12" F5 scope

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Re: 12" F5 scope

#21

Post by TareqPhoto »


notFritzArgelander wrote: Sun Oct 27, 2019 11:27 pm
TareqPhoto wrote: Sun Oct 27, 2019 10:13 pm
Ok, let me put it this way then.

I visited 2 places or centers of Astronomy in my country, and they do visual even for public, one placing C9.25, and the other placing Meade 10" SCT, i looked through both of them, both are amazing, BUT, none impressed me enough, i mean they are almost the same view or even less than my Mak, my Mak is sharper and their SCT are brighter, that's all, so i couldn't feel the difference, so in imaging even with larger aperture advantage i don't think both of C9.25 or C11 will impress me, i already saw hundreds or thousands of results from C11 on the net, none of them changed my mind from C14 or 16" Dob results, in fact even 12" Newtonian is better result than C11 from what i saw, means i have to forget about 9" or 10" or 11" and start from 12", and because i will have 20" Dob later so i feel i will not go with 16" or 14", but 14" is still in list but less priority, 12" is shining more in my list and head, but i have to wait and see, i may buy anotehr mount, or i may risk with 12" on EQ6, or maybe i can increase the 20" scope so i can buy an EQ platform and use that, but nothing is yet confirmed, but the only confirmation i have is that 9.25"/11" are not in list and also 12"/14" SCT are not in list, if i must buy a new mount for 12" SCT or 14" SCT then it is very affordable for me to get 12" Newt and another mount then, i can save more by this.

Your point about is C9.25 and C11 is very correct, i should start with that actually last year so maybe i won't think about larger scopes yet, but my mistake [maybe not] is that i went with 7" Mak and 8" Newt, and results telling me that 10" and closer aren't gonna cut for me on planetary, 12" is also not much, but it is the largest cheaper options i can get right now later.
Well since this was addressed specifically in response to me, I'll answer. You are going by "what you can see" which is fine if that is what gives you confidence. But there are other criteria such as objective measures of telescope performance For planetary observation light is almost never a problem but one is more concerned about 1) resolution and 2) contrast on small objects. Those are completely different considerations.

Now I don't like standard SCTs for visual use. They always appear "soft". However aplanatic SCTs like the Celestron Edge HD and Meade ACF are something else again. They are full up to giving crisp visual views like a refractor or Maksutov. They also cost more. But I have to say that while the plain vanilla SCTs don't hold a candle to a Rutten-Maksutov the aplanatic SCTs are worthy rivals (Edge, ACF).

Nevertheless Damien Peach's results show that at the right site a standard SCT does splendidly at planetary imaging. Visual appearances should not be taken as an adequate indicator of what to expect when imaging. I know this from experience studying and working at a university observatory in the US. For imaging, one must go by the numbers. So what do the numbers say about 1) resolution and 2) fine contrast?

1) Resolution

Without an atmosphere, resolution is determined by the aperture. The resolution is inversely proportional to the aperture. For most places on Earth resolution is limited by the atmosphere so that 10" aperture or 0.5 arc second of resolution is about all you will ever get. Board member Luc CATHALA gets exquisite lunar images with his large Newtonian optic because he is fortunate to have a site with better than average seeing. For most places on the planet for almost all days anything larger than 10" gives no resolution gain.

2) Fine contrast

Visually folks note that the large central obstruction of SCTs diminishes contrast on large objects. However the obstruction increases fine contrast.

The quantitative measure of fine and coarse contrast performance is given by the modulation transfer function or MTF.

https://www.telescope-optics.net/mtf.htm

The effects of a central obstruction are shown in figure 104 at the following link.

https://www.telescope-optics.net/obstruction.htm

The green line in the graph shows the MTF of a perfect unobstructed optic. The orange line shows the MTF of a perfect 32.5% obstructed optic. Notice that for low frequencies the orange line is below the green line showing the loss of contrast for large objects compared with the perfect unobstructed optic. However above 0.6 in frequency see that the orange line is above the green line showing that for planetary contrast discrimination an obstructed perfect optic is BETTER than an unobstructed perfect optic.
Your response simply will put me in a permanent doubts then.

I paid for Damian Peach videos on Patreon, and i can't really judge if his comments or videos are paid for him to give what he said or he was honest, but i believe even Damian can do much better with 14"-20" Newt/Dob if he has hands on them, and i think he also recommended Newt more than SCT, the only thing he recommended SCT is for their weight or compactness, other pros are weaker against pros of Newt/Dob, he already mentioned that the collimation of SCT was a nightmare few times, so even he is likely leaning to Newt more than SCT regardless he is using SCT, he started very long time ago so maybe that time SCT was like a winner choice.

Again, you said most of the world or maybe the whole planet but then there are people using largest scopes such as 14" or 16" or 24" or 30", imaging isn't my only goal although it is, but i want to see the power of visual with largest aperture scopes, maybe that visual is all worth the cost and size then.

I follow what i see by my eyes, not what i read from studies and analysis and charts and lines and curves, and i saw the best planets images so far in my life are from Space telescopes followed by 1 meter scopes and then i only say from amateur scopes up to 20", i liked from 20" then 18" then 16" then 14" and then 12", the problem is people didn't use their 16"-20" in same conditions as Damian and Go did, if they did then i am sure they won't be any less than C14 world known imagers, so i follow of what i saw as results from those, and it tells me simply that "APERTURE" rules, end of story.

I have enough time to decide until next year, I can't afford premium SCT such as EdgeHD or even Meade ACF although it is still possible, but they aren't the only options, in fact i even liked images from RC and Newtonian for DSO over SCT, and planetary is great with many scopes anyway.

Bottom line, all what you said is respected and understandable, but sometimes i go with something else more than just facts or studies or theories, many put Damian as a reference because of his results, but look at his results, Barbados and 1meter scopes are talking, while his images with C11 or C14 in UK isn't any special to be honest, so i am not that kind of guy who just go with one eye, i looked at all Damian results from the past on different planets, only his images from 1 meter and C14 in Barbados standing out, while from UK for example i saw better results than those, so i don't know if i should believe Damian in his videos or you or others or my eyes.
    Telescope: SkyWatcher: Skymax 180mm F15 Mak, StarTravel 80mm f/5 ---- Meade LX70 8" F5 Newt
      Mount: SkyWatcher AZ-EQ6 GoTo
        Cameras: QHY163M, QHY5L-II-M, ZWO [ASI174MM, ASI290MM, ASI385MC, ASI120MC(damaged)], Sony A7r + Canon DSLRs + lenses [Hasselbald, Canon, Sony, Sigma, Samyang], Hasselbald H4D-60
          Filters: Astrodon Ha 5nm, Cyclops Optics LUX-Series RGB, Optolong NB, Baader filters [M&S Neodymium, Contrast Booster], Skywatcher UHC & OIII
            Software: SGPro, PixInsight, APP, APT, DeepSkyStacker, Nebulosity, SharpCap, FireCapture, PHD2, CDC, Photoshop CC
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            Re: 12" F5 scope

            #22

            Post by notFritzArgelander »


            TareqPhoto wrote: Mon Oct 28, 2019 12:22 am
            notFritzArgelander wrote: Sun Oct 27, 2019 11:27 pm
            TareqPhoto wrote: Sun Oct 27, 2019 10:13 pm
            Ok, let me put it this way then.

            I visited 2 places or centers of Astronomy in my country, and they do visual even for public, one placing C9.25, and the other placing Meade 10" SCT, i looked through both of them, both are amazing, BUT, none impressed me enough, i mean they are almost the same view or even less than my Mak, my Mak is sharper and their SCT are brighter, that's all, so i couldn't feel the difference, so in imaging even with larger aperture advantage i don't think both of C9.25 or C11 will impress me, i already saw hundreds or thousands of results from C11 on the net, none of them changed my mind from C14 or 16" Dob results, in fact even 12" Newtonian is better result than C11 from what i saw, means i have to forget about 9" or 10" or 11" and start from 12", and because i will have 20" Dob later so i feel i will not go with 16" or 14", but 14" is still in list but less priority, 12" is shining more in my list and head, but i have to wait and see, i may buy anotehr mount, or i may risk with 12" on EQ6, or maybe i can increase the 20" scope so i can buy an EQ platform and use that, but nothing is yet confirmed, but the only confirmation i have is that 9.25"/11" are not in list and also 12"/14" SCT are not in list, if i must buy a new mount for 12" SCT or 14" SCT then it is very affordable for me to get 12" Newt and another mount then, i can save more by this.

            Your point about is C9.25 and C11 is very correct, i should start with that actually last year so maybe i won't think about larger scopes yet, but my mistake [maybe not] is that i went with 7" Mak and 8" Newt, and results telling me that 10" and closer aren't gonna cut for me on planetary, 12" is also not much, but it is the largest cheaper options i can get right now later.
            Well since this was addressed specifically in response to me, I'll answer. You are going by "what you can see" which is fine if that is what gives you confidence. But there are other criteria such as objective measures of telescope performance For planetary observation light is almost never a problem but one is more concerned about 1) resolution and 2) contrast on small objects. Those are completely different considerations.

            Now I don't like standard SCTs for visual use. They always appear "soft". However aplanatic SCTs like the Celestron Edge HD and Meade ACF are something else again. They are full up to giving crisp visual views like a refractor or Maksutov. They also cost more. But I have to say that while the plain vanilla SCTs don't hold a candle to a Rutten-Maksutov the aplanatic SCTs are worthy rivals (Edge, ACF).

            Nevertheless Damien Peach's results show that at the right site a standard SCT does splendidly at planetary imaging. Visual appearances should not be taken as an adequate indicator of what to expect when imaging. I know this from experience studying and working at a university observatory in the US. For imaging, one must go by the numbers. So what do the numbers say about 1) resolution and 2) fine contrast?

            1) Resolution

            Without an atmosphere, resolution is determined by the aperture. The resolution is inversely proportional to the aperture. For most places on Earth resolution is limited by the atmosphere so that 10" aperture or 0.5 arc second of resolution is about all you will ever get. Board member Luc CATHALA gets exquisite lunar images with his large Newtonian optic because he is fortunate to have a site with better than average seeing. For most places on the planet for almost all days anything larger than 10" gives no resolution gain.

            2) Fine contrast

            Visually folks note that the large central obstruction of SCTs diminishes contrast on large objects. However the obstruction increases fine contrast.

            The quantitative measure of fine and coarse contrast performance is given by the modulation transfer function or MTF.

            https://www.telescope-optics.net/mtf.htm

            The effects of a central obstruction are shown in figure 104 at the following link.

            https://www.telescope-optics.net/obstruction.htm

            The green line in the graph shows the MTF of a perfect unobstructed optic. The orange line shows the MTF of a perfect 32.5% obstructed optic. Notice that for low frequencies the orange line is below the green line showing the loss of contrast for large objects compared with the perfect unobstructed optic. However above 0.6 in frequency see that the orange line is above the green line showing that for planetary contrast discrimination an obstructed perfect optic is BETTER than an unobstructed perfect optic.
            Your response simply will put me in a permanent doubts then.

            I paid for Damian Peach videos on Patreon, and i can't really judge if his comments or videos are paid for him to give what he said or he was honest, but i believe even Damian can do much better with 14"-20" Newt/Dob if he has hands on them, and i think he also recommended Newt more than SCT, the only thing he recommended SCT is for their weight or compactness, other pros are weaker against pros of Newt/Dob, he already mentioned that the collimation of SCT was a nightmare few times, so even he is likely leaning to Newt more than SCT regardless he is using SCT, he started very long time ago so maybe that time SCT was like a winner choice.
            I think Damian Peach provides an honest opinion. Telescope designs and fabrication quality haven't changed much so when he started is irrelevant.
            Again, you said most of the world or maybe the whole planet but then there are people using largest scopes such as 14" or 16" or 24" or 30", imaging isn't my only goal although it is, but i want to see the power of visual with largest aperture scopes, maybe that visual is all worth the cost and size then.
            Larger aperture is to collect more light. In almost all locations seeing limits the resolution to 10" aperture equivalent.
            I follow what i see by my eyes, not what i read from studies and analysis and charts and lines and curves, and i saw the best planets images so far in my life are from Space telescopes followed by 1 meter scopes and then i only say from amateur scopes up to 20", i liked from 20" then 18" then 16" then 14" and then 12", the problem is people didn't use their 16"-20" in same conditions as Damian and Go did, if they did then i am sure they won't be any less than C14 world known imagers, so i follow of what i saw as results from those, and it tells me simply that "APERTURE" rules, end of story.
            If aperture rules then there is no reason for refractors. For what does aperture rule? Light collection. For contrast it's more complicated. I have observed with an 18.5 inch Clark refractor and a 1 meter RC. On planets the 18.5 inch regularly beat out the 1 meter RC. It provided a smaller image but there was more detail available. I did have a spectacular view of Saturn once with the 1 meter, but the seeing conditions were once in a year wonderful. On an average day the Clark took the prize.

            I don't merely go by my eyes though. I'm a physicist and I learned a little about optics from Born and Wolf.
            .....
            Bottom line, all what you said is respected and understandable, but sometimes i go with something else more than just facts or studies or theories, many put Damian as a reference because of his results, but look at his results, Barbados and 1meter scopes are talking, while his images with C11 or C14 in UK isn't any special to be honest, so i am not that kind of guy who just go with one eye, i looked at all Damian results from the past on different planets, only his images from 1 meter and C14 in Barbados standing out, while from UK for example i saw better results than those, so i don't know if i should believe Damian in his videos or you or others or my eyes.
            I believe in physics. By that I mean that one needs to understand the physics to correctly interpret what one sees. For instance you seem to be holding Damian Peach's observations form the UK against him. The physics says that's unfair. He's looking through a lot more atmosphere than from Barbados or an equatorial location.

            Collimation of an SCT is tough but not much tougher than a Newtonian.
            Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
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            Re: 12" F5 scope

            #23

            Post by TareqPhoto »


            notFritzArgelander wrote: Mon Oct 28, 2019 12:38 am
            TareqPhoto wrote: Mon Oct 28, 2019 12:22 am
            notFritzArgelander wrote: Sun Oct 27, 2019 11:27 pm

            Well since this was addressed specifically in response to me, I'll answer. You are going by "what you can see" which is fine if that is what gives you confidence. But there are other criteria such as objective measures of telescope performance For planetary observation light is almost never a problem but one is more concerned about 1) resolution and 2) contrast on small objects. Those are completely different considerations.

            Now I don't like standard SCTs for visual use. They always appear "soft". However aplanatic SCTs like the Celestron Edge HD and Meade ACF are something else again. They are full up to giving crisp visual views like a refractor or Maksutov. They also cost more. But I have to say that while the plain vanilla SCTs don't hold a candle to a Rutten-Maksutov the aplanatic SCTs are worthy rivals (Edge, ACF).

            Nevertheless Damien Peach's results show that at the right site a standard SCT does splendidly at planetary imaging. Visual appearances should not be taken as an adequate indicator of what to expect when imaging. I know this from experience studying and working at a university observatory in the US. For imaging, one must go by the numbers. So what do the numbers say about 1) resolution and 2) fine contrast?

            1) Resolution

            Without an atmosphere, resolution is determined by the aperture. The resolution is inversely proportional to the aperture. For most places on Earth resolution is limited by the atmosphere so that 10" aperture or 0.5 arc second of resolution is about all you will ever get. Board member Luc CATHALA gets exquisite lunar images with his large Newtonian optic because he is fortunate to have a site with better than average seeing. For most places on the planet for almost all days anything larger than 10" gives no resolution gain.

            2) Fine contrast

            Visually folks note that the large central obstruction of SCTs diminishes contrast on large objects. However the obstruction increases fine contrast.

            The quantitative measure of fine and coarse contrast performance is given by the modulation transfer function or MTF.

            https://www.telescope-optics.net/mtf.htm

            The effects of a central obstruction are shown in figure 104 at the following link.

            https://www.telescope-optics.net/obstruction.htm

            The green line in the graph shows the MTF of a perfect unobstructed optic. The orange line shows the MTF of a perfect 32.5% obstructed optic. Notice that for low frequencies the orange line is below the green line showing the loss of contrast for large objects compared with the perfect unobstructed optic. However above 0.6 in frequency see that the orange line is above the green line showing that for planetary contrast discrimination an obstructed perfect optic is BETTER than an unobstructed perfect optic.
            Your response simply will put me in a permanent doubts then.

            I paid for Damian Peach videos on Patreon, and i can't really judge if his comments or videos are paid for him to give what he said or he was honest, but i believe even Damian can do much better with 14"-20" Newt/Dob if he has hands on them, and i think he also recommended Newt more than SCT, the only thing he recommended SCT is for their weight or compactness, other pros are weaker against pros of Newt/Dob, he already mentioned that the collimation of SCT was a nightmare few times, so even he is likely leaning to Newt more than SCT regardless he is using SCT, he started very long time ago so maybe that time SCT was like a winner choice.
            I think Damian Peach provides an honest opinion. Telescope designs and fabrication quality haven't changed much so when he started is irrelevant.
            Again, you said most of the world or maybe the whole planet but then there are people using largest scopes such as 14" or 16" or 24" or 30", imaging isn't my only goal although it is, but i want to see the power of visual with largest aperture scopes, maybe that visual is all worth the cost and size then.
            Larger aperture is to collect more light. In almost all locations seeing limits the resolution to 10" aperture equivalent.
            I follow what i see by my eyes, not what i read from studies and analysis and charts and lines and curves, and i saw the best planets images so far in my life are from Space telescopes followed by 1 meter scopes and then i only say from amateur scopes up to 20", i liked from 20" then 18" then 16" then 14" and then 12", the problem is people didn't use their 16"-20" in same conditions as Damian and Go did, if they did then i am sure they won't be any less than C14 world known imagers, so i follow of what i saw as results from those, and it tells me simply that "APERTURE" rules, end of story.
            If aperture rules then there is no reason for refractors. For what does aperture rule? Light collection. For contrast it's more complicated. I have observed with an 18.5 inch Clark refractor and a 1 meter RC. On planets the 18.5 inch regularly beat out the 1 meter RC. It provided a smaller image but there was more detail available. I did have a spectacular view of Saturn once with the 1 meter, but the seeing conditions were once in a year wonderful. On an average day the Clark took the prize.

            I don't merely go by my eyes though. I'm a physicist and I learned a little about optics from Born and Wolf.
            .....
            Bottom line, all what you said is respected and understandable, but sometimes i go with something else more than just facts or studies or theories, many put Damian as a reference because of his results, but look at his results, Barbados and 1meter scopes are talking, while his images with C11 or C14 in UK isn't any special to be honest, so i am not that kind of guy who just go with one eye, i looked at all Damian results from the past on different planets, only his images from 1 meter and C14 in Barbados standing out, while from UK for example i saw better results than those, so i don't know if i should believe Damian in his videos or you or others or my eyes.
            I believe in physics.
            First, i believe in my eyes.

            Second, i don't like to go there, because science for me is great to a point, i have a religion that telling me to believe in science to a point, not for everything, and that maybe is something affecting my decisions and behave and many other things, Physics or no Physics, i am not a scientist and i think most my choices of astro stuff isn't a science based choices, hope this is not a rude or annoying you.

            Third, i like your posts, being honest, giving all what you have, this is helpful, and it is nice to share knowledge, and at the end there are people feeling or impressions as well, real world sometimes telling us that not everything must be about science, but you should keep science comments time to time, it will help.

            Thank you very much!
              Telescope: SkyWatcher: Skymax 180mm F15 Mak, StarTravel 80mm f/5 ---- Meade LX70 8" F5 Newt
                Mount: SkyWatcher AZ-EQ6 GoTo
                  Cameras: QHY163M, QHY5L-II-M, ZWO [ASI174MM, ASI290MM, ASI385MC, ASI120MC(damaged)], Sony A7r + Canon DSLRs + lenses [Hasselbald, Canon, Sony, Sigma, Samyang], Hasselbald H4D-60
                    Filters: Astrodon Ha 5nm, Cyclops Optics LUX-Series RGB, Optolong NB, Baader filters [M&S Neodymium, Contrast Booster], Skywatcher UHC & OIII
                      Software: SGPro, PixInsight, APP, APT, DeepSkyStacker, Nebulosity, SharpCap, FireCapture, PHD2, CDC, Photoshop CC
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                      Re: 12" F5 scope

                      #24

                      Post by TareqPhoto »


                      You added or edited your last post i see, well, i am not against Damian or using his UK, he is still well known respected planetary imager even his UK results ones, but my point is, don't take Damian as the only correct in the world, his results are well taken, but i can't based my decisions on that alone or only, if i have nearly $6000-8000 to burn then maybe i get C14, but i decided to burn that amount on 20" Dob simply, don't bring Physics in that topic then.

                      Again, your points are very clear and i got them, but i still hold my own plans, let's see if they will work or not then we can talk about it.
                        Telescope: SkyWatcher: Skymax 180mm F15 Mak, StarTravel 80mm f/5 ---- Meade LX70 8" F5 Newt
                          Mount: SkyWatcher AZ-EQ6 GoTo
                            Cameras: QHY163M, QHY5L-II-M, ZWO [ASI174MM, ASI290MM, ASI385MC, ASI120MC(damaged)], Sony A7r + Canon DSLRs + lenses [Hasselbald, Canon, Sony, Sigma, Samyang], Hasselbald H4D-60
                              Filters: Astrodon Ha 5nm, Cyclops Optics LUX-Series RGB, Optolong NB, Baader filters [M&S Neodymium, Contrast Booster], Skywatcher UHC & OIII
                                Software: SGPro, PixInsight, APP, APT, DeepSkyStacker, Nebulosity, SharpCap, FireCapture, PHD2, CDC, Photoshop CC
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                                Re: 12" F5 scope

                                #25

                                Post by notFritzArgelander »


                                TareqPhoto wrote: Mon Oct 28, 2019 1:04 am You added or edited your last post i see, well, i am not against Damian or using his UK, he is still well known respected planetary imager even his UK results ones, but my point is, don't take Damian as the only correct in the world, his results are well taken, but i can't based my decisions on that alone or only, if i have nearly $6000-8000 to burn then maybe i get C14, but i decided to burn that amount on 20" Dob simply, don't bring Physics in that topic then.

                                Again, your points are very clear and i got them, but i still hold my own plans, let's see if they will work or not then we can talk about it.
                                I never said that Damian Peach was the only correct on in the world. I have never seen anything with my eyes that wasn't explainable with physics. Physics is the only criterion for objective evaluation. The rest is subjective. So I will bring physics to the table every time. Otherwise one is simply led by mere appearances which one might not understand.

                                Let's not bring religion into the matter. Science doesn't claim to know everything, only everything factual about the natural world. My religion does not claim superiority over science. I would never claim superiority of science over religion. Science and religion should be kept separate like doctors and lawyers. Otherwise one makes logical errors.
                                Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
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                                Re: 12" F5 scope

                                #26

                                Post by TareqPhoto »


                                notFritzArgelander wrote: Mon Oct 28, 2019 1:18 am
                                TareqPhoto wrote: Mon Oct 28, 2019 1:04 am You added or edited your last post i see, well, i am not against Damian or using his UK, he is still well known respected planetary imager even his UK results ones, but my point is, don't take Damian as the only correct in the world, his results are well taken, but i can't based my decisions on that alone or only, if i have nearly $6000-8000 to burn then maybe i get C14, but i decided to burn that amount on 20" Dob simply, don't bring Physics in that topic then.

                                Again, your points are very clear and i got them, but i still hold my own plans, let's see if they will work or not then we can talk about it.
                                I never said that Damian Peach was the only correct on in the world. I have never seen anything with my eyes that wasn't explainable with physics. Physics is the only criterion for objective evaluation. The rest is subjective. So I will bring physics to the table every time. Otherwise one is simply led by mere appearances which one might not understand.

                                Let's not bring religion into the matter. Science doesn't claim to know everything, only everything factual about the natural world. My religion does not claim superiority over science. I would never claim superiority of science over religion. Science and religion should be kept separate like doctors and lawyers. Otherwise one makes logical errors.
                                Ignore religion topic, not going there definitely.

                                Back to basics and most important for me, i want to get 12" scope, can't or don't want to get 12" SCT, so can't i get 12" Newtonian or 12" Dobsonian? and if i bring Dobsonian to the table it means i somehow adding another aperture as option, 14", but i feel i shouldn't waste too much money just like that, you already said most parts in world is benefit mostly up to 10", i push it little to 12" and i am fine, no need for 14", but do you recommend 12" Dob?

                                Is capable strong EQ mount for a Newt for example or C14 is more expensive that an EQ platform for a dobsonian?

                                All that discussion went far because i only wanted a scope not SCT for planetary, and i saw enough from different scopes, and i can say safely that Newtonian or dob are both applicable here, so they are included, and because of budget they also became likely first choice, now only weight is the main big issue with them, and with a Dob it is only about tracking then, so tell me how Physics and Economy can solve it?
                                  Telescope: SkyWatcher: Skymax 180mm F15 Mak, StarTravel 80mm f/5 ---- Meade LX70 8" F5 Newt
                                    Mount: SkyWatcher AZ-EQ6 GoTo
                                      Cameras: QHY163M, QHY5L-II-M, ZWO [ASI174MM, ASI290MM, ASI385MC, ASI120MC(damaged)], Sony A7r + Canon DSLRs + lenses [Hasselbald, Canon, Sony, Sigma, Samyang], Hasselbald H4D-60
                                        Filters: Astrodon Ha 5nm, Cyclops Optics LUX-Series RGB, Optolong NB, Baader filters [M&S Neodymium, Contrast Booster], Skywatcher UHC & OIII
                                          Software: SGPro, PixInsight, APP, APT, DeepSkyStacker, Nebulosity, SharpCap, FireCapture, PHD2, CDC, Photoshop CC
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                                          notFritzArgelander
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                                          Re: 12" F5 scope

                                          #27

                                          Post by notFritzArgelander »


                                          TareqPhoto wrote: Mon Oct 28, 2019 1:54 am
                                          notFritzArgelander wrote: Mon Oct 28, 2019 1:18 am
                                          TareqPhoto wrote: Mon Oct 28, 2019 1:04 am You added or edited your last post i see, well, i am not against Damian or using his UK, he is still well known respected planetary imager even his UK results ones, but my point is, don't take Damian as the only correct in the world, his results are well taken, but i can't based my decisions on that alone or only, if i have nearly $6000-8000 to burn then maybe i get C14, but i decided to burn that amount on 20" Dob simply, don't bring Physics in that topic then.

                                          Again, your points are very clear and i got them, but i still hold my own plans, let's see if they will work or not then we can talk about it.
                                          I never said that Damian Peach was the only correct on in the world. I have never seen anything with my eyes that wasn't explainable with physics. Physics is the only criterion for objective evaluation. The rest is subjective. So I will bring physics to the table every time. Otherwise one is simply led by mere appearances which one might not understand.

                                          Let's not bring religion into the matter. Science doesn't claim to know everything, only everything factual about the natural world. My religion does not claim superiority over science. I would never claim superiority of science over religion. Science and religion should be kept separate like doctors and lawyers. Otherwise one makes logical errors.
                                          Ignore religion topic, not going there definitely.

                                          Back to basics and most important for me, i want to get 12" scope, can't or don't want to get 12" SCT, so can't i get 12" Newtonian or 12" Dobsonian? and if i bring Dobsonian to the table it means i somehow adding another aperture as option, 14", but i feel i shouldn't waste too much money just like that, you already said most parts in world is benefit mostly up to 10", i push it little to 12" and i am fine, no need for 14", but do you recommend 12" Dob?

                                          Is capable strong EQ mount for a Newt for example or C14 is more expensive that an EQ platform for a dobsonian?

                                          All that discussion went far because i only wanted a scope not SCT for planetary, and i saw enough from different scopes, and i can say safely that Newtonian or dob are both applicable here, so they are included, and because of budget they also became likely first choice, now only weight is the main big issue with them, and with a Dob it is only about tracking then, so tell me how Physics and Economy can solve it?
                                          Already covered those points. Try what you like and see how it turns out.
                                          Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
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                                          yobbo89 Australia
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                                          Re: 12" F5 scope

                                          #28

                                          Post by yobbo89 »


                                          I think I've put enough input into this thread, all I can say is it's fine to be well equipped in aperture even when most of time you will be limit to seeing, you might get that magical night with realy good seeing.

                                          Any 12" scope on a eq6 is just going to suffer in the short and long run. period...

                                          A 12" dob is not going to hit 12-15+ m fl very well which is basicly what the big scope planetary imagers are hitting and more.

                                          question. can you get stable tracking at 12-15 meter focal length if you are to go with a 14-16" dob with a go to setup or 3rd party eq platform?

                                          You mentioned you had a 20" diy dob/mirror or in the works to build one? Why not invest in completing it and spend the rest on a dual axis eq tracking platform.

                                          Picking the right planetary scope should include

                                          Tracking
                                          Practicality
                                          Achieving focal length
                                          Contrast
                                          Usability with your sky ie seeing.
                                          Price

                                          These Should be the things to consider when buying.
                                          And there is a reason why people use a sct, because it's the most practical along with the quality but if you can get over the hump with using a dob and find a cheap way for tracking then by all means go in that direction.

                                          good luck and best wishes with your purchase.
                                          scopes :gso/bintel f4 12"truss tube, bresser messier ar127s /skywatcher 10'' dob,meade 12'' f10 lx200 sct
                                          cameras : asi 1600mm-c/asi1600mm-c,asi120mc,prostar lp guidecam, nikkon d60, sony a7,asi 290 mm
                                          mounts : eq6 pro/eq8/mesu 200 v2
                                          filters : 2'' astronomik lp/badder lrgb h-a,sII,oIII,h-b,Baader Solar Continuum, chroma 3nm ha,sii,oiii,nii,rgb,lowglow,uv/ir,Thousand Oaks Solar Filter,1.25'' #47 violet,pro planet 742 ir,pro planet 807 ir,pro planet 642 bp ir.
                                          extras : skywatcher f4 aplanatic cc, Baader MPCC MKIII Coma Corrector,Orion Field Flattener,zwo 1.25''adc.starlight maxi 2" 9x filter wheel,tele vue 2x barlow .

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                                          TareqPhoto United Arab Emirates
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                                          Re: 12" F5 scope

                                          #29

                                          Post by TareqPhoto »


                                          Thank you very much all
                                            Telescope: SkyWatcher: Skymax 180mm F15 Mak, StarTravel 80mm f/5 ---- Meade LX70 8" F5 Newt
                                              Mount: SkyWatcher AZ-EQ6 GoTo
                                                Cameras: QHY163M, QHY5L-II-M, ZWO [ASI174MM, ASI290MM, ASI385MC, ASI120MC(damaged)], Sony A7r + Canon DSLRs + lenses [Hasselbald, Canon, Sony, Sigma, Samyang], Hasselbald H4D-60
                                                  Filters: Astrodon Ha 5nm, Cyclops Optics LUX-Series RGB, Optolong NB, Baader filters [M&S Neodymium, Contrast Booster], Skywatcher UHC & OIII
                                                    Software: SGPro, PixInsight, APP, APT, DeepSkyStacker, Nebulosity, SharpCap, FireCapture, PHD2, CDC, Photoshop CC
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