PHD problems

[matt-c]

I'm currently trying to start some guiding using PHD/metaguide but i have yet to find a star 

I can focus during the day and have got some nice views of the moon but for some reason when looking for stars PHD just gives me noise.

At first i was using a xbox webcam and got nothing so i tried a more sensitive logitech quickcam 4000 after seeing people had success with it but still nothing.

Maybe my guide scope is too slow? its a celestron travel scope (f5.7 ish i think   )

I tried using fast camera lenses and still nothing.

Can anyone give advice on what i can do because i'm actually starting to pull my hair out, i'm wasting majority of clear nights trying to find something to guide on. 

My moaning is getting on the wifes nerves aswell 

[MarsG76]

I suggest first locate, focus and center a star in your guide scope, then install the CCD/Camera. Set you exposure to 0.5s-1sec at max (or near max) gain. Make sure that the CCD is focused properly, so slowly move the focuser in and out until you start seeing the star, once perfectly focused, lower your gain until you don't have noise, just a nice solid guide star... now you're ready to setup your calibration and guiding in PHD.

Try using a star that is magnitude 7 or brighter.

Focus is critical as a guide star, since it doesn't take for it to be too far out of focus before the guide star is not visible anymore. Than it needs to be a pin point to accurately guide on.

[beamer3.6m]

It's probably focus. As said focus on a know bright star and then try and guide on it.

I use exposures of around 1 second for guiding.

[Starlight 1]

I give up on useing web-cam , the Altair mono is £135 and that only give me 15 or 20 Stars easy to set up and works , you can spend £ 450 on a good one .

[freiform]

Focus is critical as a guide star, since it doesn't take for it to be too far out of focus before the guide star is not visible anymore. Than it needs to be a pin point to accurately guide on.

Not directly on topic, but Is that true? Obviously you have be somwhere around the proper focus to actually have an image resembling a star, but depending on the resolution of your guidescope-/cam combination, defocusing slightly may yield better results as it may enable to calculate a stars position with sub-pixel accuracy.

[Starlight 1]

Not directly on topic, but Is that true? Obviously you have be somwhere around the proper focus to actually have an image resembling a star, but depending on the resolution of your guidescope-/cam combination, defocusing slightly may yield better results as it may enable to calculate a stars position with sub-pixel accuracy.

 Yes Phd work a lot better this way as you can see hot pix , But the down side is the web-cam , untill you get a nice Star you can see any thing in Phd.

[Thalestris24]

I'm currently trying to start some guiding using PHD/metaguide but i have yet to find a star 

I can focus during the day and have got some nice views of the moon but for some reason when looking for stars PHD just gives me noise.

At first i was using a xbox webcam and got nothing so i tried a more sensitive logitech quickcam 4000 after seeing people had success with it but still nothing.

Maybe my guide scope is too slow? its a celestron travel scope (f5.7 ish i think   )

I tried using fast camera lenses and still nothing.

Can anyone give advice on what i can do because i'm actually starting to pull my hair out, i'm wasting majority of clear nights trying to find something to guide on. 

My moaning is getting on the wifes nerves aswell 

Yeah. you probably need something faster e.g. a 50mm guide scope to pick up anything other than the brightest stars with a web cam. As suggested, something like a gpcam mono is much, much better for guiding with and it will be ok with the travelscope. Also, you need the PHD2 dev build v2.5.0dev7

Louise

[ChrisLX200]

Not directly on topic, but Is that true? Obviously you have be somwhere around the proper focus to actually have an image resembling a star, but depending on the resolution of your guidescope-/cam combination, defocusing slightly may yield better results as it may enable to calculate a stars position with sub-pixel accuracy.

PHD2 will calculate position to sub-pixel accuracy anyway _provided_ the core is not saturated (star profile graph does not show a flat top). Purposefully de-focussing is not necessary and doing so will drop the s/n ratio which may cause loss of guidestar to happen more often.

ChrisH

[matt-c]

Thanks for all the replies.

Just a quick update I took the advice from Mars about the settings and from Louise about the speed of the scope, which I replaced with a camera lens and I've had a huge break through!! (I found 1 star woo hoo) before the clouds spoilt my joy.

Now this was capella so I'm unsure how faint ones will show up.

But a huge success giving the last few blunders.

Thanks everyone.

[Starlight 1]

Thanks for all the replies.

Just a quick update I took the advice from Mars about the settings and from Louise about the speed of the scope, which I replaced with a camera lens and I've had a huge break through!! (I found 1 star woo hoo) before the clouds spoilt my joy.

Now this was capella so I'm unsure how faint ones will show up.

But a huge success giving the last few blunders.

Thanks everyone.

Nice to see you had some success, guide scoop and telescope always an exact alignment so may not be a bright star is always available.

That's the downside of the WebCam, old Technology Will always had limited success.

[Pompey Monkey]

I use a second hand QHY5-I and a Meade 9*50 finder that I cut down to the correct length to achieve focus. I've never failed to find a guide star

Total cost: £130.