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earth titan

Suggestions for a mount

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I'm planning to start some basic and low cost astrophotography, using a 80mm refractor which should be heading my way.

I'm planning to use a DSLR rather than a web cam (means the kit will remain portable and no need for a PSU).

I need to procure a cheep mount and am looking at EQ2 mounts as these appear plentiful and cheep on fleabay. One can be picked up with a scope (which can be stripped off and punted back on fleabay) for not more than £75. I hope to motorise it and work from there.

Will an EQ2 be stable enough or will I need to move up to an EQ3?

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I'd go for an EQ5 or CG5 which would give you more like the stability required for dso/dslr imaging. But I guess it depends on your budget. A goto one would cost around £300-£350 on the second hand market. I have a Meg 72 on CG5 which seems to be ideal.

You could try it on EQ2 or EQ3 but stability issues will make it a very fussy and fiddly experience with the 80mm and dslr. Imho it's allways better to go large on the mount for best results. :hello2:

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sorry but i would have to second the idea of the EQ5 as a minimum, any thing less and you will really struggle to keep things steady

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I think it will depend on how mechanically adept you are, do you have access to tools and a workshop? The mounts you mention just dont seem to be used for astrophotos. Whether they could be made suitable is another matter.

The common failing is the smaller mounts flex under load, lack rigidity to resist any external force and dont track in a smooth accurate arc with the sky objects. In particular the tripods get a lot of criticism for being flimsy.

Regards

Barry

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ive done some AP with my eq2 mount and it will track and copes ok with a webcam but i doubt it would react well to a DSLR, the eq2 is a very basic mount and the tripod whilst ok for casual observing is way too flimsy for anything else. there is no facility for a polar alignment scope and with the motor being just a bolt on unit there is scope for drive issues.

just go to a telescope shop and check out the difference between an eq2 and eq3-2 to see how basic the eq2 is. the eq5 is in a different league and that seems to be from what others say a bit lightweight with larger scopes.

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An EQ5? I'm surprised I shall need anything so robust!

I can see the EQ3 may be the one I need, as it has polarscope mount etc.

Initially the scope has been purchased as a grap and go / travel set up as I am often away from home and the lightbridge is wayyyyy tooo large to take with me.The scope is an 80mm f6 and I intend to fit a Cannon or Nikon for photogrpahic work (occasional) but I don't have the time to devote to it many people here do.

Would an EQ3 suffice do you think? I used to have one on a 150mm newt at one time and it seemed quite robust.

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As a grab and go for casual observing only, the eq2 or eq3 would fill the bill. But dslr imaging of dso's really requires far superior stability - don't forget the shutter will be opened for 5 or 10 mins at a time and the image has to stay in exactly the same place on the chip all that time. A slight gust or someones footsteps round the scope will upset the image position on the lesser tripod/mount combos :hello2:

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An EQ5? I'm surprised I shall need anything so robust!

I can see the EQ3 may be the one I need, as it has polarscope mount etc.

For any astrophotography you need to put the mount at the top of your list.

With ~1500mm focal length you need 1 arc second or better tracking (roughly.. this is where I'm at). With only 150mm focal length you'd need 10 arc second accuracy... which is still pretty demanding. Concidering stars on the celestial equator are moving at 15 arc seconds per second, if you weren't tracking you'd start getting star trails after only 0.7 seconds.

I hope that puts some context on this

Derek

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Makes sense. Presuambly this level of tracking is possible with a standard drive?

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Having tried simple (i.e. Lunar and a stab at planetary) photography with my Meg72 on a camera tripod I can certainly recommend going for the biggest sturdiest mount you can afford. Trying to focus was a nightmare as there was too much movement and the slightest breeze or vibration from the ground meant it take a while for vibrations to settle. I now have an EQ5 and (though I've only been out ONCE in the past couple of months - and that was only for observing, no AP) can thoroughly recommend it for stability. Rock solid without any trace of vibration when focussing. I'm looking forward to getting set up for AP as there are one or two targets I'd like to try while I have the chance (Albireo being the first).

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Makes sense. Presuambly this level of tracking is possible with a standard drive?

I would listen to the advice above. For any serious astrophotography the mount is the essential piece of kit IMHO. An EQ5 as a minimum will future proof you especially if you decide you want to upgrade your scope.

The EQ5 or EQ6 range will have far better motors than an EQ 2 or 3. Having said that you would still only be limited to around 3min subs, unguided. This is because of inherent errors within the worm gears etc. That is to say, not everything is machined to perfection and tiny little errors, especially at long focal lengths, will limit what you want to do.

The other thing to consider is weight and stability. You really need a sturdy mount and tripod to prevent and unwanted vibrations. This more so important with mounting a DSLR which are often quite heavy, comparatively speaking.

That isn't to say you wont get some results with an EQ3 which is motorised, just don't expect miracles. You might be able to get up to around 1-2min subs with good polar alignment and a good, tuned, set of motors (for this you may need to strip down what you get and degrease and re-grease and tune - if you are technically up to it.)

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Even with the EQ5 - I would say this is still a basic.

I bought the standard EQ5, for starters & then the basic motors - it's struggling.

Will be getting a better mount before the winter season.

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Firstly I'll echo what everyone else has said... the mount is the most critical part of an imaging setup, generally the bigger the better.

This doesn't mean you should struggle financially getting something that's way over your intended budget. A second hand motorised EQ3 is a good place to start, and if looked after you'll more than likely get your money back if you decide to upgrade.

Cheers,

Ian

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I have used an EQ3-2 and an EQ5 for unguided imaging and there is not much between them. The tripod was more stable on the EQ5 but the mount and motors on the EQ3-2 were smoother.

With only an 80mm unguided I would look for a motorised EQ3-2 or if you want to future proof your kit, skip straight to the HEQ5.

This is what I got with a whole heap of 90sec subs from a 150P + Canon 1000D on an unguided EQ3-2. Not a very good image if you are looking for pin point stars and nice colour and loads of Ha data but you can tell what it is.

It's not ideal and it's not easy but to say an EQ3-2 can't be used for imaging is not true.

post-18573-133877623677_thumb.jpg

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An EQ3 is the ABSOLUTE minimum for DSO imaging with a short focal length instrument, really the EQ2 isn't up to the job. The difference between at EQ3 and an EQ5 is not huge but every step up the ladder is worthwhile. Without a doubt, the most important piece of equipment for DSO imaging is the mount, don't go for the absolute minimum unless you really don't have a choice and don't go below the absolute minimum or you will be seriously disappointed.

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Thanks Rik. Appreciate the photo.

If I could achieve that standard, I would be chuffed.

An eq3 sounds like a good start then upgrade if I want to do better in the future. I don't want to throw thousands at this.

I want it to act as a grab and go and basic imaging set up.

Edited by earth titan

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I am glad you like the image. It is the best I have managed after a year of learning :D

I bought the EQ3-2 because I don't have ££££ to spare and I wanted to find out if imaging was something I might enjoy. It was something to get started, no more.

It is frustrating because the tracking accuracy of the RA motor is not great and it is not very stable in the wind. I made it even harder on myself by sticking a 6" Newt on the mount as well. :hello2: I did this with the full understanding that it was stupid, but I wanted the scope mainly for visual use and I simply didn't have the budget for two dedicated scopes.

I take loads of short 30 - 90sec subs and 1/2 - 2/3 of them are unusable. This means I am limited to only the very brightest deep sky objects and it takes a lot of effort for sometimes very little in the way of results.

If you are in any way serious about getting into imaging, read Steve's book first.

I wouldn't want you to be disappointed on account of something I said. Maybe my standards aren't very high, but I am not ashamed to post my best images on this forum. Like you said, "basic imaging". As soon as I can afford to (12-18 months), I'm upgrading to an HEQ5 and an off-axis guider.

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I always thought "low cost astrophotography" was a contradiction in terms ;)

Of course, it depends what you are aiming for. My first DSO photograph (on Fujichrome 400 pushed to 800 ASA, or ISO, for young whippersnappers :D ), with a 135 F/2.8 telephoto piggybacked on a Tasco 114 F=900mm on EQ2, with manual tracking. I got a result I was very pleased with, even though I could see shortcomings.

Seriously, I could upgrade my Vixen Great Polaris mount with dual axis motors and guide port, but I prefer to save op for something sturdier to attach my 80mm F/6 to. Mount first is the way of the "dark side"

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