Guiding setup - stick or twist?

[GarethA]

In an effort to improve on my ropey finder/guider setup I've tried to use what i had lying around first before buying more kit!

The hardware setup is:

QHY5 (original not II)

.5 FR screwed into nosepiece of QHY5

Scope is 62mm aperture, 4 element petzval, F8.4

Software:

PHD 1.13.6  (using windows WDM drivers - 1280/1024 Y800)

So theoretically it's running at F4.2 which 'should' be fast enough for guiding and i thought that 62mm aperture would give enough light gathering to find plenty of stars....

It guides fine but.....it only seems to work on very bright stars. When imaging i have to have it pointing at very strange angles relative to the imaging scope which causes problems!

If i play around and try and significantly lengthen the exposure time (or gain in the cam dialog) then PHD will usually just white-out before any stars become visible.

The questions is: With careful tweaking of the software should this be a usable setup or should I just stop messing about any buy an ST-80 like everyone else??? 

(I've included a photo - not sure this helps but this is what it looks like)

[Stargazer33]

The ST80 is, I believe, an f5 scope which would make it quite faster than your f8.4 scope so allowing you to use dimmer stars for guiding. At the end of the day it depends on what you can live with. If you find that pointing the guide scope at all sorts of funny angles is too much of a faf then get the ST80. Some think they are overpriced new for what they are, but demand pushes prices up. Look at the Philips SPC900NC web cam that goes for £50-£70+ that you used to be able to pick up for under a fiver! The ST80s do come up occasionally on ebay.

[Tinker1947]

I use a ST-80 plus a Lodestar, its never short of a Star to guide Pulse) from.....

[Leveye]

White out while it's dark out?  Never have that issue. I normally use 1.5 to 2 seconds exposure length for guiding. You do know that there is a slider control for contrast of the viewing screen at the bottom of it correct?

[Astrosurf]

I use a SW 9x50 finderscope and it's great. Plus cheap! I also use the old QHY5 for guiding and I've had no problems. (Some in my group have used the new II model and have had issues with it.) It's a really nice and light set-up. Some have said that the finder shoe causes play in the guider set-up, but I've not had that.

Alexxx

[GarethA]

White out while it's dark out?  Never have that issue.

The 'white out'  happened to me a few times when i've pushed up the exposure times... generally i need to restart PHD - maybe I've got a software/driver problem.

Thanks, yes - I'm aware of the contrast slider and i dont believe that it's too much/little contrast that's causing the issue - good idea though.

[GarethA]

 I also use the old QHY5 for guiding

Thanks for that. If you're successfully using the old QHY5 could you possibly confirm which OS / software / driver versions you have?  

With this white out issue I'm now concerned that I've hobbled my QHY5 by using the wrong software.

Thanks a lot!

[Uranium235]

Depends on what focal length telescope you are trying to guide. Up to 1000mm, the finderguider is good - above that would need a dedicated telescope.

But also try upping your exposure time, typically I would calibrate at 2s - then guide at something like 3.5 or 4 seconds. Also using the old QHY5 here, and havent updated my PHD for about a year or two now (ASCOM has never been upgraded either). If its all working, I see no need to tamper with it

[GarethA]

 Up to 1000mm, the finderguider is good - above that would need a dedicated telescope.

Thanks - yes I've always guided short FLs with the old finder guider but now I've trying to guide 1300mm so went for the dedicated scope option - when it works it seems to be ok but i'm just surprised I'm not seeing more stars!

[Spikey]

The QHY5 on that scope should be OK. You could try taking darks and calibrating PHD. I also found some of the noise reduction in the PHD software to be worthwhile. As others have mentioned what interval are you guiding at ? I often use between 3-5 seconds dependant on conditions and where it's pointing but I've never had a problem exposing any guide stars. 

[IanL]

I use a QHY5 with and ST80.  A few things to note:

1. All other things being equal (i.e. same camera, software, setting) aperture of the guidescope alone will determine how many guide stars you will get.  They're effectively point sources and no scope you can buy will resolve them, so all this talk of f-ratios is misleading, or to put it bluntly, plain wrong.

2. The brightness slider has no bearing on guiding.  It's purely there to help you find guide stars on screen so you can pick them.  PHD works on the raw image before the slider is applied to the on-screen image.  That said, if you can't find a slider setting that shows stars, fair bet is that there aren't any to pick

3. I don't know about the WDM drivers, I use the ASCOM (late) drivers in PHD.  When you connect to the camera, after you pick the QHY5 in the ASCOM camera chooser dialog you should get a dialog with a single gain slider (blue background).  It will be at the default 50% setting, which is way too low for the QHY5.  You need to move this up to about 90 - 95% for best results.  It's a one shot deal and can't be adjusted again, so you need to disconnect the camera in PHD by clicking the camera buttonand then reconnect to get the chooser dialog if you want to experiment.

Hope this helps.

[GarethA]

 I don't know about the WDM drivers, I use the ASCOM (late) drivers in PHD. 

Interesting - going to try reinstalling PHD - I think it may be the fact I'm using these generic windows WDM webcam drivers - will try and get it working with the 'Ascom (late)' version!

I'm generally starting at 1 or 2 seconds then upping it when I'm not seeing any stars.

[Spikey]

You should be able to install the drivers without having to re-install PHD.

[glowingturnip]

you might want to upgrade to PHD2 by the way, here - http://openphdguiding.org/

IIRC it does specifically have the QHY old version as well as the QHYii in the camera chooser dropdowns. 

With my QHY5liic, I found there were several ways I 'could' connect to PHD - via ASCOM (QHY), via the QHYii item itself, or via WDM (RGB24) but the only one that works properly at night is the named one, the QHY5liic option, and that one worked straight out of the box without any fiddling.

[GarethA]

The QHY5 on that scope should be OK. You could try taking darks and calibrating PHD. I also found some of the noise reduction in the PHD software to be worthwhile. As others have mentioned what interval are you guiding at ? I often use between 3-5 seconds dependant on conditions and where it's pointing but I've never had a problem exposing any guide stars. 

Thanks - yes i redo darks each time I change exp length - will have a look at the noise reduction tool

[GarethA]

you might want to upgrade to PHD2 by the way, here - http://openphdguiding.org/

IIRC it does specifically have the QHY old version

ok brilliant - downloading now.

I've had the same thing that by trial and error I "could" connect in a couple of ways.... but none very satisfactory

i used to have all this sorted on my old XP laptop before it died!!  When i finally get this sorted I'm writing down every single driver version I have 

[GarethA]

ok PHD2 installed - latest V4.0 ASCOM QHY5 drivers installed.

I now get the option of QHY5 in the ASCOM camera chooser in PHD and when i connect i get that gain slider with the blue background that IanL mentioned.

Just pointing it at the horizon (with a lens cap with a hole in it) the image is PHD is MUCH MUCH better than it was with the old WDM webcam drivers.

Think we may have cracked it.

thanks all --  will report back next clear night!

[Astrosurf]

Thanks for that. If you're successfully using the old QHY5 could you possibly confirm which OS / software / driver versions you have?  

With this white out issue I'm now concerned that I've hobbled my QHY5 by using the wrong software.

Thanks a lot!

I can't find the CD but I've sent an email to Bern at Modern Astronomy where I bought the camera. He'll tell me which versions as I can't see them when I look in Program Files, except ASCOM which is Platform 6. Hold fire and I'll get back to you!

[Astrosurf]

Bern gave me this Website for the QHY5 drivers and software:

http://qhyccd.com/en/top/download/

Here's also the PDF instruction sheet that came with it. Have a look and see if there's everything there that you want. If not, please get back to me.

https://dl.dropboxusercontent.com/u/40828105/QHY5%20install%20notes.pdf

[GarethA]

Thanks a lot Alex - really appreciate you coming back with the info.

Will have a read through those docs and make sure I'm set up properly.

Thought I was going to get a chance to test it tonight but the cloud seems to be back!

[Astrosurf]

It's a pleasure. Let me know how you get on.

[GarethA]

Pleased to report that the problem is solved!

It was the qhy5 drivers causing the issue.

System was guiding happily last night on a number of targets using phd2.0 with 1.5s exposures - no shortage of guide stars in any area of sky.

Thanks for your help all.