AA5 Guiding

[malc-c]

Mick,

I've fired off a couple of mails - see what they say !

[Gina]

I've been trying to get guiding going with AA5 but it doesn't see the camera - the only choice is Simulator. I'm guessing I'm missing a driver.

[JamesF]

I think there's a separate driver for AA5 for the Lodestar. You probably need to install that first.

James

[JamesF]

FWIW I was also trying to get guiding working last night, at least in terms of making sure AA5 could see cameras, get images and so on.

In the process I discovered that the new camera UI (v5.10, downloaded from their website) supports two ASCOM cameras (one to image, one to guide), though it does also seem to cause AA5 to crash if you close the application by clicking on the "x" on the window rather than by using File->Exit. I also discovered that there is now an ASCOM driver for my ASI120. I'm hoping therefore that in the short term I can guide using a finder-guider based on either my Firefly MV (which has an open source ASCOM driver), the ASI120 (which I'd need to make a bespoke adaptor for) or my LX-modded SPC900, in order of preference.

I'm having trouble at the moment though because I can't get AA5 to display the image from the guide camera. I think it's getting the image ok, but for some reason it doesn't cope well with an image of the view from my window, perhaps because it's too bright or something like that. It's probably doing some sort of transform on the image before displaying it. I need to get that sorted out to have confidence that it's really working properly before trying it for real.

James

[JamesF]

Bah. Frustration City, Arizona. I can get a picture out of the Firefly with FireCapture, but it won't reach focus in the guidescope. The mount for the lens is too long. I shall have to take the camera apart and find another or cut the mount down.

James

[JamesF]

By removing the locking ring to allow more inward travel for the objective and cutting down the board mount to allow the sensor further "in" I can get the Firefly to focus in my 9x50 finder on a target a mile or so away.

The images I get when I click "focus" or "guide" in AA5 however appear totally black. Unless I put the lens cap on, in which case they're noisy. I suspect this is something to do with AA5 setting a relatively high gain and applying a transform to the image, taking a completely blown out frame to entirely black in the first case. Unless I can work out how to turn that off I think I may not be able to make any further progress during the day.

James

[Gasman]

HI guys

Only just read this thread as I too have been getting a bit hit and miss guiding with AA5 (mainly in Dec!) and it never occured to me that EQmod would need tweaking too . I`ve just been trying the AA5 guiding settings and playing about with those . Yes there is a Lodestar driver for AA5!.

Cheers

Steve

[JamesF]

Why would you use EQMOD as well as AA5 for guiding? I can't work that one out.

James

[Gasman]

After watching Chris`s video it seems that AA5 uses the Eqmod driver therefore allowing further tweaks. Up to now I`ve only been adjusting AA5`s guide settings which may have been fighting against Eqmod`s settings. Have to start using me Dobs - much easier

Steve

[chrisshillito]

Why would you use EQMOD as well as AA5 for guiding? I can't work that one out.

James

AA5 doesn't may calculate and issue guiding corrections but it doesn't actually implement them at the mount level - EQMOD does and it provides a few parameters to allow users to change that implementation.

Chris.

[JamesF]

Ah, right, I think I see. EQMOD provides the ASCOM interface for the SW mounts for AA5 to use?

James

[chrisshillito]

Ah, right, I think I see. EQMOD provides the ASCOM interface for the SW mounts for AA5 to use?

James

Yes, EQMOD is both ASCOM driver and handset replacement for SW mounts. If pulse guiding via ASCOM then it is EQMOD that adjusts the mounts tracking rate to implement the guiding correction.

Even if guiding by ST-4 EQMOD, still has a minor role to play as it provides an interface for the user to set the guide rate.

Chris.

[andyo]

Beat me to it.

I like the AA graphics because unlike the usual line graphs (which it does also provide) the target of circles with the record of guide hits is great for interpreting certain trends. The classic is the double set of blobs, where there are two distinct centres of guide hits with a gap between them. This is a sure sign of backlash and can usually be fixed by running a little heavy on the east. Although very accurate, my Takahashi mount is sensitive in this regard.

As well as reading the manual I'd advise you to look at the little window with all those parameters and make sure you think through what each one of them means. This will allow you to see what the mount is and isn't doing.

It can be worth looking at which way the Dec error is being corrected (Dec+ or Dec-) and disabling the direction that is not needed. Genuine Dec corrections will always go the same way, the way determined by your polar misalignment. By disabling the other direction you reduce spurious input from the guider.

In bad seeing go for longer subs and increase the 'Don't guide when < ' value to avoid chasing the seeing. Note that there is no need to guide at less than the pixel scale at which you are imaging. You are nudging the mount for no good reason.

You'll get there but it's best to get your head round what the dialogue boxes are doing.

Olly

Hi,how do you disable one of the dec directions I cant seem to find any way of doing this and there is no mention of it in the manual

[stargazerslivingroom]

The settings you have in AA are a bit weird. Basically you haven't been guiding at all in DEC ....

Through the letters ....

A .... Once AA calibrates sometimes I find DEC will drift off. I get this after a meridian flip and have to check the INV box so AA guides the correct way. You'll see it if it happens - easy to see and easy to remedy. AA I believe doesn't actually know which way is up when it calibrates so in future once you start guiding just make sure that the INV box is checked if need be. More on this later ....

B .... This box is set to that any movement UNDER 0.1 of a pixel is ignored and no corrections are made. Try lowering that a bit to 0.05. The figure you will end up at (shown in the left of of the guiding spor graph) might be a lot higher than that in which case you could raise it a bit in future but at least give it a chance to guide out small errors.

D .... (Sorry its not alphabetical). This serves the same function as B.

C .... Where you have screwed everything up. The figure shown in this box represents the limit of guiding. In this case once the guide star moves 0.5 pixels away from its original position AA will not guide. This is very useful when clouds drift through and dim or obscure the guide star. It means that the mount won't go chasing something and it works pretty well. Unfortunately with the setting you have there it means that the guide star has moved over half a pixel from its original setting and so AA has stopped. That value really needs to be a lot bigger. I think the recommended value is 4 - I use 2.

Now I think your DEC guiding needs to be inverted because if you look at the DEC graph you will see that it has motored away until it has hit the +1 pixel line where because this is what you have set is the limit of guiding (the value in Box C) AA has stopped shoving in corrections. DEC has then just sat there. Look at E: you can see that DEC guiding has drifted away from the centre and then DEC is just a clump outside of the 1 pixel line. RA is fine.

So ... you need to Check the INV box on DEC guiding. (A)

Decrease the RA limit ( to 0.05 to see how fine you can get it.

Increase the Drift box © to say 2.

This should make the guiding run quite happily. You can then fine tune it in realtime in EQMod by using the Pulse Guide Width Monitor.

Please come back with your results

When I click where it says Posted image a "window" opens but no image...Anyone know why?

Steve

[andyo]

I think its because the image has been removed

[malc-c]

Whats interesting is that since starting this thread the target feature and graphs that I liked has been incorporated in PHD2, which is free.

[ollypenrice]

Hi,how do you disable one of the dec directions I cant seem to find any way of doing this and there is no mention of it in the manual

Click on 'Current' in the screen grab I posted and you have the option to disable the guiding selectively.

Olly

[JamesF]

I was having a lot of trouble getting AA5 to guide this evening, but I shall follow some of the suggestions in this thread and have another go next time.

James