ASI 130MM Mono Planetary\Guiding Camera

[blinky]

Has anybody heard of or ideally used one of these cam's?

ASI 130MM - apparently it's the same chip as used in QHY5's so should be fine for guiding with (which is why I want it) and it's about £40 cheaper than a QHY5 (Being a Scotsman, that appeals!)

Just wondered if anybody had an opinion?

SpeedFlameOut Webcams#

ASI 130MM Guide Lunar & Planetary Camera (Same chip as the QHY5) | eBay

[riklaunim]

Note that it doesn't has ST-4 so you would need a direct mount connection.

[blinky]

Thats fine as I would be using it with EQMod.

There is also this camera - Opticstar PL-130M COOLAIR video camera.

Again, same chip as QHY5 but cheaper

[Gina]

It's not just the sensor chip that determines performance. For example the Philips SPC900NC has the same sensor chip as the Imaging Source DFK_21AU04.AS_Colour but the performance of the latter is far superior, I'm told.

Personally I would stick with the very well known, tried and tested, and highly recommended QHY5. There is usually a reason why some things are cheaper.

[blinky]

Gina, I'm thinking you are correct! I just searched for the Opticstar PL130 and everybody says it is terrible BUT it's the same chip as the QHY5....

[rwg]

I have done some special features in SharpCap to support this camera, including supporting the binned modes it exposes and supporting a continuously variable exposure control from 1ms up to 1000s (as opposed to the normal Webcam control which has exposures in powers of 2).

It seems nicely made and is quite workable up to exposures of 100s or so. Beyond that there are a lot of warm pixels (admittedly not *hot*). Mind you these tests were at room temperature, might well be better outside on a cool night or with some cooling applied. At the other end of the scale, I can get 30fps at 1280x1024, although for some reason to do with USB hardware/drivers that won't play ball in 'fast' mode, I only get half this rate on my laptop.

Robin

[Gina]

I shall be buying a QHY5 from ModernAstronomy as soon as I have sufficient funds. So, yes, I shall be putting my money where my mouth is

[themos]

Ran some tests on rwg's ASI 130MM camera (which he has lent to me).At a nominal gain of "50", the gain and read noise is measured at

• 31.81 /ADU
  
• 18.0 e RMS
  

At a nominal gain of 100, they are

• 5.14 e/ADU
  
• 12.4 e RMS
  

These gain values look quite high to me, I expected the "gain=100" to be closer to real unity gain. And the read noise figures seem excessive, too. Perhaps someone can do independent measuring and compare.

[themos]

I was out trying the ASI 130MM on Jupiter last night. Decided to use FireCapture as it supports autoguiding (keeping the planet in the middle of the chip) and motorised filter wheel. I just about got to the point where I could schedule RGB captures and have them occur automatically. Didn't use my best optics as this was just a test. I think I'm ready for prime time!

[StuW]

How are you measuring this? I can try my 120MC??

[themos]

I used the calculators in

http://www.photometrics.com/resources/imaging-tools/read-noise-calculator.php

http://www.photometrics.com/resources/imaging-tools/mean-variance-calculator.php

And I compiled the statistics with IRIS which was fed BMP files produced by FireCapture. If you know a few IRIS commands like "load", "sub", "stat" it's quite easy. You need to shoot just 2 bias frames and 2 flat(ish) frames. A more thorough calculations requires shooting a number of flat frames at increasing illumination.

[themos]

I tried Craig Stark's method, the "m-v plot", http://www.cloudynig...hp?item_id=2001

and the results are in the spreadsheet

• gain: 7.295993 e/ADU
  
• noise: 25.53598 e
  

ZWO gain 100.xls

[riklaunim]

Read noise for Micron CMOS sensors is high. 25.5 is what you can get with them.