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What cable is needed for guiding?

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#1 mpgxsvcd

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Posted 24 April 2013 - 07:50 AM

What cable would I need to go from my computer to my Celestron CG-5 to guide? My plan is to do RCA inputs from a camera into my computer with PHD and then have a cable from my computer to either the autoguiding port or the hand controller port of the mount.

Both of the ports on the mount look like telephone cable inputs. What exactly are those inputs and what cable can connect to them?

Is there a good guide for setting up autoguiding with a computer and the CG-5?

#2 jrcrilly

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Posted 24 April 2013 - 08:26 AM

Your PC won't be able to connect directly to either port on the mount; neither uses any standard PC protocol. If your PC has an RS-232 port then a Celestron serial cable can connect to the port on the handbox. If not, then you'd need a USB-to-serial adaptor plus the serial cable. You won't be able to connect to the AG port without an interface. The GPUSB is popular and works well.

#3 rmollise

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Posted 24 April 2013 - 08:38 AM

What cable would I need to go from my computer to my Celestron CG-5 to guide? My plan is to do RCA inputs from a camera into my computer with PHD and then have a cable from my computer to either the autoguiding port or the hand controller port of the mount.

Both of the ports on the mount look like telephone cable inputs. What exactly are those inputs and what cable can connect to them?

Is there a good guide for setting up autoguiding with a computer and the CG-5?


What you will have to do is run your camera to a frame grabber. You can then use PHD. How do you get the guide signals to the mount, then? You can either purchase one of Shoestring Astronomy's USB guide adapters which will plug into a USB port on your computer and the ST-4 Guide Port on the mount. OR...you can guide through a serial cable to the base of the hand control with the aid of ASCOM. ;)

You may find this old blog entry of mine of interest...

#4 mpgxsvcd

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Posted 24 April 2013 - 08:43 AM

Will these two cables work if all I have is USB?

http://www.amazon.co...0_i00?ie=UTF...

http://www.amazon.co...0_i01?ie=UTF...

#5 mpgxsvcd

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Posted 24 April 2013 - 08:49 AM

Thanks a lot guys. That information helps.

Rod,

Are you coming to North Carolina to present soon or has that already happened?

#6 jrcrilly

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Posted 24 April 2013 - 08:50 AM

Will these two cables work if all I have is USB?


Should work. As Rod mentions, you may also need additional hardware to get the video into the PC if it doesn't have a built-in frame grabber.

#7 rmollise

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Posted 24 April 2013 - 09:10 AM

Thanks a lot guys. That information helps.

Rod,

Are you coming to North Carolina to present soon or has that already happened?


It will happen this Friday, the 26th... ;)

#8 mpgxsvcd

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Posted 24 April 2013 - 09:19 AM

Thanks a lot guys. That information helps.

Rod,

Are you coming to North Carolina to present soon or has that already happened?


It will happen this Friday, the 26th... ;)


I knew it was coming up soon. I will try to make it then.

#9 mpgxsvcd

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Posted 24 April 2013 - 09:21 AM

Will these two cables work if all I have is USB?


Should work. As Rod mentions, you may also need additional hardware to get the video into the PC if it doesn't have a built-in frame grabber.


I have the frame grabber already. It was a pain to find though. I had to go from HDMI to RCA because of the way my camera works. That was not fun to figure out how to do. However, I couldn't afford the proper HDMI capture setup.

#10 mpgxsvcd

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Posted 25 April 2013 - 08:15 AM

I am having trouble getting the input of my EasyCap RCA video capture device to show up in PHD. I selected the VFW option for my camera.

However, I get the Blue Screen of Death even in Windows 7 when I select that option. I am able to capture from the EasyCap in all of my other programs just fine.

Does anyone have an idea about which camera option I should choose in PHD for the EasyCap capture device?

#11 rmollise

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Posted 25 April 2013 - 09:18 AM

I am having trouble getting the input of my EasyCap RCA video capture device to show up in PHD. I selected the VFW option for my camera.

However, I get the Blue Screen of Death even in Windows 7 when I select that option. I am able to capture from the EasyCap in all of my other programs just fine.

Does anyone have an idea about which camera option I should choose in PHD for the EasyCap capture device?


If nobody has any ideas, sign into the Stark Labs Yahoogroup. Mr. S. is there helping users alla da time. :cool:

#12 mpgxsvcd

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Posted 25 April 2013 - 09:41 AM

I am having trouble getting the input of my EasyCap RCA video capture device to show up in PHD. I selected the VFW option for my camera.

However, I get the Blue Screen of Death even in Windows 7 when I select that option. I am able to capture from the EasyCap in all of my other programs just fine.

Does anyone have an idea about which camera option I should choose in PHD for the EasyCap capture device?


If nobody has any ideas, sign into the Stark Labs Yahoogroup. Mr. S. is there helping users alla da time. :cool:


Thanks Rod. I am also going to try a different computer. In addition I might just pony up and buy the proper HDMI capture device.

#13 rmollise

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Posted 25 April 2013 - 02:17 PM

If you are going to buy a camera just for guiding, think about Orion's basic StarShoot autoguider. Cheap, guide output, good drivers--plug and play.

#14 Footbag

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Posted 25 April 2013 - 02:38 PM

If you are going to buy a camera just for guiding, think about Orion's basic StarShoot autoguider. Cheap, guide output, good drivers--plug and play.


+1

Which camera are you using? Remember you won't be able to image through the camera you are using for guiding. A SSAG is cheap and it works.

#15 mpgxsvcd

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Posted 25 April 2013 - 03:48 PM

I am going to use my spare Panasonic GH2 as the guide camera, my GH3 as my narrow field camera, and my full spectrum GF1 as a widefield camera. I have created a really simplistic but very sturdy mount for a second camera and lens on my AT8IN scope.

My plan is to use GF1 with a 70-200mm(35mm Equivalent) F2.8 lens as a wide field camera and use my GH3 on my 800mm F4.0 scope to guide for wide field shots. Then when I want to do narrow shots I can put the GH2 + 70-200mm F2.8 lens in the wide field position and guide for the GH3 on the AT8IN with it.

Then if I am just doing single exposure observing I can opt to leave the computer at home altogether and just use the GH3 on the AT8IN and the GF1 as a widefield camera.

It probably isn’t the ideal solution and I bet I will end up getting the Orion Mini AutoGuider Package in the end. However, it would allow me to fully use what equipment I already have which I think would be pretty cool.

After getting the Blur Screen of Death too many times with the easycap device I just went ahead and bought an HDMI capture card. I don’t want to mess with it anymore. I want to just start guiding.

#16 mclewis1

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Posted 25 April 2013 - 05:56 PM

Travis,

Hopefully your new HDMI capture hardware and driver software are Windows WDM compatible so it looks like a Windows webcam device. This way the autoguiding software will be able to use the video stream. Most autoguiding software supports specific cameras, ASCOM cameras, and webcam devices.

And hopefully your setup won't have much video jitter. I tried using video for autoguiding a few years ago ... it worked but wasn't very accurate. It appeared that my capture setup had a bit of video jitter which seemed to enlarge the size of the stars beyond the effects of the seeing and when analyzed down at the pixel level.

So a capture capability from your camera gets the autoguiding software the image of the stars it needs. The software will then put out mount control commands and these can take two formats 1) Pulse guiding commands, this is done over the serial connection to the hand controller (HC) serial port (in the base of the HC), OR b) via an ST-4 compatible connection, this is done via the autoguide port on the mount. The PC requires an specialized interface to drive the ST-4 connection. This is provided by a GPUSB from Shoestring Astronomy.

#17 mpgxsvcd

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Posted 25 April 2013 - 06:24 PM

And hopefully your setup won't have much video jitter. I tried using video for autoguiding a few years ago ... it worked but wasn't very accurate. It appeared that my capture setup had a bit of video jitter which seemed to enlarge the size of the stars beyond the effects of the seeing and when analyzed down at the pixel level.


HDMI is a much more stable connection than rca or even s-video. The HDMI output of my cameras is just the same as the 1080p that they record to SD cards. No static. No artifacts. Nothing but a clean signal as long as your cable is up to the current specs for its length.

I bought the HDMi capture card from Amazon Prime so I can simply return it for a full refund if it doesn't work. I will get the Orion package if it doesn't work.

#18 mpgxsvcd

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Posted 26 April 2013 - 01:00 PM

I went ahead and bought the Orion Mini Autoguider package. I mounted both cameras on my scope last night and even with the lightweight of both cameras I maxed out my mount.

The two weights I already had simply were not enough and even if I got more weight it was just going to be too much for my little CG-5.

The mini guider is definitely the optimal solution and the price is not too bad either.

However, I might still keep the HDMI capture device. If it works it will give me much better results for NSN than the HDMI to RCA device did.

#19 Footbag

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Posted 26 April 2013 - 01:36 PM

I went ahead and bought the Orion Mini Autoguider package. I mounted both cameras on my scope last night and even with the lightweight of both cameras I maxed out my mount.

The two weights I already had simply were not enough and even if I got more weight it was just going to be too much for my little CG-5.

The mini guider is definitely the optimal solution and the price is not too bad either.

However, I might still keep the HDMI capture device. If it works it will give me much better results for NSN than the HDMI to RCA device did.


I think you made a good decision. I don't know about you, but I don't get out enough to be troubleshooting when I should be imaging.

In this hobby, you can fix any problem by throwing money at it. The guide camera you bought is probably the best "cheap" upgrade in the hobby.

#20 mpgxsvcd

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Posted 26 April 2013 - 02:19 PM

I think you made a good decision. I don't know about you, but I don't get out enough to be troubleshooting when I should be imaging.

In this hobby, you can fix any problem by throwing money at it. The guide camera you bought is probably the best "cheap" upgrade in the hobby.


I always thought that I could fix things if I just worked a little harder at it or if I went that extra mile to be more precise. And in a lot of cases that was true. However, now I also realize that if you spend all of that effort researching what works best then you can just buy a setup that does exactly what you want without much fuss at all.

Once I get my guiding working I will finally be able to just sit back and enjoy the night skies. Although I know I will find some way to tinker even though it probably won't really need it.

#21 Footbag

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Posted 26 April 2013 - 02:35 PM



I think you made a good decision. I don't know about you, but I don't get out enough to be troubleshooting when I should be imaging.

In this hobby, you can fix any problem by throwing money at it. The guide camera you bought is probably the best "cheap" upgrade in the hobby.


I always thought that I could fix things if I just worked a little harder at it or if I went that extra mile to be more precise. And in a lot of cases that was true. However, no I also realize that if you spend all of that effort researching what works best then you can just buy a setup that does exactly what you want without much fuss at all.

Once I get my guiding working I will finally be able to just sit back and enjoy the night skies. Although I know I will find some way to tinker even though it probably won't really need it.


You can still tinker. Just tinker during the day and image at night. :grin:

Seriously though, guiding was my biggest and most noticeable upgrade. Now, you can really put your cameras through their paces. Good luck and clear skies!






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