Guiding advice

[Rustmonkey]

Ok guys and girls,

I have just got myself set up with my first imaging rig.

i bought the SW ST80 to use as a grab and go but also with this setup in mind. I have an SPC900 (Not LX) and believe this is a favourite for using as a guidescope hence how i have it setup, however, not sure where to go from here. how do I use it? What extra do I need to get it up and running.

I have downloaded PHD, I have EQMod but not set up properly yet. Do i need a connector for the ST4 or can I run the webcam straight to the Laptop and use the software I have. Are there and tutorial on here to set this up.

Any advice most welcome.

Kind Regards

Craig

[IanL]

Sorry can't help you with the actual camera -> PHD bit, but you do not need a cable for the ST4 port.

I am assuming you have an appropriate interface to connect the EQMOD software on your laptop to the HEQ5? You will either need an adaptor (make or buy one) to connect from USB direct to the hand controller port on the mount, or if you have a recent SynScan handset you can use a cable to connect the PC via the handset in "PC Direct" mode. Start here if you are not sure:

http://eq-mod.sourceforge.net/reqindex.html

Once you have EQMOD up and running, you can then connect PHD to EQMOD very easily. You just start up EQMOD and connect it to the scope, do all your usual set-up/alignment, etc. Once ready to start guiding, you fire up PHD, check that you have 'ASCOM' selected in the 'Mount' menu on PHD, then click the 'Telescope' icon button at the bottom of the PHD window. This should fire up the standard ASCOM 'chooser' dialog box from where you select EQMOD as the mount and you're good to go.

I have no idea if PHD supports your particular camera, but assuming all the drivers are installed and working it is easy to test. Fire up PHD, click the 'camera' icon button and choose your camera from the list. You may have to google around a bit for the exact instructions for a given model. Then click the 'circular arrow' button in PHD and it should start looping exposures according to whatever you have set in the exposure dropdown at the bottom of the screen. Try waving your hand in front of the camera and you should see it get darker and light which confirms it is working.

The only issue is this a non-long exposure camera. You may struggle to get good guide stars with an ST80 - I reckon you'll be okay with really bright ones but not necessarily find anything bright enough in the field of view of whatever you want to image. Start with some really bright ones and experiment from there. The other issue with ST80 type scopes is back focus. Try getting focus on a distant object in daylight with the webcam first as this is less frustrating since you know you will be able to see the target! You may find you need an extension tube to get more back focus, things that work:

- Put it in a diagonal (not recommended for imaging/guiding as it will probably flop around too much), but okay to test.

- Unscrew the lens from a barlow and just use the tube as an extension.

- Buy a set of extension tubes (not too expensive).

You'll probably end up buying a guidecam soon enough, QHY5's are cheap and effective, but there are plenty of others out there for not that much money. Or maybe do an LX mod on the camera, but probably more hassle than it is worth these days.

The ST4 port is only used if you have a guide camera with an ST4 compatible output port. You just connect a six-way straight through cable terminated with 6P6C connectors (though check the pin-out diagrams as some models change the order of pins and need a different cable). There is no real benefit to the ST4 port over using ASCOM guiding via EQMOD, except if you are operating without a laptop, but these days can't really see how you would be imaging without one to be honest!

[Rustmonkey]

thnx...i have the Hitevastro box attached to mount and a 5m A to b USB cable to connect to the laptop but was wondering if I just plug the SPC900 into another port on the Lappy as if i was imaging using sharpcap. if so then I guess its just connecting it to EQmod and PHD?

[IanL]

Yes that sounds correct. In terms of cabling you should just need a USB from the computer to your Hitec box which in turn goes to the Hand controller port on the mount, and a USB from the computer to the webcam. You don't need anything going to the ST4 port on the mount (and in the case of the webcam, there isn't an ST4 port at the camera end anyway!)

Personally I just have a small (powered) USB hub velcroed to the side of the motor housing (the big flat area on the side of the mount just to the right of where the cables connect to the mount in your photo looks ideal). I also velcro the various power supplies to one of the mount legs and route the cables to near the USB hub and then onwards from there, along with a USB extension cable from the leg to the powered hub. The rest of the cables are then just run from the USB hub to the scope's connector panel and the cameras; obviously you need to allow sufficient length/play in the cables to allow for the full range of motion in RA and Dec without pulling/breaking the cables want watch out for snagging on protruding adjustment bolts.

Once I am happy with my routing I tend to bundle up the different sets of cables with cable ties and then wrap them in spiral cable wrap. This makes a set of neat umbilicals which spider out from the USB hub location on the side of the mount, and one umbilical carrying the mains power and single USB connection from the laptop to the tripod leg). The laptop and four/six way extension socket are housed in a plastic tool chest with a shelf I have fixed inside for the laptop.

This cuts down on the number and length of cables running from the computer to the mount and around the mount itself and makes it easy to get everything from storage to garden in a few minutes. There ares less opportunities for things to get snagged, disconnected or tripped over and it makes set-up and breakdown really easy. Just disconnect one USB cable from the computer and the power/USB cables from the cameras and you have the whole thing apart in a minute (bit harder if you need to separate the tripod and mount head which I don't).

Once you have your cabling sorted, I'd break it down in to several stages to test everything is working during daylight, as it's a lot easier than trying to figure it out in the dark:

1. Set up EQMOD and test connectivity to the scope. You should be able to use the NSEW buttons in the EQMod dialog to test slewing the mount around to make sure the laptop is able to control it. Close down EQMOD.

2. If you are planning to use a planetarium application to control the scope, that is the next step. Basically set up the planetarium, connect it to EQMod and do some Gotos to make sure it can drive the scope. (Note, the EQMOD dialog should be fired up by the planetarium, or in the case of Stellarium you use the separate StellariumScope application which fires up both the planetarium and EQMOD for you). Again close everything down.

3. Connect the webcam and start up PHD. Use the PHD 'camera' button to connect to the camera. Press the circular arrow button to set it looping exposures. Test camera connectivity by covering/uncovering the camera to see if it goes dark/light. If not you may need to play with the camera exposure/gain settings (either within PHD or possibly in the dialog that appears when you connect to the camera depending on how the particular driver works).

4. Connect PHD to the scope using the telescope icon button. Choose the 'Manual Guide' button from the tools menu. You will now have NESW buttons to press with which you can verify whether PHD is able to drive the scope. Bear in mind that you will only be moving at your chosen guiding rate and as such this isn't going to produce a noticeable movement of the mount/scope in in daylight. What may work is to set the scope to sidereal tracking rate in EQMOD, then listen to the motor sounds as you press the manual guide buttons. You should hear a very faint but clear change in the motor sounds as you press the different guide buttons. If you're not sure, the only way to test this is to look through the scope at a star (or a very distant daylight object) and test - you should see movement in the appropriate direction if you keep the guide button held down for a while.

5. Now shut down PHD, etc. and try to connect everything one after another as described at 7. below. Best to test this during daylight as you may find that your setup prefers the different components to start up in a different order than I have described (you can try out the polar and star alignment processes, but obviously you can't point at anything real so just pretend you have stars to aim at!). It doesn't make a huge difference, provided only one instance of EQMOD is started and all the software is talking to it.

Assuming all your daylight tests work you can be reasonably confident you have no fundamental issues with the set-up when you come to use it for real.

6. Now wait for dark so you can test your webcam/guider's limits.

a. Set up your scope, do a reasonable polar alignment and set it to sidereal tracking so that you can keep a star centred reasonably well.

b. If you are able to, use eyepieces to get the main scope and the guidescope/finder guider aligned so that the same birght star is centred in both fields of view. This will make it easier to get/keep the guide star on the camera chip when testing.

c. Now put the webcam in to the guidescope and start PHD. Connect to the camera (don't worry about the mount connection for now).

d. Connect to the camera and start looping exposures. Focus the guidescope (likely to be different with a webcam than the eyepiece and it is easy to think you camera isn't centred on a star or the exposure is wrong when you just haven't focussed - done it loads of times myself!)

e. Try different exposure/gain settings for the camera until you get a nice bright star image - you don't want the star to be saturated (overexposed) so you may need to turn down the gain or de-focus slightly (PHD guides better on a slightly defocussed star image than a fully focussed one).

f).Now slew to a fainter star and repeat the process until you figure out the faintest guide star your rig can work with.

7. You're good to go. The typical imaging start up process is:

a. Set up the scope, level and balance it.

b. Start the planetarium (or stellariumscope if using). Connect to the scope so it launches EQMOD.

c. Use the EQMOD polar alignment tools to polar align.

d. Start sideral tracking.

e. Slew to your first alignment star, centre it in the eyepiece using the EQMod slew buttons (or much better get a wireless/wired gamepad!) Do a planetarium 'Sync' to enter your first alignment point in to EQMod.

f. Repeat for as many alignment stars as you plan to use. (Personally I don't bother with a three point alignment, I just go to a bright star near my imaging target, center it and do a sync. Every time I go to a new target I do the same and just build/improve the model as I go).

g. Now you start PHD. Connect to the camera first and take some test exposures as described above.

h. Then connect PHD to the scope. Pick the correct EQMOD entry in the ASCOM 'chooser' dialog that pops up and it should just connect through the existing EQMOD instance that is already running. If it tries to launch a second EQMOD instance (i.e. a new EQMOD window).

i. Set up your imaging camera, start up your capture program and set it up as usual. Slew to your target and frame and focus it.

j. Now in PHD you start looping exposures with the webcam. You may need to play with different gain/exposure settings etc. until you get a guide star.