Jason Ware's LX800
#26
Posted 07 December 2012 - 11:06 AM
Peter
#27
Posted 07 December 2012 - 11:25 AM
I've been using my CGEM a lot since I fixed the encoders. It has 40" of PE and I routinely do 1.8" - and can do 1.1" if I'm really lucky - this only happens once in a while, only at certain mount positions, and doesn't last long. (note this is RMS and not peak-to-peak!)
so 1" from the LX800 should be doable... but if I can get 1.8" from my CGEM, I would expect a CGE Pro would handily beat that, and cost less than the LX800. Celestron claims about 12" p-p for the CGE Pro (3.39" RMS) and 0.91" RMS with PPEC.
Peter - mount quality will affect autoguiding performance. The CGEM has a huge PE so I don't expect guiding performance to go below 1" in fact I've never achieved 1" - only 1.1" when I'm lucky. The lower the native PE, the tighter the guiding will be.
#28
Posted 07 December 2012 - 11:54 AM
Blueman
#29
Posted 07 December 2012 - 01:18 PM
People that can buy this system also have cameras that can expose for over 15 minutes. This is an area Meade has never entered, and I had a LOT of discussions with them that if they wish to be successful here this mount HAS to be able to guide accurately for more than 5-10 minutes.
One of the reasons for the recall was because of this issue, and that fact that native PE was so high any exposure over 10 minutes would be riddled with elongated stars and guiding errors.
I have yet to see a single successful exposure over 10 minutes from this system. I know from my tests anything over that I had to throw out. I hope the changes have fixed this but that is yet to be seen.
#30
Posted 07 December 2012 - 01:38 PM
1" RMS guiding is not bad as I've said - but you don't need $7K equipment to get that level of performance. And as for not needing a PC for the guiding, I think this is a false economy - there is no 15-minute camera out there that does not need a PC. So you will be hauling the PC around anyway.
If the market was "drop it, let it align, take 5-minute subs with a DSLR" then yes the Starlock is good for that. I don't see that market dropping $7K for a mount though...
#31
Posted 07 December 2012 - 01:57 PM
I do not belong to Facebook and have no interest. Can anyone copy Jason's text from Meade's facebook and paste the text here so we all can read more information about the images?
I agree that 5 minute subs is not long enough to make a judgement of this new mount. I take narrow band images at 15 to 30 minutes per sub with my Mach1 and C-8 EdgeHD at 2000mm focal length with reasonable success and round stars. I would like to see that with LX800. At five minute subs, I can easily do that with my previous CPC0800 mounted on Mitty wedge. I even imaged at 30 minute subs with CPC0800 with fairly reasonable round stars.
This is a combination of 15 and 30 minute subs totaling 570 minutes of NGC7331 taken with CPC0800 with Mitty wedge. Not bad for costing less than $3K including Mitty wedge. This was taken at f/10 at 2000mm without focal reducer so the stars are typically elongated at the corners.
NGC7331-CPC0800
Peter
#32
Posted 07 December 2012 - 02:17 PM
I do not belong to Facebook and have no interest. Can anyone copy Jason's text from Meade's facebook and paste the text here so we all can read more information about the images?
I also have no interest in belonging to Facebook, but you don't need to belong to see the posts.
"This is the longest exposure so far with the 12" Meade LX800. Total of 8.3 hours in HA, SII and OIII. The seeing was a little soft so the stars are not as sharp as I would like but not bad."
Facebook page link
#33
Posted 07 December 2012 - 02:26 PM
Where does it say "5 minute subs"?
Peter
#34
Posted 07 December 2012 - 03:10 PM
That's as far as I can go but when I want to look inside more of Jason's images or information, it prompts me to login.
Where does it say "5 minute subs"?
Peter
It doesn't. His last one did.
http://galaxyphoto.c...0_eline_m42.htm
#35
Posted 07 December 2012 - 04:09 PM
Peter
#36
Posted 07 December 2012 - 05:05 PM
And while you're at it, dump your common sense down the drain too.
#37
Posted 07 December 2012 - 05:50 PM
I've said it before, if you have nothing to add constructive or if you feel the need to rehash old, worn out news, leave it at the door. Nothing will get this thread locked quicker than snarky, rehashed information.
David
#38
Posted 07 December 2012 - 06:04 PM
Personally I hope Meade sort their issues out, competition is good. I was always going to get a Meade scope, orange isn't really my colour.
#39
Posted 07 December 2012 - 08:36 PM
I have been a Meade beta tester for over 20 years, however, I was not a part of the first round testing of the LX800. I received a 12” LX800 after the recall which already had some enhancements beyond what was first released. I have provided feedback on several issues, some of which have already been addressed. The mechanics of this telescope and mount are first rate in my opinion compared to earlier Meade products. Can you find better? Yes, but at a much higher cost. It represents a good compromise between price/availability and performance. I have suggested a few more enhancements, like reducing the stiffness of the unlocked clutches and more travel in the azmuth adjustment. Not show stoppers but fixing these would make a great product even better.
The majority of the testing has been with regard to the Starlock software. Guiding is hard. Quite frankly I was very skeptical of the idea of a self guiding telescope but as I am using the system I am beginning to believe. The biggest hurdles are flexture in the system. This is a concern anytime a separate guidescope is used. But Meade has done a good job in this respect. The last bit of flex I can see is coming from movement of the main mirror which Meade tells me they are working on. Although the new Crayford focuser is OUTSTANDING, there is some movement. I have been able to eliminate it by locking the mirror with a ¼-20 long-bolt and nut in the shipping bolt hole.
Once the mirror is locked I use a Meade zero image focuser to fine focus. It works well although I found a bit of a light leak that was eliminated with a.... sock.
As for the images. The wide field Helix and PacMan were done with early version of the Starlock firmware and without locking the mirror. I am currently doing 10 minute subs and the guiding is very good. I never do longer then 10 minute subs, I find this is a good compromise between readout noise and number of subs. I want more subs to eliminate cosmic ray hits, affect of any polar misalignment and to take a advantage if dithering.
I also use a non-antiblooming gate camera so I often drop back to 5 minute subs to avoid blooms. The Hubble Helix comparison was with the newest firmware and is much better guided, but still a little trailing. See below.
Meade claims a guiding accuracy of about 1”. This is based on the resolution of the guide scope. All my images are done prime focus with an Apogee U9 6303. With this combination the image scale is about .76”/pixel. What I am finding with the current firmware is a 1-2 pixel elongation which is pretty much within spec, this may improve with upcoming firmware revisions but is not bad considering the Starlock
is about 1/5 the focal length of the 12” f8 OTA. Those desiring better guiding can use an off axis guider and supplemental software. Starlock will shut off when outside guiding is received, it does not fight it.
As for the optics, they are very good. I do most of my imaging from Plano, about 25 miles due north of downtown Dallas. A Metroplex of 6 million people. For the last few months we have had very bad seeing. The Clearsky clock is light blue most nights. The best I can get when focusing is a FWHM of around 2.9” at 2400mm f.l.
The field is almost flat across the 6303 chip with some elongation at the corners. The M42 shot was a mosaic so you can see some elongation at the center since that is the pane boundary. Again, the built in focuser is kick-*BLEEP* but I lose that capability when locking the mirror . Life is full of engineering trade-offs.
All and all this project is shaping up. I was seeing some pointing, initialization errors in the HPP pointing mode and I have received a new firmware version that is supposed to address this. Have not had time to test it yet. Forecast is for snow on Sunday, maybe. (Yes it does that sometime in North Texas).
Hope this answers some the questions and “speculation” (most of it wrong). If you want to ask more questions send an email through my web site since I don’t post here very often.
#40
Posted 07 December 2012 - 09:48 PM
#41
Posted 07 December 2012 - 09:51 PM
#42
Posted 07 December 2012 - 11:24 PM
-Rich
#43
Posted 08 December 2012 - 03:14 AM
#44
Posted 08 December 2012 - 10:26 AM
Anytime you have questions about that, just contact a mod (David or I on mounts for example).
Again, this was a valuable and information dense post, thanks.
Please consider more active participation.
#45
Posted 08 December 2012 - 11:29 AM
#46
Posted 08 December 2012 - 12:41 PM
I have suggested a few more enhancements, like reducing the stiffness of the unlocked clutches and more travel in the azmuth adjustment. Not show stoppers but fixing these would make a great product even better.
The clutch stiffness has been addressed few months ago. I did not see much difference though. However, one user disagreed with me. I was told by Meade that there isn't much else they could do about it. Some A-P mounts have very stiff clutches too and that was done on purpose. A mount with stiff axes can withstand wind gusts better.
Travel in the azimuth is not an issue. Just release the bolt underneath the tripod base plate and rotate the mount head 360 degrees. This is a great feature which Meade failed to advertise/document.
#47
Posted 08 December 2012 - 01:48 PM
If your seeing conditions the past few weeks/months were limiting you to 2.9" on focus frames, that by itself is enough to explain much of what I see in the linked images. Images at 2,400mm focal length just aren't going to look their best if the seeing is poor.
Frankly, the only thing disappointing in the material you provided is that you are seeing 1-2 pixels of trailing on guided subs even with the mirror locked down. I wish Meade had gone with an OAG solution rather than a small guide scope. But, as you mentioned, one could always switch to an OAG after the fact. And I suppose a lot of people would rather have the flexibility of more guide stars that comes with a smaller guide scope.
#48
Posted 08 December 2012 - 04:55 PM
I wish Meade had gone with an OAG solution rather than a small guide scope. But, as you mentioned, one could always switch to an OAG after the fact. And I suppose a lot of people would rather have the flexibility of more guide stars that comes with a smaller guide scope.
Yes...I've wondered about this since Starlock was announced. Wouldn't it be cool if a scope was like Hubble - with integrated "fine guidance sensors" (essentially off-axis guiders) outside the normal imaging frame. Of course, as you mentioned, there are downsides to that.
#49
Posted 08 December 2012 - 05:56 PM
#50
Posted 08 December 2012 - 06:58 PM
I wish Meade had gone with an OAG solution rather than a small guide scope
Hmm? As if finding a guide star with OAG could be easily automated.