C8 with ED80 on HEQ5

[Astro_king]

Hi,

Long story short, I have been away from the hobby for few years now and contemplated on selling my gear which included a 200p Newtonian/heq5 for DSO astro imaging and a nexstar 5se for planets.

However, a quick look at Saturn this week and I realised why I loved this hobby so much.

 

This time, I want to setup my own pier for Heq5 in the backyard along with some sort of cover with hinges to easily remove and reattach.

 

Since I can't setup a shed the Newtonian 200p has to go. I was contemplating putting a C8 onto the Heq5 and then mount an ED80 on it for DSLR astro imaging. The C8 would then be used for autoguiding and planetary photography along with visual (the 5se is actually quite impressive with DSOs visually from manchester's polluted skies given the limited aperture). I already have a QHY5 II colour camera for this which I intended to use with the 9x50 finderscope but never got it to work (sighhh).

 

This would be a permanent setup that would allow DSO photography with a DSLR on ED80 and visual/planetary photography on the C8. Also for those small sized DSOs that need "Zooming in", the C8 would be used with a DSLR and ED80 as guide scope.

I have checked nd the Heq5 can only do max 11kg for imaging and the ED80 is 2.5 KG and the C8 is 5.6 kg so still well within the 11kg limit which leaves almost 3kgs for guide camera and DSLR/dovetails.

Reason for this post is for the knowledgeable peeps in this great forum to guide me with what is wrong with this setup so that I can avoid mistakes or shelve the whole idea altogether.

 

 

[valleyman]

Glad you started this thread, was thinking of doing exactly the same thing.

So am watching with interest.

 

Pat

[Astro_king]

yes Valleyman,

 

It's the best of both worlds thread

Nothing beats the views you get of planets on the SCT! imho. I looked at Jupiter forever from my 200p dob trying to figure out more detail apart from 2x bands and then when I bought the nexstar 5se, me and my mrs spotted the great redspot!

 

 

[Chris]

I had a very similar setup pier mounted at my old house and loved it, I'd say go for it   

Mine was a C8 Edge HD plus WO66, but I think various combos would work e.g. 150Mak and 80mm f/5 Esprit triplet, C8 xlt and WO61 etc. 

[Astro_king]

thanks Lockie, that setup looked amazing!

[pete_l]

One thing, the quoted weight limit for the HEQ5 is not an absolute "X" kg: 1 gm less will be fine and 1 gm more will be a complete failure. It is just that things (balance, tracking, wind resistance) get progressively harder with more weight, with bigger (even if they are light) scopes, with long OTAs.

An HEQ5 is marvelous with an ED80, DSLR, guider+cam (pity you couldn't get that sorted - what went wrong?). And will easily return 9 out of 10 subs as being pretty close to perfect. To the point where, if the alignment is good and it isn't windy, it's almost boring!

But add another chunk and things get much, much, harder. Even if it is still within the notional "limit".

If it was me, I'd use the mount for either one: SCT for eyeballing or ED80 for imaging,which ever takes your fancy on a given night. But I wouldn't mount both at the same time. The key to that would be to get the guider to play nice.

[Astro_king]

1 minute ago, pete_l said:

One thing, the quoted weight limit for the HEQ5 is not an absolute "X" kg: 1 gm less will be fine and 1 gm more will be a complete failure. It is just that things (balance, tracking, wind resistance) get progressively harder with more weight, with bigger (even if they are light) scopes, with long OTAs.

An HEQ5 is marvelous with an ED80, DSLR, guider+cam (pity you couldn't get that sorted - what went wrong?). And will easily return 9 out of 10 subs as being pretty close to perfect. To the point where, if the alignment is good and it isn't windy, it's almost boring!

But add another chunk and things get much, much, harder. Even if it is still within the notional "limit".

If it was me, I'd use the mount for either one: SCT for eyeballing or ED80 for imaging,which ever takes your fancy on a given night. But I wouldn't mount both at the same time. The key to that would be to get the guider to play nice.

Cheers pete.

I bought the guider 2 years ago, tried guiding on a clear night, took forever to test on PHD (was trying to find stars on 9x50 finderscope) then clouds came and ruined it. Fell sick next day maybe caught a cold and that was when this hobby became too painful for me. I only returned last week to it thanks to my portable nexstar 5se.

So if the C8 along with ED80 is too much for Heq5, maybe I can sue the 5se SCT OTA with ED80. Even though the 5se is a great OTA, I do feel like I suffer from aperture fever on it wondering what the 8e would have looked like.

[Chris]

1 minute ago, Astro_king said:

Cheers pete.

I bought the guider 2 years ago, tried guiding on a clear night, took forever to test on PHD (was trying to find stars on 9x50 finderscope) then clouds came and ruined it. Fell sick next day maybe caught a cold and that was when this hobby became too painful for me. I only returned last week to it thanks to my portable nexstar 5se.

So if the C8 along with ED80 is too much for Heq5, maybe I can sue the 5se SCT OTA with ED80. Even though the 5se is a great OTA, I do feel like I suffer from aperture fever on it wondering what the 8e would have looked like.

I never bothered with guiding, just wasn't ever for me the few years I was imaging. I was quite happy with the simplicity of 2-3 minute unguided subs at a sensible focal length suitable for the mount. 

If I was to get back into imaging properly now days I would be looking at the new generation of cooled CMOS cameras. You use much shorter subs with these but just stack more of them, similar to planetary imaging really. No guiding required, yaay! 

[pete_l]

Set the guider + cam up during the day. You might find that the camera won't come to focus without an extension tube. I needed to get a 35mm extension from Telescop Express for this.

[Astro_king]

Just weighted my 200p Newtonian which was taken out of a dob base. It weighs 9.5 kgs. So along with DSLR weight, this explains why I would get trails on subs beyond 45 seconds. But I suspect my poor polar alignment had to do something with it too.

The great thing about a set pier is your polar alignment can eventually be accurate to the T.

So based on this new checked information I might be able to get the same performance out of this setup too. Then its like pete said - down to guiding.

Seems like Heq5 will just about do on this setup but Neq6 would fare much better.

[Chris]

2 minutes ago, Astro_king said:

Just weighted my 200p Newtonian which was taken out of a dob base. It weighs 9.5 kgs. So along with DSLR weight, this explains why I would get trails on subs beyond 45 seconds. But I suspect my poor polar alignment had to do something with it too.

The great thing about a set pier is your polar alignment can eventually be accurate to the T.

So based on this new checked information I might be able to get the same performance out of this setup too. Then its like pete said - down to guiding.

Seems like Heq5 will just about do on this setup but Neq6 would fare much better.

The 1200mm focal length of the 200p f/6 Dob OTA will have contributed to tracking difficulties as well as the weight. Keep what ever DSO imaging scope you get short and it will make life easier. Think about how steady you can keep your finger with your arm out stretched, then think about how steady you can keep the end of a pool que at arms length (likely not very steady), this is the same for how tracking accuracy is effected by focal length for a given cameras pixel size.