Seeking advice on GSO RC 8" & HEQ5 PRO for Astrophotography

[Digital_Artist]

Kindly be patient and read it and of course help me to decide

First thing first, i am newbie in astronomy and i don't have any telescope or mount what so ever but i want to do Astrophotography. But there are two problem:
1) I have limited budget and
2) There is no authorized dealer or shop for telescope where i live.
So i have to buy all the equipment from abroad in fact from Australia cause i have someone who lives there.

After researching about it on internet i realize that a HEQ5 PRO mount and GSO Richey-Chretien 8" telescope will be good just within my budget and as the budget is an issue for me I will use that telescope for visual usage for now as i will gather more money (God help me) for a camera (may be canon DSLR) i will switch to Astrophotography just like this guy (http://deepspaceplace.com/gso8rc.php).

Source for the equipment:
1) HEQ5 PRO ----- http://www.bintel.com.au/Mounts---Tripods/EQ-Mounts/Skywatcher-HEQ5-Pro-GoTo-Mount/96/productview.aspx
2) RC-8" f/8 astrograph w/M-LRC focuser Aluminium tube ------ http://www.andrewscom.com.au/site-section-10.htm

Now, question
1) what kind of Eyepiece do i need to have?
2) What kind and size of extension tube and/or focal extender do i need? (it seems it is needed as pictured in these websites:
http://deepspaceplace.com/gso8rc.php
http://www.cloudynights.com/item.php?item_id=2006

3) Do i need right angle telescope eyepiece? If yes which one will fit with it?

4) Will any of this set will work with this telescope?------- http://www.bintel.com.au/Eyepieces-and-Barlows/Eyepiece-Kits/27/catmenu.aspx

5) What else do i need? for visual now but switch to Astrophotography later.

6) Any other better options available?

As i have to import these things from Abroad i have to be just right so that i can use it right out of the box.

Please help me with your valuable advice.

Thanks in advance.

[rogerco]

I would consider if you intend getting into Astro photography later on. If you do then check that the mount you are considering has a guide port. I have been adviced that the EQ 6 pro mount would be the better long term option. The mount is what you want to carefully choose as you are likely to be stuck with it and it will be the limiting factor into the future. If you get into photography you will probably want to get a guide scope. Bintel sell a good package made by Orion.

Others more qualified might talk about the choice of a RC scope as these are generally designed for photography rather than visual, althought I don't understand myself why they wouldn't be suitable. Visual scopes don't always made good photo scopes but photo scopes should be ok for visual.

You will generally get some pretty ordinary quality eye pieces with the scope which you will want to replace. If it is possible for you to look at other people's setup in your area then I suggest you do that as eye pieces can get very expensive. The scope you are looking at is fairly long focal length so you would want to decide what you are wanting to look at and then assess if you want a focal reducer or a Barlow. For some of the larger brighter nebulas such as Orion you may want a reducer whereas for planets you would want a Barlow.

[Paul Haese]

If you have never done any astrophotography my suggestion is to get a wide field telescope such as an ED80 first with a EQ5pro mount. Wide field imaging is easier to learn and is less demanding on skill set at the beginning.

You should consider that you will need to learn polar alignment techniques as well as processing skills. To make it enjoyable you ought to start with the easiest and work up to harder.

[allan gould]

Thoroughly agree with every point Paul has made. Best advice and its free.

[swannies1983]

I recently purchased an RC8 and can only comment regarding astrophotography work because that's all I have used it for. If astrophotography is the way you will eventually head, don't bother with an EQ5. You will likely need an EQ6 or something with a higher payload capacity.

If you can afford it, get the CF model. It has better thermal stability.

[TrevorW]

Heq5 would not be suitable IMO for the combined weight of the GSO 8", guide scope, camera etc

[Poita]

Pick up a 2nd hand EQ6Pro for the same money as a new HEQ5Pro, or get a new EQ6Pro.

For visual an ED80 will be disappointing, but great for photography later.

If you think you are interested in photography, start downloading and processing some subs that other people have done, it is a good way to find out whether you enjoy processing or not. Processing is probably where you spend the most time really.

The RC-8 is good value, and works well on an EQ6. It will be difficult for photography, but I would piggyback an ED80 on it when you get around to photography.

[LightningNZ]

My 5 cents is to get an HEQ5 and ED80 for astrophotography with the money you've saved buy a 10" dobsonian for visual use. Get the best of both worlds!

Cheers,
Cam

[toc]

This.

Ive got a 90mm refractor, and its a joy to image with - I can even just get away with using Celestron's polar alignment routine most of the time - no need to drift align. (which I detest personally)

Start with unguided first, and then slowly build the skill set.

Just for fun, Im trying some unguided photography with my 3000mm Meade SCT. Its a bit of train wreck so far :lol: Glad I didnt start with that.

And I should add - even though the results Im getting are not worth a pinch of goat $%#@ compared to what a lot of people get here, Its extremely rewarding to get something half decent.

[Digital_Artist]

My calculation my calculation on weight was:
GSO RC 8" (metal) 7.5 kg
DSLR camera 1.0 kg
Orion Mini AG link http://www.optcorp.com/product.aspx?pid=210-16639
package 0.6 kg
Ring, plate 1.5 kg
Total 10.6 kg

Is the calculation correct or should i add something? Even though prescribed payload for HEQ5 pro is 15 kg but it is said that for AP it should be less than 10 kg.

However, in some other places i read that if the balance is right then payload can be increased. Even in an youtube channel one person said that he put up 50 pounds of weight on EQ6 pro even though its maximum capacity is 40 pounds and it works. If it works for EQ6 pro why not HEQ5 pro? please explain.

[Digital_Artist]

thanks to everybody for your good advice. However, EQ6 pro would be over my budget. However, see the link to let me know if it will do the job:
http://www.bintel.com.au/Telescopes/Reflector/Bintel-BT200-f/5-HEQ5-Pro-GOTO/1006/productview.aspx
again do i need field flattner/ corrector if yes then which one will fit it?

Thanks in advance.

[rmuhlack]

Yes you will need a corrector. My suggestion is the Baader MPCC
http://www.bintel.com.au/Astrophotography/Reducers--Correctors--Flatteners/Baader-MPCC-Coma-Corrector--2--/676/productview.aspx

I have a MPCC too, and reckon it would be a perfect match with the f5 newtonian you're now looking at.

[rmuhlack]

Pics as requested by Digital_Artist via PM (note that my mount is a EQ6 and not a HEQ5)


1. Camera + MPCC
2. how Camera + MPCC is attached to mount
3. Camera + MPCC attached to mount
4. 200mm f4 with piggyback guidescope
5. 200mm f6 with side-by-side guidescope

[Meru]

I agree with everyone else, go with a small APO refractor for now. They do just fine for visual, and excel in Astrophotography. I have a RC8 and very surprisingly, it does quite well in visual, considering it wasn't designed for it. I find my 17mm Stratus to be a perfect combo for viewing. You definitely need a diagonal otherwise you will break your neck, same applies for if you get a refractor. You don't really need anything else for the RC8, it's fine as is. Also I have a NEQ6, and I can tell you that a HEQ5 would not be able to handle it, especially once you start adding cameras and guiding to it. The mount is by far the most important item in your arsenal, and I know you mentioned you cant afford it but if you can save up a little longer, I'd say get a NEQ6. Even if you dont plan to image with 10" beasts. It was a diabolical cominbination with my 80ED, I could practically kick the damn thing and the stars wouldn't move (Though advisable not to repeat my experiment lol).

I personally went through quite a few scopes before settling on a RC8. With a CCDT67 (Focal reducer), it becomes a ~1000mm F/5.6 scope so it's kinda like a two in one. But it is quite challenging to guide at these FLs compared to a 80ED or the likes, and it might be so hard with a RC8 that it will put you off Astrophotography for a very long time trust me. Be sure to consider other small-ish APOs not just the 80ED if you wish to go down this path. They seem to sell a little overpriced here, I mean I sold mine for $480 shipped to NSW... so keep an eye out for any second hand bargins :) an ST80+QHY5 will comfortably guide anything up to 1000mm, provided you have good Polar alignment. And that will take time to perfect!

Lastly an DSLR, even a very old one, will teach you ALOT about astrophotography. My ~7 year old DSLR gave me some of the best pics I've ever taken and dont have to faff about with cooling, drivers etc. Just turn it on and click. So just take your time and see where it takes you :) Good to see you're atleast doing your research before delving into it. Good luck!

[swannies1983]

Yes, generally you want the total weight to be well less than the prescribed payload for imaging purposes. There is a rough % of total but I can't remember it off the top of my head. Maybe 75% of max payload? I'm sure someone will know.

I wouldn't get to excited about one person saying they have gone well beyond the maximum payload of their mount. For every one person who has success, there are likely to be many more unsuccessful attempts. Just as example of someone who had issues imaging with a RC8 on a HEQ5 mount, dugnsuz (Doug) ended up selling his RC8 because his setup was too heavy (see threads here (http://www.iceinspace.com.au/forum/showthread.php?t=86688) and here (http://www.iceinspace.com.au/forum/showthread.php?t=85613)). You also have to consider Doug was using a reducer and still having problems. Guiding issues will be even worse if guiding at the native focal length.

Also, I'm not sure how well the Orion Mini AG will work with the setup, particularly at the RC's native focal length (then again, I have had success using my Skywatcher finderscope as a guidescope but I still need to do more testing). You might need something with a longer focal length to get better guiding. If you do, then that will add more weight to your payload. I use an old 60mm f/11 tasco refractor as my guide scope (see picture here (http://www.iceinspace.com.au/forum/showpost.php?p=928998&postcount=819)). I generally only go out to 5mins and get round stars most of the time. However, I just did two 1hr sessions of going out to ten minute subs over the last two nights and probably 80% produced pretty good stars. I also don't use a focal reducer.

This (http://www.flickr.com/photos/47268787@N05/8401833164/sizes/l/in/photostream/) is what I was able to achieve with my RC8 and a modded Canon 30D. I have just finished collecting 9hrs of The Running Man Nebula which I will process over the coming week.

BUT in saying all this, I agree with what a lot of people are saying. Imaging is a tough ball game and you need to work your way up. Wide field imaging is more forgiving. A lot needs to go right if imaging with scopes of long focal lengths such as the RC8. I spent several frustrating months sorting out guiding issues when I started imaging with my 8" Newt. The RC8 (with no reducer) is less forgiving so I've had to tighten up my guiding again.

I hope all this helps :)

Dan

[Meru]

My friend had a HEQ5, and with 12kg worth of telescope and equipment, it was struggling with the guiding. Trust me you dont want to be that close to the limit for AP it will just cause you big headaches down the road. You also have to take the limits of the mounts posted by the manufacturers with a grain of salt, they're usually more optimistic than realistic. It might be able to move and guide the scope around but doesn't mean it'll do it well! It's like driving your car flat out on the freeway. Sure, the car will do it but is it safe and how much will the car wear out? Probably a bad analogy but you get the point!

[toc]

I would also add - its like driving a 1984 Daihatsu Charade Flat out down the freeway - works, but the slightest gust of wind blows you off the road :)

[Meru]

LOL good one Tim, yes thats basically what I was getting at.

Though I could go one better - Datsun 120Y with 5 adults on the freeway?

[cybereye]

Wow, I have a HEQ5 Pro mount and had a 1984 Daihatsu Charade!!

I have a CF RC8 on the HEQ5 Pro mount together with an ST80, QHY5 and QHY8L cameras. So far so good, I've had no issues with guiding or wind. I did have problems when I had my old 8" newt on the mount in wind - it was like putting up a spinnaker - but I'm quite happy so far. Having said that, I'd quite happily upgrade to a bigger mount if I could - then I could upgrade to a bigger scope!

Always look to the future is my AP motto... :D

Cheers,
Mario

PS Once you start guiding you can always remove the finderscope to reduce the weight...