Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Mounts

Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | (show all)
rmollise
Postmaster
*****

Reged: 07/06/07

Re: EQ 8 Release new [Re: scopefreak]
      #5949907 - 07/01/13 03:32 PM

Quote:

Does anyone think this mount will be better than the CGE? Just wondering because the price that I have found for the EQ8 is just a tad below the CGE. Makes me wonder if it will be worth trying out a new product as opposed to a tried and reliable mount like the CGE. I can't do anything at present as my bank account is hitting the "E" mark.




Do you mean "CGE" or "CGE Pro"? In either case, it's too soon to say which--if either--it is better than.


Post Extras: Print Post   Remind Me!   Notify Moderator  
alpal
Post Laureate


Reged: 06/15/09

Loc: Melbourne Australia.
Re: EQ 8 Release new [Re: rmollise]
      #5950168 - 07/01/13 06:54 PM

This mount sounds very exciting.

The dual encoders put it in a similar league to the ASA mounts.
The encoders should mean no periodic error so I don't know
why they have PEC? - a correction for periodic error.

Encoders can be troublesome if dirt gets on the optical disc.
They need to be sealed properly.
I wonder if these encoders are sealed?

The weight would be too heavy for me as I have hurt
my back sometimes even with my much smaller EQ6.
( which I modified with an astro-physics counterweight bar)

Still if those encoders really work just like the ASA mounts then this mount is a steal for the price
& would beat any CGE mount in a permanent setup.

I want to see some images taken with it using a heavy telescope - 35 Kg load for imaging is the figure I read.
That's the real test.

Actually you could put 2 telescopes on it & double your data for the same imaging time.


Post Extras: Print Post   Remind Me!   Notify Moderator  
orion69
scholastic sledgehammer


Reged: 05/09/10

Loc: Croatia
Re: EQ 8 Release new [Re: alpal]
      #5950301 - 07/01/13 08:17 PM

EQ8 encoders are nothing like ASA absolute encoders, therefore comparing performance of these two mounts does not make sense.
I'll be happy if EQ8 has nice, easy guidable PE curve, with that capacity that would be enough for me to buy it...


Post Extras: Print Post   Remind Me!   Notify Moderator  
frozen.kryo
super member


Reged: 01/28/11

Loc: East of the Sun, West of the M...
Re: EQ 8 Release new [Re: alpal]
      #5950470 - 07/01/13 10:20 PM

Those encoders are low-resolution, 1.2 arc-minute/tick.

SW EQ8 Specs

Probably just for general pointing, and not used for tracking at all.

This mount is a performer regardless. 4 to 5" p2p PE from user reports so far.

Edited by frozen.kryo (07/01/13 10:37 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
alpal
Post Laureate


Reged: 06/15/09

Loc: Melbourne Australia.
Re: EQ 8 Release new [Re: frozen.kryo]
      #5950537 - 07/01/13 11:07 PM

Quote:

Those encoders are low-resolution, 1.2 arc-minute/tick.

SW EQ8 Specs

Probably just for general pointing, and not used for tracking at all.

This mount is a performer regardless. 4 to 5" p2p PE from user reports so far.




It says 0.12 arc second!

Are you saying that the encoders are not part of a dual axis closed loop control system like the ASA mounts?


Post Extras: Print Post   Remind Me!   Notify Moderator  
frozen.kryo
super member


Reged: 01/28/11

Loc: East of the Sun, West of the M...
Re: EQ 8 Release new [Re: alpal]
      #5950572 - 07/01/13 11:35 PM

I guess 0.12 arc second is the stepper motor resolution?

The "Resolution of Aux. R.A./Dec. Axis Encoders" is listed as approx. "1.2 arc minutes". Please see the end of the spec list.

Edited by frozen.kryo (07/01/13 11:43 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
andysea
Pooh-Bah
*****

Reged: 09/03/10

Loc: Seattle, WA
Re: EQ 8 Release new [Re: alpal]
      #5950578 - 07/01/13 11:37 PM

Actually 0.12" is the resolution of the stepper motors. If this mount is like the EQ6 it uses stepper motors as encoders. It essentially counts the steps to determine the position of the mount, once it's been synced of course. My focuser motor uses the same technology.
The aux. encoders resolution is 1.2 arc minute, I'm no expert but it seems to be way to coarse to use them for PE correction, hence the need for PEC. However if the PE is so small and very smooth, any autoguider can take care of that even without PEC.
If I understand this correctly the aux. encoders are there so that the telescope can be manually moved by loosening the clutches and the mount will not loose the star alignment. The auto-home feature seems to be very nice if people are going to use the mount for remote imaging.
This mount sure looks like a steal at that price. I won't run off and get one but it looks nice.


Post Extras: Print Post   Remind Me!   Notify Moderator  
alpal
Post Laureate


Reged: 06/15/09

Loc: Melbourne Australia.
Re: EQ 8 Release new [Re: andysea]
      #5950592 - 07/01/13 11:51 PM

Quote:

Actually 0.12" is the resolution of the stepper motors. If this mount is like the EQ6 it uses stepper motors as encoders.




That's no good.
I thought it was like the ASA mount with separate Renishaw encoders as an optical disc on each axis.


http://www.astrosysteme.at/eng/mounts.html

Quote:

Our answer is to employ high resolution encoders mounted directly on the axes of the mount.

ASA uses Renishaw Encoders, which are verified electronically and resolve to an unbelievable 0,01-0,02 seconds of arc.




That explains why it's 1/4 the price of a DDM 85.


Post Extras: Print Post   Remind Me!   Notify Moderator  
BPO
sage


Reged: 02/23/10

Loc: South Island, NZ
Re: EQ 8 Release new [Re: alpal]
      #5950669 - 07/02/13 01:18 AM

Hi alpal.

As a big admirer of the direct drive mounts of ASA and other European manufacturers, I have to say those should not be used in any comparison with Synta's/Sky-Watcher's EQ8.

The latter is for people unwilling or unable to invest the kind of capital required to possess a DDM-85 or similar, so criticising the EQ8 for not being a super high-end ASA, Astelco, or Planewave direct drive mount is more than a little unfair, in my opinion.

And at any rate the first reports are very positive from the growing number of EQ8 owners in Australia. It appears to be yet another bargain from Synta and will likely be as successful as its little brothers.


Post Extras: Print Post   Remind Me!   Notify Moderator  
andysea
Pooh-Bah
*****

Reged: 09/03/10

Loc: Seattle, WA
Re: EQ 8 Release new [Re: alpal]
      #5950672 - 07/02/13 01:28 AM

I wouldn't say that it's not good. The resolution of the steppers seems to be more than adequate for precise gotos. At least it was fine on my old EQ6.
The absolute encoders are nice, however it is my understanding that if you want to shoot unguided you need to build a pointing model. That might be fine for those lucky ones that have a permanent setup. For the rest of us who have to travel to dark spots it seems that building a pointing model at the beginning of every session would be a waste of precious imaging time.
I can tell you that both my mounts have a guaranteed PE that is higher than what I read on this forum and each one of them cost at least about twice what the EQ8 costs plus they have a lower payload. I think that even without the Renishaw encoders The EQ8 looks pretty good.
I don't see a built in polarscope tho.


Post Extras: Print Post   Remind Me!   Notify Moderator  
alpal
Post Laureate


Reged: 06/15/09

Loc: Melbourne Australia.
Re: EQ 8 Release new [Re: BPO]
      #5950681 - 07/02/13 01:41 AM

Quote:

Hi alpal.

As a big admirer of the direct drive mounts of ASA and other European manufacturers, I have to say those should not be used in any comparison with Synta's/Sky-Watcher's EQ8.

The latter is for people unwilling or unable to invest the kind of capital required to possess a DDM-85 or similar, so criticising the EQ8 for not being a super high-end ASA, Astelco, or Planewave direct drive mount is more than a little unfair, in my opinion.

And at any rate the first reports are very positive from the growing number of EQ8 owners in Australia. It appears to be yet another bargain from Synta and will likely be as successful as its little brothers.




I agree & I can't wait to see some images & some FWHM values
that were obtained for long exposures.


Post Extras: Print Post   Remind Me!   Notify Moderator  
alpal
Post Laureate


Reged: 06/15/09

Loc: Melbourne Australia.
Re: EQ 8 Release new [Re: andysea]
      #5950689 - 07/02/13 01:49 AM

Quote:

I wouldn't say that it's not good. The resolution of the steppers seems to be more than adequate for precise gotos. At least it was fine on my old EQ6.
The absolute encoders are nice, however it is my understanding that if you want to shoot unguided you need to build a pointing model. That might be fine for those lucky ones that have a permanent setup. For the rest of us who have to travel to dark spots it seems that building a pointing model at the beginning of every session would be a waste of precious imaging time.
I can tell you that both my mounts have a guaranteed PE that is higher than what I read on this forum and each one of them cost at least about twice what the EQ8 costs plus they have a lower payload. I think that even without the Renishaw encoders The EQ8 looks pretty good.
I don't see a built in polarscope tho.





True but when they talked about encoders it was misleading -
I thought they meant a cut down version of a Renishaw encoder -
maybe not as accurate as a Renishaw but still a dual axis closed loop
control system based on optical encoders attached to the axes -
which it appears that it's not but to be honest -
I'm still not sure as the spec sheets really don't go into
that sort of technical detail.


Another thing:
I notice with my EQ6 that it can be polar aligned & drift aligned for one part of the sky
- then when I turn the mount to a different target -
say from North to South - that it's no longer drift aligned.
The stars will be moving across the frame where as they were stationary before.
(I do level the mount with a carpenters level)

The only reason I can think of is that the mount is not square -
not orthogonal.

I hope the EQ8 is a bit better in this regard?


Post Extras: Print Post   Remind Me!   Notify Moderator  
andysea
Pooh-Bah
*****

Reged: 09/03/10

Loc: Seattle, WA
Re: EQ 8 Release new [Re: alpal]
      #5950707 - 07/02/13 02:22 AM

Quote:


Another thing:
I notice with my EQ6 that it can be polar aligned & drift aligned for one part of the sky
- then when I turn the mount to a different target -
say from North to South - that it's no longer drift aligned.
The stars will be moving across the frame where as they were stationary before.
(I do level the mount with a carpenters level)

The only reason I can think of is that the mount is not square -
not orthogonal.

I hope the EQ8 is a bit better in this regard?




That is quite peculiar. I have never heard of that. You might want to start a new thread about it. I'm sure a lot of people will chime in. Your assessment makes perfect sense tho. I've only had the Atlas/EQ6 for a few months and I never drift aligned it so I can't provide any useful feedback.


Post Extras: Print Post   Remind Me!   Notify Moderator  
alpal
Post Laureate


Reged: 06/15/09

Loc: Melbourne Australia.
Re: EQ 8 Release new [Re: andysea]
      #5950712 - 07/02/13 02:30 AM

Hi Andy,
I don't think we need a new thread on it.
I would be interested to see what others have found & to see what the EQ8 does.


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

Reged: 07/06/07

Re: EQ 8 Release new [Re: frozen.kryo]
      #5951017 - 07/02/13 10:06 AM

Quote:

Probably just for general pointing, and not used for tracking at all.






No "probably" about it. The encoders are there to let you move the OTA by hand without losing alignment.


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

Reged: 07/06/07

Re: EQ 8 Release new [Re: alpal]
      #5951021 - 07/02/13 10:09 AM

Quote:


I notice with my EQ6 that it can be polar aligned & drift aligned for one part of the sky
- then when I turn the mount to a different target -
say from North to South - that it's no longer drift aligned.
The stars will be moving across the frame where as they were stationary before.
(I do level the mount with a carpenters level)




Something is wrong with your mount or with your procedure. I would guess your procedure, since there's little way for non-orthogonality to cause different polar alignments in different parts of the sky. All that would cause that would be for the RA axis itself to move.


Post Extras: Print Post   Remind Me!   Notify Moderator  
rigel123
Postmaster
*****

Reged: 06/29/09

Loc: SW Ohio
Re: EQ 8 Release new [Re: rmollise]
      #5951101 - 07/02/13 10:48 AM

Quote:

Quote:


I notice with my EQ6 that it can be polar aligned & drift aligned for one part of the sky
- then when I turn the mount to a different target -
say from North to South - that it's no longer drift aligned.
The stars will be moving across the frame where as they were stationary before.
(I do level the mount with a carpenters level)




Something is wrong with your mount or with your procedure. I would guess your procedure, since there's little way for non-orthogonality to cause different polar alignments in different parts of the sky. All that would cause that would be for the RA axis itself to move.




I would agree with Rod here, I don't have that issue with my Atlas. Maybe a balance issue?


Post Extras: Print Post   Remind Me!   Notify Moderator  
telfish
sage
*****

Reged: 11/17/10

Loc: Adirondack Mountains NY
Re: EQ 8 Release new [Re: andysea]
      #5951440 - 07/02/13 02:32 PM

Quote:

I wouldn't say that it's not good. The resolution of the steppers seems to be more than adequate for precise gotos. At least it was fine on my old EQ6.
The absolute encoders are nice, however it is my understanding that if you want to shoot unguided you need to build a pointing model. That might be fine for those lucky ones that have a permanent setup. For the rest of us who have to travel to dark spots it seems that building a pointing model at the beginning of every session would be a waste of precious imaging time.
I can tell you that both my mounts have a guaranteed PE that is higher than what I read on this forum and each one of them cost at least about twice what the EQ8 costs plus they have a lower payload. I think that even without the Renishaw encoders The EQ8 looks pretty good.
I don't see a built in polarscope tho.




The polar scope is a separate item supplied with the scope. It sits on it's own bracket and is not part of the central axis like the eq6 scope.


Post Extras: Print Post   Remind Me!   Notify Moderator  
alpal
Post Laureate


Reged: 06/15/09

Loc: Melbourne Australia.
Re: EQ 8 Release [Re: rigel123]
      #5951895 - 07/02/13 06:53 PM

Quote:

Quote:

Quote:


I notice with my EQ6 that it can be polar aligned & drift aligned for one part of the sky
- then when I turn the mount to a different target -
say from North to South - that it's no longer drift aligned.
The stars will be moving across the frame where as they were stationary before.
(I do level the mount with a carpenters level)




Something is wrong with your mount or with your procedure. I would guess your procedure, since there's little way for non-orthogonality to cause different polar alignments in different parts of the sky. All that would cause that would be for the RA axis itself to move.




I would agree with Rod here, I don't have that issue with my Atlas. Maybe a balance issue?




Don't think so.
I am surprised that no one else has noticed this.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Coastal
sage


Reged: 04/23/09

Loc: Vancouver island, Canada
Re: EQ 8 Release [Re: alpal]
      #5951911 - 07/02/13 07:06 PM

Quote:

Quote:

Quote:

Quote:


I notice with my EQ6 that it can be polar aligned & drift aligned for one part of the sky
- then when I turn the mount to a different target -
say from North to South - that it's no longer drift aligned.
The stars will be moving across the frame where as they were stationary before.
(I do level the mount with a carpenters level)




Something is wrong with your mount or with your procedure. I would guess your procedure, since there's little way for non-orthogonality to cause different polar alignments in different parts of the sky. All that would cause that would be for the RA axis itself to move.




I would agree with Rod here, I don't have that issue with my Atlas. Maybe a balance issue?




Don't think so.
I am surprised that no one else has noticed this.




The only time I've had a situation somewhat similar I was able to track it down to mirror shift on an old 10" Meade SCT.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | (show all)


Extra information
30 registered and 54 anonymous users are browsing this forum.

Moderator:  Dave M, richard7, bilgebay 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 9895

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics