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A used STL-11000? Still on the fence.

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#1 dawziecat

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Posted 26 July 2013 - 09:08 AM

I posted an enquiry a week or two ago about the wisdom of buying a used STL-11002.

I am still undecided about this. I have some concern that they seem NOT to be selling on Astromart.
There are several (5?) that have been listed for many weeks. None have sold! Prices range from $3750 (bare camera only) to a pretty high figure for a European location. I understand why the European one is priced high. Not sure why the ones in NA seem not to be selling either though. Or that matter why the European one isn't selling in Europe either.

This gives me pause.

I see the downsides to an older camera as follows:
1/ Slow USB 1 downloads.
2/ Built in FW has only 5 spaces.
3/ Guiding takes place behind the filters. Tough for NB.

Considering what a new STXL-11000 costs, using the very same Kodak KAI-11000 chip, it seems the “old” STL is a bargain at used prices.

But they aren't selling.

Why? Are there downsides I've missed? :question:

Also, I can find nothing on a "Class X" chip, supposedly the best available?

#2 garret

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Posted 26 July 2013 - 10:45 AM

Kai 110002:
9 micron pixels: to large for my F# 3.6 telescope.
Interline ccd: fine for video...

KAF 8300: 5.4 micron pixels, full frame ccd: just what I need...but, ccd size to small for my telescope.

A 35 degree C. below ambiant cooled Canon 5Dmk2: just what I need and what I have...

#3 raf1

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Posted 26 July 2013 - 11:16 AM

Hi Terry - I'm surprised there are not more "older" SBIG cameras on the market with the introduction of SBIG's new offerings. But considering the prices for the new ones, I can also understand why there are not many. The issues you are concerned about, are indeed legitimate. I've had my 11000 since '06 (Class 2 chip) and apart from normal maintenance it has performed flawlessly. I purchased it new so always "caveat emptor" on purchasing used.

To me the one agonizing shortcoming of the 11000 is the slow download time. Since my sessions are now automated by CCDAutoPilot, they are no longer painful only because I'm not sitting there waiting on them.

The standard 5 position wheel was adequate until I wanted to include narrowband imaging so I purchased an FW8-STL 8 position wheel to address that. Guiding behind the filters can even be frustrating when only shooting LRGB. I remedied that with an Astrodon MOAG and an SBIG Remote Guide Head.

You may now be thinking that, "well yeah - if I throw enough money at imaging I can mitigate the things which give me pause regarding buying an older camera." Honestly speaking, that is correct. I built my system over the past seven years as I could afford the accessories I needed to get me to an automated solution. Besides the equipment mentioned earlier, I also have an SBIG AO-L and an Optec 3" rotator in my image train. I try to spend my hard earned money wisely and I'm willing to save and spend on what in my opinion is important for me to enjoy this hobby (addiction ;)).

You can go here to see the last two images taken with my system:

M13
M27

The STL-11000 is a great camera when coupled with the right OTA. If you have any other questions, just let me know. Hope this helped a little.

CS, Ron

#4 elbee

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Posted 26 July 2013 - 12:47 PM

terry -- i too am surprised to see them not (or very slowly) selling. if i didn't already have an STL-11000M class1 camera, i would buy one for sure. all of the points you mention are valid. slow download only is an issue for me when it comes to sky flats (cuts in on the time to get them but just means i have to collect fewer but on more days). as in your case, ccdautopilot even makes that pretty painless.

i really like the camera. great match for my scopes but best of all is the field of view. you can't get that without paying 2-3x if you want one of the newer cameras. i had a class2 used camera for a couple of years but bought a new class1 when sbig had their sale a couple of years ago (of course no knew it was an inventory clearance sale :-)

i would hold out for a package that is fairly new (2009-2010 or later; first 2 digits of the serial number), with an STL-FW8 filter wheel and check the darks and bias frames to confirm they are fairly clean. also, best to hold out for astrodon gen2 (i-series) filters. don't spend money on gen1 (you could, but realize resale on those is only going to be $250-$275)

the class X was not offered for very long. supposed to be the cleanest chip kodak could make. i saw that camera for sale and thought it was a very good deal (i bought my first class2 STL camera from that guy). if you can pick up a remote guide head, that eliminates the concern about guiding from behind the filters. i used a separate guide camera for a couple years but recently got a used RGH.. really nice and clean to use.

for anyone wanting big real estate on a chip, i think those sales are a very good deal (keeping in mind some comments above).

#5 raf1

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Posted 26 July 2013 - 02:34 PM

slow download only is an issue for me when it comes to sky flats (cuts in on the time to get them but just means i have to collect fewer but on more days).


Lee makes a really good point here. I have a light panel which I use to shoot flats so no worries. There are instructions on the web for constructing inexpensive DIY illuminated panels.

#6 dawziecat

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Posted 26 July 2013 - 05:11 PM

Looks like I'm gonn'a do it.

Now I am confused as to the backfocus the STL-11000 consumes.
This SBIG link gives three figures, one each for "mechanical focal plane," another for "optical focal plane" and a third for "optical focal plane with 3mm filter."

My understanding is that additional refractive elements in the train, like filters, effectively LENGTHEN the BF. This engineering diagram indicates the opposite. :confused: :confused: :confused:

#7 vpcirc

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Posted 26 July 2013 - 06:32 PM

This is the problem
QE
Red 34%, Green 37%, Blue 42%

That means only that percentage of photons hitting the sensor are captured
A low QE makes imaging a little tougher. I'll never buy another interline chip

#8 dawziecat

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Posted 26 July 2013 - 07:32 PM

Hmmmm . . .

Yes, this link has a nice graphical comparison of the QE figures for popular chips. No doubt about it, the KAI11000 is way down there. :(

But I just don't see a full-frame, high QE chip camera in my price range anytime soon. :bawling:

#9 dsnope

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Posted 26 July 2013 - 07:34 PM

This is the problem
QE
Red 34%, Green 37%, Blue 42%

That means only that percentage of photons hitting the sensor are captured
A low QE makes imaging a little tougher. I'll never buy another interline chip


You wanna double-check those numbers?

#10 vpcirc

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Posted 26 July 2013 - 08:47 PM

Parameter Value Architecture Interline CCD; Progressive Scan
Total Number of Pixels
4072 (H) x 2720 (V) = 11.1M Number of Effective Pixels 4033 (H) x 2688 (V) = 10.8M
Number of Active Pixels
4008 (H) x 2672 (V) = 10.7M Number of Outputs 1 or 2
Pixel Size
9.0 μm (H) x 9.0 μm (V) Imager Size 43.3mm (diagonal)
Chip Size
37.25mm (H) x 25.70mm (V) Aspect Ratio 3:2
Saturation Signal
60,000 electrons Quantum Efficiency KAI-11002-ABA KAI-11002-CBA (RGB) 50% 34%, 37%, 42%
Output Sensitivity
13 μV/e Total Noise 30 electrons
Dark Current
< 50 mV/s Dark Current Doubling Temperature 7 °C
Dynamic Range
66 dB Charge Transfer Efficiency > 0.99999
Blooming Suppression
> 1000X Smear < -80 dB
Image Lag
< 10 electrons Maximum Data Rate 28 MHz
Package
40-pin, CerDIP,
0.070” pin spacing Cover Glass AR Coated
All parameters above are specified at T = 40 °C

#11 dawziecat

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Posted 27 July 2013 - 06:19 AM

The QE of this chip is not it's strong suit.
But there seems no ECONOMICAL alternative at the present time for a full-frame chip. Is that not correct?

Also, the low QE is more than made up for in actual use by the large pixel size. Is this not also correct? The STL-11000 has pixels 9X9=81 sq. microns, vs, for example, 5.4X5.4=29 sq. microns for a KAF8300 chip. It's sort of making a virtue of necessity, looking at it that way.

People rave about the high QE and low noise of the Sony chips, but they are also small chips. Is that not also correct?

So, it's a bit harsh to dwell on the low QE of the KAI11000.
It is still very much a player in the astro CCD camera field
and most makers seem to offer it for reasons of economy and size.

I'm not being combative here. I am still learning the ropes on these cameras.

#12 raf1

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Posted 27 July 2013 - 09:54 AM

The QE of this chip is not it's strong suit. ........ So, it's a bit harsh to dwell on the low QE of the KAI11000.


Terry - I don't think you are combative at all, these are good questions which should be asked. In fact, I had no idea my QE was so low until reading this thread. Then again, I don't care to understand all the statistical data and analysis that goes into explaining how my camera performs. That may seem a bit naive since I do believe that you should be diligent in doing pre-purchase research but I've always been a "proof is in the pudding" user. I looked at the images the 11000 was producing for other astro photographers and looked for any negative comments - I liked what I saw and this was heavily weighted in my purchase decision. So based on actual performance and production quality in the field, I'd buy another STL-11000 in a heartbeat if mine were to give up the ghost.

CS, Ron

#13 vpcirc

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Posted 27 July 2013 - 10:58 AM

No, pixel size isn't going to make up for low QE. Well depth can help. SBIG started to unload these at 5k last August I think. I'm only speaking from experience. A lower QE means to gather the same data, your image times per frame will need to be longer than a chip with a higher QE. I knew none of this when I bought an interline chip until Tony Hallas told me what my problem was. Once I switched to the 16803, it was night and day. I cut my exposure times by 1/3. I'm not suggesting the camera won't work. I'm just sharing what I learned from my experience.

#14 dawziecat

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Posted 27 July 2013 - 12:03 PM

No, pixel size isn't going to make up for low QE. Well depth can help. SBIG started to unload these at 5k last August I think.


Hi Mike:

At a given pixel size, of course, higher QE will translate to shorter exposures in a linear fashion. But I am used to a camera with 5.4 micron square pixels. If I bin 2X2, the effective size of the pixels quadruples and the exposure time needed to achieve a given ADU shortens by that factor.
That's how I understand it. I haven't measured ADU values to confirm it but it is obvious enough that shorter exposures are needed when binning. So, I think I will see precious little differences in exposures of like duration between the two chips. Am I wrong in that? :question:

SBIG surely did not "unload" the STL-11000 because of the KAI-11000 chip. After all, the STXL-11000 supplanted it and uses the very same chip. The STL-11000 is very long in the tooth. That USB1 download speed is irksome. But the reason SBIG replaced it in the lineup had nothing at all to do with the chip itself and they continue to use the very same chip in their current offerings. . . as do most other camera makers.

None of this disputes the superiority of the KAF-16000 chip. That's just a given! I don't see any in my price range though. :(

#15 Rick J

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Posted 27 July 2013 - 12:25 PM

The 16803 Mike uses is also a 9 micron pixel chip so yes the higher QE makes a noticeable difference. You have to compare QE at the same image scale. Once the image scale is the same the higher QE chip wins every time. This is why many 11000 users are moving to these non interline and larger chips.

Problem with them is with my scope the added pixel area is wasted as my scope can't handle the larger FOV. It barely works for the 11000. So do I want to pay for the even larger chip I can't use to get the higher QE? Considering I can work remotely so time isn't all that big an issue and my budget isn't all that great being retired for many years I'll stick with the 11K for a while longer. But the larger chip is certainly on my wish list especially if I ever can also swing a good wide field scope that can support such a large chip. Two budget busters. Now where's that winning lottery ticket when you could use it?

Rick

#16 neutronman

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Posted 27 July 2013 - 03:33 PM

My STL-11000M is in its 6th year and is still going strong. Sure, it is old tech (USB 1, cooling not the greatest, etc.) but the proof is in the pudding, and the pudding still tastes great!
It is a dandy match for FSQ f3.6 WIDE field imaging.
I'll probably keep shooting with it until it blows up :dabomb:

#17 blueman

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Posted 27 July 2013 - 03:51 PM

One thing to consider when looking at ANY used camera is the number of hours the camera has been used. Most any chip will degrade some with time. More hot pixels or white columns or other defects can become more prevalent with age.

So a used camera that has not been used much and is discounted a lot, can be a good deal. But one with a lot of time on it and not deeply discounted might not be.
Blueman

#18 JWalk

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Posted 27 July 2013 - 04:18 PM

There have been and continue to be some amazing images that come from the 11000 chip. I have enjoyed mine.

#19 vpcirc

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Posted 27 July 2013 - 04:26 PM

Maybe I've been misunderstood that I think the camera is a bad deal under any circumstances. That's certainly not how I feel. If I remember correctly when I was at Mt Lemmon a year ago May, I think Adam Block was still using one before he switched. The camera can obviously produce quality images, I'm just saying the QE hurts interlines. I think SBIG deeply discounted the price last year was sales were not there with that model as I wouldn't buy one with the OAG behind the filters. They have wisely built a different setup and are getting ready to be on the forefront with the new AO system. I wish I didn't have so much invested in an Apogee D7, as I'd love the Stx with the adaptive optics option

#20 Jared

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Posted 27 July 2013 - 05:45 PM

Nothing wrong with the STL-11000 even in today's market. The only disadvantages vs a current 11002 based camera are the slow download speeds and the relatively limited cooling. The quality of the hardware is good, the built in filter wheel is convenient, and if you want to do narrow band you can always add a MOAG and remote guide head (or a second guide camera). Depending on the price, there is no reason to avoid the camera. The 11002 is still a competitive chip, despite the poor QEmcompared to a 16803. Sony has nothing in this size range. Look at some of the finest wide field images out there, and you will find that quite a few of them were taken with this camera. If you can't or don't want to afford a 16803, it's a good way to go.

#21 dawziecat

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Posted 27 July 2013 - 06:23 PM

Thanks all. Especially to Mike for bringing up the relatively poor QE. It was something else I needed to investigate before commiting to the camera.

Floyd:
It this camera has more than a mere handful of hours on it, I'd be surprised!

It's decided. I'm going to buy it! :jump: :jump:

I have more gear about than any guy without a mount I know! :p

#22 blueman

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Posted 27 July 2013 - 09:33 PM

[quote name="dawziecat"]Thanks all. Especially to Mike for bringing up the relatively poor QE. It was something else I needed to investigate before commiting to the camera.

Floyd:
It this camera has more than a mere handful of hours on it, I'd be surprised!

It's decided. I'm going to buy it! :jump: :jump:


Like I said, a barely used camera that is well discounted can be a good deal.
Blueman

#23 Rick J

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Posted 27 July 2013 - 11:08 PM

My 11K has been used every clear night all night for 7 years now. Yes there's a few changes, especially with more hot partial columns. But all vanish with proper calibration, even without dither which would (if I took enough frames) help even more. At least with my camera I don't see those many thousands of hours hurting the final image at all. I keep expecting the cooling fan to die. I've gone through three of them on the imaging computer. Apparently SBIG uses a really high quality bearing. Unfortunately its been getting a lot of rest this past year with the rotten weather :(

Rick

#24 Alph

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Posted 28 July 2013 - 12:24 AM

Like I said, a barely used camera that is well discounted can be a good deal.
Blueman



Every CCD ages regardless of whether it used or not. After all the dark current always accumulates unless you store the CCD at -100C.

#25 blueman

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Posted 28 July 2013 - 01:45 AM

Like I said, a barely used camera that is well discounted can be a good deal.
Blueman



Every CCD ages regardless of whether it used or not. After all the dark current always accumulates unless you store the CCD at -100C.

That is true too. What I was mentioning was how most all chips get more hot pixels and column defects may also increase with hours of use.
Not to mention of course, wear and tear on the plugs, fan and TEC cooler system.
Blueman






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