Re: weak pixels, etc.

[Robert Creager <robert@carolinecreager.com>]

Alright, I've made them big enough to see.  Blew them
up 800%.  I included another image Normalized (n).

---- Robert Creager <robert@carolinecreager.com>
wrote:
> 
> Hey Folks,
> 
> I've put up png images of the region 1940:1980,
> 700:750 from the images Andrew indicated at
> http://www.carolinecreager.com/tass.  The images
with
> an e at the end have been histogram equalized to
show
> the abnormality better.  If anyone wants something
> different (image type, size, region, etc...) just
ask.
> 
> Later,
> Rob
> 
> ---- Andrew Bennett <andrew.bennett@ns.sympatico.ca>
> wrote:
> > On Fri, 8 Feb 2002 09:48:20 -0700,
> <aah@nofs.navy.mil> wrote:
> > > ...
> > >  I still don't understand the problem with weak
> pixels.
> > >Andrew says:
> > >>Not in this case! The defect is hard to see on
> both the Darks
> > >>and the Flats but is much more obvious (i.e. I
> found it when I
> > >>knew exactly where to look) on an actual image.
It
> looks as though
> > >>electrons smear out over the full affected
length
> of the column
> > >>(or is that row? It's vertical on my plot: AXIS2
> direction)
> > >This doesn't make sense to me, unless what he is
> experiencing is
> > >blooming.  I'd like to see four images posted:  a
> raw, a flat,
> > >a dark, and the processed image for one of these
> cases.  Again,
> > >processing is supposed to make all pixels equal. 
> If this is not
> > >the case, then something is wrong.
> > >Arne
> > 
> > Yes - it looks like some sort of blooming (says
he,
> not
> > knowing the precise definition of the term.)
> > 
> > An obvious example is to be found near X1=1960,
> X2=712
> > raw coordinates, FITS style, counting from 1, in
> file
> > hira2199915.fits. The smeared columns are
> X1=1960,61,62
> > starting abruptly at X2=459 and extending to the
> data
> > cutoff at X2=2032.
> > 
> > Perhaps somebody with the appropriate software
could
> > crop out this bit from this image and from a
> corresponding
> > raw flat (e.g. hira2244571.fits) and dark (e.g.
> hira2244620.fits)
> > for us? I don't have suitable software at the
> moment.
> > 
> > Andrew Bennett, Avondale Vineyard
> > 
> > 
> > 
> 
> 
>