Click here if you are having trouble logging into the forums
Privacy Policy |
Please read our Terms
of Service | Signup and
Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User
saga01
member
Reged: 09/20/08
Loc: Kansas City, MO
|
Increasing Camera Sensitivity By Binning
#4905562 - 11/09/11 12:19 AM
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
I've seen several Orion StarShoot Pro OSC cameras for sale recently. I understand that if I binned one of these cameras at 2x2 and used it in monochrome mode if would increase the sensitivity of this camera. Is there a way to compare the resulting sensitivity of the binned camera to comparable cameras like the StarShoot Monochrome Camera III or a ATIK 314L. At this point and into the foreseeable future I don't see myself having the time/interest/money to really get into color imaging. Thanks for the help.
Mike
|
Jared
Post Laureate
Reged: 10/11/05
Loc: Piedmont, California, U.S.
|
Re: Increasing Camera Sensitivity By Binning
[Re: saga01]
#4905610 - 11/09/11 12:55 AM
|
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
It is a common misconception that binning a camera increases its sensitivity. It doesn't. The quantum efficiency of the individual pixels is the same as the QE for the new 'super' pixel. If one out of three photons was going to be detected prior to binning, the same one out of three photons will be detected after binning.
That being said, your signal to noise ratio does improve with binning. There are two reasons for that. First, as signal increases (you'll be collecting four times as many photons per pixel), the SNR improves. This is because shot noise is equal to signal divided by the square root of the signal. As signal goes up, SNR improves. You can get this same result just by binning in software afterwards, though. The second improvement from binning can't be duplicated in software, though. With binning, you are increasing signal while holding read noise constant. This further improves SNR.
Since improved SNR has much the same result in your image as improved sensitivity, many people think of binning as a way to improve the sensitivity of the camera. Technically, it's not, though, and if you are already in a situation where shot noise dominates over read noise, in camera binning isn't really an improvement on software binning (down rez'ing in Photoshop, for example).
|
CounterWeight
Postmaster
Reged: 10/05/08
Loc: Cloudyopolis, OR.
|
Re: Increasing Camera Sensitivity By Binning
[Re: Jared]
#4906142 - 11/09/11 10:19 AM
|
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
On another note - binning an OSC doesn't = true mono as the Bayer matrix filters are still there passivly doing their job. In a true mono all color filtering is done 'off chip' with filters and filter wheel and every pixel is used the same.
|
*skyguy*
Pooh-Bah
Reged: 12/31/08
Loc: Western New York
|
Re: Increasing Camera Sensitivity By Binning
[Re: Jared]
#4906269 - 11/09/11 11:13 AM
|
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
Quote:
It is a common misconception that binning a camera increases its sensitivity. It doesn't.
Hey Jared .... I agree completely with your statements, however it sure comes out sounding funny! So technically binning doesn't increase a camera's sensitivity, but it does in the real world (somewhat). Sounds like we're splitting hairs here and no doubt confusing for a newbie. 
|
Jared
Post Laureate
Reged: 10/11/05
Loc: Piedmont, California, U.S.
|
Re: Increasing Camera Sensitivity By Binning
[Re: *skyguy*]
#4907441 - 11/09/11 08:26 PM
|
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
I think it's actually an important distinction. If binning increased sensitivity it would offer improved SNR or improved image depth in virtually all cases. Not only does it not help in all cases, I'm not sure it helps in very many cases. The obvious exceptions, of course, are narrow band imaging (where improvements in read noise are critical) and oversampled situations.
Most of us shoot under light polluted skies where it is relatively easy to capture images that are dominated by shot noise rather than read noise. The original poster was asking explicitly about capturing luminance data not color data (albeit with a color camera). Rather than binning 2x2 and generating a synthetic luminance frame, I think a better choice would be to shoot 1x1, demosaic as usual, and discard the color data. If the noise is too high, you can just lower the resolution on the image and achieve the same result as if you had binned in camera. At least this way there is the opportunity to keep as much resolution as possible (assuming you're not oversampled), and only down sample till the noise gets bearable.
As far as the sensitivity of a OSC camera as opposed to a monochrome camera using the same (or similar) chip... The quantum efficiency is almost the same for the Atik 314L and the Orion SSP OSC. The catch is, of course, that the Orion won't allow you to remove the color filters, so you end up capturing somewhere between 1/3 and 1/2 of the photons of the monochrome camera in a given period of time. Binning isn't going to change that.
To the original poster, if you don't expect to care about color images in the near future (as you stated), I would recommend getting a monochrome camera right from the start. Binning simply isn't a substitute for the lost photons of a OSC camera used to capture monochrome data.
|
saga01
member
Reged: 09/20/08
Loc: Kansas City, MO
|
Re: Increasing Camera Sensitivity By Binning
[Re: Jared]
#4907832 - 11/10/11 01:19 AM
|
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
Jared,
Thanks for the good information and in-depth explanation. I'll definately start researching monochrome cameras.
Mike
|
JoseBorrero
Carpal Tunnel
Reged: 09/04/09
Loc: MI
|
Re: Increasing Camera Sensitivity By Binning
[Re: saga01]
#5244906 - 05/28/12 11:31 PM
|
|
Edit
|
Reply
|
Quote |
Quick Reply
|
|
|
Thanks, for making these statements, I'm recently again in off axis guider and the topic of binning while using OAG makes thing easier.
|
|
12 registered and 15 anonymous users are browsing this forum.
Moderator: Undermidnight, fishonkevin
Print Thread
|
Forum Permissions
You cannot start new topics
You cannot reply to topics
HTML is disabled
UBBCode is enabled
|
Thread views: 548
|
|
|
|
|
|
|
Previous
Index
Next
Threaded
