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C5/Maxbrights on Jupiter

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#1 Eddgie

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Posted 20 November 2012 - 11:02 PM

Ok, this was an abject reminder of why I don't don't use these little toy telescopes for planets.

And the binoviewer for the first time may have worked against me.

Not that the view was worse than mono-vision, but I don't think it was better.

These little scopes just don't have enough brightness in mono-vision to allow very much high power observing, but the binoviewer for me dimmed the image enought at this aperture to work against me.

Now there was a fair amount of detail visible. I tuned in just as GRS had rounded the limb, and I could see the vorticies that trail it, and I could resolve three of the Gallileen moons as disk but Io was more point like. But I can do that in Mono vision too.

But the problem was the image was just to dim at 150x.

To be fair, I usually get my best planetary result at 1mm exit pupil, and at this power, the image was just acceptably bright, but I think I have seen it at least as well using mono-vision. and I think that the added brightness in mono-mode made up for only having one eye to observe with.

This is the first experinece with the binoviewer that has been less than great, but it was not at all bad.

It just wan't better either.

But again, I just am not a fan of little telescope for planetary observing. Just wanted to give it a try for the fun of it.

#2 thesubwaypusher

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Posted 24 November 2012 - 11:14 PM

Ok, this was an abject reminder of why I don't don't use these little toy telescopes for planets.

And the binoviewer for the first time may have worked against me.

Not that the view was worse than mono-vision, but I don't think it was better.

These little scopes just don't have enough brightness in mono-vision to allow very much high power observing, but the binoviewer for me dimmed the image enought at this aperture to work against me.

Now there was a fair amount of detail visible. I tuned in just as GRS had rounded the limb, and I could see the vorticies that trail it, and I could resolve three of the Gallileen moons as disk but Io was more point like. But I can do that in Mono vision too.

But the problem was the image was just to dim at 150x.

To be fair, I usually get my best planetary result at 1mm exit pupil, and at this power, the image was just acceptably bright, but I think I have seen it at least as well using mono-vision. and I think that the added brightness in mono-mode made up for only having one eye to observe with.

This is the first experinece with the binoviewer that has been less than great, but it was not at all bad.

It just wan't better either.

But again, I just am not a fan of little telescope for planetary observing. Just wanted to give it a try for the fun of it.


I don't think you have enough experience with binos yet, Ed (no offense). The C-5 has a focal length of 1250mm. You're using 150x, which is too high, really, it's not the fact that you're binoing. I think you are asking too much from that setup. BUT, if you insist on using it, put a black shroud over your head, and give it time. It has always been my experience that binoviewing is better, period. I think the exponential improvement that comes with two eyes is often understated.

I used to use binos even in my 2000mm FL ETX-125, and they worked very well, but I recall not going over 80x.

The view in the FSQ is unbelieveable with binos, but even that $5000 OTA starts to grow quickly unattractive as you get past around 80x.

Good luck, Chris

#3 Eddgie

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Posted 28 November 2012 - 09:29 AM

Well, I have been using them in the EdgeHD 8" and the C14 for about 10 months, and in these scopes, it is not a problem becuase I don't normally have to use small exit pupils to get planetary powers.

But in the C5, 150x is an exit pupil that is not even .8mm.

I have used a .8mm exit pupil in the C5 many times in monovision and while it is at the top end of what I normally use even in my 6" APO, I found that with the binoviewers, the dimming induced by the binoviewers negated some of the benefit of the binocular vision.

The result was that I did not feel the same benefit I have experienced when using them in larger apertures.

I did use them on the moon before in the C5 and loved them, but the moon starts so much brighter that even with a small exit pupil there was brightness to spare, and in fact, I feel that the binoviewers were better than monovision for lunar viewing.

But for high power planetary viewing in such a small aperture, I did noat feel the same benefit I see at larger apertures where you seldom use such small exit pupils.

But that is me. I find that having a brighter image for a given magnification is a great aid to me personally because it helps me see the lowest contrast detail. That is why I prefer larger scopes for planetary viewing.

Anyway, this is the only time I felt like the Binoviewers were not giving me any advantage over mono-vision. At 100x, it was not a problem, but 100x is too little for most planetary work. I think I would stick to Mono-viewing in the C5 if the desire was to use higher powers. Again, just my own personal preference.






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