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First light with ASI 174

Zakalwe

By Zakalwe
in Imaging - Solar

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Zakalwe

Zakalwe

Posted
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Yesterday was an exercise in frustration. Spots of blue sky with rapidly moving clouds. Rubbish seeing when the skies did clear for a minute or two due to the high wind.

I only managed to get a single shot before I had to pack up.

17698757316_c1c8480664_b.jpg

Quark chromosphere, ASI 174, Altair 115mm triplet. Stacked in AS!2, Lucy Richardson deconvolution in Astra Image. Final processing in Photoshop.

Thoughts on the ASI 174? It's very, very fast and needs a fast system to keep up. I was using a dual-core Intel chip at 3.2Ghz, 8 Gb of RAM, a 256Gb SSD drive for the operating system, a 2TB HDD and a 1TB external 7200RPM USB3 disk. When recording to the internal HDD FC kept losing the connection to the camera and crashing. Lots of dropped frames. Using the external USB3 drive was a bit better, though still flaky (I was also having to use a USB3 PCI-E card as the PC didn't have USB3 ports).

I ended up having to get another internal SSD drive, otherwise the camera was swamping the system. I would have thought that the external 7200 USB3 drive would have kept up, but it couldn't. Using a 1024 x 768 ROI it could manage it, but full-frame it crashed and burned.

Oh, and you will need lots of disk space. At full chat, a 60 second full-frame 16-bit avi ends up at nearly 10 Gb!

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dazzaa1966

dazzaa1966

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Absolutely stunning images Stephen. Your thoughts on the

ASI174 were very informative. For the amount of disk space required as given me second thoughts about buying this. For know I think I will stick with my PGC.

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Zakalwe

Zakalwe

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Great first light. I tend to limit my stacks in terms of frames, not time, as this gets more consistent results. After all, the ASI174MM can capture in ten seconds what took my DMK21 9 stacks of 40s or so.

I do the same Michael, on solar. I see no real point in capturing thousands of frames over minutes, especially as the solar feature move so much. A few hundred frames is ample, especially if the gain is low.

Lunar imaging is a different kettle of fish as the features are static, and more frames really help to lower the noise.

The ASI is so fast though, it makes capturing large number of frames very easy.

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DrRobin

DrRobin

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Stunning Stephen.

As hardware improves, so does the software, so no problem in pushing the boundaries. It's a viciuos circle, but nice to ride the upwards curve and just goes to prove that yesterday's exceptional is tomorrow's norm.

Robin

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Zakalwe

Zakalwe

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Thanks all. One thing that I can see the need for is good flats and/or a way to ensure that everything is orthogonal. There's clear Newton Rings in these images (the bands of light and dark can be seen). I'm pretty sure that I can dial these out, either with flat - fielding or getting the camera and Quark screwed together.

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Zakalwe

Zakalwe

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I think so Michael. There's another thread on here about the thread types on the rear of the Quark. I've managed to bodge a method which gives me a screwed connection to the camera rather than the crummy single clamping screw that comes as standard. I also drilled and tapped two extra clamping screws into my 2" extension tube which should also take another source of flex out of the equation. It should also be possible to get a screwed connection between the focuser and the front of the Quark - hopefully without spending a fortune with TS!

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The Admiral

The Admiral

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Wonderful images.

Having no experience of using dedicated astro cameras like this, can you tell me please whether the frame rate can be controlled other than by shutter speed? In other words, if ones pc/storage media can't keep up with the information throughput, can the frame rate be lowered to match, independently of the exposure setting?

Ian

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Zakalwe

Zakalwe

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Wonderful images.

Having no experience of using dedicated astro cameras like this, can you tell me please whether the frame rate can be controlled other than by shutter speed? In other words, if ones pc/storage media can't keep up with the information throughput, can the frame rate be lowered to match, independently of the exposure setting?

Ian

There are ways to throttle it back, by varying the USBTraffic variable. Generally though, if you set the exposure to 50 FPS, then the camera will output 50 FPS. If the recording system cannot keep up, then frames will be dropped. If you set the recording limit to, say, 500 frames, then the system will keep going until 500 frames are written to the disk. If you select, say, 30 seconds, then the recording will stop after 30 seconds regardless of how many frames were written to the disk.

Its best to ensure that the recording system can keep up with the camera though. These cameras are becoming faster and faster as the sensors get more sensitive, grow in size and the electronics improve. They can easily exceed the bandwidth offered by USB2. USB3 offers 5Gb/second (if it actually delivers this in the real world is another thing though), and Gigabit Ethernet even higher speeds. I'd expect to see more and more cameras to use Gigabit Ethernet as the sensor size increases. The slowest part is now, no doubt, the hard disk recording systems. SSDs will be the way forward as capacity increases and price decreases.

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msh1

msh1

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I think so Michael. There's another thread on here about the thread types on the rear of the Quark. I've managed to bodge a method which gives me a screwed connection to the camera rather than the crummy single clamping screw that comes as standard. I also drilled and tapped two extra clamping screws into my 2" extension tube which should also take another source of flex out of the equation. It should also be possible to get a screwed connection between the focuser and the front of the Quark - hopefully without spending a fortune with TS!

hi zakalwe i went to flo yesterday got one of these http://www.firstlightoptics.com/adapters/baader-adapter-t2-female-to-m48-male-2458110.htmlunscrew the silver 2" adapter screw the new part in and attach extension tubes then one of these  http://www.firstlightoptics.com/adapters/flo-2-inch-t-mount-camera-adapter.html on the other end

hth

mark

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