[Aavso-photometry] DSI Pro Photometry text by Arne Henden, published in S&T

[Wolfgang Renz]

Hi Michael

It was published in late 2005 so it was written some time earlier
using a prototype he got in late 2004.
Article:
    Sky & Telescope; Oct 2005; 76
    Meade DSI Color CCD Camera - Johnny Horne
Box:
    Sky & Telescope; Oct 2005; 79
    And Science Too - Arne A Henden; 

Its about the DSI I _Color_.

A)
At that time most image processing packages have just started
to support color cameras and DSLRs. They often showed severe
errors reading these different formats in the beginning (e.g.
AIP4Win V2 came out in July 2005 and it took some time to
get rid of all the color related bugs).

I don't know which formats the original AutoStarSuite software
could save. But I guess something like JPGs, tri-color FITS and
monochromized grey FITS.

B)
In the beginning just the AutoStarSuite could handle DSI cameras
for image aquisition.
The AutoStarSuite might have some nice features like Drizzling,
but not all users are satisfied with its functionality and the user
interface.


Maybe some who used a DSI camer in 2004/2005 can explain how
the situation was in more details.


Clear skies
 Wolfgang

-- 
Wolfgang Renz, Karlsruhe, Germany
Rz.BAV = WRe.vsnet = RWG.AAVSO



----- Original Message ----- 
From: "Michael Newberry" <mnewberry at ...>
To: "Wolfgang Renz" <w_renz at ...>
Sent: Saturday, July 21, 2007 8:55 PM
Subject: Re: DSI Pro Photometry text by Arne Henden, published in S&T


> Thanks for the article. I don't understand what Arne means by "once other 
> software packages start supporting it". If the camera software produces a 
> FITS image, then other software packages already support it, right?
> 
> Michael
> 
> 
> 
> ----- Original Message ----- 
> From: "Wolfgang Renz" <w_renz at ...>
> To: "Michael Newberry" <mnewberry at ...>
> Cc: "AAVSO-PHOTOMETRY" <aavso-photometry at mira.aavso.org>
> Sent: Saturday, July 21, 2007 11:41 AM
> Subject: DSI Pro Photometry text by Arne Henden, published in S&T
> 
>> I found the S&T article inset text (I knew I have it somewhere):
>>
>> "Preliminary Science Tests of a DSI-Pro
>> by Arne A. Henden
>>
>> I’m continually asked the question “Can I do photometry with a
>> brand X CCD?”  I decided about a year ago to pursue the answer
>> in a scientific manner, and have gotten one grant and some vendor
>> loans of inexpensive CCD cameras. The DSI-Pro was one of these,
>> with John Hoot of Software Systems Consulting providing me an
>> early prototype late last year.
>>
>> I have been favorably impressed with this camera. It has low readnoise
>> (about 6-7 electrons), very low dark current (2.5electrons/sec/pix at
>> 36F), and excellent cosmetic quality.  The prototype had a fair amount
>> of amplifier glow that could be subtracted cleanly if a dark frame was
>> taken at the same ambient temperature.  The camera gain is set such
>> that the system is reasonably linear to 50K ADU.  However, since ABG
>> cameras usually become nonlinear about half-well capacity, this gain
>> setting means you lose  the top end of the dynamic range in an individual
>> exposure; I much prefer the camera gain to be set to reach the pixel
>> saturation limit.  Displaying the non-square pixels makes star images
>> elongated but this does not affect the photometry.
>>
>> On-sky tests show excellent blue response (I was able to get U-band
>> images).  A 30-second V-band image on the 1.0m telescope had a
>> faint limit of V=19.3, not much different from our science cameras.
>> A preliminary reduction of a 2-hour time series on my favorite cluster
>> (NGC7790) shows 4mmag photometric errors over the entire 245
>> frame series, with the delta Scuti NSV 14781 0.1mag light curve
>> amplitude easily resolvable.
>>
>> I would definitely recommend this low-cost camera as an entry into
>> astronomical photometry, especially once other software packages
>> start supporting it."
>>
>>
>> Other reviews:
>> - Cloudy Nights Discussions
>>  Dsi Pro for Variable Star Photometry
>> 
>> <http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/577365/>
>>  DSI choice: Meade DSI, DSI pro, Orion DSI? which
>> 
>> <http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/1122736/>
>> - Jeff Hopkins
>>  Astronomical Photometry with a DSI Pro
>>  DSI Modifications
>>  http://www.hposoft.com/Astro/DSI/DSI.html
>>
>> Clear skies
>>  Wolfgang
>>
>> -- 
>> Wolfgang Renz, Karlsruhe, Germany
>> Rz.BAV = WRe.vsnet = RWG.AAVSO