HEQ6 for future astrophotography.

[FarSide]

First of all i hope you guys enjoyed/are enjoying Perseids!

Here's a question for you. I will be starting to construct an astrophotography rig in the next few weeks but i'm a little worried about my mount. I currently own a 250px newt piggybacked by an ED80 that i'm using primarily for viewing at the moment, but i'm a little worried by the payload that i'm going to be adding to it as i start collecting and fitting other bits and bobs to the set up for photography. I really don't want to be photographing with a dslr, and ideally i want to begin with a CCD camera. I am however worried about the stresses this will put onto the mount once i start adding CCD cameras; guild cameras; filter wheels etc, and late next year i will be upgrading to a 10" Altair Ritchey Chretien which i believe is very heavy in itself.

So here's the question: with a full CCD set up, and the Ritchey Chretien, will my HEQ6 be able to hold out or will i need to further upgrade to a larger mount? A larger mount will be a big investment.

Thanks for your answers in advance.

BTW no idea why i put HEQ6 when i meant NEQ6.

[crazyjedi]

I don't have experience of mounting an RC but I do know that they are heavy.

Check on-line and compare the weight of the RC you are buying to a 250 newt (look at me being all modern and metric). I think the 250 newt plus piggy back frac guide scope etc is ok on an EQ6 but if the RC is a serious increase in weight you may be pushing the stability of the mount for long exposure images.

If you are buying an RC you are obviuosly taking your atrophotography seriously and there will be someone on here that has more experience than I on these things but I reckon you are pushing the stability of an EQ6.

The step up in mount is going to be ££££££££

[FarSide]

Hey Rob,

Yes this is my problem; i think the RC will completely go over the payload that the HEQ6 can handle, particularly with the rest of the hardware on the back. I would rather not yet have to buy a heavier mount if i can balance out the RC and CCD gear on the HEQ6, and if it comes to me having to i'd rather get the mount first, if you see what i'm saying. I've had permission from the wife for the gear so i might as well open the window while i can!

[crazyjedi]

I think you will need to take the plunge and get a new mount. If the mount is anywhere near it's full payload it won't be steady enough for good long exposure images and won't do that RC credit. If you've been given permission to spend the money (you lucky fella) you should do a proper job of it. (I wish my wife would let go of the purse strings too )

The SW NEQ6 is a fab mount but I think it'll be pushing it's capabilities handling a fully loaded 250mm RC.

Any tips for pursuading my wife to let me spend more on my kit?

[ollypenrice]

Don't get obsessed about payloads. Think accuracy. That is the real issue and is under-discussed by beginners in AP. Those those who have been at it for a while know how critical it is.

An EQ6 tends to be plug and play (with autoguider) up to a metre of FL. Then it gets harder. I call a halt at a metre and put longer FLs on better mounts. However, Tim has posted stunning images from a C11 at about two and a half metres FL. Very impressive indeed, no doubt about it, but I very much doubt that it was remotely plug and play. My own EQ sixes wouldn't have a hope in hell of guiding at those FLs without major intervention from me. If the scopes weighed a gram apiece that would still be the case. It's the FL and its need for very high precision.

The weight of the AA RC is considerable. The FL is considerable. The F ratio is slow so exposures are long. I would put this scope on a different class of mount to the NEQ6 or think again. Go for the Mesu Mount 200.

Don't guide a long FL refelector with a guidescope. You need an off axis guider.

If you are building your first AP rig do you realize how serious an undertaking it is to go straight in at long focal lengths? The standard, and sound, advice is to be over-mounted by using a short FL and physically small telescope. And have you considered the UK seeing? The long FL requires good seeing or you might just as well use a shorter FL and have a wider field of view because the seeing will consume you long FL resolution on many nights of the year.

You do not need aperture to get great astrophotos. You need a mount that keeps you nicely sub-pixel in guidnig. You need a fast F ratio and - you are onto this already! - you need a CCD camera.

Olly

http://ollypenrice.s...44788&k=r8HTK72

[FarSide]

Hello Olly, thank you for your reply. I guess my assumption of buying a dedicated astrograpth was wrong, i think i assumed the RC with it's design would aquire better results. Would you advice then, putting the 250mm newt and RC aside that a 190mn might work due to it's faster f ratio coupled together with a OAG and low weight? Or would spending the money on astrophotography hardware and a top quality ccd camera would be better spent money and stick with the 250px?

[ollypenrice]

Personally I would say the priority is mount, camera, optics. Mount first is not contested and I'm right on the rest ( ).

I would give yourself a chance as a beginner and go for a small fast apo, a mount that carries it easily from FL and weight point of view, and a mono CCD with filters. You don't need to spend a bomb on an electric wheel. All my images other than those using Yves' 14 inch are with a manual wheel.

Altair Astro do some good triplets like the 80. The SW 80 is good but not available and the flattener is an extra. The Atik Sony chipped cameras are a dream of low noise and high sensitivity.

What is an astrograph? To me it has to have small spot sizes, good colour correction, a fairly flat field and a fast F ratio.

Olly

[crazyjedi]

Well here's my big plan for myself. my next scope will be the SW 250 on the SW NEQ6 SynScan.

Then When my wife has recovered from her heart attack I will buy a good short focal length Apo that I will mount on the NEQ6. As the Apo will be much lighter than the limit for the mount it'll be rock steady. I'm planning to strap a Canon DSLR on to the back end of the Apo plus a guide camera + scope but the weight of all this should be well inside the mount's limits.

I reckon this will be a good entry into astrophotography for me. I will try the camera on the 250 newt first and then if It takes off I'll go for the Apo

Now any idea how I convince my wife? :p

[FarSide]

Olly, i've given you PM; i hope you don't mind.

And Rob, you put your foot down and tell her how it is. Who am i kidding? You grovel, grovel like there's no tomorrow, and plead insanity.