Basic HEQ5 not worth it?

[Bizibilder]

Basic motors - the mount moves at "siderial rate" and in theory will follow an object as it "moves" across the sky. (The movement being due to the earths rotation).  This is OK for visual use and will keep an object in the field of view for quite a while as long as the mount is accurately polar aligned.  The Dec motor is normally off, unless you need to make a correction (due to poor polar alignment).  The rate of tracking is slightly "out" for the Sun and Moon as these do not move at siderial rate.  To upgrade you have to replace the motors, control board and handset - this costs far more than buying the "better" mount in the first place.

SynTrek is more or less as above BUT the motors are different (ie suitable for goto or computer control) and the mount can be upgraded to full SynScan by the purchase of the SynScan hand controller.  The mount is not goto. Alternatively it can be made goto by using a computer and freeware like EQMOD - you will still need to buy a relatively cheap cable connector from the computer to mount.

Synscan is goto and will "find" objects for you and will track them as above.

Guiding is completely different.  To guide you use a second camera and telescope (or an off axis guider).  The guide scope "locks" on to a star and then sends signals to the mount via software like PHD to tell the mount to correct for any drift in the guide star.  Many folk use EQMOD/ASCOM/PHD for guiding and discard the handset completely.  This will only work with the Syntrek or Synscan type mounts.

The goto handcontrollers and EQMOD have to be "told" where the scope is pointing - usually three bright stars - hence the name "three star align".  They then have an inbuilt "starmap" that they use to "goto" your chosen object.  For the handset this is about 14000 objects.  With EQMOD it depends on your chosen star atlas - I use Cartes du Ceil with the extra databases loaded and I have a database of several million objects and can "goto" any one of them.

Hope this helps - it is confusing for beginners.

[ianpwilliams]

Thanks, that does help a bit. It does seem that SynTrek and a laptop with EQMOD (and other software) is the way to go then. I was a bit concerned when you started talking about having a second camera and telescope (one telescope and camera isn't enough?!?), but then it sounds like you can get around that if you have a laptop, so that's hopefully ok.

But if I did buy, say, a 150PDS on an HEQ5 SynTrek, and to begin with I just wanted to do visual, how could I find objects, knowing that I wouldn't have GOTO, and bearing in mind that I don't have a laptop at the moment (I would eventually buy one for photography)? I mean, I was initially quite keen on the idea of finding objects myself in order to learn a bit about the sky, but at the same time, it sounds like that it might not even be possible to do that? Or does the SynTrek hand controller allow you to find some objects? And I think I'm right in saying that the SynTrek already has built-in motors, so it would be able to track objects for visual, correct?

[malc-c]

Could someone please give me a brief explanation of how guiding and tracking works in relation to dual axis motors, SynScan, SynTrek, GOTO etc?

As far as I understand, you first need something to help you find the object you want to photograph, which may not be as hard for planets etc, but would be hard for deep space objects, which you wouldn't be able to see. The FLO website says for the HEQ5 SynScan says "Object database containing complete M, NGC, and IC catalogues.", but doesn't say that for the SynTrek, so I'm guessing that must be what the GOTO does? In which case, how would you locate an object using the HEQ5 SynScan? Would you need a laptop with software?

Then it seems you need to track the object while you photograph it, and the better the tracking, the longer the exposures you can get away with. Which means dual axis motors (the most basic option), or SynTrek/SynScan, where the FLO website says "automatic tracking of celestial objects.", or a laptop with various GOTO and tracking software on it?

Is any of that anywhere near correct?

And how do the SynTrek and SynScan hand controllers vary? FLO says one is manual and one is automatic. What does that mean?

Also, as it does look like PRO won't be a option for me, it seems like a SynTrek with laptop would be the way to go. If I did go down that route, would a basic netbook do the job, maybe something like this:

http://www.thelaptopcentre.co.uk/cheap-refurbished-laptops/dell-latitude-d620-intel-core-duo-166ghz-1gb-ram-40gb-hdd-141-widescreen-dvdrom-wi-fi-windows-xp.html

Let me try to clarify the points you raised;

The HEQ5 syntrek and Synscan have identical motors and control borads as stated above.  The difference between the two is that the syntrek handset has basic 4 buttons for North South East and West movement of the scope and will drive the RA at the siderial rate to keep the target in the field of view.  The synscan handset contains the database of objects and other utilities including the alignment procedure and PEC etc.  This is why the pro sysnscan costs a couple of hundred pounds more than the syntrek version.

Both mounts will track an object once in the field of view as you mentioned, assuming you have polar aligned to a degree of accuracy, which is essential if you want to take images without guiding.

Guiding is different to tracking, in that to the eye a target will remain in the field of view of a polar aligned scope, but over the period of an hour or so it will have drifted from its original position in that field of view due to backlash in the mount or other factors such as cone error etc.  Guiding, either manually or using a second camera makes small corrections to constantly keep the target in the same place in the field of view through out the imaging run.

Using a syntrek HEQ5 syntrek mount connected to a laptop / PC via an EQDirect cable, with  EQMod, CdC, and PHD to handle the scope control is generally typical of an imaging set up (the laptop with EQMOD and CDC is effectivly replacing the synscan computerised handset)

[ianpwilliams]

Thanks, I'm learning all the time here!

So it sounds like some imaging can be done with tracking but without guiding? Would it be the case that planetary would require tracking, and deep space would require tracking plus guiding?

Also, is there ever an argument for taking lots of short exposure subs and stacking them (which Zi've heard some people talk about) rather than trying to track and guide and take long ones?

Also, I believe that GOTO requires mains power or portable power (ie not batteries), as opposed to a laptop which could run on batteries, correct? Because had it been possible to run GOTO on batteries then I would have preferred that option for convenience. Although the database of several million objects has put paid to that somewhat anyway now!

Finally, I'm considering going second hand on an HEQ5, and new on the OTA. If a SynScan Pro came along that was reasonably priced rather than a SynTrek, then presumably I could remove the GOTO (maybe even sell it if it was worth doing), and use a laptop with The SynScan instead?

[malc-c]

So it sounds like some imaging can be done with tracking but without guiding? Would it be the case that planetary would require tracking, and deep space would require tracking plus guiding?

Planetary imaging is a lot simpler.  Most use webcams (or dedicated astro cameras) that capture video at around 15 frames a second and then using software each frame is stacked.  You don't even need tracking to capture planetary imaging this way as you can get enough frames by letting the planet drift across the field of view (although tracking obviously helps and makes thing easier.  The problem is that a good planetary scope is one with a long focal length to give the magnification.  But a long focal length scope is not ideal for DSO imaging where it's less magnification but aperture that is preferred.

Also, is there ever an argument for taking lots of short exposure subs and stacking them (which Zi've heard some people talk about) rather than trying to track and guide and take long ones?

Yes, on bright DSO's like the Orion nebula you can get a fairly decent amount of data with a single 30s exposure.  But fainter objects require longer exposures which is possible if the polar alignment is spot on, if not you will start to notice drift after 60 seconds or so

Also, I believe that GOTO requires mains power or portable power (ie not batteries), as opposed to a laptop which could run on batteries, correct? Because had it been possible to run GOTO on batteries then I would have preferred that option for convenience. Although the database of several million objects has put paid to that somewhat anyway now!

No - both mounts run of low voltage DC - You can use a 13.8v (3 amp) power supply fed from the mains, a 12v car battery, or one of those jump start power packs from Maplin.  It all depends on where you observing.

Finally, I'm considering going second hand on an HEQ5, and new on the OTA. If a SynScan Pro came along that was reasonably priced rather than a SynTrek, then presumably I could remove the GOTO (maybe even sell it if it was worth doing), and use a laptop with The SynScan instead?

Yes - the "goto" is the handset. 

[ianpwilliams]

Well I would be more keen on DSO imaging really, and I was considering a 150PDS - would that be a decent enough aperture while retaining a low focal ratio do you think? Or should I be considering the 200PDS instead?

Also, I didn't realise that both mounts require power. If they both require a car battery or similar, then I wonder if I would better off going Pro, and having a car battery and small handset rather than a car battery and a large laptop. Portability really could be an issue after all. Although obviously the laptop

[ianpwilliams]

...gives more flexibility

[ianpwilliams]

And presumably the tracking motors in both HEQ5 mounts are battery-powered like on the EQ5, so you could do tracked visual or tracked imaging without car battery power?

[malc-c]

Ian,

All SW motorised mounts run on low voltage DC, either 6v or 12v.  The difference in the EQ5 motors and those fitted to the HEQ5 syntrek and HEQ5 synscan have been discussed above, but both run off 12v DC, drawing around an amp each axis when slewing at 8x rate.

Under good conditions an 150PDS will perform well, but a 200 PDS will gather a lot more light having the extra 2" of aperture.  But the 200P is larger and heavier than the 150PDS, and the overall rig is larger, but either OTA on an HEQ5 mount is still classed as portable, requiring two or three trips from the car / store to set up.  I've not used a 150 so can't personally compare the difference, but even under light polluted skies I am really impressed with my 200P.

You can still do planetary -  I used two 2x barlows stacked and a Philips webcam to get the video that resulted in this image of Jupiter

And using a MS Livecam webcam  this one of Mars taken two year ago

So even though both 150 and 200 pds scopes are f5, using additional barlows, patience and a little luck you can still do planetary imaging, and then have the advantage of doing DSO imaging like this

[ianpwilliams]

Thanks again. It looks like I'll hopefully be going for a 150PDS or 200PDS on an HEQ5 SynTrek mount, eventually buying a DSLR, net book, and car battery. Expensive, but better than having to lose money upgrading later. Also not the most portable setup, but people talk about allowing the scope to cool outside before using it, so setting all that stuff up would no doubt fill that time.

[JanH]

How to start? I'm lazy. Often when there is a chance of nice weather next night or so I leave the mount outside and tube attached so I don't have to redo polar alignment and telescope is cooled down and settled. But forcast is often wrong and what seemed to be a nice weather turns into rubbish with clouds and then suddenly I weak up in the morning and there is 10cm of new snow.

 

Some 4 days ago I came to the mount, set it up, plugged in, turned on and nothing, just the LED blinked and the mount did the first characteristic sound. OK, so I took it back home, took apart to find that RA motor is blocked (DEC was running well including slew). I grubbed the shaft with pliers and with just little force rotor started turning freely. So I put everything back together and made some decent images that night.

 

Same scenario happened last night again except the shaft didn't move. I was so angry and impatient that I grubbed pulley housing with pliers and it seemed as the motor started turning but with huge resistance. Later I discovered it wasn't motor that was turning but pulley on the shaft. I couldn't get it off - grub screws made a nice cut in the shaft and pulley stuck there. I managed to tear it apart without any visible permanent damage (except appearance).

 

Rotor was completely stack, I was a challenge even to push it gently out. whole connecting surface was wet and rusty. Rusty water. I swabbed it with ear swabs with some red spirit and rubbed away all the rust and the motor is now turning freely with normal resistance and when plugged back in: IT'S RUNNING!!!!!

 

I guess the water got inside by the shaft. Coils, wires, housing, everything is shining like new.

I was surprised to find NEMA 14 motor (35x35mm)  and not 17 (42mm sq), and it's 34mm long. There is a number on it: HM5GT-F00-1 but uncle google doesn't know anything.

So next time I'll cover it up.