Telescope Reviews: Question for Losmandy Imagers

· 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

You are not logged in. [Login]

Entrance · Main Index · Search · New user · Who's Online
FAQ · Calendar

Equipment Discussions >> Mounts

Pages: 1 | 2 | 3 | 4 | 5 | (show all)

waassaabee
Post Laureate

Reged: 11/26/07

Loc: Central California Coast

Question for Losmandy Imagers
#2948842 - 02/25/09 11:59 AM

I've read that the GM-8 and G-11 mounts have instrument capacities of 30 and 60 pounds respectively. Most folks say cut that in half for imaging. Is that the case with the Losmandy mounts?

Post Extras:

Jared
Post Laureate

Reged: 10/11/05

Loc: Piedmont, California, U.S.

Re: Question for Losmandy Imagers new

[Re: waassaabee]
#2948881 - 02/25/09 12:25 PM

Quote:

I've read that the GM-8 and G-11 mounts have instrument capacities of 30 and 60 pounds respectively. Most folks say cut that in half for imaging. Is that the case with the Losmandy mounts?

I can't speak to the G11 as I have never used one, but I imaged with a GM-8 for about 18 months with a range of equipment. I would say that the GM-8 is good up to 20 pounds with a reasonably short optical tube. I pushed that to twenty five pounds for a little while (with a light guide scope) and was not happy with the results. At least with my sample, 15 pounds would be quite conservative for imaging, 20 pounds was reasonable if the tripod was kept at minimum height, and 25 pounds was really pushing it.

Post Extras:

nighthound
Pooh-Bah

Reged: 08/30/06

Re: Question for Losmandy Imagers new

[Re: Jared]
#2948954 - 02/25/09 12:59 PM

Gary, I've loaded my G-11 down in the past with about 40-45 pounds and it wasn't happy, nor I. I've since lightened my optics to a Vixen R200SS/Sky 90 or Sky 90/FS-60C side by side and the mount has behaved very well. My G-11 seems happy between 20-30 pounds max and even better with the lighter 90/60 combo. Learning to perfect balance a side-by-side set up has helped in a big way.

Steve

Post Extras:

blueman
Vendor Blue Sky Accessories

Reged: 07/20/07

Loc: California

Re: Question for Losmandy Imagers new

[Re: waassaabee]
#2949067 - 02/25/09 01:56 PM Attachment (37 downloads)

Much of the answer for this lies in the type of scope you are mounting.
A long scope would be more of a problem than a short scope for instance. So a 6" f/11 would be more of a problem than a 12" SCT, though the weight might be very similar.
I have not used more than 35-40 lbs on my G-11, so I am not certain about the actual max.
However, I do know those that push the 60 lb limit and get good results.
How well you balance will also have an effect as would a permanent pier in an observatory.
So, I do know those that do 60+ lbs with the G-11 and they say that there is not a problem. But that said, any mount loaded to its limit is not the best situation in my opinion.
So, if you need 60 lbs of gear, then a G-11 is not the best choice, maybe an AP1200 would be a much better one for that load. You never know if you will be increasing the load later!

Blueman

Post Extras:

D_talley
Carpal Tunnel

Reged: 07/07/05

Loc: Richmond VA

Re: Question for Losmandy Imagers new

[Re: blueman]
#2949083 - 02/25/09 02:11 PM

I am one of the guys who loads his G11 to the max. I have a Meade 14 inch OTA that weights in at around 65 lbs on the mount. Works great for me since I am shooting with the Hyperstar system (F2). This would not work well if I shot at F10 or even F6.

Post Extras:

waassaabee
Post Laureate

Reged: 11/26/07

Loc: Central California Coast

Re: Question for Losmandy Imagers new

[Re: D_talley]
#2949270 - 02/25/09 03:59 PM

Thanks all!! This info is very encouraging as I am getting near the time to move up to the next level in equipment. The GM-8 is looking like a real contender, but I keep telling myself might as well go G-11.

Post Extras:

rsbfoto
sage

Reged: 06/10/06

Re: Question for Losmandy Imagers new

[Re: waassaabee]
#2949399 - 02/25/09 05:15 PM

Hi Gary,

It all depends how the mount behaves and what you have underneath. Also if you are prepared to tune it or not.

Last weekend I made some tests and here here is a nice result. 240s unguided image with 3000mm focal length ( Mewlon 250S f12). That night I made a ttal of 15 images NO guiding and 9 images came our woith very nice round stars. I even have 4 images one after the other with round star which means that for a period of 16 minutes the mount had no periodic error. That night it was even a little bit windy. Here you can see a screencopy of my weather station for that specific imaging hour.

That is from a G11 with a total load of about 55 pounds equipment and 55 pounds of counterweight.

Edited by rsbfoto (02/25/09 05:15 PM)

Post Extras:

waassaabee
Post Laureate

Reged: 11/26/07

Loc: Central California Coast

Re: Question for Losmandy Imagers new

[Re: rsbfoto]
#2949729 - 02/25/09 08:30 PM

Rainer, Thanks for the encouragement!! That's a helluva Horsehead you have there!! The more I think about it, the more it makes sense to turn up the gain a bit and go with the G11.. The $ difference for the extra capacity seems worthwhile.

Post Extras:

hersey0308
super member

Reged: 12/04/08

Loc: Ontario Canada

Re: Question for Losmandy Imagers new

[Re: waassaabee]
#2949752 - 02/25/09 08:38 PM Attachment (32 downloads)

hi gary - i love my gm 8 but if i had it to do over, i would take the g11 simply to give me flexibility for heavier imaging configurations. the attachment is the gm 8 with about twenty five pounds. it did work but only after lots of attention to balancing. with 25 lbs on board i was on "pins and needles" for both sessions but the images came out well.
nonetheless, everyone will agree the gm 8 is quite a handsome piece of business.

best
david

Edited by hersey0308 (02/25/09 08:47 PM)

Post Extras:

Joselo
professor emeritus

Reged: 02/26/08

Loc: Texas

Re: Question for Losmandy Imagers new

[Re: waassaabee]
#2949760 - 02/25/09 08:39 PM

Rainer,
have you done any updgrades/tuneups to your mount?

Post Extras:

rsbfoto
sage

Reged: 06/10/06

Re: Question for Losmandy Imagers new

[Re: Joselo]
#2949806 - 02/25/09 09:09 PM

Hi,

Yes. I made the first one piece wormblock It was maybe 3 years ago. Nobody wanted it because of the price of roughly US $ 450.00. Nowadays the Ovision worm for US $ 500.00 is selling like warm rolls

. The RS-Wormblock has ball and thrust bearings inside. which is not the case fot the Ovision worm. Risk of having the 76second error due to the preload of the ball bearings.

Here it is assembled

Also I have the latest brass worms from Losmandy. All Losmandy mounts now come with the brass worm.

The next tune up is the gearbox exchange. The first one to do this tune up is Floyd. The PE is not so nervous anymore (small jumps up and down with a very high frecuency per second) according to the ones who already exchanged the standard gearboxes for McLennan gearboxes.

The whole tune up for one axis is about US $ 550.00 to 600.00, but if you ask me it is good spend money.

Edited by rsbfoto (02/25/09 09:15 PM)

Post Extras:

Jared
Post Laureate

Reged: 10/11/05

Loc: Piedmont, California, U.S.

Re: Question for Losmandy Imagers new

[Re: waassaabee]
#2949959 - 02/25/09 10:25 PM

Quote:

Rainer, Thanks for the encouragement!! That's a helluva Horsehead you have there!! The more I think about it, the more it makes sense to turn up the gain a bit and go with the G11.. The $ difference for the extra capacity seems worthwhile.

If you don't absolutely need the extra portability of the GM-8, I would definitely recommend the G11 instead. The extra capacity is well worth the price increase (assuming you can afford it).

Post Extras:

blueman
Vendor Blue Sky Accessories

Reged: 07/20/07

Loc: California

Re: Question for Losmandy Imagers new

[Re: rsbfoto]
#2950098 - 02/26/09 12:22 AM

Hi,
I have replaced both gearboxes and installed the Ovision Worm and Block as well.
The PE is now about +- 2.3" or 4.5" peak to peak uncorrected and is pretty smooth too.
Total cost was about $600 with shipping and all, for everything on the upgrades.
The Ovision Worm is a much better worm and the worm block is quite good too and made with stainless steel.
Blueman (Floyd)

Post Extras:

blueman
Vendor Blue Sky Accessories

Reged: 07/20/07

Loc: California

Re: Question for Losmandy Imagers new

[Re: Jared]
#2950106 - 02/26/09 12:26 AM

Hi Jarad,
How do you like the VC200L?
Blueman

Post Extras:

Strgazr27

Reged: 10/04/04

Loc: StonyHill Observatory

Re: Question for Losmandy Imagers new

[Re: blueman]
#2950412 - 02/26/09 08:16 AM Attachment (39 downloads)

My new to me G11 showed up this past Friday replacing my EQ6. Thanks to Joe B. for an incredible trade. The mount was in better condition than he stated and looks brand new

As usual the performance of the RA clutch was basically non existant. As you know I can't keep my hands out of anything so I tore it completely apart and rebuilt the mount. Not only was it incredibly easy to work on but I'm more than happy with the results. While I had it apart everything was cleaned and relubed. I also spent about 5 hours polishing the RA worm and ring gear. I setup a jig to hold an electric drill and let her run. I would wipe down and apply new polishing compound every 30 minutes and make a minor adjustment to the worm position. Not having $500 to spend on the Ovision block I used the stock block cover to make a support to hold the worm blocks square to each other. I'll have pictures up in a little while. The Pempro run below was with 32 lbs of equipment on the mount using a piggyback setup. As it still shows the 76 second error I have some adjusting to do. The magnitude doesn't look that bad so I wunder if it's going to be a big issue? Most of my imaging is under 1000mm. I have also ordered a set of ABEC7 replacement bearings for the worms from a link Floyd posted (Thanks Floyd!). I was not able to get any images after the run as clouds cut short even the PE trials but I'm pretty happy with the results. I am planning to do the gearbox mod next. At under 2 arc seconds peak to peak uncorrected I think I'm going to be happy

Here are a few screen shots from the run. Larger images can be seen

Here

Post Extras:

Strgazr27

Reged: 10/04/04

Loc: StonyHill Observatory

Re: Question for Losmandy Imagers new

[Re: Strgazr27]
#2950422 - 02/26/09 08:24 AM Attachment (32 downloads)

One more...

Post Extras:

waassaabee
Post Laureate

Reged: 11/26/07

Loc: Central California Coast

Re: Question for Losmandy Imagers new

[Re: Strgazr27]
#2950631 - 02/26/09 10:25 AM

All of this talk about upgrades, modifications, 76 second error, concerns me a bit. How are they 'out of the box'? Brand new? Or maybe look for one someone has tinkered with?

Post Extras:

Jared
Post Laureate

Reged: 10/11/05

Loc: Piedmont, California, U.S.

Re: Question for Losmandy Imagers new

[Re: blueman]
#2950852 - 02/26/09 12:08 PM

Quote:

Hi Jarad,
How do you like the VC200L?
Blueman

For the price, it's an excellent imaging scope. As advertised, it has a flat field right to the corners of a 42mm imaging circle. My sample has some slight astigmatism that is noticeable only at high powers when used visually. The focuser is pretty good, but isn't quite as beefy as I would like for my relatively heavy SBIG STL series camera. Still, it seems to work fine. Biggest gripe is that the relatively thick spider vanes cause somewhat blocky star images.

If you are looking for a long focal length imaging scope in this aperture range that can handle a full frame CCD chip, there really isn't anything else that's close.

Post Extras:

Strgazr27

Reged: 10/04/04

Loc: StonyHill Observatory

Re: Question for Losmandy Imagers new

[Re: Jared]
#2951000 - 02/26/09 01:28 PM

Quote:

If you are looking for a long focal length imaging scope in this aperture range that can handle a full frame CCD chip, there really isn't anything else that's close.

Actually the AT 8RC will easily do it, features a Feathertouch focuser, fully baffled tube and normal spider vanes. Oh yeah and it's almost $500 cheaper

Post Extras:

rsbfoto
sage

Reged: 06/10/06

Re: Question for Losmandy Imagers new

[Re: waassaabee]
#2951018 - 02/26/09 01:37 PM

Quote:

All of this talk about upgrades, modifications, 76 second error, concerns me a bit. How are they 'out of the box'? Brand new? Or maybe look for one someone has tinkered with?

Hi,

It is like with new cars. You can get a good one but you can also get a lemon

and you can get the standard between these 2 stages which is by far more common. If you get a good one you will only know it after a few months you have used it. If you have a bad one too.

A good one I would say has a PE of +-3", a standard one has maybe +-4to7" and a bad one more then +-10". With the new brass worm after maybe a month of continous use the PE will surely settle down on a value an then you can say what you have got. My 2 cents to the PE ...

When I got my first G11 the only thing I did in the first 6 months is to learn how to use it and that was it. Nothing else. I did not even touch the worm/gear mesh just because I did not know how to do it correctly. After knowing how th mount works I spend another time month after month just using it and doing visual as well as imaging and when I finally felt confident about the mount I started to tinker woth the mount.

That is what I can say in regard to your question.

Edited by rsbfoto (02/26/09 01:40 PM)

Post Extras:

blueman
Vendor Blue Sky Accessories

Reged: 07/20/07

Loc: California

Re: Question for Losmandy Imagers new

[Re: Strgazr27]
#2951280 - 02/26/09 03:54 PM

I heard the AT RC8 will no longer feature (or offer) the Feathertouch and that they can not say a Feathertouch will even fit the scope. It seems to be the same focuser that the 6" uses and it will not handle a 3 lb camera, according to Astro-Tech. So, not sure what to say about the 8" model, may not be good for cameras like my ST2000xm with filter wheel.
Cost $1395
Blueman

Post Extras:

blueman
Vendor Blue Sky Accessories

Reged: 07/20/07

Loc: California

Re: Question for Losmandy Imagers new

[Re: Strgazr27]
#2951283 - 02/26/09 03:57 PM

Hi,
This looks very good indeed. If you can get the two blocks to line up without causing the two bearings to bind, the 76 error will diminish a lot.
I am not sure what it is saying the actual Peak to Peak is, but it looks smooth enough.
Blueman

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: blueman]
#2951372 - 02/26/09 04:46 PM

So with all of the need to rebuild, and The GM-8's performance being so average at a medium load capacity, what is the advantage to paying such a premium for this rather light weight mount? An Atlas is cheaper, and a Sirius has as good a capacity. What DO you get from a GM-8 that justifies the cost? I looks great, but that in itself doesn't seem to warant the $1000 premium. For a thousand or more dollars over the 2 Orion offerings wouldn't one expect a premium performance? What am I missing here?

Post Extras:

Strgazr27

Reged: 10/04/04

Loc: StonyHill Observatory

Re: Question for Losmandy Imagers new

[Re: blueman]
#2951413 - 02/26/09 05:13 PM Attachment (23 downloads)

Quote:

I heard the AT RC8 will no longer feature (or offer) the Feathertouch and that they can not say a Feathertouch will even fit the scope. It seems to be the same focuser that the 6" uses and it will not handle a 3 lb camera, according to Astro-Tech. So, not sure what to say about the 8" model, may not be good for cameras like my ST2000xm with filter wheel.
Cost $1395
Blueman

Floyd,

As of today the Feathertouch will be offered as an option with the adapter for $450 on top of the base price of $1395. There are no issue with fit of the FT. I don't know who gave you that information but it's incorrect. Both the 6 and the 8 are going to use a newer style focuser that uses a rail and bearing system and will easily support more than 3 lbs

and should be good to at least the 8lb mark. The optics will easily cover an APS-C chip and will do a FF with perhaps the need for flat frames. There is plans for a .75 reducer for the scope also.

I have attached a picture of the new focuser which shows the new design. There are 4 bearings that guide/support the drawtube and should work very well.

I do stand corrected though. With the FT focuser the price difference is basically a wash between the VC and the ATRC. The baffled tube and FT focuser are a big step up from the VC's as well as the AT having a normal set of spider vanes.

Hope this info helps clear things up a bit

Post Extras:

waassaabee
Post Laureate

Reged: 11/26/07

Loc: Central California Coast

Re: Question for Losmandy Imagers new

[Re: Strgazr27]
#2951435 - 02/26/09 05:25 PM

Back on subject here...

Dan, I'm with you.. Maybe that CGEM isn't such a bad deal after all...

Post Extras:

blueman
Vendor Blue Sky Accessories

Reged: 07/20/07

Loc: California

Re: Question for Losmandy Imagers new

[Re: alanon]
#2951524 - 02/26/09 06:21 PM

The Mods that I and others have performed are not required, but rather elective. We are trying to get the G-11 and GM-8 to perform to a degree that rivals mounts costing 2-3x more. Out of the box, they work very well, but with Mods they can be made to work even better.
It is this quest for excellence that is behind the Mods, not a lack of quality or capability in the mounts in my opinion.
Blueman

Post Extras:

blueman
Vendor Blue Sky Accessories

Reged: 07/20/07

Loc: California

Re: Question for Losmandy Imagers new

[Re: Strgazr27]
#2951542 - 02/26/09 06:28 PM

Hi Strgazr,

That is good information, but it is not found on the site. So when I was told that the FT had been withdrawn and all, it was from someone that had talked with them about the new RC8. I will have to call again and see what is being said by the vendor.

The new focuser could work well, though I have not yet heard of any real reviews of it using a heavier load. The original one was lacking for cameras above 1 lb or so.

This is still a Chinese focuser that is certain and I have had issues with some of them, so I will hold judgment until I hear more from the field tests.

So, where do you find the information on the FT option, which vendor or site? Who actually has these for sale? it is my understanding that there is a pre order list only at this time.
Blueman

Post Extras:

blueman
Vendor Blue Sky Accessories

Reged: 07/20/07

Loc: California

Re: Question for Losmandy Imagers new

[Re: blueman]
#2951547 - 02/26/09 06:31 PM

Oh, I ask about the availability, because I am actually interested in one myself. The $1395 would be a great price if the focuser works with a bigger camera. But the $450 FT option would not be out of the question either.
Blueman

Post Extras:

jshalpha
professor emeritus

Reged: 04/30/05

Loc: SF Bay Area

Re: Question for Losmandy Imagers new

[Re: blueman]
#2951564 - 02/26/09 06:43 PM

I'm interested in one myself, but I also want to see the specs on the 10 inch so I can decide between it and the 8 inch.

Jim S.

Post Extras:

Astronomics
Vendor if you must, AKA The Mighty Kong.

Reged: 06/07/04

Loc: Right Here

Re: Question for Losmandy Imagers new

[Re: jshalpha]
#2951726 - 02/26/09 08:13 PM

Here's the skinny then back on subject.

1. $1395 is the new price.
2. With that price came some concessions.
3. No case.
4. No Feathertouch as standard equipment.
5. A 90x1 metric adapter is what is needed. Ballpark price would be $100 or so hence the $450 upgrade price once you throw in the focuser.
6. Werner made the original adapter and the new owners of Starlight will need his drawings to produce the adapter for the RC.
7. The RC6 and RC8 share the same back housing so the adapter will work on either.
8. The original focuser will hold a decent load, we just didn't want people trying to put an ST series camera with filter wheel and the works. We were trying to impose a ceiling of some sort and may have gone overboard.

I hope this helps clear some things up.

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: Astronomics]
#2952025 - 02/26/09 10:47 PM

Thanks Mighty Kong!

I think that my question still stands though. If an average performance in PE is + or - 4"to 7", then this mount does little (if anything) to warrant the extra cash out of the box. I should think that an Atlas, Sirius, or CGEM is capable of these numbers as well. Plus rebuilds if I recall, the hyper tuning jobs on the Atlas Mounts do not entail an expenditure of $500 for a part.This doubles the cost of the competitive offerings at this load bearing capability. Please correct me if I am wrong ,but is there something I am that missing? What other qualities are there that would justify this price? I don't mean to be confrontational, but really would like to know.

Add on... I am in the market and haven't scratched the GM-8 from the option list. So, any help would be very useful. Thanks All!

Edited by alanon (02/26/09 10:50 PM)

Post Extras:

jrcrilly
Refractor wienie no more

Reged: 04/30/03

Loc: NE Ohio

Re: Question for Losmandy Imagers new

[Re: alanon]
#2952038 - 02/26/09 11:00 PM

Quote:

If an average performance in PE is + or - 4"to 7", then this mount does little (if anything) to warrant the extra cash out of the box. I should think that an Atlas, Sirius, or CGEM is capable of these numbers as well.

I think you are being very optimistic. +-5 arcseconds is both very, very good and very difficult to achieve. If they could achieve those numbers consistently, Synta would publish it. Everyone who produces mounts that can be relied upon to achieve that performance range - Tak, AP, MI, others - publishes the fact. Otherwise, why would anybody invest in higher-end mounts? I know that I would not.

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: jrcrilly]
#2952270 - 02/27/09 03:13 AM

Thanks John! I appreciate the clarification.

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: alanon]
#2952284 - 02/27/09 03:34 AM

I also wish to say that I went back and looked at other PE data that I could find. I learned that you are quite correct that those types of numbers are pretty exceptional.

I also made the mistake of thinking those numbers were for the GM-8. When in actuality the conversation was about the G-11.

Thanks for setting me straight!

edit:One note though... Given we are really talking about the G-11, and not the GM-8, then we are talking a different load class, and more than double the cost of the mounts I mentioned. I was really asking about the GM-8. (GM-8 is what I would consider a somewhat close competitor to the Synta entries load wise) So, how would the GM-8 stack up against the Synta competitors?

Edited by alanon (02/27/09 04:09 AM)

Post Extras:

Gardner
scholastic sledgehammer

Reged: 01/19/04

Loc: New Hampshire

Re: Question for Losmandy Imagers new

[Re: alanon]
#2952407 - 02/27/09 07:01 AM

One of the important reasons I stepped up to a GM-8 from a CG-5 was the Losmandy clutch system. I do a lot of public sky watches and didn't want to see a CG-5 motor wiped out from an accidental push on the scope.

Another reason is that the club I belong to has a permanently mounted Titan so my dovetails are compatible with that if I choose to use it.

I do image on my GM-8 with the SV80S and the Mini Borg guiding. The focal length of the 80mm scope with the TV 0.8 reducer is very short at 384mm. So I am not stressing the mount there in weight or tracking accuracy. I have not modded the mount at all other than an occasional worm gear adjustment.

One more thing. When I bought the GM-8 I was not intending to get into imaging. If that was my goal I would have moved to a G11 instead as the price difference is not really that great for a large jump in capacity. So I keep my setup well within the capability of the GM-8 and I am quite happy with it. If cost means a G11 is not within reach, I would not shy away from the GM-8 as it can be a capable imaging mount if one works within its load range.

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: Gardner]
#2952429 - 02/27/09 07:26 AM

Yes my budget is a bit too tight for the G-11. In fact the GM-8 Gemini would be a hard stretch, but if there is a clear advantage for AP over the Synta brands then I could push it to go the GM-8 Gemini. My load is a projected 20-25lbs with my WO98mm, WO66 guide scope, Orion autoguider, Canon 450d, and hardware. Is this asking too much of this mount?

Post Extras:

Carl M
scholastic sledgehammer

Reged: 02/21/07

Loc: Vermont, USA

Re: Question for Losmandy Imagers new

[Re: Gardner]
#2952457 - 02/27/09 08:00 AM

I own both a GM-8 and G-11. The GM-8 I bought used a few years ago and was made in 2000. The G-11 is brand new. I needed more weight handling capacity the G-11 has. But alas, it arrived two days before knee surgery ( ACL reconstruction) two weeks ago so I haven't been out with it yet. I had a Gemini add-on and a polar scope on the GM-8. I quickly and easily moved both over the G-11. The stepper motors on the G-11 are newer and upgraded compared to the older GM-8 so when I took them off the G-11, I put them on the GM-8. ( I did have the original GM-8 492 digital drive that went on as well) Why do I mention all of this? As others have said, it's easy to service any Losmandy mount and in many cases, the parts are interchangeable.

I have imaged with the GM-8 with a SV-80(NHNG) unguided for 3 min subs without any problems. I have an SV102ED with FT focuser and will guide with a SV F60 and SSAG. The weight isn't as much of a problem as the added length of the SV102ED. Visually with the GM-8, you could see movement if it was windy.
OK, what about new worms, modifications to improve PE, etc? Some one used a car as an example and I will too, but somewhat differently. When I got my first car, it quite functional, worked well, and performed well within normal uses. What did I do? Started 'improving' it. A lot of my time (and all of my money...

) went into the car and in the end, had something quite fast, and perfectly tuned. I think many of us treat mounts like we did cars in our 'younger' years. I must admit, I'm a gear head and I enjoy that aspect of astronomy just as much as the stars themselves!
In summary, both mounts are great and you can't go wrong. I would plan for the future and buy the larger G11 if you can. Chances are you'll upgrade your equipment and need the extra capacity.
Hope this helps!

Post Extras:

blueman
Vendor Blue Sky Accessories

Reged: 07/20/07

Loc: California

Re: Question for Losmandy Imagers new

[Re: alanon]
#2953120 - 02/27/09 02:22 PM

Try looking around for PE on Atlas and you will find that +- 15-40" is not unusual.
Blueman

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: blueman]
#2953183 - 02/27/09 02:50 PM

Hi Blueman,
That is what I found when I corrected myself earlier. I was off by a factor of 10 for Synta when I first posted. Sorry for the mistake all!

Post Extras:

hersey0308
super member

Reged: 12/04/08

Loc: Ontario Canada

Re: Question for Losmandy Imagers new

[Re: alanon]
#2953747 - 02/27/09 08:02 PM Attachment (21 downloads)

dan's point still stands. what do you get for the extra $1,000? i'm not certain if modeling is available for the other mounts but it is certainly a welcome part of the gemini system. without half decent pointing afforded in part by a well built model, imaging can become a difficult chore.

another poster mentioned interchangeable parts (motors, cables hand paddles) and if you have a few different mounts this can be very helpful. this has saved me waiting for parts twice in five years.

worth a grand? probably not but i'm still pretty darn happy with my gm 8.

good thread all.

david

Edited by hersey0308 (02/27/09 08:11 PM)

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: hersey0308]
#2953930 - 02/27/09 09:37 PM

Hello Heresay,
I appreciate the direct answer.

Post Extras:

WidowMaker
Catchy Title

Reged: 12/29/07

Loc: Frankfort, Ky

Re: Question for Losmandy Imagers new

[Re: hersey0308]
#2953940 - 02/27/09 09:43 PM

David, can I ask what the screen shot came from?
Is that a program youre using to control the G11?

Post Extras:

jackk
member

Reged: 10/14/08

Re: Question for Losmandy Imagers new

[Re: alanon]
#2953972 - 02/27/09 10:12 PM

Quote:

Thanks Mighty Kong!

I think that my question still stands though. If an average performance in PE is + or - 4"to 7", then this mount does little (if anything) to warrant the extra cash out of the box. I should think that an Atlas, Sirius, or CGEM is capable of these numbers as well. Plus rebuilds if I recall, the hyper tuning jobs on the Atlas Mounts do not entail an expenditure of $500 for a part.This doubles the cost of the competitive offerings at this load bearing capability. Please correct me if I am wrong ,but is there something I am that missing? What other qualities are there that would justify this price? I don't mean to be confrontational, but really would like to know.

Add on... I am in the market and haven't scratched the GM-8 from the option list. So, any help would be very useful. Thanks All!

It seems like you are kind of looking for a reason NOT to buy a G-11. Im sure if you look around hard enough, you will be able to find it.

My personal reasons for buying the G-11 is that it is a great stable imaging platform to begin with, I have about +-8 arcsec of periodic error right out of the box. Id say this is an average build quality for a G-11. If i want to get down to +-3, I have the option of upgrading the $3000 mount for only $500 with the ovision worm. I like this option to upgrade better than having to sell my G-11, and spend $9k-12k and buy a AP or Paramount to get that level of stability.

Also, you with the G-11 you have a super active user community that in my experience will go to great lengths to provide information. You may or may not find that with other mounts, not sure.

Post Extras:

blueman
Vendor Blue Sky Accessories

Reged: 07/20/07

Loc: California

Re: Question for Losmandy Imagers new

[Re: Astronomics]
#2954085 - 02/27/09 11:40 PM

I have the ST2000xm with the filter wheel, that is why I stated the the Chinese focuser was thought to not be able to support the load.
So, I would probably need the FT focuser or I would worry about that.
So, I assume that at this time the AT8RC is not available and there are no adapters available for the FT focuser, which is what I stated earlier. Is this correct?
Blueman

Post Extras:

Astronomics
Vendor if you must, AKA The Mighty Kong.

Reged: 06/07/04

Loc: Right Here

Re: Question for Losmandy Imagers new

[Re: blueman]
#2954087 - 02/27/09 11:43 PM

The AT8RC is due end of March.
The adapter should be available to purchase from Starlight. They know what is needed and it is up to them to keep the part in stock.

Post Extras:

Patrick
Postmaster

Reged: 05/16/03

Loc: Franklin, Ohio

Re: Question for Losmandy Imagers new

[Re: alanon]
#2954103 - 02/28/09 12:01 AM

Quote:

Yes my budget is a bit too tight for the G-11. In fact the GM-8 Gemini would be a hard stretch, but if there is a clear advantage for AP over the Synta brands then I could push it to go the GM-8 Gemini. My load is a projected 20-25lbs with my WO98mm, WO66 guide scope, Orion autoguider, Canon 450d, and hardware. Is this asking too much of this mount?

The GM-8 is obviously a nice mount with great build quality. But, I don't think it has any show-stopping advantages over a Sirius mount. If you're planning on autoguiding you should have no problem getting accurate tracking in the +/- 5 arc second range. With the focal lengths you're planning on using, you should be able to get very long exposures...probably longer than the sky fog will allow you if you live in a suburban setting. Even a CG5-GT is capable of getting fairly long exposures at <1000mm focal lengths.

I think the thing you're missing is that the Losmandy mounts have a very real feeling of quality to them. They exude quality...better fit and finish, better machining, all made by skilled craftsmen...but you pay for that. If budget is an issue, I wouldn't hesitate to go the Orion Sirius/EQ6/CGEM/CG5 route. Astrophotography is expensive enough with all the accessories you'll need beside the mount. If you can get round stars nearly 100% of the time, that's the important criteria.

Patrick

Post Extras:

blueman
Vendor Blue Sky Accessories

Reged: 07/20/07

Loc: California

Re: Question for Losmandy Imagers new

[Re: Astronomics]
#2954175 - 02/28/09 01:21 AM

Thank you Michael, that answers my questions. I will talk with Starlight concerning the adapter and focuser.
Do you know what length the draw tube will be, so I can ask about that too?
Floyd

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: Patrick]
#2954229 - 02/28/09 02:27 AM

Thanks Patric!

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: jackk]
#2954248 - 02/28/09 02:48 AM

Hi Jackk,

I don't have a problem with the G-11 it is just more mount than I want. It is most definitely over my price range by 2X. If you read the rest of my posts you will see that I am interested in a GM-8, and am trying to justify what is so much better about it verses a Synta like the Atlas. I could maybe scrape together some more money for it, but I need to know if my money is well spent in doing so.

I know this thread is about both the GM-8 and the G-11 as well. Somehow it became a thread about Catadiopteric focusers also. It gets a little confusing

Post Extras:

Astronomics
Vendor if you must, AKA The Mighty Kong.

Reged: 06/07/04

Loc: Right Here

Re: Question for Losmandy Imagers new

[Re: blueman]
#2954476 - 02/28/09 08:52 AM

You should be able to use the 1.5" or 2" drawtube without issue.

Post Extras:

blueman
Vendor Blue Sky Accessories

Reged: 07/20/07

Loc: California

Re: Question for Losmandy Imagers new

[Re: Astronomics]
#2954993 - 02/28/09 02:06 PM

Hi,
Thank you, that will help. I have a 1.5" FT here, but I am wondering if a 2" would not be better. But, I will worry about that when the time comes I guess.
Blueman

Post Extras:

hersey0308
super member

Reged: 12/04/08

Loc: Ontario Canada

Re: Question for Losmandy Imagers new

[Re: WidowMaker]
#2955249 - 02/28/09 05:08 PM Attachment (23 downloads)

hi widow - the screenshot is from the gemini control center software from daniel gorlich. i use it to remotely model build and additional align. i have just scratched the surface with this control program because there is fantastic stuff you can do with it. if you goog gemini control center there is an overview and trial.
i'm still digesting the manual which is very thorough...just another intangible reason why dan and wass should be gemini/losmandy guys!?

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: hersey0308]
#2955272 - 02/28/09 05:17 PM

I am still seriously thinking of the GM-8.
One other question about the AP ability of the Gemini system. Does the software come with proper drivers for Vista 64 bit OS? This would certainly clinch it for me, as all of the other systems out there are 32 bit only.

EDIT: Like it or not, the reality is that the 32 bit OS is rapidly going the way of the dinosaur. I don't wish to start an XP vs. Vista scrap here. I just think that those companies that wish to keep selling computer driven equipment really have an obligation to keep there software workable.

Edited by alanon (02/28/09 05:22 PM)

Post Extras:

Strgazr27

Reged: 10/04/04

Loc: StonyHill Observatory

Re: Question for Losmandy Imagers new

[Re: alanon]
#2955498 - 02/28/09 07:35 PM

Quote:

EDIT: Like it or not, the reality is that the 32 bit OS is rapidly going the way of the dinosaur. I don't wish to start an XP vs. Vista scrap here. I just think that those companies that wish to keep selling computer driven equipment really have an obligation to keep there software workable.

Actually MS announced recently continued support for XP users (Still the best OS MS has IMO) and is treating Vista like a redheaded stepchild. It will be quite some time before 32 bit OS's go the way of T-REX

Post Extras:

blueman
Vendor Blue Sky Accessories

Reged: 07/20/07

Loc: California

Re: Question for Losmandy Imagers new

[Re: alanon]
#2955647 - 02/28/09 09:11 PM

What software would you be talking about? The G-11 or GM-8 work with a hand pad or you can use a computer with a program like Starry Night, but there is no software for a computer required to run the mount.
As for the 32 bit vs 63 bit, well there is not that much 64 bit software out there really. Maybe the OS is 64 bit, but the programs are mostly not.
Blueman

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: Strgazr27]
#2955666 - 02/28/09 09:26 PM

Hi Bobby,
I appreciate, and certainly respect your opinion, but the fact is...
It took a long time for Windows 98 to go away too. Many argued (like you are for XP) that 98 blows XP out of the water. The reality is that less and less 32bit computers are being made. The day will come when the industry is just going to leave 32 behind for the faster 64 bit processor. Sooner, or later the astronomy industry will have to upgrade. Either Vista 64 or the next OS down the road will rule as the Hardware seems to all be going that way in the real market. So our miniscule nitch needs to come along just like the DSLR has. That just my $0.02.
but I digress...

The question was if the Losmandy/gemini system supports the newer OS with drivers?

EDIT: It would be nice if this industry would start give the customer the option at any rate.

Edited by alanon (02/28/09 09:30 PM)

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: alanon]
#2955755 - 02/28/09 10:16 PM

Add on:

There are a growing number of people out there (like me)who have completely upgraded their equipment in the last year or so, and are now completely changed over both with the home and Lap top to the Vista 64. Even Moderately priced gear comes that way these days. I am happy that the industry didn't do us the same as they did when they switched from the old 486 16bit Windows 3.11 to the Pentium 32 processor and Windows 95. They just, slammed everyone into the next era with lack of support, and the software companies fell right in line with Microsoft. We were Scruged! At least they have been, what I consider more than gradual this time as the 64 bit computer has been around for a while.

Now, if I can't find AP hardware companies with enough foresight to move forward with 64 bit drivers, I will be forced to either buy a sub parr cheapo laptop and upgrade the memory just so it is functional. Or.. I will have to dumb down an otherwise decent laptop to just to be compatible with a brand new mount and autoguider. (My DSLR is on board already)

I hope that Losmandy has addressed this issue. It isn't a deal breaker if it hasn't as it would just be in line with the rest of an already backward industry.

Remember, it isn't our nitch that guides the computer industry. That is a bit like the tail wagging the dog. Have you looked at Laptops lately? It is even getting hard to find an rs232 jack on new ones.

Now I realize that it costs money to upgrade and pay for drivers to make your equipment up to date compatible, but isn't that the cost of business if you wish to remain viable in a changing industry? I mean come on...

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: blueman]
#2955768 - 02/28/09 10:21 PM

Quote:

What software would you be talking about? The G-11 or GM-8 work with a hand pad or you can use a computer with a program like Starry Night, but there is no software for a computer required to run the mount.
As for the 32 bit vs 63 bit, well there is not that much 64 bit software out there really. Maybe the OS is 64 bit, but the programs are mostly not.
Blueman

Hi Blueman,
Does this mean that I don't need drivers for the 2 components to talk to each other?

That is not what I have been told.

Post Extras:

jrcrilly
Refractor wienie no more

Reged: 04/30/03

Loc: NE Ohio

Re: Question for Losmandy Imagers new

[Re: alanon]
#2955775 - 02/28/09 10:25 PM

Quote:

Does this mean that I don't need drivers for the 2 components to talk to each other? That is not what I have been told.

The Gemini uses RS-232. There are no equipment-specific drivers required for that.

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: jrcrilly]
#2955787 - 02/28/09 10:29 PM

Hi John,
Please excuse me if this is beginning to sound like a circular discussion, but where do you get a laptop that still has such a connection?

EDIT: I am getting more confused. I really need help guys!

Edited by alanon (02/28/09 10:33 PM)

Post Extras:

jrcrilly
Refractor wienie no more

Reged: 04/30/03

Loc: NE Ohio

Re: Question for Losmandy Imagers new

[Re: alanon]
#2955822 - 02/28/09 10:45 PM

Quote:

Hi John,
Please excuse me if this is beginning to sound like a circular discussion, but where do you get a laptop that still has such a connection?

I don't see how that relates to a 32 bit/64 bit driver issue. The mounts intentionally use an interface that avoids the issue entirely. My imaging computers all have serial ports but for those using computers not so equipped there are plenty of ways to add them. It's up to the folks offering RS-232 addons to provide compatible drivers; that's not up to Losmandy (or any other mount manufacturer).

Post Extras:

Gardner
scholastic sledgehammer

Reged: 01/19/04

Loc: New Hampshire

Re: Question for Losmandy Imagers new

[Re: alanon]
#2955842 - 02/28/09 10:59 PM

Astronomics has the Gemini to serial cable here

Add a USB to serial adapter to complete the connection.

I'm not going to get into the 32 bit vs. 64 bit discussion other than to say in my own opinion it's a non-issue when talking to a Gemini mount.

I think the drivers are through the ASCOM platform.

Edited by Gardner (02/28/09 11:01 PM)

Post Extras:

blueman
Vendor Blue Sky Accessories

Reged: 07/20/07

Loc: California

Re: Question for Losmandy Imagers new

[Re: alanon]
#2956023 - 03/01/09 01:44 AM

What exactly are you talking about?
Blueman

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: Gardner]
#2956024 - 03/01/09 01:46 AM

This is very good news, Gardner, and John. I was always under the impression that no matter what the device be it a mount, mouse, printer, Monitor, or whatever an appropriate driver was needed to get the computer to recognize the periferal hardware.

Things like the Orion Autoguider, for instance, will work with a vista 32bit system, but specifically state that they will not work with a Vista 64 OS. I just assumed that this was a driver oriented problem since the connection to the computer is virtually the same (USB2).

I appreciate you guys helping me out. This is good to know that I can use the laptop I have and run the GM-8 remotely with only the addition of a cable. Many thanks.

Edited by alanon (03/01/09 01:50 AM)

Post Extras:

blueman
Vendor Blue Sky Accessories

Reged: 07/20/07

Loc: California

Re: Question for Losmandy Imagers new

[Re: alanon]
#2956026 - 03/01/09 01:48 AM

You use a USB to serial port adapter. Are you really such a computer geek, but are completely unaware of these things?
Blueman

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: blueman]
#2956046 - 03/01/09 02:14 AM

Quote:

You use a USB to serial port adapter. Are you really such a computer geek, but are completely unaware of these things?
Blueman

No I never claimed to be a computer geek. In fact I am quite the opposite, blueman. I just brought up the question because when looking for guide cameras, I was told that many will not work with Vista64. If you have something constructive to say that would help then I would shurely appreciate it. If I am wrong(which I am the first to say happens often) then please correct me. Please guys... I am not trying to be rude. If I come off that way, then I apologize. It is truly unintentional. I am trying to make sure because the CCD and guide camera buffs tell me that without the correct drivers most of them will not operate on these computers that I own. They say that I need to go with an older OS system as the "drivers" for the 64 bit OS do not exist.

If you guys are saying that this is a non issue for the GM-8 I believe you. Thanks for your help!

Edited by alanon (03/01/09 02:23 AM)

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: alanon]
#2956070 - 03/01/09 02:46 AM

Perhaps I am asking the wrong question then. Is there software out there that is compatible with my Vista 64 bit OS that is also compatible to remotely run the GM-8 mount? Is this what I need to ask? I am so totally lost with this issue. Please somebody set me straight!

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: alanon]
#2956086 - 03/01/09 03:04 AM

I apologise guys I have gone as off topic with this issue as the focuser for a Cat was. Perhaps I should start another thread. My quick question due to my lack of knowledge has turned this into a complete hijack. Sorry folks!

Post Extras:

Carl M
scholastic sledgehammer

Reged: 02/21/07

Loc: Vermont, USA

Re: Question for Losmandy Imagers new

[Re: alanon]
#2956331 - 03/01/09 09:00 AM

Quote:

Perhaps I am asking the wrong question then. Is there software out there that is compatible with my Vista 64 bit OS that is also compatible to remotely run the GM-8 mount? Is this what I need to ask? I am so totally lost with this issue. Please somebody set me straight!

Alanon - this question comes up a lot so I thought I'd take the time and really try and explain what's up with a 64bit OS...
I am a Software Engineer by trade and also oversee the IT infrastructure for the facility I am based out of. I’ve done some development for a couple of ASCOM applications ( a fairly common astronomy standard used today) and to answer, I’ll put those hats on for a second….
Answer - MS 64 bit Operating Systems do not do well with 32 bit drivers for serial I/O. This is not limited to astronomy related stuff…
Why?
When you create a project in say, Visual Studio, which is a common development platform for .NET applications, it assumes you will be creating both 32-bit and 64-bit code for maximum compatibility. The default architecture is set to "Any CPU" by default. Most of the time this is OK, but for most drivers that exist out there, this causes a compatibility problem. You see, most of the I/O components, like the ASCOM platforms out there, were generated with tools that are much older than 64-bit CPUs and therefore, contain only 32-bit code. Presently,.Net Framework does not easily allow 64-bit applications to call into 32-bit COM objects. So, things compiled will run fine on 32-bit systems, but when they are run on a 64-bit system they run as native 64-bit application and will go belly-up when it tries to bind to a 32-bit object. Now there are some work arounds, but everything I’m talking about requires some sort of new development. In essence, there isn’t any physical way for backwards compatibility in regard to existing code.

In summary, a 64 bit OS is wonderful at Enterprise level server applications where non-serial I/O is utilized. It's great for virtual hosting and allows access of much more memory for Terminal Services and Virtual Hosting operations. On the reverse side, it’s weakest point is utilizing any I/O interface drivers (there’s also a separate subject on VPN stuff I won’t get into…). In the enterprise world, this isn’t too much of an issue – you don’t find many folks plugging things into a blade server, but for most desktop and portable applications, a 64 bit OS is more of a hindrance then advantage as serial I/O becomes more prevalent. Lots of folks plug things into their laptops or home PCs. I’ve stress tested applications running on both 32 and 64 bit machines and for what the average person does with a laptop or PC, there isn’t really an advantage with a 64 bit OS – that’s not where most ‘bottlenecks’ occur…
What do I do?
If hardware serial I/O is in the cards for your computer equipment, load a 32 bit operating system. You can also wait for the world to completely cut over to 64 bit I/O, but that’s not as practical as 32 bit architecture is very much main stream still. If you do this now, you’ll regain the compatibility with many kinds of drivers, including those used for astronomy-related programs.

I hope this helps…..

Post Extras:

blueman
Vendor Blue Sky Accessories

Reged: 07/20/07

Loc: California

Re: Question for Losmandy Imagers new

[Re: alanon]
#2956901 - 03/01/09 01:39 PM

Sorry Alanon,
The way you were talking, I was assuming that you were a computer geek. But I did add something constructive, I told you to use a USB to serial port adapter. That is what you do.
Blueman

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: blueman]
#2958475 - 03/02/09 09:09 AM

Carl, Thanks for the succinct and to the point answer!

Blueman, I know, but that wasn't the question. I first asked about the OS compatibility. I used the lack of a RS232 port as an example of the change in the computer industry and the slowed pace of the Astronomy equipments lag behind. I am aslo not the best typist, so it is probably my fault that I did not make myself clearer. Thanks for your help.

Edited by alanon (03/02/09 09:14 AM)

Post Extras:

Tom Picciani
newbie

Reged: 03/24/06

Loc: Lancaster, Pa.

Re: Question for Losmandy Imagers new

[Re: alanon]
#2966405 - 03/05/09 09:13 PM Attachment (17 downloads)

Hi, Alanon. I haven't posted on CN in a couple years and just got back to this site. I've been a G11/Gemini user since '06. My PE is roughly +/- 6" or 12" p-p. I don't see much evidence of the 76 second error.
First, about the 32/64 bit issues. While I won't go into the details, I think compatibilty is the key here. If you're going to need a pc that works with all the software and drivers, then the applications needs dictate the OS. Not that it's an easy decision, but you have to go with either XP or Vista 32. I use XP since Vista is annoying and slow. I run a technology Help Desk at a university.

As to the GM8 or EQ6/Atlas. There's no doubt that I've seen some great Atlas mounts. But I've never seen these poeple do more than 5 minute exposures, and that was pushing it. If you want to image, get the 8 or 11.

You haven't posted the type of optics you plan to mount nor how dark the area is. That will dictate the quality of the mount too. If you're going to use a 90 mm refractor, yea, a GM8 or Atlas will be fine. But if you want to mount a medium to large SCT and want to track accurately without getting frustrated, then you need the G11! I run a C9.25 with a Stellarvue 80. I have an ST7.

Remember, if you can spring for it, the G11 is a lifetime mount, especially if you buy new. Unless you want to buy some really big optics it will last you a lifetime.

Tom P.

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: Tom Picciani]
#2966777 - 03/06/09 01:04 AM

Thanks for the info, Tom.

My loads on the mount are as follows...

WO 98mm FLT (aluminum)
WO ZS66 Guide scope
Canon 450D
Auto guider cam
Mounting hardware,Field flatner, etc.

This is a load of 20-25 lbs.

I am interested in the GM8 if I go Losmandy. It is a major chunk outside the budget I had set at $1500 anyway, so the G11 is out of the question. I just can not afford $3K. My question was mainly about the GM-8. would it make a reliably good AP mount under those load conditions? Will it still out perform a mount (the Atlas) that is touted as handling that much weight with ease? For a Gemini version the extra expenditure is a 66% increase in cost.

Yes I am interested in the GM-8, but for the extra cash is it 66% more capable? Or is it even somewhat more capable for a 25lb rig? People do astounding work with the autoguided Atlas. So I think that the question of How much better the GM-8 will do in comparison. Would I be getting a step up in performance with my load requirements?

I would certainly love to own a G-11 or for that matter an AP mount. If Money were not the issue then I would be all over the G-11. The GM-8 is a very big stretch as well for my retired income. I'm just asking that if I can swing that much more, what do I get for the money, over the Synta offerings? This is a reasonable question right? Since my expendable cash is limited, It is only reasonable to get the biggest bang for that amount.

Some here have made a couple of fair cases for the losmandy GM-8, but just as many have brought up issues of load capacity. I can't spend more to fix it with an upgrade to a G-11. The GM-8 has to compete for my dollars without its illustrious big brother. Specially since I have to buy an OS now.

I love the sexy look of the GM-8. In my mind there is an asthetic value to the mount. I just want to be certain before I pull the trigger that I will get the extra value for my load requirments out of that extra $1000.

Correct me if I am wrong but the issue boils down to something like this.

GM-8
Pros. Better build, tighter tolerances.
cons. weight capacity is not so good. Cost is high, need to purchase extras seperately.

Atlas
Pros. Holds a heavier load, cheaper, comes with most of the accessories like polar scope, and more counter balance weight
cons. Not as tight tolerances. PE not as good.

To me a sports car is very cool and sexy, but if you need to haul lumber it isn't the right tool for the job. Similarly at some point that great PE is not going to look so good if the load I place on it is too much. Is 25lbs that proverbiale straw that broke the camels back, or would I still be better off with the GM-8?

I am really interested to hear from all of you guys as to how you would choose under these circumstances? I really do appreciate all of the time you guys spend in helping this old newby to AP. I want to buy once, and want this to be a good experience. As always thanks for the help.

EDIT: Tom, that is one great looking rig you have there.

Edited by alanon (03/06/09 01:08 AM)

Post Extras:

Charlie Hein
Postmaster

Reged: 11/02/03

Loc: 26.06.08N, +80.23.08W

Re: Question for Losmandy Imagers new

[Re: alanon]
#2967011 - 03/06/09 07:26 AM

Hi Dan - I've got a couple of comments...

Remember, you will be autoguiding. The amount of your mount's PE is a complete non-issue as long as that PE ramps up and down smoothly enough for your autoguider to correct it out.

I think that the GM-8 would pretty much be pushing the limit of its load capacity for imaging with your scopes, but it would *probably* be okay. I cannot say this from first hand experience but even so I believe it to be true just based on the rated capacity of the mount and it's quality.

The Atlas would definitely handle that load - it falls right in the "sweet spot" for the mount actually. There are a number of guys in my club that own the Atlas mount. I was one of them until last week when I sold my Atlas (I now have a G-11).

As for exposure times, remember that if you can autoguide sucessfully through an entire rotation of the worm gear you can expose for as long as you need to barring any other factors like wind, cable interference or someone bumping the scope. The worm period for the Atlas is around 8 minutes or so. Pretty much every Atlas owner in our club exposes for at least that long. I personally would routinely do 10 minute exposures on the Atlas and have even gone as long as 30 minutes with good results.

Bottom line - either mount will definitely please you in some fashion. I don't envy your decision.

Charlie

Post Extras:

Tom Picciani
newbie

Reged: 03/24/06

Loc: Lancaster, Pa.

Re: Question for Losmandy Imagers new

[Re: Charlie Hein]
#2967347 - 03/06/09 10:58 AM

Charlie,

In my experience, PE is much more important than you make it out to be. Remember, autoguiding corrects after the error occurs. If the error is not periodic and predictable, as in lesser quality mounts, then the error must be guided after the fact. It will show on the image prior to it being moved back to the correct position. This can reduce the sharpness of the image. This is the reason that a 20 arc second average mount is not nearly as desirable as a 10 arc second mount.

Perhaps the best thing to do is go to an EQ6/Atlas group and ask what sort of guiding times these people can manage. I think you'll find the Atlas, while a good, solid scope, isn't up to the standards of Losmandy, either the GM8 or the G11. But that's my opinion. For the most part, the error of the Losmandy 8 can be predictable and mapped iwth PemPro. And the Gemini can be purchased separately, although that will cost a few hundred more to go that route.
And finally, don't underestimate the quality of the new Ovision worm that can be purchased from France at a later date.

That raises another point. If someone were to purchase an ovision GM8 worm assembly, is it the same as the G11? I could see someone upgrading a GM8 with the expensive worm then putting the original back when they upgrade to a G11. If that's possible.

Tom P.

Post Extras:

Tom Picciani
newbie

Reged: 03/24/06

Loc: Lancaster, Pa.

Re: Question for Losmandy Imagers new

[Re: Tom Picciani]
#2967581 - 03/06/09 12:39 PM

Just to clarify my last post. It is certainly possible to guide out error, whether periodic or not. But doing it after the fact often leaves evidence of the error. If you can see it in guiding, you can see it in the image.

Theoretically and in practice, using PEC can guide out the periodic elements of the error as the error occurs. It's advantageous to do it this way rather than just having PEC turned off and correcting the problem after the fact.

Post Extras:

rsbfoto
sage

Reged: 06/10/06

Re: Question for Losmandy Imagers new

[Re: Tom Picciani]
#2967611 - 03/06/09 12:55 PM

Hi Dan,

If you are able to get a G11 tripod instead of the flimsy GM-8 tripod your GM-8 will instantly improve.

If you keep the GM-8 well adjusted 20-25 pounds are no problem for it.

Post Extras:

Charlie Hein
Postmaster

Reged: 11/02/03

Loc: 26.06.08N, +80.23.08W

Re: Question for Losmandy Imagers new

[Re: Tom Picciani]
#2967701 - 03/06/09 01:27 PM

Quote:

In my experience, PE is much more important than you make it out to be. Remember, autoguiding corrects after the error occurs. If the error is not periodic and predictable, as in lesser quality mounts, then the error must be guided after the fact. It will show on the image prior to it being moved back to the correct position. This can reduce the sharpness of the image. This is the reason that a 20 arc second average mount is not nearly as desirable as a 10 arc second mount.

I'll certainly agree that my statement is a pretty simplistic viewpoint, and deliberately so. It's true that guiding corrects an error only after the error has occurred. However this is true of any mount that is being autoguided. If you have corrections to make and you use autoguiding to correct them there will always be this "lag" regardless of the quality of the mount. It is a function of the process of autoguiding, not the mount itself.

If the mount is guiding correctly (as in gathering enough samples to react as quickly to changes as possible without overcorrecting and thereby "chasing the seeing") I stand by the statement that almost any amount of PE can be well corrected - unless the error is ramping up and down stronger and faster than the system (guider and mount) can accomodate for. If the mount has a "spike" that ramps up hard and fast no guiding solution (including adaptive optics and PEC) can react to the event quickly enough to be effective.

If the system is working correctly and the error ramps up and down in a controllable fashion then the only real difference between correcting a 5 arcsecond error and correcting a 30 arcsecond error would be the number of individual corrections required to keep the star centered. As you say this will definitely result in an image that is somewhat less sharp than it could be if you use adaptive optics guiding or PEC, but it's also safe to say that this is a phenomenon that is common to every autoguided mount regardless of build quality.

When it comes right down to it at a certain point the "desirability factor" of a 10 arcsecond peak to peak mount versus a 20 arcsecond peak to peak mount ends up being almost a philosophical question:

If you are going to be guiding with either mount (this is a given), and you can guide effectively with either mount (this will take some amount of work to achieve in either case but is certainly possible in both cases), then does it really make a difference to you if the error is successfully corrected in 10 steps or 20 when the outcome will be indistinguishable?

The real question (in my mind) is if the extra quality in build makes the work required to get good guiding easy enough to warrant a difference in price, or in Dan's case, a difference in carrying capacity.

Quote:

Perhaps the best thing to do is go to an EQ6/Atlas group and ask what sort of guiding times these people can manage. I think you'll find the Atlas, while a good, solid scope, isn't up to the standards of Losmandy, either the GM8 or the G11. But that's my opinion. For the most part, the error of the Losmandy 8 can be predictable and mapped iwth PemPro. And the Gemini can be purchased separately, although that will cost a few hundred more to go that route.

Bear in mind that it is these quick "spikes" in PE that can't be guided out well that are the real issue here. Although statistically speaking you are going to see more errors of this type on a mount like the Atlas, these quick PE "spikes" can certainly be a problem in the GM-8 and G-11 too. The now legendary "dreaded 76 second error" on the G-11 is a perfect example of this. A worm bearing block that is out of square with the worm causes a predictable "spike" in the PE at 76 second intervals. The amplitude of this "spike" can easily be large enough to wreck your guiding - even when using PEC to correct the errors. In fact, the Ovision worm was developed specifically to correct this problem with the Losmandy mount.

I guess what I'm trying to say is that even with mounts of the class of the Losmandy you may still need to do some serious tweaking to get things just right. My G-11 definitely has the 76 second error. However, I've been able to adjust the worm block so that the error is brought down to an amplitude that as far as I can tell doesn't even trigger a response from the autoguider and doesn't seem to affect my images even at just over 1 arcsecond per pixel resolution. These problems can be remedied, even in the Atlas mount. A quick read of the Losmandy_users and EQ6 Yahoo! groups will show that many people in both groups are doing so and getting better performance out of their mounts for the effort. Again, you have to ask yourself if the amount of work that may be required would be worth it, although no matter what there is going to be some level of effort required in rder to achieve good results - there is no such thing as a totally "plug-n-play" guiding system.

Quote:

And finally, don't underestimate the quality of the new Ovision worm that can be purchased from France at a later date.

The Ovision worm is a really good option if you're having problems getting rid of the 76 second error on your mount. In the majority of cases it also improves the peak to peak PE figure of the mount over the stock worm and block(s).

Quote:

That raises another point. If someone were to purchase an ovision GM8 worm assembly, is it the same as the G11? I could see someone upgrading a GM8 with the expensive worm then putting the original back when they upgrade to a G11. If that's possible.

I believe that the worm is interchangable between the GM-8 and G-11 but I can't say so with 100% certainty.

Charlie

Post Extras:

Charlie Hein
Postmaster

Reged: 11/02/03

Loc: 26.06.08N, +80.23.08W

Re: Question for Losmandy Imagers new

[Re: Tom Picciani]
#2967706 - 03/06/09 01:30 PM

Quote:

Just to clarify my last post. It is certainly possible to guide out error, whether periodic or not. But doing it after the fact often leaves evidence of the error. If you can see it in guiding, you can see it in the image.

Theoretically and in practice, using PEC can guide out the periodic elements of the error as the error occurs. It's advantageous to do it this way rather than just having PEC turned off and correcting the problem after the fact.

Yes, I completely agree - and PEC is an option for either the GM-8 or the Atlas.

Post Extras:

Patrick
Postmaster

Reged: 05/16/03

Loc: Franklin, Ohio

Re: Question for Losmandy Imagers new

[Re: Tom Picciani]
#2968086 - 03/06/09 04:40 PM

Quote:

In my experience, PE is much more important than you make it out to be. Remember, autoguiding corrects after the error occurs. If the error is not periodic and predictable, as in lesser quality mounts, then the error must be guided after the fact. It will show on the image prior to it being moved back to the correct position. This can reduce the sharpness of the image.

The amount of PE that can be 'handled' is more a factor of the imaging scope's focal length and the pixel size of the imaging device than the lag time of the autoguiding process. At the short focal lengths Alanon is currently showing in his sig line and with his current DSLR he should not have any problems autoguiding his way out of the Atlas's periodic error...without recording those errors. That's simply because the light sources will not cross over from one pixel to the next before the autoguider corrects the error. The autoguider uses sub-pixel correction algorithms.

I know this is a 'Losmandy' thread, but with his scopes and cameras, the lowly CG5-GT would be capable of doing a good job. Alanon has said on more than one occassion that budget is a big consideration. A GM-8 would also be more than enough to do the job very well, but is it worth the extra cost? I don't think so, UNLESS the plan is to image unguided. Then the mount's native PE would be a deciding factor.

If Alanon wants to upgrade his scopes in the future to longer f/l and heavier instruments and doesn't want to upgrade his mount as well, then the Atlas is the clear choice because it already has the capacity to handle those loads, whereas the GM8 does not.

That's my story and I'm sticking to it!

Patrick

Post Extras:

waassaabee
Post Laureate

Reged: 11/26/07

Loc: Central California Coast

Re: Question for Losmandy Imagers new

[Re: Patrick]
#2968276 - 03/06/09 06:12 PM

So what I seem to be picking up here is a new, out of the box GM8 will image with 20 lbs. if well balanced. Some tinkering and modifications could push it to 25 lbs. Stouter tripod recommended.?.?. User maintenance friendly?

Right now I plan on continuing with the optics and guide setup I have, but I'm sure that will change over time. The WO and everything else is a touch over 13 lbs so as it stands the GM8 would fit just fine. Where's that stimulus...

Lowly CG5-GT? I resemble that statement...

Great info all around, and very informative.
Keep it rollin'!

Edited by waassaabee (03/06/09 08:51 PM)

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: waassaabee]
#2978323 - 03/11/09 05:49 PM

Thanks to everyone! I had been at the hospital for some abdominal surgery since my last post, and I just now got home to read your responses. Like waassaabee said,"Great info all around, and very informative."

Post Extras:

alanon
Nobody tells me anything

Reged: 06/29/07

Loc: Las Vegas

Re: Question for Losmandy Imagers new

[Re: waassaabee]
#2978334 - 03/11/09 05:54 PM

Quote:

Lowly CG5-GT? I resemble that statement...

Why do we all associate with such lowbrow types?

Edited by alanon (03/11/09 08:45 PM)

Post Extras:

hersey0308
super member

Reged: 12/04/08

Loc: Ontario Canada

Re: Question for Losmandy Imagers new

[Re: waassaabee]
#2978781 - 03/11/09 10:46 PM Attachment (27 downloads)

hey gary - in the pic i have one 7lb plus 21 lbs counterweight high on the shaft to balance about 26 pounds on top. like other parts, the counterweights are compatible for gm8, g11 and the titan.
david

Post Extras:

Pages: 1 | 2 | 3 | 4 | 5 | (show all)

Extra information

9 registered and 28 anonymous users are browsing this forum.

Moderator: Bowmoreman, bilgebay, iceblaze

Print Thread

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

Thread views: 2386

Jump to

CN Forums

Home

Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics