Dithering with a self guiding camera?

Sequence Generator Equipment Compatibility
1

Hi all,
I’ve been toying with the idea of someday getting a self guiding autoguider like the SBIG SG-4 that does not require an interface with PHD. Is there a way to dither with SGP using self guiding cameras?

Stuart

2

You can use the “Direct Mount Guider” which will nudge the mount a given distance. However it’s very likely that your auto guider would bring the mount back into position or completely lose the guide star.

Using a guider that the software can’t control also means you miss out on this like:

  • Automatic centering
  • Automatic meridian flips
  • Automated slewing
  • Pretty much anything that requires the mount to move

Those stand alone guiders are primarily geared towards folks using a DSLR with an interval timer and no PC attached. Just out of curiosity what is the draw of this guider as opposed to using something like a Lodestar?

Thanks,
Jared

3

Hi Jared,
Thanks for the reply, and you answered the question perfectly. The appeal to me is having one fewer program running in the background (PHD can sometimes be buggy for me), and one fewer cord to keep track of. Also, the idea of push-button autoguding appeals.

At the moment I use a Lodestar and it’s fine. I’m just musing–every good astrophotographer worth their salt is always thinking about the next piece of equipment to buy. :smile:
Stuart

4

Hi Stuart,

I hope I’m not going off on too much of a tangent responding to this part of your post.

I would urge you to report your PHD issue whatever it is. If you do, there is a good chance that the PHD2 developers will be able to fix the bug or otherwise improve PHD2 (if it is a usability issue and not a bug.) Getting the bug fixed would not only benefit you but also all the other PHD2 users who might run into the same problem. Here is a page with instructions for reporting phd2 issues.

That is our ultimate vision for PHD2. Any insight from our users on what is NOT push-button simple is feedback we would take very seriously.

Andy
PHD2 developer

5

Hi Andy,

I’m so sorry, I was lazy in my writing, and I apologize. PHD2 was fine. My problem was my USB connection–and I’d get intermittent freezes of the program because all of a sudden my computer wouldn’t recognize that it had a camera attached. That would result in a Windows freeze and I’d have to ctl-alt-delete out of the problem, and then restart my imaging run.

I didn’t report the issue to the PHD2 Google forum because I knew it was a hardware issue causing a software issue. Ultimately I got a new laptop and things are better.

But it got me thinking, what if I could avoid the USB completely and just have a stand-alone camera? Also, I have a friend with one who uses SGP, and he was asking me, so I thought I’d ask here.

Stuart

6

Hi Stuart,

Thanks for the info. Glad to hear you got your problem resolved.

Coincidentally, one of the major changes in the most recent development builds of PHD2 is prevention of PHD2 hangs when hardware stops responding. PHD2 will now detect the dropped communication and disconnect rather than hanging, so it should no longer be required to ctrl-alt-delete when hardware stops responding or refuses to connect.

I have never used one of those stand-alone guiders. I have a friend who uses one of these with his DSLR and likes it for when he is travelling and imaging without a laptop.

Andy

7

Cool, I’ll download the latest build.

8

Sorry Andy,

That was lazy writing on my part. My problem was with my USB port. What happened was that in the middle of a calibration run it would all of a sudden disconnect and then PHD would freeze, causing Windows to freeze. The laptop was ancient and slow so I got a new laptop and things are better.

Since the problem was clearly my hardware causing a software freeze I didn’t bother requesting help on the phd forum.

Stuart