7 replies to this topic

[Laskaw]

Trying to find information on the read errors in Sony IMX 415, 678, 462, and 347 CMOS cameras. Any suggestions on where I can find this information is much appreciated. 

[Tapio]

What kind of read error information are you looking for?

[happylimpet]

Do you mean read noise?

[Laskaw]

Many apologies for not using the correct terminology, but yes I'm looking for read noise. I'm trying to wrap my hands around comparing Sony IMX family of sensors. Many variables to consider i.e. sensor size, pixel size, resolution, etc., thinking if one knows the read noise you could better make a comparison. Also, this may be useful in determining "optimal" exposer time and gain.  

[nic35]

If you are interested in a camera made by ZWO, they always provide this and more info on their web pages.  See  https://www.zwoastro...oduct/asi462mm/

 

scroll down to see the read noise as a function of gain

 

john

[mgCatskills]

I'm glad you clarified you were looking for read noise.  That said, on most CMOS cameras with HGC circuitry, once you set gain so that HGC is active, read noise is often immaterial except at extremes.  And even at extremes there are usually reasons you need to go to them, which renders it irrelvant.

 

For example, early in my EAA career I was observing off of a not terribly stable wooden deck that would vibrate in even a slight breeze.  So I had to set FWHM filtering tight and use 10 second exposures.  Read noise might have been high,  but results were way better than the alternative.

 

SharpCap Pro offers a sensor analysis that allows you to determine this with some precision:  https://docs.sharpca...rtHistogram.htm

 

That said, I'm going to venture read noise will be swamped by other considerations including your mount's tracking accuracy, mount stability, wind, and other factors.

 

As a simplifying assumption, I'd venture you could actually ignore read noise.  Other factors like the type of targets you're after, matching the pixel size to your telescope's focal length, size of sensor, and budget, are all going to be way more important that the relatively immaterial differences in read noise when making a selection.

[RodgerDodger008]

Recommend watching this, it is long but if you break it up it is quite manageable.

This will put noise from various sources into perspective including read noise in CMOS sensors.

https://youtu.be/3RH93UvP358?

[Michael Covington]

On newer sensors, such as the IMX series, read noise is almost always negligible compared to shot noise of the sky background, especially if the sensor is cooled.