I can't remember having to re-boot the camera or having PictorView crash on
me for the last 12 months usage. It is surprisingly stable now
('Surprisingly' compared to older versions which would fall over at the
slightest provocation). The salt 'n pepper display is simply not a problem
IF you set the display parameters correctly, otherwise the automatic
selection of the maximum and minimum display levels can result in a grainy
image. However, using PictorView's excellent 'Sticky Enhancement' feature
allows you to preset the display levels - no automatic scaling method will
cover all image types (planetary, lunar, stellar, galaxy, nebulae). Take
Mars for example, most of the background will be black, the planetary disk
will be bright - but you are most interested in the subtle contrast
variations in the 'bright' planetary disk - and that narrow range (starting
way above the background level ) is what you want to cover with the bulk of
the greyscale. That's an entirely different situation from a nebula image
where you want to cover the scale from just above background (to capture
faint wisps of nebula) but without bright stars overpowering the image. For
each of these different types PictorView allows you to preset the display,
and new images are displayed with that setting.

For focussing I find PictorView's rapid screen update great, and the ability
to adjust exposure times during focussing is also useful - as focus gets
closer the well count naturally increases as the light is 'concentrated' so
it's good to be able to reduce exposure to maintain the sharpest image. I
use a 2-hole mask rather than rely on the numerical readout which I find to
be less accurate when seeing is anything less than perfect. Auto-mosaic and
Auto-center are the 'extra' features I use most and they work fine for me.
Auto-exposure is a waste of time - the anti-bloom feature might be useful
but could use a bit of work. I think the extra 'object goto' feature in
later versions is also a little redundant given that many users probably
make use of a planetarium program at the scope (or even ACP!!).

Temperature readout and control relies on the sensors within the 416XT
camera body, I've not heard of any software-related problems with
temperature readout? Any problems with camera temperature appear to be
hardware related - or the actual operating conditions (i.e., hot). It's the
controller box firmware that provides the temperature control anyway, the
software merely provides a readout from the sensors. Used with intelligence
the chip temperature, body temperature, and power usage are all you need to
know.

I can't believe anyone uses a serial connection for a 416XT! The difference
in download speed between SCSI and serial renders the latter a complete
non-starter for full resolution images. It seems Maxim are still having
problems with their SCSI implementation - no doubt they don't want to issue
an unstable product but it's well overdue.

Maximum Entropy is just one of several de-convolution algorithms available,
Richardson-Lucy (as provided in CCDSharp) I find better for recovering good
stellar images. ME entropy can sometimes reveal better detail image but
usually at the expense of increased background noise and/or dark/bright
rings around bright stars (especially if they are embedded in nebulosity).
Success here depends on fine-tune of the PSF and values used for background
noise on any particular image. I would rather use a weak un-sharp mask than
trust to an 'automatic' implementation of a complex deconvolution routine,
the chances of producing the typical 'over-processed' appearance is high.
Image Scientist provides both LR and ME, excellent control over both, and
many other features besides for just $129 -excellent value I think. A
completely revised edition of Image Scientist is due for release this summer
according to the author.

I personally feel the near $400 is not a good price for Maxim CCD (it's well
over £300 here in the UK, and are disadvantaged further because Cyanogen
sells through an agent who take their own cut, so there's no chance to buy
direct). Anyway, PictorView provides all the camera control functions I need
and it does it very well indeed. It doesn't pretend to be an image
processing package - nor should it be. I never perform sophisticated image
processing at the camera, all I need to do is differentiate a good image
from a bad one and leave further processing untill later. Both ME and LR are
CPU hungry algorithms, the usual portable PC for field use (data capture)
will be crippled by having to do so much number crunching. I save that for
my desktop which (at 500MHz, 512Mb RAM, 21" display) is better suited to the
job.

Chris Heapy


----- Original Message -----
Sent: 21 June 1999 16:10
Subject: Re: [M]: Pictor 416XT Software


> Scott Baker wrote:
> > 3) I noticed an ad in Sky & Telescope for MaxIm DL/CCD software,
> which
> > claims to support the 416XT (in serial mode only). Has anyone tried this
> > software? Does the CCD control function better than PictorView?
>
> yes, yes, though it does not have some of PictorView's advanced
> features like auto-focus and auto-mosaic.
>
> MaxIm DL/CCD's 416 camera controller is rock solid. I have never had
> to re-boot the camera... never... when using Maxim DL/CCD. I have
> never had a crash/GPF. I have never had it "get lost" and had to
> re-connect to the camera. I have had 100% success with the temperature
> readout and control, exposure times are right on. The display is much
> better auto-scaled (no horrible looking salt and pepper look on
> just-input images), the focusing mode is brilliant (you get a 3-D
> contour plot of the star, and full-width, half-max readouts for X and
> Y as well as the brightness), download times are as fast or faster
> than PV (I believe it really works at 115K and I suspect PV does not),
> etc.
>
> Given that you will want to do image processing on your images anyway,
> and MaxIm DL is great for that (Maximum Entropy is great), I feel it's
> well worth the price (almost $400). But then I appreciate well-done
> software -- I'm not one of those "Oh it's trivial, I would write it in
> a weekend" type of guys :-) :-)
>
> -- Bob
>

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