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Ode to the C4-R

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#26 Bill Cowles

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Posted 06 May 2010 - 06:37 PM

:waytogo:

Bill

#27 WillCarney

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Posted 06 May 2010 - 07:10 PM

Here's an image taken a few nights ago. I used a Celestron C102. 31 Lights, 76 darks using DSS no other processing.

Posted Image

K5 Mcnaught is the fuzz ball in the center.
William

#28 BoriSpider

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Posted 09 May 2010 - 04:40 AM

Great image Will. The C4R is awesome.

I really enjoy sunspot viewing with my
C4R and a white-light filter.

#29 Knygathin

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Posted 25 January 2013 - 06:05 AM

The only thing I regret about the C4-R is the CG-4 mount. It has resulted in the telescope not being used much. It is too heavy, and awkward, to spontaneously carry outside in the evening and start watching. I don't have the patience or ability for aligning it equatorily out in the dark; I can't find Polaris through the hole, and the ground back of the house is uneven or sloping. It's a nuisance! I just can't do it.

I wish it had come with a simple and easy altaz mount instead. I just want to be able carry it out, sit down and start working immediately with both of the remote controls. I have been trying to find an altaz mount, for a reasonable price. The 'Celestron Alt-Azimuth mount' or the 'Skywatcher mount AZ-3' don't seem to be workable options, since the weight of the telescope will not be center-balanced in all positions, but will be hanging to the side, and straining down on a single fastening of the mount when pointing upwards toward zenith, making positioning high up unreliable. The only reliable altaz mounts seem to be big boxlike structures. I have tried to adapt the CG-4 to altaz mode, but it is still kind of awkward and heavy.

This aside, the views through C4-R are fantastic. Mostly I have watched from inside the house out the window. The moon is incredible. I chased it with both remote controls when the mount was in equatorial mode, which was quite difficult.

I feel that equatorial mounts are for proffessionals, and real astronomers who want to make scientific observations of single objects. But for an ordinary observer like me, who want to go star-treading intuitively, and move around the telescope to new exotic locations, an altaz mount would have been much better.

#30 csrlice12

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Posted 25 January 2013 - 10:03 AM

For quick visual use, you don't need to use the polarscope. Just align the North leg of the tripod with a compass and make sure the tripod is level. I keep the CG4 in the shed and the OTA inside. It takes me about 10 minutes total from unlocking the shed to going inside and grabbing the scope, tolooking thru the eyepiece.

#31 BoriSpider

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Posted 25 January 2013 - 11:59 AM

csrlice12 +1.
I keep my C4-R/CG4 set up in the guest bedroom and when I want
to view I pick the whole thing up(legs retracted) and walk it
down the hall and out the door. I plop it down in a somewhat
northerly direction and start viewing. No motors. It's the
only mount I've used so I guess that's why it doesn't bother
me that it's not perfectly aligned.

#32 Knygathin

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Posted 25 January 2013 - 03:38 PM

Thanks for the tip csrlice12. I will try that. So with that rough alignment, you will follow a sky object with just one remote control nob?

#33 Jon Isaacs

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Posted 25 January 2013 - 03:56 PM

Thanks for the tip csrlice12. I will try that. So with that rough alignment, you will follow a sky object with just one remote control nob?


To polar align using a compass, you should account for the http://en.wikipedia....tic_declination, the difference between "true" north and magnetic north.

In San Diego where I am, it's about 12 degrees which is enough to cause difficulties with polar alignment. You don't need to be super close, a few degrees is good enough.

Jon

#34 csrlice12

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Posted 25 January 2013 - 04:25 PM

Like Jon said, you have to account for the differece in "True North" (The internet will provide that info), but once you have that, I just put the compass up against the flat part of the mount where the mount joins the leg, and turn the scope till it points "North". For visual use, this has been pretty dead on, I did this for Jupiter the other night, and I only had to use the RA (OK, maybe I did adjust the DEC slightly once or twice an hour; but it wasn't much and was easy.) I know I went inside for about 1/2 an hour, came back out, grabbed the RA knob and brought Jupiter back into the FOV without touching the DEC knob. NOW, I gotta learn it all over again as I've ordered the motor drives.....

#35 rlk

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Posted 25 January 2013 - 05:00 PM

I loved, loved, loved reading posts by Jay in sci.astro.amateur back in the day (late 90's); do you happen to know if he's is still active?

Jay Reynolds Freeman Astronomy Page

A friend of mine did nearly the entire Hershal 400 in one night with a 4" refractor (TeleVue 101). He got 388 of them using a Go To mount but the fact that he used a 4" scope was impressive.


Hi:

Your mention of the Herschel 400 reminded me of Jay Reynolds Freeman. He is probably best known for completing the Herschel 400 with his 55mm Vixen Refractor "Big Red." (No GOTO... of course) The other night I was viewing some faint Galaxies with my NP-101 but Jay raised the bar...

Comments on the Herschel 400

Jay Reynolds Freeman Astronomy Pages

Jon



#36 Knygathin

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Posted 25 January 2013 - 07:45 PM

When you have seen enough of an object, and you want to move on, and explore other parts of the sky, . . . that is kind of frustrating with the equatorial mode, because at least one of the knobs (don't remember if it's the RA or DEC) will not move the tube in a straight line, left to right, or up and down, making it difficult to get where you want (sort of like having a steering wheel on a car that is not directly connected to the wheels). Do you move to the next sky object by first checking coordinates in a star chart, and then readjusting the telescope to the same coordinate numbers on the setting circles?

#37 Jon Isaacs

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Posted 25 January 2013 - 08:19 PM

When you have seen enough of an object, and you want to move on, and explore other parts of the sky, . . . that is kind of frustrating with the equatorial mode, because at least one of the knobs (don't remember if it's the RA or DEC) will not move the tube in a straight line, left to right, or up and down, making it difficult to get where you want (sort of like having a steering wheel on a car that is not directly connected to the wheels). Do you move to the next sky object by first checking coordinates in a star chart, and then readjusting the telescope to the same coordinate numbers on the setting circles?


You can move to the next object by checking the coordinates with a star chart and then moving to the coordinates on the setting circles.

This generally requires rather careful polar alignment. To reduce the need for accurate polar alignment, make smaller steps from one object to the next and before leaving an object, make sure the RA and dec are correctly set for that object. If there is a bright star near the object, locate it using the finder and then set the RA and Dec and move the new object.

In general, I loosen both axes and then use the finder and a chart, either paper or electronic, to find that next object by "starhopping."

Jon

#38 kevint1

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Posted 25 January 2013 - 08:32 PM

You can turn the CG-4 into a nice alt az mount in about 10 minutes. I've used one set up this way with my 102 ED for a couple of years without any problems. No counterweights, no alignment, just open the legs, attach the spreader and scope and start looking at stuff.

#39 Knygathin

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Posted 25 January 2013 - 09:22 PM

Thanks for the tips Jon. I think it confirms that using eq mode does involve more work and time than altaz mode.

Kevin T.: This is more in my line of philosophy, the altaz mounting. Well, I have tried setting the altitude axis to 0 degrees, but it doesn't work completely satisfactory. I understand that turning it to 90 degrees is better. I will try that.

#40 Wilsonman

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Posted 25 January 2013 - 09:54 PM

I've sung the praises of the good quality 4" refractors for a long time. My old 4" Unitron matched up surprisingly well against the 10" Cave Deluxe I used to own. The Uni put up images of Mars, Jupiter and Saturn which were very close to the larger instrument. Lunar observing with the refractor was amazing- the amount of power it could handle on clear nights was surprising- sometimes as much as 300X!

#41 Knygathin

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Posted 26 January 2013 - 06:34 AM

Has anyone tried stuffing newspaper into the thin aluminium legs of the CG-4 to lessen vibration? Supposedly it will make them behave more sturdy, like wooden legs.

#42 BoriSpider

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Posted 26 January 2013 - 11:18 AM

I've heard of sand in the legs. I haven't heard of newspaper.
I've also heard of hanging some weight down the middle of the tripod
or placed on the accessory tray.






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