ICEINSPACE
Moon Phase
CURRENT MOON
Full Moon 99.8%
|
|
18-04-2018, 02:36 PM
|
.....
|
|
Join Date: Oct 2016
Location: Melbourne, Australia
Posts: 2,974
|
|
GIANT Monochrome Sensor - 75 µm Pixels, 9inch x 11inch, 12 MegaPixels
For your interest, just what you can't use, unless you have your own national observatory ????
A GIANT Monochrome sensor (camera actually, but you could hack it or maybe it's available as a digital back) , by LARGESENSE. It has 75µm sized pixels, is 12 megapixels and 9 inches x 11 inches. Forget the view camera attached up front and hack it. Easy to do as it's only US$106K . And you can all handle that sort of size image circle right?
Here are some details.....
http://largesense.com/products/8x10-...al-back-ls911/
also....
https://www.dpreview.com/news/984647...ra-for-106-000
There is also a much smaller 4x5 in the works.
Best
JA
Last edited by JA; 18-04-2018 at 03:02 PM.
|
18-04-2018, 02:41 PM
|
|
ze frogginator
|
|
Join Date: Oct 2007
Location: Sydney
Posts: 22,062
|
|
Only $100k. Do they throw in the filters?
|
18-04-2018, 02:57 PM
|
|
PI cult recruiter
|
|
Join Date: Apr 2010
Location: Brisbane
Posts: 10,584
|
|
Gonna need a very looong focal length to avoid single pixel stars
|
19-04-2018, 10:21 AM
|
Registered User
|
|
Join Date: Sep 2007
Location: Australia
Posts: 896
|
|
Hmmm !
Out of curiosity I wonder what the real CCD specs are - Well depth, Dark noise, Read noise ?
|
19-04-2018, 11:48 AM
|
|
Oh, I See You Are Empty!
|
|
Join Date: Apr 2010
Location: Laramie, WY - United States of America
Posts: 1,543
|
|
Quote:
Originally Posted by multiweb
Only $100k. Do they throw in the filters?
|
Look, let's be serious, if filters are not included, I'm not buying...
|
19-04-2018, 12:08 PM
|
|
Novichok test rabbit
|
|
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 10,388
|
|
Surely you could use 1.25" filters....
|
19-04-2018, 02:00 PM
|
|
Farting Nebulae
|
|
Join Date: Jan 2014
Location: Tamleugh, Victoria, Australia
Posts: 1,384
|
|
Actually not bad value! But the precise parts quotation would be a killer
|
19-04-2018, 03:09 PM
|
|
Oh, I See You Are Empty!
|
|
Join Date: Apr 2010
Location: Laramie, WY - United States of America
Posts: 1,543
|
|
Quote:
Originally Posted by SimmoW
precise parts quotation would be a killer
|
When isn't it...
|
19-04-2018, 06:49 PM
|
|
Registered User
|
|
Join Date: Sep 2014
Location: North Queensland
Posts: 3,240
|
|
Quote:
Originally Posted by RickS
Gonna need a very looong focal length to avoid single pixel stars
|
One could always drizzle the data...
Another use would be to put this sensor in an autoguider and a short FL finder scope - a perfectly flat guiding graph every night even with a $500 mount!
|
19-04-2018, 07:39 PM
|
Registered User
|
|
Join Date: Sep 2007
Location: Australia
Posts: 896
|
|
I got the following information from the developer for interest.
Oh, and you get an IR filter !
==============
Thanks for asking.
Someone asked about astro use before. You need a 380 mm image circle for the LS911. I really assume the LS911 won't be too good for astro as the noise increases quickly over time till about 10 seconds max.
Your 100 mm image circle telescope will only partially cover the LS45, so you can calculate the pixels you will have with 50 micron pixels. The lens I'd think about using for stars would be the Kodak Aero Extar 7 inch f/2.5 as it is sharp and bright and should cover the sensor. That leaves you with just a standard lens. There are some longer aero lenses though.
The LS45 sensor is a newer generation sensor and that I assume would be better for astro than the LS911, but I would expect it would be bad a exposures more than a few seconds. I don't have all of the details yet. The FWC is around 1.6 Me- (or up to 2 Me-) with noise around 300 electrons, which gives about 12 stops of DR. But when gain is applied, the FWC and noise are reduced. Once I get the sensor I'll play around with gain and see how it works out. I am assuming the base ISO is over 2,000. It could be possible to have clean ISO 16,000 with low DR, I'll have to see.
The sensor is 16 bit but once you start applying gain your effect bit rate goes down.
You can publish it as tentative info. I actually don't have the full info yet but I have an engineering sample on order. Production won't happen till the end of the year.
The LS45 will have a swappable IR blocking filter.
I'm open to adding extra cooling for a special LS45, it could be the LS45a. I'm planning 5mm of aluminum heat sink behind the sensor, but that could be thicker and other stuff added. I was looking into some cooling options such as a Peltier cooler, though those take a lot of power.
============
|
19-04-2018, 10:14 PM
|
Registered User
|
|
Join Date: Jul 2008
Location: Killara, Sydney
Posts: 4,147
|
|
9" x 11" ... heck you may as well load a sheet of Ilford Multigrade IV paper directly. Bung it through a desktop scanner afterwards to obtain a digital version at rather higher DPI.
$100k buys an awful lot of paper.
|
23-04-2018, 09:21 AM
|
Registered User
|
|
Join Date: Sep 2007
Location: Australia
Posts: 896
|
|
One piece of interesting information I was provided by the developer is : "the LS45 sensor has a non destructive readout function . . . . So you can read the sensor data as fast as 1/30s while it still builds up signal."
I wonder how you could integrate this novel ability (compared to our standard sensors) with a process that can do automatic calibration during the image acquisition process
It also means that you no longer need to take a whole series of different length subs to get your HDR, you just read out at whatever intervals you want during each long exposure.
It might also mean that you could identify (temporally) when a cosmic ray or satellite trail went through and potentially eliminate that part of the subexposure by simple addition and subtraction of the series of readouts !
It might be a stretch, but if some bad seeing/poor tracking went through you might also be able to subtract that out too !
We're so used to a particular paradigm in our image processing due to inherent design issues that you dont even think about the alternatives.
What do you think Ray ?
|
15-05-2018, 10:02 PM
|
Registered User
|
|
Join Date: Sep 2007
Location: Australia
Posts: 896
|
|
Was informed today
FWC is 1Me-
Wow !
|
15-05-2018, 10:26 PM
|
Registered User
|
|
Join Date: Jul 2008
Location: Killara, Sydney
Posts: 4,147
|
|
This really deserves a MOTS (Minitrack Optical Tracking System) Camera in front of it - 8" F/5 with monochromatic filters and designed to cover an 8x10" plate.
These were made by Perkin Elmer in the 50's.
There was one in amateur hands in Canberra in the 1980's... picture of one at Honeysuckle Creek at the bottom of this page https://www.honeysucklecreek.net/oth...ck_photos.html
... it's probably the same scope I knew of. Not particularly sharp from a visual perspective, and 12MP x 75 micron pixels is probably overkill.
But... to be honest a modern full-frame sensor with a modern 200mm f/2.8 lens would beat what the MOTS could do, very easily.
A Riccardi-Honders, even a Celstron Fastar setup with similar field would do a LOT better.
Last edited by Wavytone; 16-05-2018 at 08:59 AM.
|
16-05-2018, 02:10 PM
|
|
PI rules
|
|
Join Date: Jul 2006
Location: Sydney
Posts: 2,631
|
|
So all we need now is a scope with 15m focal length to get 1" per pixel. However you'd probably want to use it in Chile somewhere where the seeing is good, 0.5". Let's go for a 30m focal length at, say, f/4. Only 7.5m aperture--about 300"
|
16-05-2018, 05:58 PM
|
Registered User
|
|
Join Date: Sep 2007
Location: Australia
Posts: 896
|
|
Geoff,
Yere image scale is tough !
And image circle is a bit of a problem for a mere amateur, but I can't help thinking that 1,000,000 e- well depth might be useful - I assume the read noise and dark noise are probably pretty standard for a typical CMOS designed chip. Thats a huge dynamic range
Ignoring the cost - you dont have to use all the photosites/pixels !!
Rally
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT +10. The time is now 09:30 PM.
|
|