EQ5 pro, accurate tracking? and axis problems.

[Bill B]

Hey, I have a slight query concerning astrophotography. I use an EQ5 pro synscan with a SW 200p (and a Nikon d3100 for photography). I follow the procedure of levelling the mount, accurate polar alignment, balancing the telescope, home position and three star alignment. I think I get these pretty exact - selecting objects with the hand controller will slew the telescope and put the object exactly in the centre of the eyepiece. However, I start to get star trails after 30 seconds. I'm sure the mount is capable of longer accurate tracking than this? What gives me this belief is seeing what other people, using the same equipment, can achieve - although do you think that to get exposure times of 1.30-2mins plus, requires an autoguide camera? But also, what's odd is that the mount performs differently when tracking different parts of the sky: if im tracking something to the east I get less star trails (if ant at all), but something to the south means more star trails (same exposure times). Is this a problem anyone else has? I figure it's something to do with the axis's maybe - to the east mainly the declination axis is being used (because the stars are appearing to move vertically upwards), whereas to the south mainly the right ascension axis is being used (because the stars appear to move from left to right). So perhaps my R.A axis isn't so good - out of alignment to where the mount thinks it is? (seems unlikely as the mount can slew to objects well). Poor motor cogs? I don't know - am I expecting too much and instead should invest in an auto guide camera and guide scope to get some decent astrophotography done?

So; is a 30s exposure time about the limit of a non-guided EQ5 pro? If not, am I doing something wrong, or any ideas of what this tracking problem might be?

Any help will be much appreciated,

Regards, Bill

[dph1nm]

Depends totally on your pixel scale, of course, but I would think 30sec was about par for the PE on the mounts, if you have ~1" pixels. My HEQ5 only gives around 45sec at that scale. Given PE is usually of order +/- 10s of arcseconds every 10 minutes or so (depending on the worm.gear design), then imaging at 1" is very demanding. PE will vary with the declination of your object as well, remember.

NigelM

[Bill B]

Hadn't considered that Nigel, thanks. So do you think that 30s exposures are adequate for half-decent astrophotography? Or would an autoguide system significantly help?

Bill

[Freddie]

An guiding setup would definately help as you would then be into multiple minute exposures.

[astromartian]

I'm just in the process of saving up for a goto upgrade for my eq5 (with a similar photo setup to Bill .

Will it be adequate for half-decent deep sky photos?

[Marc1980]

Astromartian. What scope do you have to mount on it?

[Velvet]

I have eq5 and 200p and mounting finder, and canon 40D modded etc etc on I found that it is very close to max weight for that mount.

I have since moved up to NEQ6 because of the loading issues

But 30 sec subs if you take lots i would have thought would achieve a nice result. Obvioulsy guiding would help but watch the weight issue

velvet

[astromartian]

200P on an EQ5

I'm devided between buying a goto upgrade or trying to sell my EQ5 and buying a HEQ5 with Syntrek.

Not sure if anyone is prepared to buy an EQ5 mount and tripod these days.

[Marc1980]

I think if you are looking at progressing in imaging then a heq5 is the minimum you would want. As I have been lookin through forums I have been surprised to see how many people are putting their 200p's on a eq5. The worst you could do is put it up for sale and noone buy it but I think it would sell. Heq5 with syntrek is a good option with a laptop and software providing goto function and if you wanted to upgrade with a handset later you could. Some will say save for the neq6 if thats an option I would say do it but for many its not. I am hopefully going to be upgrading to a 200pds and I plan on putting it on a heq5 and imaging with it. I am not expecting to win astrophotographer of the year but will hopefully get some good images and enjoy it aswell.

[Capricorn]

I have eq5 and 200p and mounting finder, and canon 40D modded etc etc on I found that it is very close to max weight for that mount.

The max weight given will be for visual use not astrophotography use, in AP the rule tends to be 1/2 to 2/3 of the quoted max.

The 200P has a fairly long focal length, 1200mm, so that amplifies any tracking error, if you had a short focus apo, say 600mm, then you could track for longer without trailing, possibly double the time.

[malc-c]

Doing imaging with a 200P on an EQ5 seems to be the topic of the month on this forum

There are so many variables involved when imagine and as a novice in this field who has gone through the same route of EQ5 pro goto / Explorer 200P I would suggest that you try to make life easier by removing as many variables as possible.

• The EQ5 has lower resolution stepper motors, thus doesn't have the same precision as the HEQ5 / EQ6 when it comes to tracking
  
• The 200P is more or less on the limit for the weight carrying capacity for the EQ5, so it's fine for visual, but not as stable when it comes to imaging, especially if you bolt on dslr cameras etc.
  
• The HEQ5 having better stepper motors means that any auto-guiding system has less work to do, and unless you have perfect conditions, most of the Dso's require long exposures so guiding is a must.
  
• The explorer 200p has an f5 ratio (1000mm focal length) which is a good balance for DSO's and with a decent barlow, planetary images. Bright Dso's like M31 and M42 can be taken without guiding.
  

Having gone down the route and now have a 200P sat on a HEQ5 I would seriously recommend putting the £300 the EQ5 pro upgrade cost towards a HEQ5 syntrek and use EQmod to control the mount.

[Sammyb]

Agree with all of the above as someone that has tried DSOs on with a 200P on an EQ5 pro. Without guiding I could do OK with 30 second subs of M31 etc. If I took enough subs I could select the ones with no trailing. I went down the EQMOD/CdC route and guiding using the SPC900 on the finderscope with PHD. Initially it worked like a dream - i was getting 5 minute subs of M27 and M57 no problem - after a few goes I seemed to have trouble with the guiding and it always seemed to drift - i think I was having issues with the backlash which I never got round to reslolving. I might try it again sometime but i've since been doing more planetary and lunar which I find less frustrating and more rewarding.

[Daniel-K]

i have ran the same set up and could get 90 secs unguided its down to good balance and PA you may think your PA is good but until you use ascom or alignmaster its never going to be AS accurate, have your tried degreasing you gears and using whit lithium grease makes a big improvement and make sure there meshing properly

[astromartian]

Doing imaging with a 200P on an EQ5 seems to be the topic of the month on this forum

There are so many variables involved when imagine and as a novice in this field who has gone through the same route of EQ5 pro goto / Explorer 200P I would suggest that you try to make life easier by removing as many variables as possible.

• The EQ5 has lower resolution stepper motors, thus doesn't have the same precision as the HEQ5 / EQ6 when it comes to tracking
  
• The 200P is more or less on the limit for the weight carrying capacity for the EQ5, so it's fine for visual, but not as stable when it comes to imaging, especially if you bolt on dslr cameras etc.
  
• The HEQ5 having better stepper motors means that any auto-guiding system has less work to do, and unless you have perfect conditions, most of the Dso's require long exposures so guiding is a must.
  
• The explorer 200p has an f5 ratio (1000mm focal length) which is a good balance for DSO's and with a decent barlow, planetary images. Bright Dso's like M31 and M42 can be taken without guiding.
  

Having gone down the route and now have a 200P sat on a HEQ5 I would seriously recommend putting the £300 the EQ5 pro upgrade cost towards a HEQ5 syntrek and use EQmod to control the mount.

Thanks for all the advice to all, I've pretty much decided to do as you say. I'll sell my EQ5 and either find a used HEQ5 Synscan or buy a new HEQ5 Syntrek.

[Aenima]

Can anyone give me advice as to getting accurate goto slews and the general procedure for aligning the EQ5 synscan from scratch?

So far I have been only roughly polar aligning, so polaris sits in the center of the polarscope, and then pointing the scope at polaris too before pressing start alignment 1 star.....

I know this is too basic for accurate tracking so wondering if anyone with experience of my set-up can advise on better alignment habits and tips on the set-up for taking images?

Thank you,

Regards

Aenima

[malc-c]

Basic crude alignment for visual:

• Set the mount to the same angle as your latitude.
  
• Point the mount North
  
• Rotate the mount's DEC axis so you can view through the polar scope.
  
• Centre Polaris on the cross in the middle.
  
• Place the scope in the default home position of weights down in line with the N tripod leg, and the scope pointing North.
  
• Run through the synscan start up - making sure you input your location in for long / lat as hours minutes seconds and not decimal values, and the date is in US format
  
• Just before the star alignment option the handset will display the position of Polaris as a clock position (24hr format). Release the DEC axis lock so you can look through the polar scope, and then release the RA lock so you can rotate the mount until the bubble on the ring is in this clock position. Remember that 12:00 hrs will be at the bottom, 06:00 hrs to the right. (this isn't essential but will give better results) - Lock off the RA axis
  
• Use the alt / az bolts to position position Polaris in the bubble.
  
• Release the locks and place the scope back in the home position, and lock the axis
  
• Select 2 star alignment and pick your first star you can identify.
  
• let the mount slew to where it thinks the star should be and wait for the beep
  
• Use a low power eyepiece and check the position of the star. It will probably be off target.
  
• Release the locks and manually position the star in the centre of the eyepiece and lock the axis one more
  
• Confirm the target is centred and select a second star
  
• Let the scope slew to where it thinks it should be. It will probably be out but not by a lot
  
• This time use the directional buttons on the handset to centre the star.
  
• Alignment should be complete
  

Hope that helps

[Aenima]

Much appreciated Malcom, thank you.

Thats very helpful as a guide, I was only guessing the first time and happened to get it close enough but the same trial and error approach was nowhere near as accurate when trying it in a different (out the back instead of the front, door) position, and polar alignment also guesswork - but now I want to start doing proper multi star align, polar-align and use periodic error correction all together to increase goto and tracking accuracy.

Thank you for the excellent step-by-step how-to guide...

Regards

Aenima

[AstroAndy]

Just saw this old post looking for s/thing else..dunno whether this is still relevant, but I have an EQ5 w/ a 200P, After thorough drift alignment, I can get up to 30min continuous exposure. That is one exposure @ 30 minutes.

[Aenima]

Just saw this old post looking for s/thing else..dunno whether this is still relevant, but I have an EQ5 w/ a 200P, After thorough drift alignment, I can get up to 30min continuous exposure. That is one exposure @ 30 minutes.

Yeah, I was looking through this too - totally forgot my settings were still following it to be honest.

30Min exposures are absolutely amazing for this set-up, although it's doubtful that everyone actually spends the time and effort to thoroughly Drift-align, I know I dont.

I have found the 200p/eq5 combo a lot of work, and would advise anyone with the money spare to get the HEQ5 or for the flush of funds the NEQ6 due to the advantage they will give to those trying to take images with any reliability.

Having said that I have surprised myself with some of the results i've manged to wrangle from my 200p/eq5 set-up.  Every image in my gallery and elsewhere was done using this combination unguided.  

Guiding does help but try to get the basics first - polar alignment can be hit n miss with the stock polar scopes so using drift or software enhanced alignment helps, and having good balance and well maintained mount, luck changes night to night so instead of going straight to 1min exposures try 20sec and check star shapes, then - if good - up it to 30secs and so - on - you might get lucky

Hope this helps folks in the future who want the most from the 200p/EQ5 or would prefer the easier but more expensive route.

(however, if you end up having to upgrade over and over coz you bought the lesser kit first then it may not be the most expensive route to go for the right set-up the 1st time. I still enjoy using my eq5 and can happily learn on this equipment for years while waiting for the day when i can finally upgrade to a decent astrophotography rig)

Regards

Aenima

[malc-c]

To be honest, any scope that is set to be balanced correctly, aligned correctly, and not pushed beyond it's capability will give really good performance.  Whilst an HEQ5 may be more forgiving, it too will perform poorly if out of balance or poorly polar aligned

[AstroAndy]

What Malcolm said..@ Aenima..I've been known to drift align for a while, lol, my best RMS values on PHD are 0.11, and 0.13 at Max RA 300, and Max Dec. at 285.

One can get on the nose values w/ PHD drift alignment, works quite fast unless you have an axis problem you don't know about..

Now I gotta figure out how to repair my EQ5 mount, been unlucky lately, what with my dec. drive quitting, now I have a new handset and motors, and now my Alt. axis bolt thread is stripped in the southward direction, and it looks like the bolt bored through the metal piece a bit. The fun never ends around here, lol.

[Scott]

I found with my 200p/eq5 setup I could do 60 sec subs (90 sec if everything was working in my favor) but I was throwing away up to 70% of my subs. I was fortunate enough to be able to upgrade to an NEQ6, but rest assured, if I hadn't, I'd still be plugging away with the eq5. Whilst frustrating at times, It's also extremely rewarding when it all comes together. Having said that, I'm not sure I'd spend £300 on an upgrade for the eq5. Not when you see heq5's 2nd hand for £450 occasionally.

[AstroAndy]

Scott

Unfortunately, I wasn't aware of the bolt problem until after I got the Synscan Upgrade, (I got a refund on the previous one, which developed a fault). If I had known about it, I might have gone for an HEQ, or s/thing like that (not getting the new upgrade, I would have had 300lbs more towards a bigger mount. Still and all, I'll now see whether I can cut a new thread, and weld some metal on the piece in the EQ5. Other than all these problems, I usually have good results w/ my setup, even though I must be close to the weight limit. Average sub time is about 10min, w/ 20min not unusual, and like i said up there, 2ce i got 30min ones.

Andy

[arioch1st]

Great thread full of some really useful info. As I am just starting out in AP

this is superb. thanks guys.

[Aenima]

wow old thread here, as arioch says there's useful info glad its being helpful to someone else as i definitely learned a few things - in general SGL is great for information, grateful to have received so much advice here

regards