Chuck, Here is my current response note file on the Synta EQ-6s, written last month for an offline reply to a SLAS member. To update those comments, please note: 1) My comments on tracking are based on non-autoguiding mode with PEC or non-PEC tracking. Imaging is usually done with auto-guiding. 2) The yahoo EQ6 group posts indicate the newest mounts are now shipping with a good low temperature grease that will work at subfreezing temperatures. I still haven't gotten up the guts to disassemble my 2005 mount purchase and replace the grease. 3) With the hand-controller software at version 3.21, I consider it controller now to be "ready-for-prime-time." - Kurt ============= Prior Synta EQ6 reply xxxx - I am not an experienced astrophotographer, so I don't feel like I'm in a position to give you good advice. With that qualifier, here is what I know. In this mount class it seems to be a toss up between the Syntax EQ6 (lower priced) and the better Celestron CG5 or CGE - which cost more but perform better. I do not have experience with the Syntax EQ5 mount. The Synta EQ6 is heavy mount. I use it as a "portable" but at 30-40lbs it is a back strainer to lug around. They do not sell it with a decent hardcase. It took some doing to find a case sturdy enough and to line it with foam for transport. The Synta EQ6 generally gets good reviews for those who use it for astrophotography with 5 1/4" or smaller refractors. The mount is mid-priced, and when disproportionately underweighted is reputed to track well. But being mid-ranged in price, it is not as well constructed - getting performance substituteing bulk for fine machining. In tests with PEC training, it turns in a 20 to 60 arcsecond error over 200 seconds, depending on the year of manufacture and the skill of the amateur user. I mount both a 5 1/4" refractor and a 10" Newt on mine. The 5 1/4" refractor is extremely stable and tracks well in visual testing. In my first limited visual test, it drift tracked with the 20lb 5 1/4" for over 10 minutes without PEC and without any visual error. The EQ6 mount is so bulky that it does not seem to feel the weight of a 20lb refractor. I have yet to do photographic mount analysis. When a 35 lb 10" Newt is mounted, it is much less stable. I had to buy an XHD specialty mount bar to really get the 10" to point and track reliably. I bought the Syntax EQ6 based on price point and a general non-PEC error rate of around 20 arcsecs over 200 arcsecs shown at this French amatuer mount testing site: http://demeautis.christophe.free.fr/ep/pe.htm The Christophe site shows the Celestron CGE and CG5 as an inherently better performer in terms of tracking. In addition to the Christophe site, the yahoo EQ6 group has has a folder containing various amateur PEC and non-PEC tests. http://tech.groups.yahoo.com/group/EQ6/files/EQ6_PE_Graphs_Folder/ In the attached zip folder, I have attached the best result with PEC training on a Synta EQ6 is 5 arcsecs across 200 seconds. A more typical example by a new scope owner, without PEC training, is 20 to 60 arcsecs across 200 seconds. I have yet to see, and have not performed, a photographic test with an autoguider and PEC. The appended review that I snatched from the net summarizes my feelings - it boils down to whether with autoguiding, the Synta EQ6 mount will tracking passably as well as the CG series, with the CG being either autoguided or with PEC only. Don Colton recommends by the CGE series - a mount that I have not used. He may be a good follow-up comparison contact. For Synta EQ6 mounts that test poorly out-of-the-box, in the yahoo EQ6 newsgroup, the usual fix is to open the side panel and adjust the tensioning screws on the RA gearwheels. That is usually reported to bring the non-PEC error rate to within 20 arcsecs over 200 seconds. This is something that I have not attempted on my mount. Another problem that I had with the Synta EQ6 - which I purchased in 2005 and that may not be an issue on the current scopes - is the mount was delivered with a high-temperature grease. Below 25-30 degrees, the stock grease solidifies. The 2005 and earlier mounts really need to be disassembled and regreased with low-temperature lithium grease. I have not regreased mine and do not operate powered in low temperatures because of it. I do not know if this has been corrected in the later production models. If you do buy an EQ6, make sure the handcontroller is 3.0x or later (2006 or later). The software in the 2.0x handcontroller cannot be updated and it operates in an unuseable dedicated mode. You cannot link a 2.0x handcontroller to a planetarium program. Replacing the handcontroller alone with a 3.0x version is $300-$400. The mount uses Celestron 5 emulation and open source ASCOM drivers. This makes autoguiding using a Meade camera using the Meade Envisage problematic. Over the winter, I found a software emulator that have begun testing direct autoguiding with a Meade DSI Pro. Otherwise, you are back to mounting a second small refractor for off-axis autoguiding. Autoguiding requires separately buying the Shoestring Astromony GPUSB autoguiding adapter. It is specifically designd to control ST-4 compatible autoguider ports. I have not used an SBIG camera with the mount but understand from reading the yahoo EQ6 group that high-end imagers do autoguide using SBIG products. Other minor annoyances that I have with the mount are: 1) The polar axis scope reticule light is too bright. Can be solved with a resistor or painting the led inside the mount with red paint. 2) The polar axis scope isn't of the best quality. I am considering replacing mine. 3) Although the scope has manual setting circles, it is not really set up for manual operation. The levelers are two far from the eyepiece to use effectively on a 1200 mm fl scope. There are no cable RA and Dec releases. I have used the mount powered down, but it is really designed to be used in power up mode and the hand-controller. I've tried to give you my unvarnished feelings about the mount. Don't misread those as me dissatisfied with it. I like the mount and enjoy using it. I enjoy your images and research work. Looking forward to more. - Kurt ============== Addendum a 2004 amateur review on the EQ6 RE: EQ6 Tracking accuracy for Astro-Photography Steve: There are two problems with mount errors that bear mentioning here. First is the amount of total error in the system. Second is the frequency of oscillation across the PE. The first problem can be solved with an autoguider. The second problem can make it difficult to get an autoguider to work in the first place. The EQ-6 (and Orion Atlas) are reputed to have large amounts of total periodic error, in the area of 50 to 60 arc seconds. See http://www.astrosurf.com/demeautis/ep/pe.htm for PE of this and other mounts. You'll need to open it in the Google translator. This is quite a bit, but it can easily be tamed by an autoguider if the movement is slow. If it jitters up and down really quickly, then the autoguider will have a hard time locking on to the star since it can't keep up with the corrections, especially at longer focal lengths. This is why, with a good alignment, you are getting a couple of minutes unguided. But the autoguider might not work with it. So, you have to map the error. Try PemPro, a new software (demo) from www.ccdware.com that maps out the PE for you (it does this for free in the demo mode). The full version is susposed to add PEC functions, but many mounts aren't supported yet. Still, it's worth looking into. For the record, this is the problem I had with my LX200. The periodic error itself was a managable 30 arc seconds or so, but the motions were too quick for the autoguider most of the time...and poor seeing just made it even worse. Your EQ-6 might be the same way, but if so, you could still easily use shorter focal length instruments, or at least a shorter scope for guiding. Signaturejay www.allaboutastro.com ____________________________________________________________________________________ You rock. 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