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80mm APO: TS optics or SW Evostar


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I assume you mean the 80mm F/7 ED from TS, not the F/6 triplet? I have the APM counterpart of the latter, and it is very nice indeed. It is great for lunar shots, but for planets I must say I prefer a larger aperture

This leads to my question: why an 80mm APO? A (cheaper) 127" Maksutov Cassegrain will outperform it on the moon and planets easily.  They are nice and compact too, and show essentially no CA.

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Answer me this before I comment- what kind of imaging down the line DSO's or Lunar Planetary? Imaging wise both the scope you mention are great for DSO's, but you would want more aperture for resolution and a longer focal length for image scale for planetary and lunar imaging.

The 127 Mak as mentioned would be a better place to start for Lunar/Planetary imaging, if not a bigger Newtonian or SCT.

 

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1 minute ago, nightfisher said:

I agree a 127 masutov will be better for moon and planet imaging

With "imaging" being the key word here. The OP asked about primarily *viewing* the moon and planets. The SkyWatcher 80ED blows away the 127 Mak in planetary viewing. I had actually set them up side-by-side once (aimed at Jupiter) for fun and was asking people to take a look. The 80ED's better contrast, color and generally sharp image rival much larger reflectors. For planetary imaging, after processing the Mak will be able to show some more detail, but that's the only thing it does better (and the 80ED is not too shabby see my test here). And I assume the OP when talking about "photography down the road" probably means DSO photography, which would be very limited for a Mak.

Back to the original question, the answer is that you can never go wrong with the Evostar 80ED. Especially if you want a lot of planetary stuff, there is no reason to go to a more expensive, faster OTA. Save the extra money for accessories (e.g. a reducer/corrector if you go to DSO imaging).

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For viewing the moon and planets aperture is king, I find. My Celestron C8 hits the (excellent) little APM 80mm F/6 for six every time. I have compared the two on moon and Jupiter, and there is just no contest. The Mak-Cas design with its typically smaller central obstruction is even more suited to planetary observation than an SCT. I have looked through a Mak-Cas 127mm at Jupiter and Saturn, and although it did not resolve the finer detail the 8" SCT could, it certainly had a very nice constrasty image at the same exit pupil as my SCT.

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18 minutes ago, ecuador said:

With "imaging" being the key word here. The OP asked about primarily *viewing* the moon and planets. The SkyWatcher 80ED blows away the 127 Mak in planetary viewing. I had actually set them up side-by-side once (aimed at Jupiter) for fun and was asking people to take a look. The 80ED's better contrast, color and generally sharp image rival much larger reflectors. For planetary imaging, after processing the Mak will be able to show some more detail, but that's the only thing it does better (and the 80ED is not too shabby see my test here). And I assume the OP when talking about "photography down the road" probably means DSO photography, which would be very limited for a Mak.

Back to the original question, the answer is that you can never go wrong with the Evostar 80ED. Especially if you want a lot of planetary stuff, there is no reason to go to a more expensive, faster OTA. Save the extra money for accessories (e.g. a reducer/corrector if you go to DSO imaging).

I've owned both too (actually a number of times such is my terrible scope buying/selling addiction), and I can to some extent see what you mean about the ED80 on planets as I was very surprised by the colour and contrast on Jupiter on a number of occasions......But! The Mak 127 once cooled shows a fair bit more fine detail owing to it's extra light grasp, and nearly but not quite as good contrast, not quite as good due to the central obstruction (but this is a small central obstruction).

The main issue with Maks is cooling time, are you sure your Mak was cooled properly during your tests?

Or faulty yes, just seen Jules post and this would also explain the result.

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10 minutes ago, ecuador said:

With "imaging" being the key word here. The OP asked about primarily *viewing* the moon and planets. The SkyWatcher 80ED blows away the 127 Mak in planetary viewing. I had actually set them up side-by-side once (aimed at Jupiter) for fun and was asking people to take a look. The 80ED's better contrast, color and generally sharp image rival much larger reflectors. For planetary imaging, after processing the Mak will be able to show some more detail, but that's the only thing it does better (and the 80ED is not too shabby see my test here). And I assume the OP when talking about "photography down the road" probably means DSO photography, which would be very limited for a Mak.

Back to the original question, the answer is that you can never go wrong with the Evostar 80ED. Especially if you want a lot of planetary stuff, there is no reason to go to a more expensive, faster OTA. Save the extra money for accessories (e.g. a reducer/corrector if you go to DSO imaging).

Must have been a faulty 127 Mak, Luna and planet observing AND imaging benefit from aperture and focal length , if i had to choose one of these 2 for the above it would be the Mak, BUT seeing the OP`s newer post then a ED80 might prove to be more useful

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17 minutes ago, andy435 said:

I totally agree but, I'm a hobbyist photographer and I thought maybe a APO would be good if not better for astro, terrestial and photo. As a allround telescope.

With a good mount I could always get a 5" newt later...

For terrestrial take a look at this.

As for TS vs SW, if you mean the doublet TS f/7 which is at comparable price, it uses FPL-51 glass, so with only two elements it cannot have the correction of the SW.

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18 minutes ago, Chris Lock said:

The main issue with Maks is cooling time, are you sure your Mak was cooled properly during your tests?

Or faulty yes, just seen Jules post and this would also explain the result.

Nope, apart from mine, we had an additional Mak 127 (both Celestrons), plus a 200PDS and they had been out for a couple of hours by that time. There was even a person, looking first time through a telescope that thought the 80ED was better even than the 200PDS. More seasoned observers could see the extra detail on the 200PDS, but, yeah, on first look the 80ED was impressive. Have you tried looking through them side by side? I can see a little more detail (or I could, I no longer have it) with the Mak as expected, but I too thought the 80ED image was "prettier" with colors showing up on planets etc. That part is subjective of course, that's why I set up the "test", I asked the 5-6 people around, from absolute beginner to relatively experienced.

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54 minutes ago, ecuador said:

Nope, apart from mine, we had an additional Mak 127 (both Celestrons), plus a 200PDS and they had been out for a couple of hours by that time. There was even a person, looking first time through a telescope that thought the 80ED was better even than the 200PDS. More seasoned observers could see the extra detail on the 200PDS, but, yeah, on first look the 80ED was impressive. Have you tried looking through them side by side? I can see a little more detail (or I could, I no longer have it) with the Mak as expected, but I too thought the 80ED image was "prettier" with colors showing up on planets etc. That part is subjective of course, that's why I set up the "test", I asked the 5-6 people around, from absolute beginner to relatively experienced.

Interesting stuff! I've not tried them at the same time but alternate sessions. Sounds crazy almost but my best view of Jupiters Great red spot was with an ED80, it was sooo red! Although others were reporting the same GRS views that night so it could have been more the night rather than the scope....I like to think it was the scope :)

Isn't the 200pds leaned towards imaging with an over sized secondary for better field illumination? In which case probably not the best scope for planetary contrast but the resolution would have been better if the seeing was good.

This is another point! If the seeing is bad, smaller longer focus scopes can punch above their weight.

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5 hours ago, Chris Lock said:

Interesting stuff! I've not tried them at the same time but alternate sessions. Sounds crazy almost but my best view of Jupiters Great red spot was with an ED80, it was sooo red! Although others were reporting the same GRS views that night so it could have been more the night rather than the scope....I like to think it was the scope :)

Isn't the 200pds leaned towards imaging with an over sized secondary for better field illumination? In which case probably not the best scope for planetary contrast but the resolution would have been better if the seeing was good.

This is another point! If the seeing is bad, smaller longer focus scopes can punch above their weight.

Well, that's the point, the 200pds is not great at contrast (although the difference with the 200P seems very minor) and neither is the Mak when compared to an APO, so while you get more resolution and can indeed see more detail, side-by-side the difference in contrast/color is rather obvious and more than makes up for the resolution for most people. And not just side by side, the first time I pointed the little 80ED that I bought (with wide field DSO exclusively on my mind) to a planet, I was like "Really??? This is 80mm???".

Oh, and the seeing as you say is another thing, a 16" SCT can't do more than say a 8" on a bad night - and bad nights are common here... The little scopes don't have such issues ;)

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I have a somewhat different experience. I set my APM 80mm F/6 up next to the 8" SCT, and at the same exit pupil, the difference in contrast was evident: The 80mm gave more contrast. However, the magnification in the C8 was 2.5x higher, so 6.25x more surface area, and more detail was clearly visible. At the same magnification the image in the 80mm was predictably rather dimmer. Seeing does of course come in to the equation: under poor seeing conditions the advantages of the C8 are largely lost

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ecuador, michael makes a good point, did you account for the different focal lengths with the test scopes, and use different focal length eyepieces to give the same magnification?  

Also have you ever tried an ED100 or ED120? I've got a feeling you'd approve ;)

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Not all Sky-Watcher apo doublets perform the same. We had two side-by-side, aimed at Jupiter a couple years ago, one was a little sharper, could have somewhat less purple halo, too (they are very fine semi-apo's, really). Comparing different scopes of different design and aperture make the result even more vague.

But that's an off-topic; to answer the first question, the SW uses better glass (FPL-53) than the TS (FPL-51), and is a bit less steep in f/ratio: f/7.5 versus f/7. Thus it's a bit better corrected on paper. In practice the star-test in the SW is better. I once star-tested the Astro-Professional clone of that TS scope; it was clean and well-centered, but more achromat-like than the star test in three (or four?) SW's I looked through. Plus, the SW costs less.

Ask an astrophotographer: a 600mm focal length apo is by far easier to control than a 1,500mm focal Maksutov for a beginner. Imagine you have to write with two pencils, one is 600mm long, the other is 1.500mm long. Which will make clearer letters? The light beams are like pencils writing on the camera sensor, it's obvious the longer one is much easier to disturb, especially with today's minuscule pixels, which pick up the slightest deviation.

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2 hours ago, Chris Lock said:

ecuador, michael makes a good point, did you account for the different focal lengths with the test scopes, and use different focal length eyepieces to give the same magnification?  

Also have you ever tried an ED100 or ED120? I've got a feeling you'd approve ;)

The Mak vs the 80ED were not far in magnification, otherwise the small disk would be the complaint on the ED and nobody would prefer that. Even though 127 vs 80 would indicate more than twice the light gathering, if we calculate that the mirror is oversized (about 120mm real aperture), that there is a significant central obstruction (33% IIRC) and that in addition to the front lens there are 2 extra mirrors which further drop transmission, then the difference in light gathering is not so pronounced. As I said, it is all subjective in the end. The Mak of course is amazing for its size, that's why I kept it for quite a while (after getting rid of its SLT mount - I understand the appeal, but it wasn't for me). But of course vs an 8" SCT the 80ED can no longer compete. In fact, my 8" SCT was better at planets compared even to the 200PDS, as long as I had perfect collimation - not sure why, most people tell me they should be similar - but again I am reporting my subjective opinion from the experience with them ;)

Yes, I have tried the ED 100 and 120 :) Of course I like them, although the ED 100 is not really an all-rounder like the 80 and 120... 

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Sounds like a pretty decent side by side test, can't really find fault so the Skywatcher ED80 must just be that good :) I think the OP will really like the ED80 if they go that way, especially with them wanting to do terrestrial photography, probably way more suited than the Mak for that lol.

I did know a guy who used a Celestron ED80 for wildlife photography, mainly birding I think. The poor thing got really battered about as a result, but it did mean I got to buy it very cheap and carbon wrapped it to hide the sins.

Don't forget the light loss on the rafractor side of the equation with the front elements and mirror diagonal (usually), so the ED80 won't be batting at 100% light transmission either.

I've got an ED100 currently and plan to run it with the Altair 0.8 for the DSO imaging side...I've tried these reducers with the ED's before and they are a great bang for buck. f7.2 shouldn't be too bad. Without the reducer for galaxies at f9 the field is pretty flat, so might be good for galaxies if you subscribe to OllyP's f-ratio myth. The ED100 is a stunning visual scope I've found but that's probably down to fpl53 glass at the relatively slow f/9, plus visually things get interesting at or above 4" with fracs.

200pds vs 8SCT - I found I prefered the 8SCT on planets too, but then again I'm not a fan of the faint wide diffraction spikes you get coming out of planets sometimes on some newts. The Edge800 HD SCT I had gave me my best ever planetary views of any scope I've owned. That was a great night now seared into my brain :) 

Wishing the OP lots of fun with their new scope, yeah just get the Skywatcher ED80 f7.5 :)

 

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5 minutes ago, Chris Lock said:

Don't forget the light loss on the rafractor side of the equation with the front elements and mirror diagonal (usually), so the ED80 won't be batting at 100% light transmission either.

The Mak has a lens as well, and lenses are in the order of 97% transmission, they don't make that much of a difference, it is mirrors that drop down to close to 90% (unless you get very expensive mirror coatings which I have not heard these Maks having).

5 minutes ago, Chris Lock said:

The Edge800 HD SCT I had gave me my best ever planetary views of any scope I've owned. That was a great night now seared into my brain :) 

That's until you try a C9.25 :D

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29 minutes ago, ecuador said:

The Mak has a lens as well, and lenses are in the order of 97% transmission, they don't make that much of a difference, it is mirrors that drop down to close to 90% (unless you get very expensive mirror coatings which I have not heard these Maks having).

That's until you try a C9.25 :D

No the Orion Optics Newts and Celestron XLT SCT's have pretty decent coatings but the Synta Maks just seem to have the standard coatings, probably reflecting about 90% like you say. Of course lenses lose less refracting light than mirrors do when reflecting light, but should we ignore a 3% drop in light transmission when comparing the finer details of scopes?

I was lucky enough to use some really big 16" SCT's for several years, but sadly as they were for research I rarely got to stick an eyepiece in any of them.

I might try a C9.25 one day :)

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Note that 33% central obstruction is by diameter, not area. By area it is only 11%. The Mak 127 has an oversized mirror, just as my SCT. It is the diameter of the corrector plate, 127mm in the Mak127 and 203mm in my C8, not the mirror that specifies the aperture. Assuming 93% reflectivity of the mirrors (fairly bog-standard GSO level, nothing special), we get a transmission of some 77%, and given the aperture difference than means 94% more light in the Mak127 compared to the 80 ED, assuming no losses in the ED.

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On 1/13/2017 at 12:42, michael.h.f.wilkinson said:

Note that 33% central obstruction is by diameter, not area. By area it is only 11%. The Mak 127 has an oversized mirror, just as my SCT. It is the diameter of the corrector plate, 127mm in the Mak127 and 203mm in my C8, not the mirror that specifies the aperture. Assuming 93% reflectivity of the mirrors (fairly bog-standard GSO level, nothing special), we get a transmission of some 77%, and given the aperture difference than means 94% more light in the Mak127 compared to the 80 ED, assuming no losses in the ED.

No, the working aperture of the Mak 127 has been measured by many people and it is found between 118 and 122mm (depending the unit, examples), hence 120mm is the usual accepted "middle" value. The secondary is 42mm. If you assume say 77% transmission for the Mak and 95% for the 80ED, you get 60% more light on the Mak. It is significant difference, but my point is that it is not something like "over twice" as the difference in nominal aperture would indicate on first look. 

Anyway, not to get too off-topic.

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On 12/01/2017 at 20:22, Chris Lock said:

 The ED100 is a stunning visual scope I've found but that's probably down to fpl53 glass at the relatively slow f/9, plus visually things get interesting at or above 4" with fracs.

 

apologies for the threadjack, but

can somebody tell me what interesting means here please, as I have been looking at a possible startravel 120 purchase.

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