New Beta Feature - AM5 guide speed settings adjustability

Kevin_A

My mount runs fine at an average 0.5rms but it does have a bit of sawtooth pattern when looking at the graphs. Currently my settings are 300-450ms max durations on both axis at 50% aggressions. It uses guide exposures of 1s and really does not get any better or worse guiding going to 0.5s.
Now that the latest beta is out for public testing I am going to be trying to reduce the sawtooth patterns I see quite frequently by trying the slower 0.25X guide speed. I know that reducing the guide speed rate by half would require doubling the max durations but is it also advisable to try using 0.5s exposures and keeping the max durations where they are? Should this approach reduce and smooth out the sawtooth pattern better than just dubling the durations and keeping it at 1s guide exposures. I know that some of this sawtooth might be due to seeing but will it help smoothing out the PE as well allowing me to reduce the durations even further.

ASIMount@ZWO

Kevin_A Looking forward to your try and result.

kaiyung

Kevin_A where can I get hold of the latest beta firmware and the change log?

Kevin_A

@w7ay they finally added this feature in asiair… what do you think about my prior question regarding using 0.25x

w7ay

Kevin_A what do you think about my prior question regarding using 0.25x

It matters if you are already guiding consistently (assuming no wind gusts) to better than 0.5 " RMS total -- allows me get down to 0.35" without breaking a sweat. I doubt it will do the ZWO mounts any good when they decide to go for the wild swings.

Chen

Kevin_A

w7ay mine does not have wild swings but rather the sawtooth pattern that i just want to reduce further… see if I can get it down to 0.4 consistantly. Prevoiusly you had posted about reducing the guide rate and multiple pulses per exposures to reduce sawtooth but I am unsure if a shorter guide exposure with a single pulse at a slower guide rate of 0.25x would be beneficial for reducing the peaks of the sawtooth patterns compared to 0.5x.

Kevin_A

This is my scenario in a nutshell…
I get very acceptable guiding from picking the brains of more technically oriented people in this forum and others. w7ay Has been a great provider of clues to help myself drop my guiding numbers by means of our discussions. I have improved my guiding mechanics by means of a bigger and better guide scope and camera, increasing gain to get more equal size stars etc. and i have reduced my max durations and aggressions based on my own mounts slope. This has gotten my guiding between 0.45-0.7rms consistantly depending on the size of my setup as my heavier scopes seem to do better. The one constant that I still seem to not be able to tame is what seems to be is constant small sawtooth shaped guide graph overshoots. No matter what size durations between 200-650ms or aggressions between 10-65 or guide exposures between 0.5 to 1s. I still see many 1-2 arcsec sawtooth corrections at the 0.5X guide rate all night long even with low pulse durations. I know that a MinMo of 0.2 made my guiding worse, so hopefully it is back to 0.1 so that it is not lagging and have to overcorrect, but I am hoping that a slower guide speed may decrease and smooth out my sawtooth patterns. I have been plagued with clouds now for over a month so I post here looking for more confirmation and direction that doing so might work when the clouds finally do clear. Maybe this is all my mount can do but it does not hurt trying new things that maybe one day I can help and pass ideas onto others that have similar issues. Cheers.

w7ay

Kevin_A I am unsure if a shorter guide exposure with a single pulse at a slower guide rate of 0.25x would be beneficial

They are "equivalent" if you use many short exposures. So, make sure that FPS is set to at least 2 FPS (and remember 12 stars plus 20 dB extra gain; it is essential with the louzy ASIAIR centroid algorithms), or the slower correction rate might not help.

Stop using gains like 100; start using large scopes and use gains like 300 to 400 (my favorite guide scope is currently a Vixen 55mm flourite). Just rememeber, increase gain to get 12 stars, and then increase the gain by another 20 dB. I have mentioned this repeatedly.

With my RST-135E, I could back the corrections off so that the max pulses are just dozens of milliseconds. Coupled with setting aggressiveness to less than 25%, it then gives me the "no worse than 0.35" total RMS." Most of the time, it averages around the 0.28" region until a wind gust hits. If you are not sure about what is caused by winds, get yourself a Netatmo wind gauge -- it uses ultrasonic sounds to measure wind speed/direction, and is very fast reacting to small and fast gusts.

Chen

Kevin_A

ASIMount@ZWO just waiting for the clouds to clear here in Canada!

ASIMount@ZWO

Kevin_A Wish clear nights always be with you

Kevin_A

w7ay i am using bigger guide scopes and higher gain and that is what got me to 0.45 to 0.6 rms average and my stars are always 12. Sometimes Asiair tries to use 11 equal weight stars and 1 huge one still and when it tries I stop guiding and restart it until it gives me 12 equal weighted stars. It even tries that with gain set high sometimes. I just hope using 0.5s at 2 frames per second at 350ms pulses with 0.25X guide speed it will reduce the sawblade from a roughcut to a fine cut saw blade.
Right now my guiding just seems like it loves to overshoot even with low aggressiveness and low max durations.

Kevin_A

kaiyung under the asiair forum discussions here, there is a link to the testfight download.