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Subject: Re: [M]: Pictor CCD Cameras
From: Valery P. Deryuzhin
Reply To: mapug@shore.net
Date: Thu Mar 20 00:52:50 1997

Michael Hart wrote:

>I own and use several CCD cameras. The SBIG ST-7, the Meade Pictor 416
>and the Pictor 201XT. The Pictor 416 is the one I currently use the most.
I have
>almost 500 hours experience with the Pictor 416. Why would anyone own both?
>Read on... you will soon see why.
>

>no completely wrong choices, just better choices for individual needs that
evolve.

Mine ( Pictor 416 ) was one. Totally wrong! In any respects compare to the
ST-7.

>I'll attempt to address some of the comments and statements made about
>Pictor CCD cameras without confrontation. Why has Meade dropped the price
>of the Pictor 416XT? There has been a statement that Meade uses a lessor
>grade chip than Brand X. What is the evidence for this statement, because
>Meade doesn't publish chip grades? Am I to take a leap of faith and assume
>that because Meade doesn't publish chip grades, Meade is using a cheaper
>chip, then state so without personal knowledge when my experience with my
>camera says otherwise? I am familiar with the Kodak chip grades. When a new
>computer comes out with more features and performance for less money should
>I assume the worst? Or, could the 416 CCD camera price reduction be Meades'
>attempt to increase the market by getting the price level for a Kodak 0400
based
>CCD camera down to the buy threshold? I do know that the reasonably priced
>PixCel is selling quite well though there is no real new technology here.
>I can speculate as well as anyone.

I think that Meade really use poorer chips than SBIG. In my Pictor 416 the
quantity
of hot and cool pixels is noticably larger than in ST-8 which friend of
mine has.
Note, please, that ST-8 has four times more pixels than Pictor 416.
So, all not so simple as you think. And, of course, Meade has decreased
their prices
with intention to remain on the market with their nearly failed Pictor
program on the
brilliant background of SBIG's success. Also the PixCel's appearence also
play their
role.

>Before Meade came out with the first Pictors, separate boards that required
a PC
>slot and a full sized computer were common for large CCD chip arrays used by
>permanent observatories. While faster, the then bi-directional parallel
ports offered
>data transfer speed increases, but has anyone used a parallel port hard drive?
>Arguably parallel ports are acceptable for small data transfers less than
700K, but
>CCD chip array sizes are growing much faster than the newer enhanced parallel
>port transfer rates. SCSI for the larger Pictor cameras made sense then
and now.
>The problem is the ASPI (Advanced SCSI Programming Interface) standard was not
>fully implemented at that time and still needs work. Even now, the leading
SCSI
>adapters don't fully comply with standards they produced. I had a SCSI
removable
>cartridge hard drive configured for DOS and Windows 3.1 to enable hard
drive restore
>in case of disaster, so I was able to have my Pictor up and running in a
few minutes.
>I have posted guidelines to help those with problems getting PictorView 2.0
using
>SCSI transfers under Windows 3.1.

Let us know ( honestly, please ) haw much the Pictor 416 via SCSI wins against
ST-7 with full frame downloading time ( on the same objects, please ). And the
same in 2x2 binned mode. I am sure that nearly no visible win in the time.
But ST-7 can be connected with computer by much longer cable and works much
more reliable. I also subscriber of SBIG's list and see no any wave of
discussions
about troubleshooting in ST CCD cameras. Nothing!

>Is it possible to produce a high quality 4" fluorite OTA for $800? I don't
know, but, if I
>could deliver and order for 500,000 such scopes to Aries, I bet they could
find ways to
>get the cost down while only giving up 5% or less of the image quality.

The high quality 4" triplet fluorite APO tube ass. is absolut impossible
for $800.
No profit. Only money loss. As more we will make as quickly we will be bankrot.
I do know well about what I am speaking.

>Let's explore advertising claims a little. Some have complained of
outrageous Meade
>claims and slick advertising. I have found the Pictor to perform pretty
much as advertised.
>For example, the Pictor 416 will transfer data under SCSI in under 1
second. If you put
>a SCSI line monitor in the chain, you will see this is the case. Will we
see an image
>1 second from shutter closure? No, because you have to ad integration time
and
>hardware transfer times, then the individual computer configuration adds
more time,
>so now we are up to 8-12 seconds. This is similar to hard drive transfer
speeds advertised

See my question above, please.

>Look on the back cover of Astronomy at the SBIG/Celestron ad for the PicCel
255.
>Notice the happy spouse, back yard lit up enough to see green blades of
grass and the
>fantastic image of M-51 on the computer screen with detail all the way to
the core that
>rivals professional images all done with a modestly priced Celestron
Celstar 8 without a
>focal reducer or guiding of any kind. BUT... the PixCel 255 has a 240 X
320 array of
>10 micron pixels that would give a field of view in an 80" focal length (8"
f/10) around
>5.4 X 4.1 arc minutes. My last image of M-51 measures around 11 X 7 arc
minutes.
>How can that image be possible? Is that marketing hype? I personally like
this ad.
>You get my point.

I am sure that they used the f/6 focal reducer or Optec f/3.3 one.

>Why do I own both a 416 and a ST-7? Well, because they compliment each other.
>Each has their strengths and weaknesses. Am I claiming there are no problems
>with the Pictor 416 series. Absolutely not, but most seemed to have
cleared up as
>I gained personal experience and added a few mods such as simple clips to
>assure no head disconnect (which never damaged my camera, but others felt it
>did, so I added the clips). Am I claiming no problems with the ST-7,
absolutely not,
>but again, experience cleared these up. Both share nice low dark current
but rather
>poor quantum efficiency (40-45%). Both have the small well capacity
(85,000) that
>translate into lower dynamic range. Based on my current imaging patterns,
I use
>the Pictor 416 about 40% of the time, the ST-7 about 30% and emulsion 30%
>of the time and manually guide 60% of the time. I'm not going to comment on
>416 VS ST-7 other than to say I like and use them both and neither is for
sale.

I can't see any Pictor's advantage against ST-7. I want to see, but I can't.

Regards,

Valery.