Choosing a guide scope Askar 52mm f/4 Guide Scope · bluespeck · ... · 35 · 821 · 4

bluespeck 1.51
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Hi all. I am looking for opinions and general guidance. 

I recently upgraded from a 61mm wide field refractor to the Askar 107 PHQ, but am still using it with my old William Optics Uniguide 32.

I am now looking to upgrade the guide scope as well and was thinking about the Askar 52mm F4. 

Any thoughts and reviews would be much appreciated. 

Cheers smile
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andreatax 9.89
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It's a guide scope, they are all the same and for what it is worth get the cheapest you can get.
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Gondola 8.11
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My question is, do you need to upgrade? What kind of numbers is your old guiding setup giving you?
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Alexn 12.25
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If your stars are round in your images - don't change anything.
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AstroTrucker 6.22
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I agree with Tony and Alex. If you need to upgrade the guider. I use the WO 50mm Uniguide w rotolock. Very secure coupling with the 120mini. I am sure the Askar 52 will be fine. I haven't seen it and too lazy to look. However, if it has rotolock, or similar on the focuser, it should be fine. 

CS

Tim
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dkamen 7.44
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Hi,

I have been using the same ZWO 30/120 guide scope. I have guided with it a 350mm refractor and the error was 2", I have guided with it a 1500mm Maksutov and the error was 0.5". All the difference was in the mounts.

I think sometimes we are forgetting that guiding (at least with an equatorial mount) isn't really supposed to be doing much. Its job is to correct tiny deviations from ideal tracking, once every few seconds, IF needed. If you somehow had perfect PA and perfect tracking, guiding would not be necessary, at all. If your rig deviates too much from that ideal, it is probably a mount problem (or a wind problem), not a guide scope problem.

If everything else stays the same, changing the guide scope for a bigger one in an attempt to comply with the "1/3rd effective focal length rule" (or was it a 1/2nd rule) can arguably cause more bad than good because of the added weight, torque and increased sensitivity to seeing which results in incorrect star position calculations. Don't do that unless your stars are not round and you are certain guding (and the guide scope in particular) is to blame.

Cheers,
Dimitris
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bluespeck 1.51
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@dkamen@Tim Ray@Alex Nicholas@Tony Gondola@andrea tasselli

Thank you everyone for some good advice. I am still relatively new to all this and appreciate your wisdoms. 

Cheers,
Irwin
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TiffsAndAstro 1.81
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@dkamen@Tim Ray@Alex Nicholas@Tony Gondola@andrea tasselli

Thank you everyone for some good advice. I am still relatively new to all this and appreciate your wisdoms. 

Cheers,
Irwin


One noob to another.... If it ain't broke don't fix it

I really don't like my zwo f4 guide scope, but it guides my sw gti under 0.9" so I leave it alone
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StewartWilliam 5.21
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I have to say after trying few guide scopes for my Esprit 100, the best by far is the Askar FMA180 pro, just superb…👍🏻
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zermelo 7.22
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My 0.2 cents:

I'm currently using the cheapest autoguiding system I could find: the Svbony 30mm f/4 scope + SV905 camera combo (u$130 for the whole kit). The camera isn't even monochrome, as recommended everywhere. Paired with an AM3 and PHD2, I'm getting typical RMS error of under 0.7" with good streaks of 0.4"-ish and bumps of up to 1.1" in windy conditions:
469869833_10230849149545675_2205696332672794464_n.jpg
I feel that these guiding figures would be more than enough for any system that could ride on top of the AM3.
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Critter 0.90
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Late to the conversation but if you are just getting started do an off axis guider and you will use your OTA for guiding.  I got the Askar OAG and it has all the connections for different image trains and the the Prism is 11mm by 11mm.  My RMS frequently is .3 to .5 or so with multiple stars on Asiair.   Can’t get better than your original tube for finding guide stars.  Get an asi120 or 220 for guide camera.  Or I got the asi174 to give me some extra gain when using on my 120 Evostar.  i can get by with asi120 on AskarV but its much nicer on the larger sensor.  I was using the Uniguide 50 and I would get around .8 to 1.2 Rms with it.  OAG is the way to go. The best other option is to get a dual sensor camera.  YMMV.

BTW anyone want to buy a WO Uniguide 50 almost new has a little scorch mark from a cheap heater.  Btw you don’t need a heater .
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bluespeck 1.51
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Franco Grimoldi:
My 0.2 cents:

I'm currently using the cheapest autoguiding system I could find: the Svbony 30mm f/4 scope + SV905 camera combo (u$130 for the whole kit). The camera isn't even monochrome, as recommended everywhere. Paired with an AM3 and PHD2, I'm getting typical RMS error of under 0.7" with good streaks of 0.4"-ish and bumps of up to 1.1" in windy conditions:
469869833_10230849149545675_2205696332672794464_n.jpg
I feel that these guiding figures would be more than enough for any system that could ride on top of the AM3.

Excellent indeed. Thanks.
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Critter 0.90
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Yeah the Askar OAG and with Askar 2 inch filter holder & 10mm spacer perfect 55mm for your Askar.   

let us know what you do.

Tony
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bluespeck 1.51
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Right now it's winter up here and we don't usually get too many nights with clear skies. When we do, I'll get out and do some testing. For the immediate future, I'll stick with my existing set up of WO Uniguide 32/Askar 107PHQ and will reevaluate in the spring. Thanks again everyone  for all the help. 

Cheers,
Irwin
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claytonostler 3.34
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I had been using the ZWO 32mm mini for a very long time. I bought the askar 52mm hoping for better guiding. I get almost no difference. With 1 caveat,  I can use lower exposure times. But for me this made no noticeable difference. Ive not used a focal length over 500 with either guide solution, but that's not part of the equation anyway.
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SpaceMan-56 1.20
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I totally disagree with the theory that guide scopes don't matter.  I had a little 30F4 ZWO thing that was very poor in performance.  

I was using it in combination with my Takahashi FSQ-106 and it was bad.  terrible focus.  I upgraded it to an EVOGUIDE 50 ED and was impressed how much better the Doublet EvoGuide was in respect to focus particularly, and Star HFD as well. the EvoGuide 50ED gave much tighter guide stars, and generally overall better guiding.

I am now using a Stellarvue 80mm Doublet as a guidescope for my 10 inch RC, and whilst some people assure me that an OAG would be better, I have found the Stellarvue works splendidly, and I have no intention of moving to an OAG in the near future.

I would always choose a Doublet as a minimum for a guidescope, for the obvious reasons of Doublet performance verses Achromat.
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TiffsAndAstro 1.81
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David Russell:
I totally disagree with the theory that guide scopes don't matter.  I had a little 30F4 ZWO thing that was very poor in performance.  

I was using it in combination with my Takahashi FSQ-106 and it was bad.  terrible focus.  I upgraded it to an EVOGUIDE 50 ED and was impressed how much better the Doublet EvoGuide was in respect to focus particularly, and Star HFD as well. the EvoGuide 50ED gave much tighter guide stars, and generally overall better guiding.

I am now using a Stellarvue 80mm Doublet as a guidescope for my 10 inch RC, and whilst some people assure me that an OAG would be better, I have found the Stellarvue works splendidly, and I have no intention of moving to an OAG in the near future.

I would always choose a Doublet as a minimum for a guidescope, for the obvious reasons of Doublet performance verses Achromat.


Zwo f4 is a bit poo
My stars all look like a dot with a big cloud around each
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andreatax 9.89
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David Russell:
I would always choose a Doublet as a minimum for a guidescope, for the obvious reasons of Doublet performance verses Achromat.


Achromats ARE doublets, and most guide-scope/finders are specifically cemented achromat doublets. And some are better than other. Russian ones being top performers in my experience. But they are air-spaced, not cemented.
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andreatax 9.89
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TiffsAndAstro:
My stars all look like a dot with a big cloud around each


*Because you don't use filters. If you did, and are picky about focus then they'll be all dots.
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TiffsAndAstro 1.81
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andrea tasselli:
TiffsAndAstro:
My stars all look like a dot with a big cloud around each


*Because you don't use filters. If you did, and are picky about focus then they'll be all dots.

i am thinking of trying a cheap red filter, see if it makes any difference
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claytonostler 3.34
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I'm glad there are different opinions and experiences here. I think it's important to recognize that the guide scope is 1 variable. There's things like focus, camera, filters, mount etc. There are theories that you get better guiding a hair out of focus anyway. I can't say I agree with that, but there's a whole heard of people who do. I'm not saying my stars aren't tighter with a bigger and better scope. I'm saying my guiding went from  0.8 to 0.72 and at my focal lengths this made no difference. 

Maybe if was trying to do 10 minute sub it would matter… But I don't
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Gondola 8.11
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David Russell:
I totally disagree with the theory that guide scopes don't matter.  I had a little 30F4 ZWO thing that was very poor in performance.  

I was using it in combination with my Takahashi FSQ-106 and it was bad.  terrible focus.  I upgraded it to an EVOGUIDE 50 ED and was impressed how much better the Doublet EvoGuide was in respect to focus particularly, and Star HFD as well. the EvoGuide 50ED gave much tighter guide stars, and generally overall better guiding.

I am now using a Stellarvue 80mm Doublet as a guidescope for my 10 inch RC, and whilst some people assure me that an OAG would be better, I have found the Stellarvue works splendidly, and I have no intention of moving to an OAG in the near future.

I would always choose a Doublet as a minimum for a guidescope, for the obvious reasons of Doublet performance verses Achromat.

An Achromat is a doublet. You mean an ED doublet...
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dkamen 7.44
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TiffsAndAstro:
andrea tasselli:
TiffsAndAstro:
My stars all look like a dot with a big cloud around each


*Because you don't use filters. If you did, and are picky about focus then they'll be all dots.

i am thinking of trying a cheap red filter, see if it makes any difference

You can just test with your OSC camera, they all have a filter.
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Gondola 8.11
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My own experience is that adding a 25A red filter to my guide scope improved my average RMS numbers considerably. The guide scope is an 80mm F/5 achromat.
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TiffsAndAstro 1.81
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TiffsAndAstro:
andrea tasselli:
TiffsAndAstro:
My stars all look like a dot with a big cloud around each


*Because you don't use filters. If you did, and are picky about focus then they'll be all dots.

i am thinking of trying a cheap red filter, see if it makes any difference

You can just test with your OSC camera, they all have a filter.


AH, apologies. It's my guide scope that gives dots with massive looking coma.
My imaging scope is bad, but not that bad
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