QHY5

[wackyscot]

Hi all, ok had my 1st light with the guide cam, failed miserably:confused: I managed to do my alignment etc, then connected my cam and scope using the method on the info sheet from Bern. Success, cam connected, scope connected via st4, went through the calibration mode successfully, BUT when I watched the view from guide cam, the image was drifting badly right to left. I was guiding but getting the ping ping noise and tried a few exposures only to find massive star trails. I tried a new alignment, - same result. Disconnected guide cam and the star trails were still horrendous. I was doing some tests last week (unguided) and they were fine. Any Ideas

David

P.S. the alignment was done with cam and cables connected, would this be the problem, should I do my initial alignment, then connect cables???

[wackyscot]

As a PPS to the above, I spoke to a friend and he MAY have unwittingly solved this. I am using a 102mm Celestron as a guide scope with an erecting 45 degree diagonal, could this be the problem (the diagonal) ??????

i.e. it is correcting the image and sending the scope the wrong way???

David

[riklaunim]

GoTo 1-3 stars alignment is only for GoTo. For accurate star tracking - good polar alignment, balanced setup (with all the cameras).

For guiding with QHY5 I use PHD. It has some settings that can be matched if for example the drift is fast (as the resolution is high etc.)

[wackyscot]

The alignment appeared to be ok, balance etc I think is ok also. I was taking good images before I connected to the guide cam, The settings part may be needing looked at though hmmmm. Using PHD also and used the default settings, never went into the depth of the settings yet as this was my 1st crack at it.

David

[riklaunim]

What scopes are you using?

In the PHD settings check if "Dec guide" is set to "North". The app sometimes may turn it of if the calibration in PHD will partialy fail.

[wackyscot]

Scope is C8NGT - the calibration did seem fairly quick so the setting thing needs checking for sure.

David

[wackyscot]

Just checked and the setting was set to auto, changed to north now, are there any others in there I need to look at, sorry if I'm a pain, but like all newbies it's trial and error with these things lol.

David

[wackyscot]

Hi Again, I have changed my guide setup, and once again failed to guide properly. I went through all the usual checks, (cables kept from trailing, bolts all tightened etc) before, the problem may have been too much weight, so I have addressed that as you can see from my pics below. I have also posted 2 screen captures, I tried guiding through the st4 port and also through the handset. It went through the calibration etc but after a few seconds quickly lost the guide star.

I'm just learning be gentle lol.

Any help would be appreciated

David

[martin_h]

Both those screen shots show a low SNR, are you sure you wern't trying to guide through cloud? Pick a brighter star - but not the brightest, or were you trying to guide on a hot pixel - it happens!

[wackyscot]

I tried various stars of varying brightness, same results - sky was very clear also. I mucked around with the settings, but went back to defaults, all had the same result.

David

[swag72]

You're guiding with a QHY5 and a finderscope - yes?

[wackyscot]

Yes Sara went down this route as my previous attempts with a larger guidescope failed also.

David

[swag72]

I use a 9x50 finderscope and QHY5 - Here's my settings in PHD - it may help you. I generally get a pretty flat graph if you ignore the occassional gremlin that seems to get in the way!! Calibration wuse, it does it in about 9-10 steps - A great set up I think that works well.

[whirlpool5194]

Ok,

A couple of things that helped me crack phd. Increase your guide calibration from the default (its 750 I think) to around 900. Increase your RA Hysteris to 50%. Make sure your polar alignment is very good, drift align if you can. Slightly offset the balance in RA to the east (it helps keeps the gears in mesh).

I can guide my EQ6 and my 10" newt with a camera lens, so it can be done!!! Oh and check for backlash in your gears and adjust if needed. Hth

Wp

[wackyscot]

Thanks to all of you, thats very helpful

David

[adamsp123]

I am using Nexremote on my Vixen mount with a finder guider.

My settings are 90% 20% RA 600ms DEC cal step 2400ms takes about 20 plus steps to calibrate.

Using 3 sec integration time - I see you have 1 sec I think that is too short

min motion 0 yes ZERO - max I would use for finder 0.05.

Make sure that you have reasonable polar alignment, and yes pick the right star - no dead pixels or too bright a one.

If you still get big spikes do significant changes on the fly but only one parameter at a time to see what affect it has.....

[wackyscot]

Hi Pete, not sure what you mean by 90% 20% also do you mean 0.05 on the camera exposure setting?? I'm new to this guiding thing !!

David

[adamsp123]

Hi Pete, not sure what you mean by 90% 20% also do you mean 0.05 on the camera exposure setting?? I'm new to this guiding thing !!

David

Sorry - 90% agressiveness 20% hysteresis in RA

Camera exposure 3 secs - do not go much lower than 2.5 maybe or up to 4 secs

Minimum motion 0.05 pixel or zero!

Reduce star mass tolerance if it misses many loops - I use 0.4

ok here is a pic

[swag72]

Is your finderscope a 9x50 Pete? I ask as it is interesting to see other people's settings for what could be essentially the same set up.

[adamsp123]

Is your finderscope a 9x50 Pete? I ask as it is interesting to see other people's settings for what could be essentially the same set up.

Yes it is

[wackyscot]

Thanks again Folks very helpful info, all I need is a clear sky to try again lol - will keep you informed, fingers crossed

David