First autoguider help

[killswitch]

New year new gear. Im looking at getting into the realm of autoguiding with PHD2.

Im choosing between the QHY5L-ii, Starshoot Pro & AS120 as a starting point. I know they all use the same high QE mono sensor.

Are there any key differences like driver/software support?

I also plan to do some planetary imaging with it.

[glend]

Hi Edison, I went through this last year. I run a ASI130MM as my guide camera sitting on a ZWO 60mm guidescope mounted on a Skywatcher guidescope mount. I tried using PHD2 initially because it is regarded as very easy to use, but it does not work well with high frame rate video camera's like the ASIs (can't comment on your other camera choices). After weeks of frustration trying to get PHD2 to work reliably (it just kept dropping out), I moved to Metaguide and can say it has been fantastic. Metaguide is designed for high frame rate video cameras and is very easy to setup and adjust, in fact it worked right away when I started it the first time. It will configure itself for the ASI camera if you select it. Metaguide also is much quicker to calibrate on stars than PHD2 (in my experience). I haven't tried planetary imaging with my guide camera. As you would remember I use a Canon 450D as my imaging camera. I have never had a Metaguide drop out once it is set up and running and tracking a star (assuming a cloud doesn't get in the way), and that includes long all night runs, (obviously meridian flips do interrupt things).
I am sure you will hear from many PHD2 people signing it's praises but for me it was a pain to setup and get to stay on a star.

PS I highly recommend the Skywatcher guidescope mount, as it makes aiming the guidescope so much easier than the common ring adjusters on many guidescopes (my guidescope/camera would sometimes slide down the rings when adjusting the aim with the ring screws, and directionally three rings are not very intuitive). The Skywatcher guidescope mount is not light, it does add some weight but is very well made and provides good X and Y axis control. I started out with an Orion 50mm guidescope (the one without the focuser) but found it a pain to use compared to the ZWO guidescope which does focus. So get a guidescope that can focus, as opposed to the parafocal ring solution, its easier imho.

Your welcome to see my setup working at the next Bretti outing.

I bought the ZWo guidescope from Aliexpress (ZWO has a store on there) and they ship direct from China to your door pretty quickly compared to US sources). Here is an ad for a ZWO guidescope kit from a US supplier:
http://www.highpointscientific.com/zwo-60mm-guidescope-kit-60280

[peter_4059]

Hi Edison. I'm using the AS120M with PHD2 without any issues. Very happy with how it performs. I went for the AS because it has a t thread to make a rigid attachment to the guide scope

[Amaranthus]

I went with the ASI120MM-S. I chose this over the QHY because I wanted the faster framerates that come with having a USB 3.0 connection. I also think the body of the ASI cools passively a little better than the gun-barrel designs.

[killswitch]

Thank you for the insight



Interesting, i see it also has a collimation tool

I will install metaguide tonight and test it out with an old logitech webcam.



Good to hear. Do you have any issues with the frame rates at all?



Is the faster USB3.0 connection only an advantage for planetary imaging?

I agree the ASI body looks like it can dissipate heat better

[peter_4059]

none - works perfectly for me.

[SamD]

I use the colour version of the QHY5L-II for both guiding with PhD and for planetary imaging. It was useful to have the colour version of the webcam for planetary imaging before I had LRGB filters. Obviously, it would be better to get the mono version if you already have a set of filters.

PhD and the QHY5L-II work pretty well together (using on-camera ST4 guiding). Apart from the odd galaxy target with only dim stars nearby, I get plenty of guidestars at 1 sec intervals using either a Skywatcher guidescope or Skywatcher ST80, normally guiding at about 1000mm focal length.

I couldn't get MetaGuide to work as reliably as PhD. When I did get it working it was no better at guiding.

[killswitch]

Will choosing a colour sensor compromise its ability to pick up stars as a guidecam?

The reason i ask this is because i plan to use it on an OAG for my C8 in the future.

[SamD]

In my experience, the Bayer matrix in a colour QHY5L-II doesn't affect guiding with a guidescope to any real extent, as long as you have a fairly low f ratio. It's plausible that guiding on a red star might make the centroid jump about through a Bayer matrix, but as long as the guide star covers more than around 10 pixels on the sensor it's fine. I've ran a numerical simulation to see how the centroid would move about with a Bayer matix, and it's really not very much even on red stars.

With a OAG (and high f ratios) guiding is likely to be more difficult with a colour webcam. You're losing around one third of the light with a Bayer matrix and you tend to need as much light as possible with OAG at high f ratios in order to get a guide star. My guidescopes operate at around f/5 so that a colour webcam is fine. Dropping down to guiding at f/8 I would need a mono webcam to get the same number of guidestars, since 8x8 / (5x5) is roughly equal to the factor of three you gain with mono vs colour.

[traveller]

Just thought I jump in here. I have a QHY5II and got this M42-1.25" adapter off eBay and it works with M42 threads on OAGs.
http://www.ebay.com.au/itm/New-M42-to-1-25-1-25-inch-Adaptor-anodized-aluminum-Telescope-Adapter/321097986680?_trksid=p3693.c100102. m2452&_trkparms=aid%3D333008%26algo%3DRIC .MBE%26ao%3D1%26asc%3D2014021212124 9%26meid%3Dc162533c815c45b588dee7a7 8cab179f%26pid%3D100102%26prg%3D201 40212121249%26rkt%3D4%26
Bo

[ZeroID]

AS! 120mc with Metaguide works for me. Can't seem to get PHD(2) to work somehow. Between that and BackYard EOS suddenly I can image all night.

[glend]

Ditto, my setup is very similiar. Love Metaguide.

[Amaranthus]

There was a problem with PHD2 and the ASI cameras due to the ASCOM driver, but that is now fixed (just update). They work fine together.

I think MetaGuide is overall an excellent guiding package, in some ways better suited to CMOS guiders that can do fast frames, due to its use of centroid averaging. BUT (and it was a big but for me), it didn't integrate with my particular capture software for dithering, so I typically use PHD2.

PHD2 has simply the best drift alignment tool out there too.

[killswitch]

Thank you guys for the information

I've decided to go with the ASI120MM and a 50mm finderguider to start with. This setup easily attaches to my ED100.

I've been testing out simulator PHD2 and Metaguide using a webcam. Both feel like very capable software.

Any suggestions on what settings to start off with?

[Amaranthus]

Maybe start with PHD2, since the polar align tool is also well worth using, and it is really simple to setup and calibrate. Metaguide allows for potentially better performance, so I'd try that too, maybe down the track.

[multiweb]

Good call. With a 8x50 finder I typically chose from 2500 to 3000ms for calibration steps. Whatever gives you 15 samples both in RA and DEC. Max RA/DEC corrections anything from 250 to 1000 and guide every second or so.

[killswitch]

Thanks Marc i will start off with those settings.

Ive received the guider and scope along with a new T-adapter and lens.

Will test it this weekend and then take it to Wiruna the week after.

[Camelopardalis]

Nice one Ed! Look forward to seeing it in action... :D

[killswitch]

Hopefully soon Dunk...not a clear night since i've received the guider.

So far i've lined up the guiderscope to the main scope and set the rough focus. I also played around with firecapture and found my atom netbook can capture up to 32fps at full res (max is 35fps)

I do have a question re PHD, do i use 2x2 binning or native res for a 50mm finder?

[Camelopardalis]

If the forecast is to be believed, we may have 2 or 3 heading our way this weekend... ;)

[killswitch]

Okay i did a test run.

How does my graph look? The seeing was shocking tonight.

[peter_4059]

looks pretty good. try increasing the guider exposure to 2sec if the seeing is poor so you don't chase the seeing.

[glend]

I'd disagree with that advice when using an ASI camera. I have never had to increase exposure rate beyond about 500ms. Don't forget your using a high frame rate video camera.

The graph looks ok to me well the bolt trace anyway. As I use Metaguide the graph is a little different but importantly you want to get it contained within the +-2 range if you can.