EQ mount for my 10" newt

[iceman]

Hi all.

I'm starting to investigate the possibility of getting an EQ mount for my 10" newt.

While my EQ platform works great, it does make for some hard work when trying to track accurately at over 8m focal length. It adds untold frustration to an already frustration pursuit so I'm looking at reducing frustration and getting better images by putting my newt on an EQ mount.

I suppose it will also allow me to do some DSO photography, but that is not the main concern right now, as I can't bring my 350D or DMK to focus (at newt prime focus) without moving the mirror up the tube. Lunar/planetary photography is still my passion so any DSO photography that results is a secondary benefit and not my main purpose of getting an EQ mount.

So what sort of mount do I need, and how much do they cost?

I'm guessing that my 10" newt + imaging train (filter wheel + DMK + cooling system) will weigh something like 35lb (15-16kg). I'll put it on the scales tonight to make sure.

My budget is limited. Well, actually I can't afford it at all right now, but i'm just doing my research.

Will a HEQ5 hold it? EQ6? Orion Atlas? G8? A G11 is so far out of the budget it's not funny :)

Goto is preferrable, but I realise it will add extra cost in most cases. For now, accurate RA tracking (at over 8m focal length) with RA/DEC adjustments via hand controller is all I really need.

I'll probably keep my dob base for the option of swapping to it for visual work, though I might sell the EQ platform to help fund the EQ mount. Haven't really thought that far into it yet.

What else do I need to think about? Added costs?

I know I need to get some rings, for a start..

Input/suggestions most welcome.

Thanks

[matt]

EQ6 should hold it fine Mike.

[Striker]

Get the syntrek EQ6 mount if no goto is needed..you can always buy the skyscan hand controller later on thats just simply plugs into the existing port for full goto.

I would be staying away from the HEQ5 for a 10" Newt.

[Dennis]

Hi Mike

More of a list of things you should consider, rather than a specific recommendation.

You need to distinguish between:

Accurate tracking, and...
Accurate auto guiding.
To keep the planetary disc in the central region of the FOV may not require an expensive, premium mount with a low periodic error that is designed specifically for auto guiding hour long deep sky images.

Auto guiding at focal lengths greater than 2m is difficult, regardless of mount, e.g. Losmandy G-11, Takahashi EM200, etc.

Your “long” Newtonian will be more vulnerable to the wobbles compared to an SCT which has a short, stumpy tube. Likewise larger refractors have a longer moment arm, due to their longer tube lengths.

Having the option to select Sidereal, Lunar and Solar tracking rates can help minimise corrections you make to keep the image centred at high magnifications.

The Moon moves in Dec as well as RA compared to the sidereal rate, so expect to be making constant (but small and consistent) corrections to keep highly magnified lunar features centred. I use the circular red reticules in K3CCDTools to help keep a lunar feature reasonably stationery whilst I capture a 3 or 4 minute avi.

When trying to image the moons of Uranus with my C9.25 and x2.5 Powermate, I am working at F25 which is an effective focal length of 5.875m. More than 50% of the images show elongated trails with exposures of 3 or 4 seconds. At these magnifications, you cannot auto guide and the periodic error of the mount is magnified due to the long effective focal length.

Cheers

Dennis

[ving]

i am looking at a heq5 for my 8" mike, you'll need something bigger. an eq6 will do the job tho :)
good luck in your search :)

[Starkler]

I have heard it said that the eq6 really is undersized for a 10" f5 newt.

Is it going to be any better for Mikes purposes than the platform he currently has? I suspect not. At long focal lengths the slightest breeze could have it oscillating and wobbling all over the place.
Maybe on a solid pier with a solid dovetail it might be ok

[h0ughy]

Get an EQ1 and be done with it mike!!!


this is the third time you have mentioned this, get the eq6 and some mounting rings...........re conversation a few months back!

[gbeal]

Ahh, a good start, I thought you were destined to be the only IIS member without a GEM.
I have a scope the same as you, a 10" f5 newt. I have had this on a succession of mounts, from a G-11, then an EM200, and now an AP600E. All have handled it well, but more recently the scope has been to a weightloss clinic, and the result is about 4 - kilos of weight reduction.
OK, while I haven't used an EQ6 I feel (perhaps wrongly) that it will "only" just do what you require.
My suggestion is the G-11 at the least, sorry. But if you sell the tracking platform you will be part way to a G-11 anyway, especially used, so maybe think along those lines. My newt in the sonotube was about 14 kilos as an OTA bare. It is now about 10 and a bit. Plonk a guidescope onto that, then a camera, and a few other bits and I am well over the 15 - 16 kilo mark, and that is in the "skinny" version. It was possibly near 20 kilos before.
Like has been pointed out, the scope is long as well as heavy, and this taxes a mount as much as anything.
I suppose at worst try an EQ6 and be prepared to make do for a while, or see if you can try your scope on one, with someone else on the forums. In my case the dovetail and rings (Vixen) weigh heaps as well which doesn't help.
Gary

[Dave47tuc]

Hi Mike,
I have an Atlas same as EQ6. In all honestly don't bother with this mount for your 10". Please don't waste your money.
The EQ 6 is ok for little scopes like mine or an 8" sct or 9.25"sct. But thats about it. People will say different, but that's there opinion, this is mine after using one.:D

Save your money and get at least a G11 or bigger.:)

[Striker]

Everyone does have there opinion Mike and I am a lover of the Losmandy G11 but the EQ6 use to handle my C11 with Orion ED80 ontop just as well as the G11..they are rated about the same....I do think the G11 can handle more weight slightly but weight is not the issue.

Both rated with 25kg payload.

If you did go down the EQ6 trail get a modified EQ6 dovetail and some solid tube rings..this will make all the difference....anyone using the standard aluminium EQ6 dovetail with a large OTA is wasting there time.

I also would like to see you with G11 but its a huge difference in price.

[Astroman]

I agree with Tony, if you do get the EQ6, get a dovetail made up out of a solid billet of Aluminium. and get it at least 13" long if not a bit longer. The EQ mount takes a little getting used to with a Newt sitting on top. If you want accurate GOTO go the Gemini and G11 :D

[iceman]

Thanks for all the advice so far guys, isn't the G11 like $5k?

If so, I'll be stuck on the EQ platform for a long time to come :(

If the G11 and EQ6 are rated the same, then what's the difference? Stronger gears? More solid tripod? Less PE?

[Striker]

All of the above and thats what make s a good mount.
big difference in quality Mike...havn't you seen a G11 at any of the star parties.?????

Its like comparing a Skywatcher 80mm to a Takahashi.
Much better build quality....but saying that the EQ6 are great value for money.

[[1ponders]]

You might want to check this out (http://www.myastroshop.com.au/products/details.asp?id=MAS-010)Mike. I once asked Steve Massey how heavy the Skywatcher with finder and eyepieces were. He came back with 14.5kg. Since then Gargoyle_Steve and I have weighted his 10" GSO/Bintel? dob with eyepiece and finder scope: 15kg with the bathroom scales.

Seems pretty straight forward to me :shrug: especially if your major interest is only planetary imaging.

[DaveO]

Mike

I have the SkyWatcher Paul refers to above, but with the GOTO version of the mount. I have been very happy with it. The mount is very solid (and heavy). Glad I made the decision, and once I got the alignment process sorted, have been very happy.

[bird]

C'mon, get serious. Sell a couple of the kids and get a Losmandy TITAN!!!

Oh, ok, ok. Sell just the one child then, and get a G11 :-)