of caution, and it has been mentioned before, neither visual or AP are instant gratification pursuits. Buying a lot of high-end kit all at once may not be the best idea as you stand the chance of being overwhelmed as the learning curve becomes a tsunami.

But, if you are confident, then why not. You can sell on any kit which becomes surplus in the future and recoup some of the investment. 🙂

[codingquark]

Thanks guys, I this has helped me clarify my thoughts a lot. The GSO distributor is out of stock for RC8 but has ES 102mm FCD100 in stock. Let's see how this goes. RC8 is supposed to be back in stock in a few months. I will take my time while I have it. I will be sure to post my decision here, and will keep posting my other adventures

Thanks!

[Clarkey]

5 hours ago, codingquark said:

Buy RC8, mount it on EQ5 GoTo mount and use it for visual. Save for NEQ6 + imaging train and start AP.

Yes this is realistic.

Personally, I would buy the NEQ6 and a something like a 150 or 200PDS then you have an good AP set up and a pretty decent visual set up too. The finder on the newt could be converted to a useable guidescope quite easily using a converter (look on the FLO site for guidescopes).  Then save and get your AP equipment and then if you are still enjoying it 'upgrade' to the RC8. Also you can get some practice in with the collimation of a newtonian. The benefit of this way is you will not be needing to sell or replace anything on the way. A 200PDS at F5 and 1000mm FL is a good set up. You will need a coma corrector - but they regularly come up for sale second hand.

Good luck whatever you choose. Keep asking the questions on SGL - the people on here are always eager to help. I would have been lost without the forums. In AP terms I am still a relative beginner (but very experienced at spending money on it), but there are some experts on here that I always worth listening too.

[nfotis]

I would like to recount my trip so far:

Bought a Skymax 127 second hand, because the light pollution in home meant no capacity to see faint objects. Planets, moon and double stars are easily viewed, though.

A Maksutov type scope offers a long focal distance and a contrasty view. And these are quite rugged and less fiddly than an RC or similar scope.

I then bought a used HEQ5 mount, which is considered the most basic German equatorial mount for astrophotography. Still I haven't optimized it, but it offers a very stable platform for my Skymax 127. I bought a planetary imaging camera, which gave me nice shots of the lunar surface and the gas giants, and I added a Skymax 180 (which is rightfully termed a "planet killer" due to its very long focal distance).

Now, I have an C9.25 SCT and I may experiment with both large scopes after the heat waves pass (yes, it works with the HEQ5 mount - barely - for planetary imaging). A focus motor makes life much more enjoyable. I am doing visual and planetary imaging for now only.

For wide field astrophotography on this mount, I think that a 80ED or 102ED refractor will be quite pleasant.

N.F.

[codingquark]

Thanks nfotis

I received Bresser hunter 8x40 Binoculars the other day and spent 3-4 hours observing (it was cloudy, so actual object hunting was much less). After all the unaided activities, these binos are a refresher. It looks like I love visual, but my eyes may have astigmatism detectable at such high magnifications which I shall find out tonight (I will consider this to be a big let down TBH).

I think I will spend a month with these (or two, w/e) binoculars and then decide if I want to build separate setups for visual and AP. This is going to be fun. I've planned for bortle 3 next weekend with the binoculars 😁