Trap close up

[Dennis]

Based on this assumption, with the Moon exposed for 10ms (= 1/100 sec) I would have expected a frame rate of around 100 frames per sec but my average was a miserable 12 fps in the example above.

Cheers

Dennis

[multiweb (Marc)]

Originally Posted by Dennis

Based on this assumption, with the Moon exposed for 10ms (= 1/100 sec) I would have expected a frame rate of around 100 frames per sec but my average was a miserable 12 fps in the example above.

Cheers

Dennis

Still doing some testing. Changing ports, will try another PC this arvo. FPS seems only related to specific resolutions from early testing. I found those log files too. and flat fielding. It was right under my nose. What a douche. Will post results this arvo.

[multiweb (Marc)]

Ok, moving a bit forward with all this. Figured out a few more things including flat fielding and dark subtraction.
Found the log files and the fps on the night was pathetic. ~1 to 3 fps. No surprise I couldn't even separate those stars. There's just barely a hint of them as a line at 11'oclok from the brighter one but that's about it.

I managed to get a sustained 25fps today on the bench with res ranging from 960x960, 1024x960 and native 1280x960. I went from under 1ms exposures up to 10ms no problem, from 100ms onwards the fps quickly drops to 15 then 10fps. Also played with the RAM buffering settings. Didn't seem to make a big difference. CPU usage is 50% on the dual core, HD speed is fine, so I can only conclude the bottle neck is simply the USB2.0 connection. A faster lappy or more RAM would make jack squat difference. I did the test with a 1.5m cable straight to the notebook. Tried 3 various ports. Killed all the background processes to make sure FC was the only thing running. Same result.

So if I can get around 20fps on the night I should be ok. Just waiting for another clear night now.

[Dennis]

Did an indoors run today with my 3 to 4 year old Samsung Ultrabook (Intel Core i7-3517U dual-core CPU that runs at 1.9GHz, Graphics are also handled by the CPU (Intel HD 4000), 8GB of DDR3 SDRAM, 128GB solid state drive (SSD)) and a USB3 connected external WD 1TB My Passport Ultra HDD which runs at 5400rpm.

I managed to get bursts of 128fps with an average of 118fps over 3,000 frames.

The ASI174MM and WD HDD were connected to native USB3 ports on the Ultrabook.

I opened the ZWO camera app (no recording running) and it showed that it was connected to a USB3 port with a frame rate of 128fps.

Cheers

Dennis

[multiweb (Marc)]

Very cool. USB 3.0 is a lot faster. Now the SSDs are much cheaper I'm considering getting one for my notebook. I checked a few gaming forums and I possibly could get a 25% gain in performance.

Found this interesting article on the point grey website and also some good generic trouble shooting tips on USB.

Got out again last night. Didn't get much higher fps. Around 18fps max, 10fps full res.

Decided to use the AO later around 22:00 which was a bit of a challenge to set up between remembering which cable was which in the dark and what software to use. I ended up using PHD2 which I've never used before. The calibration and AO detection etc... was a walk in the park. You just press buttons and follow the prompt. Guiding results not so good though. Lots of latency.

Got a bright star around the trap and managed to have the lodestar lock at 0.1s on a good guide star. Corrections weren't even close to 2 per second though listening to the plate. I recall getting up to 5Hz with the native Starlight Xpress program. I captured 10s and 5s subs in 16Bit FITS on Nebulosity 3 using the ZWO-ASI ASCOM driver. That seems to work best I also tried the Microsoft WDM setup as well and that proved to hang all the time.

Then moved on to the cone nebula thinking I could try to do the tip of the xmas tree. Good luck with that. Moon glow was a bit of a nuisance. I got some stars that I think are in the field but no neb. I'll have to platesolve to see where I ended. The fov of the 120MM is so tiny it's hard to see where you land even with an "accurate" GOTO. Also tried to go to the HH. The top of the head should have fit the FOV. Couldn't find any guide star. Probably because of the sky glow.

So ordered two active USB extensions from Lindy and a SanDisk Extreme PRO 240 GB Internal Solid State Drive see if I can boost the transfer rate. It has the best reviews for write rate on Tom's hardware. The plan is to have the ASI on its own USB port. I suspect it clogs all USB traffic to the Mount Hub Pro from HitecAstro, including guiding corrections and AO, which goes through the GPUSB. So ideally it should works as follow:

Video Cam on USB2.0 port by itself.
Mount Hub Pro on another port.
If I have to use the AO I'll use ST4 from the lodestar rather than GPUSB as my new Gemini box allows for that. Never tried it as I'm still using the old way from my old box. Maybe time to move forward.

Will post new pics when I've processed them.