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Guiding with PHD via ASCOM



My first question to the forum so hope someone can assist. I have searched previous threads but cannot see one that answers my specific query. Forgive me if I missed one though.

I have set up BYN with my D7100.  I have PHD software for guiding BUT I control the mount and the camera via EQMod and BYN respectively with a USB connection to my laptop in my shed.  The guide camera is connected via USB NOT ST4. Stupid question perhaps but in guiding settings for BYN do I select PHD or ASCOM? I assume PHD should only be selected if using the ST4 cable and that ASCOM should be selected in my situation. In the later do I need to open PHD manually or will BYN still recognise PHD and use it. I ask as the "TEST" button is shaded out if I select ASCOM.

I understand that ASCOM\USB guiding is considered preferable to ST4. I am using Carte de Ciel for my Planetarium programme. Any help would be much appreciated. Many thanks.

Edited by GrahamFinch
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You are trying to guide only for now, not dither, correct?

If this is the case BYE is irrelevant.  BYE does not guide.

These are 2 methods of guiding, ST4 and pulse guiding via ASCOM.  You need to pick one.  The advantage of pulse guiding over ST4 is that you have one less physical cable... this is pretty much it.  

You seem to be at the start of your astro journey.  Keep it simple.  Use the ST4 cable to start and understand the basic process of guiding first.

Hope this helps.

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There is a lot of misunderstanding to clear up. I hope this helps.

In BYN, you select what application BYN needs to communicate with to initiate dithering between exposures. In  your case that is PHD (not ASCOM). This tells BYN how to dither between exposures.

In PHD, on the Connect dialog, you choose how to talk to the mount. In your case that would be either an ASCOM driver or the On-camera setting. For you I would assume that you have the EQASCOM driver installed to expose your mount to ASCOM through EQMOD. So this is one mount connection option. The other option On-camera would be used when you have the ST-4 cable plugged into the guide camera and the autoguide port on the mount.

I do not agree that guiding via ASCOM is better than guiding via ST4. They are both fairly equivalent. Choosing On-camera as the guiding method in PHD means that the camera is actually controlling the adjustment pulses, rather than the PC when you choose an ASCOM connection. However, as Guylain said, you do need the extra cable to connect from the guide camera to the autoguide port on the mount.

BYN offers 3 choices for dithering (PHD, Metaguide, and ASCOM). Note that these are for dithering, not guiding. So you misunderstood when you thought that since you want to guide your mount via ASCOM that you should choose ASCOM in BYN. If you are running PHD for guiding then you must choose PHD as BYN's Dither Provider.

Even though you will not be using direct ASCOM dithering, I will describe what it does. When you choose ASCOM as your Dither Provider in BYN you are saying that you are NOT GUIDING but that you want BYN to dither the mount directly through ASCOM. In order to use ASCOM dithering with BYN, you must have the premium license and BYN must be manually connected to the mount via the ASCOM Telescope panel before you start imaging. For this reason the Dither TEST button is disabled when ASCOM is selected as the Dither Provider.

BYN does not automatically start PHD. You need to start PHD, connect PHD devices, calibrate PHD guiding, and start guiding. Then you can connect BYN with PHD.

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55 minutes ago, GrahamFinch said:

Thanks for the reply. I would use dithering within PHD. I understand that BYN is just for capture but it obviously connects to and uses PHD. I assume from your reply that I need to just select ASCOM rather than PHD then?




Forget BYE for the moment and forget dithering for now.

Concentrate on guiding and for this you need PHD only.  Get confortable with this first.  Keep it simple and only takle one new item at a time.  Once you are confortable with guiding and you got this going then and only then you should introduce dithering.... and this is where BYE will come in handy.  So for now forget BYE and forget dithering.  Focon only on guiding with PHD and to keep things simple I would use the ST4 cable so start with.

Hope this helps.

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