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 Post subject: Re: Guide camera/view finder
PostPosted: Mon Feb 18, 2013 12:43 pm 
Yeah I was waiting for that !! In fact I'm going to attempt using the circles next time. There isn't a way of connecting the canon to the finder as its so small, the original celestron one, I could get another Phillips and connect it to this but it's yet another camera to faff with. I think either a mega wide lense on guider or a goto is the only solution really, laser mount is on its way so that may help a bit if its perfectly aligned..... Always something eh


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 Post subject: Re: Guide camera/view finder
PostPosted: Mon Feb 18, 2013 2:45 pm 
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dean_kos wrote:
I'm going to attempt using the circles next time.
I could get another Phillips and connect it to this but it's yet another camera to faff with.

But won't you need to fit another web-cam on the side of your mount, so that you can read those setting-circles from indoors? ;)


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 Post subject: Re: Guide camera/view finder
PostPosted: Mon Feb 18, 2013 3:50 pm 
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Dean I can only go off my own experience with the setup your after.

I struggled to begin with :!: Made worse by the fact that I don’t have any terrestrial objects to go off, still the Go-To made a difference. The mount is now set that even without alignment points the object will appear in the Camera VF. It becomes a problem when the camera is disturbed (mainly me hitting my head on the camera as I move the roof :roll: ).

Even then the go-to gets me roughly in the vicinity enough for me to slew west before the object appears in the eyepiece. After which I set the camera again.

If you are looking for a remote set-up then a Go-To is the way forward.

Can't think anyone else who has this setup (camera view finder) so there must be a reason why not everyone has jumped on the idea, but I don't give it a second thought these days. I just work around it when it stops working or curse the sky for an optical viewfinder.

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Celestron 11" Telescope
Eq6 Pro Mount
Eq5 Mount
EQ Mod
QHY5 Guide camera
Cannon 1000D SLR Camera

I choose to image with an 11" SCT Celestron in this decade and do the other things, not because they are easy, but because they are hard......


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 Post subject: Re: Guide camera/view finder
PostPosted: Mon Feb 18, 2013 8:21 pm 
I have just emailed Altair Astro regarding a goto kit for my vixen sp mount and they replied saying they no longer supply them, some issues with the retro fit apparently.
They suggested trying a kit that skywatcher do...... Does anyone have a clue which kit would work for my mount ? I know there is another thread on this subject and David suggested one but just want to make certain before I take the plunge .....


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 Post subject: Re: Guide camera/view finder
PostPosted: Mon Feb 18, 2013 9:38 pm 
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Dean!

I'd hold onto your pennies and try and go for a pre-built Go-To, even try and purchase second hand.

The reason being is that if you develop a problem you'll be asking the question is it the quality of the kit or did I do something wrong when fitting the drives. Plus also will your guiding work with the new motors. Its an unknown area for me, there are too many variables for problems to develop.

Even if you get a second hand Eq6 there is some knowledge within the group (Gerald) to help rebuild the drive. There is even AstroBaby

You can then use your vixen when out and about like I do with the Eq5. I saved for a year for the Eq6 worth every penny, think long and hard is all I can say!

But then don't let me stop you. I did come across this a while back. Retrofitting Meade Auto-star GOTO, might be worth a nosy and good for a laugh. :D

http://tech.groups.yahoo.com/group/RoboScope/

_________________
Celestron 11" Telescope
Eq6 Pro Mount
Eq5 Mount
EQ Mod
QHY5 Guide camera
Cannon 1000D SLR Camera

I choose to image with an 11" SCT Celestron in this decade and do the other things, not because they are easy, but because they are hard......


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 Post subject: Re: Guide camera/view finder
PostPosted: Mon Feb 18, 2013 10:11 pm 
Yeah I agree Carl and to be honest I have had some relative success this evening although had problems too.......
Using the laser to get me in the general area worked a treat, I made a makeshift bracket for it until the proper one arrives and lined it up with the c8, then I take a minute exposure and figure out where I am matching the stars on screen to a map and adjust to the object. Doing this I managed to find the owl nebula relatively easily.
The problems arose when I tried to guide ...... I'm using the Phillips webcam on 3sec exposures in phd, anything less and phd keeps loosing the star. Guiding seems to set off fine and the graph settles close to the middle on both axis and then every now and again I get a fuzzy frame on phd and the graph looks like someone having a heart attack! I think it's these frames that are causing the problems as my stars on the image are all manner of different squiggles...... Is it the camera that's not ideally suited to guiding ?


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 Post subject: Re: Guide camera/view finder
PostPosted: Tue Feb 19, 2013 8:16 am 
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It is true that the webcams aren't ideal for guiding, since they have a colour sensor (so not as sensitive as monochrome, and with an uneven response from adjacent pixels due to the Colour Filter Array) but they are good as a low-cost starter camera.

It's also very common to get "dropped frames" in the video stream when operating them in LX mode - it's worth spending some time trying different combinations of frame rate (fps) on the camera and LE read delay in PHD Guiding to get the most consistent response on your PC. You can do this test with an illuminated target in a darkened room, rather than wasting a clear night on it.
But in my experience, the odd dropped frame doesn't upset the guiding much - it yields zero errors in both axes, so no resultant guiding control signals will be to be sent to the mount on that iteration. Obviously if you get a series of consecutive dropped frames then there will be no correction to the mount's errors, so the target will begin to drift, but the odd one shouldn't cause any problems with a well-behaved mount.

The PHD_log files produced by PHD Guiding are very useful in debugging auto-guiding problems, since they record all the calculated error signals and resultant control signal outputs from each iteration as the program calibrates and then runs.


Last edited by rwilkinson on Wed Feb 27, 2013 3:34 pm, edited 1 time in total.

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 Post subject: Re: Guide camera/view finder
PostPosted: Wed Feb 20, 2013 6:35 pm 
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Modern Astronomy sell an adapter that can be configured to attach a camera to a viewfinder but a dslr might be a bit on the heavy side to attempt this.


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 Post subject: Re: Guide camera/view finder
PostPosted: Wed Feb 27, 2013 9:22 am 
On the topic of viewfinders I recently invested £40 in a Telrad viewfinder - best £40 I ever spent. A straight through viewfinder but the variable brightness red circles make it possible to find many objects once it is properly aligned with my C14 image on my laptop screen on a bright object. On occasion I do something to mess up my C14 pointing and believe me it is difficult to find even the Moon through the C14 if the software is not working without a finder. If the Telrad is aligned it is easy to centre an object on the screen even if I cannot see it with the naked eye because of the surrounding stars seen through the Telrad. I have an 8 X 50 finder but rarely need it now that I have the Telrad. Obviously faint objects in blank areas of sky are more difficult. I would be interested to hear if any other members have Telrads and their experiences.They usually seem to be out of stock because they are so popular but persistence will find one. Link http://www.altairastro.com/product.php?productid=16261&cat=260&page=1.
PS - You can get Telrad finder charts to help locate popular objects.


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 Post subject: Re: Guide camera/view finder
PostPosted: Wed Feb 27, 2013 3:23 pm 
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Well I have not got a Telrad but do use a Red Dot Finder in conjuction with my 8 x 50 Right Angled Spotter Scope on my C8. As I have setup each time and carry out a 2 star alignment I find it easier to use the Red Dot Finder to get to the reference star and then move to the spotter scope to tweek the alignment before finally centring the star in the eyepiece.

The only reason I have not bought one is the fixing, I'm lead to beleive you have to stick the base to the scope tube and get another base if you want to use it on a different scope.

There is also an Telrad Ocular in Stellarium.

Bill


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