Gaps In Star Trails

[Liza]

I apologize if this is a duplicate - my message disappeared earlier today, while I was typing.

I have made three attempts to create star trails, using the ML intervalometer, with a Canon 7D, always ending up with great gaps in the light streams, no matter how short the inverval. Even with the ML 0 seconds "like crazy" setting, I get great gaps. I see such beautiful photos of this type online and I would like to achieve something near the quality I see here and other sites. For post processing, I used StarStax in gap-filling mode, but it doesn't seem to matter how I adjust the overlay/amount. For now, all I am interested in is the technique - composition/creativity, I can tackle later.
I have used the settings below, all with pretty much the same results.

ISO:      400     800   100   
Aperture:   f4   f4   f4   (largest for the EF 24-105)
Time:      30s   30s   30s
Focus:       M   M   M
Interval:   0s   0s   1s

I wasn't able to embed my example, but here is the URL:
https://photos.google.com/share/AF1QipMdbtmALguPejCX4CHasRVQeyRl6Tw_JTHH6KQ_2IdejDPHl9OyQG_NHM1dcpwsFw/photo/AF1QipP3QI6X1KNFVtoYaSflLYxiJGxJQdM-7EMRczCZ?key=QWV4Q2RGdXhmbExfWW1uc29qaU9TNk0zNTJJQ2ZB

Any suggestions would be greatly appreciated.

[Audionut]

Given your exposure time is 30 seconds, it looks like there's quite a delay between exposures.

Turn off all the noise processing things in Canon menu.

[Greg]

Six months ago, I tried with continuous FRSP (500D 10x60s):


With this hack will be better :
http://www.magiclantern.fm/forum/index.php?topic=12523.msg167874#msg167874

[Liza]

Thank you Audionut - there seems to be a marked improvement with the noise reduction turned off.
https://photos.google.com/photo/AF1QipNRl354u3LFahynIxTDulUikBMPbjhdhKHP1gr7

Greg, I will have to spend some time looking at full-resolution, silent pictures as this seems beyond me, at the moment.

[Levas]

Turn off long exposure noise reduction in Canon menu.
It's enabled by default, my guess is that this is causing the gaps.

Long exposure noise reduction takes another photo (without opening the shutter) with same exposure settings and uses it as a black frame to substract from the actual photo to remove noise.

[Audionut]

Your last link isn't working here, but I can imagine the difference it made.

Seeing that FRSP star trail really makes me want to use my camera more.  Someone should develop an app that slows the spin of this planet.......20% should be enough.