Neximage 5

[Gary085]

I've always had lines , noise and dead pixels on screen even more so since using 3x barlow and having to set exposure higher, are all neximage5's like this or did I get  a dud? 

Gutted I bought it last year from FLO now after using another camera temporarily and seeing other peoples results with their camera's, but it had some good reviews. I should have done more research

[riklaunim]

Post some images. The sensor used in Neximage 5 can show fixed pattern noise, and can be quite noisy. It also has small pixels so 3x Barlow would be rather good only for fast telescopes (what's your telescope?)

[ronin]

What are you imaging and what are the exposure durations, also anything else.

From a review in S@N it seems the supplied software is a bit strange or undocumented.

The Nesimage 5 does seem to produce noise when the exposures are around 1 second and above.

There is this post on SGL about imaging with the NI5.

I see it gets referred to as "Neximage 5 Planetary Cam", meaning a webcam type of operation - avi file more then anything.

Very few reviews of the camera, jsut about all are on retailers sites and they seem to reproduce what Celestron issue, and Celestron will only say how good it is.

[Gary085]

Post some images. The sensor used in Neximage 5 can show fixed pattern noise, and can be quite noisy. It also has small pixels so 3x Barlow would be rather good only for fast telescopes (what's your telescope?)

I haven't been on this site for a while. My telescope is Skywatcher 120/1000 F8.33 so not very fast.  it's okay until I use an exposure of about 1/8 seconds or higher when using a barlow for higher mag view of planets.

[JamesF]

Unless you're binning I'm not sure I see the benefit of using a 2x barlow with the Neximage 5 and your scope.  Perhaps something like a 1.4x at the most, but generally I think I'd probably just stick with the native focal length.  If you want a bigger image, enlarge it during processing.  If you're using 2x binning then a 3x barlow might be appropriate, but I still struggle to get my head around what binning really means with a colour camera.

I've no experience with the Neximage 5, but 125ms seems a very long exposure time.  I'd expect probably a third of that at most for planetary imagers.

James

[JamesF]

Re-reading your last post, are you using it more for video astronomy/EAA than for planetary imaging?

James

[Gary085]

I have no idea what bining is either to be honest, I need to experiment with that. I use it for planetary imaging although I haven't had much practice recently.

2 x barlow seems to work okay with my set up but it struggles with the 3x.

[Gary085]

[JamesF]

I have no idea what bining is either to be honest, I need to experiment with that.

Binning is combining the values of a number of adjoining pixels to make a single pixel.  For example, 2x binning would divide the imaging sensor up into lots of 2x2 "superpixels" and return a single pixel value made by adding the values in all four pixels in the superpixel.  In a manner of speaking it increases the sensitivity of the camera by halving the resolution.

The thing with colour sensors is that the adjoining pixels are actually sensitive to different colours, and in the case of those sensitive to red or blue none of their immediate neighbours are usually also sensitive to the same colour, so what binning achieves in that instance isn't entirely clear to me.

James