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Has the $1200 large chipped ASI 1600 made existing modestly priced CCDs obsolete?

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#201 josh smith

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Posted 07 May 2016 - 11:26 AM

We're drifting into the bad place again. Could people self censor emotion and emotionally laden words, please?

Focusing on information. Ppeople involved with this discussion should also look at this thread. Dim detail, some narrowband, Amp glow seems to have not been a barrier.

http://www.cloudynig...asi1600mm-cool/

Mandatory disclaimers. Not saying the camera is anything other than, perhaps, the best entry level choice. Still need more examples, that is a very early camera, production models are just shipping now..


I'll counter that none of the targets are dim or extended. Need and very looking forward to more of those examples.

That's part of the issue with this thread. I don't think anyone would argue it's a bad choice for an entry level camera. I also think there were some good points about bang for the buck. It certainly is that even if there is amp glow, trouble calibrating, and less than perfect integrated package. At its price point, I think it would make high end APS-C dslrs obsolete for solely imaging astronomy targets. The versatility of allowing for planetary imaging is also awesome. Even based on the limited examples and ZWO's reputation, it is going to be a good product! But the original question was comparing to the Sony sensors as well as 8300s. I just don't think even if it lives up to the hype we can say it'll make them obsolete, especially the Sony sensors.

#202 WesC

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Posted 07 May 2016 - 11:46 AM

I agree with Josh.

 

Where I think this thread leaves the rails is in the posting of these hyperbolic statements claiming that this camera spells end of CCDs, that the 8300 is suddenly obsolete, and that anyone who disagrees is somehow in denial, living in the past or similar inflammatory comments.

 

Why is that necessary? Is the purpose of being here to denigrate other people for their choice of equipment?

 

The people who are taking a wait and see approach, testing the camera to find its limits and placing the 1600 camera in its proper place in the market appear to me to be reasonable and level headed. The constant, "my opinion is more valid than yours" bickering, hand waving and tossing around of "proof images" is just petty and does nothing to move the conversation forward. In fact, dragging images that are not your own into this conversation and arguing over them is immature and thoughtless. 

 

This is not a contest. But for some people it certainly seems to be. This thread has long since run its course and decided nothing. 


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#203 FirstC8

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Posted 07 May 2016 - 12:08 PM


Hi!

I shoot from 15 miles outside of NYC. so please don't tell me about LP, bad weather and seeing conditions. And you guys tell me my equipment is expensive. How much did that EMCCD camera cost?

You can get second hand EMCCDs for 4.000 to 5.000 EUR, so comparable to your QSI. But this doens't matter because the small frame EMCCDs are not produced any more. That's the reason why everyone who is interested to use shorter exposures is looking for alternatives. So far, the ASI 1600 seems to be the only reasonable alternative.

But I, too, would be skeptical until I have seen the first ASI 1600 results with a reasonable long integration time, let say more than 5 hours.

CS, Carsten
I don't think the 1600 is at the same level of a small EMCCD. There are sCMOS cameras available and at the EMCCD level. Maybe a few used ones will emerge at a reachable price.

In the hands of a seasoned EMCCD user, actually 2 seasoned EMCCD users, the ASI290m prototype is in fact giving the low end EMCCD's a run for their capabilities. $400 vs $15000, easier to use and results have in some cases been better. If you want to look at a market at risk...

We do very narrow fields with the airy disk spread across 3-5 pixels (speckle imaging) and are getting to the Dawes limits with double stars. Speckle is only good with a handful of stars in the field, but "triple correlation" is more general purpose and has better data extraction capabilities. So these techniques are not limited to fast systems, I'll use my ASI290 at f/10 - f/20 depending on the target for doubles and at f/4.2 for some other imaging. We prefer monochrome cameras, ADCs and filters to OSC and generally work in only 1 filter band.

Note too, as FWHM >1" you'll want an ADC... which can be built into a corrector/reducer... We don't have the combined units yet.

So think 50ms exposures and like Adaptive Optics, there's a 6-10x gain by putting all the photons in a few pixels (increased resolution) , losses in the frames that are thrown out, some additional noise from the stacking, but it's swamped by other sources in most if not all cases. Lucky is one technique, but the newer (more compute intensive) techniques like triple correlation will do even more... Are we there yet? not on large frame CMOS chips but the ASI1600 is a first and apparently good step. We also don't have the software support to make this easy. JMHO, we'll have to see.
Facinating stuff, I hope you are talking DSO lucky imaging not planetary?

I just started paying attention to the 290mm chip. Can you provide links to the images shot with ASI290mm by the two EMCCD imagers?

A BSI chip (high QE and less amp glow issue) similar to the 290mm but at the 1600 chip size or bigger would still be too expensive right now. But maybe that is what needed to nail it shut the high end CCD market.

Edited by FirstC8, 07 May 2016 - 12:12 PM.


#204 Peter in Reno

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Posted 07 May 2016 - 12:18 PM

I understand what AMP glow is but does it come from the sensor itself or surrounding/associated circuitry close to the sensor? If it's in the sensor itself, then there's nothing any camera manufacturer can do but if it's heat from external circuitry, then that's the manufacturers' responsibility to prevent from heat radiating close to the sensor.

 

Peter



#205 Jon Rista

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Posted 07 May 2016 - 12:47 PM

On the topic of when to recommend the ASI1600 cameras. Personally, I don't think the question at this point is whether to recommend one of these new CMOS cameras to someone over CCD, if they were considering a CCD. Even assuming ZWO completely corrects the amp glows, the fundamental data quality just doesn't quite seem to be there with the ASI1600. While I am not sure it is a huge issue, it is a 12-bit camera, which actually prevents the camera from even attaining it's maximum potential. 

 

I see the ASI1600 as more a potential altenative to DSLR than to CCD. CCD cameras are very good these days. Particularly the Sony based ones. Specs wise they are not far from the ASI1600, with the one key exception being FoV. 

 

On the other hand, the ASI1600 has the potential to solve some of the more serious shortcomings of DSLR. The biggest being lack of temperature regulation on DSLR cameras, the ASI1600 color version could easily solve the problem of thermal noise for those imaging in warmer climates or during the summer, without being more difficult to use. There is no such advantage over CCD. The ASI1600 mono version also solves the pixel fill factror/sensitivity shortcoming of color DSLR sensors, and opens the door to narrow band imaging. Again, no such advantage over CCD.

 

The ASI1600 supports USB 3 and extremely high frame rates, so just like a DSLR it could double as a planetary camera...however, it can be a much better planetary camera than a DSLR. This right here seems to be the only true, solid advantage over CCD...yet one which likely won't matter much to most CCD imagers who use their cameras to get deep exposures on faint objects or extended regions. 

 

In answer to the original question posed, I don't think the ASI1600 in any of it's forms poses any threat of any kind to most CCD cameras. The only ones that it may offer a nice alternative to, I think, are the KAF-8300 parts. It is very comparable in almost every respect, and offers that unique opportunity to image at higher frame rates and do video imaging. For a  beginner who is likely to still be exploring the options, the versatility of the ASI1600 might be useful, allowing them to explore planetary/solar system, LRGB, as well as NB imaging with a single camera, and one that does not cost much...allowing them to invest more of their budget into a mount, say an Atlas Pro vs. an AVX. 


Edited by Jon Rista, 07 May 2016 - 12:49 PM.

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#206 JMW

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Posted 07 May 2016 - 12:51 PM

I am wondering how well the cooled color ASI1600 would compare with a Canon 7D that was modified for Ha sensitivity? I have an SBIG STF-8300M with filter wheel but sometimes I don't want to fool with LRGB when I go to dark sites and don't have a lot of time. I also thought the ASI1600 cooled color would work well with my C11 EdgeHD in Hyperstar mode. I have the ASI120MM-S and ASI174MM and am impressed with using them for solar or lunar at high frame rates. 

 

I was thinking about also buying the EOS adapter and using some of my wide field EOS lenses with the ASI1600 for doing Milky Way shots.


Edited by JMW, 07 May 2016 - 12:56 PM.


#207 Peter in Reno

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Posted 07 May 2016 - 12:55 PM

I am wondering how well the cooled color ASI1600 would compare with a Canon 7D that was modified for Ha sensitivity? I have an SBIG STF-8300M with filter wheel but sometimes I don't want to fool with LRGB when I go to dark sites and don't have a lot of time. I also thought the ASI1600 cooled color would work well with my C11 EdgeHD in Hyperstar mode. I have the ASI120MM-S and ASI174MM and am impressed with using them for solar or lunar at high frame rates. 

 

I think ASI1600 would be awesome for Hyperstar because Hyperstar uses f/2 focal ratio which mean short sub-exposures and that's great for CMOS cameras that can handle Lucky Imaging.

 

I currently own the color version of ASI 120MC-S and it's fantastic for planetary imaging so I think color version of ASI1600 would work great for Hyperstar.

 

Peter


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#208 TheRock

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Posted 07 May 2016 - 12:56 PM

Since I made the mistake of posting this question during the middle of this morning's testosterone match, I'll post it again with the hope that folks have cooled down enough to get back to a thought provoking discussion...

 

Perhaps folks can elaborate for us less experienced imagers: What indicator(s) in the spec sheet shows a more competent ability to do more/shorter subs as opposed to the fewer/longer subs?



#209 Jon Rista

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Posted 07 May 2016 - 12:59 PM

 

Since I made the mistake of posting this question during the middle of this morning's testosterone match, I'll post it again with the hope that folks have cooled down enough to get back to a thought provoking discussion...

 

Perhaps folks can elaborate for us less experienced imagers: What indicator(s) in the spec sheet shows a more competent ability to do more/shorter subs as opposed to the fewer/longer subs?

 

 

I see the ability to use a widely variable gain, at very high gain (as little as ~0.2e-/ADU), with extremely low read noise around 1.2e-, with very low dark current around 0.0062e-/s, as well as the ability to record video (namely to uncompressed .ser) as the things that improve this camera's capability when it comes to doing higher speed imaging, lots of short subs. 


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#210 JMW

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Posted 07 May 2016 - 01:34 PM

Well with AstroLive USB coming out very soon, and owning a C11 EdgeHD Hyperstar, I decided to order the color version of the cooled ASI1600. I also ordered the EOS adapter and the holder ring for the ASI1600 cooled so I can also use the camera with my EOS lenses for very wide field. 



#211 gregj888

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Posted 07 May 2016 - 01:38 PM

To the topic, The ASI1600 is risky until we see data.  I don't think it's the "Game Changer" the IMX224,290,185,174 are, but it's likely to do as well as the CCD's that have been mentioned as competitive.

 

If you expect and want to use the camera as a CCD, you'll probably be happier with a CCD.  If you can treat it as something new and different, learning and applying different techniques, the ASI1600 is probably a very good option.  12 bit and smaller wells aren't an issue, but you will need to stack.

 

Rock, as Jon said, low TDN (Temporal dark noise, ie CMOS read noise) is the big one.  Frame rate is a practical consideration especially for high frame count techniques.  The 290 is though to have a peak QE of ~82% and TDN <0.8e, dang close to photon counting.  The ASI1600 isn't that good on either spec bit it's kind of the first gen.

 

FirstC8, EMCCD vs ASI290 information is being published by others.  Expect it to be in the JDSO soon.  Triple correlation is being used on star fields and extended objects: it goes by a few names and is Fourier based. 

 

Peter, for most CMOS, the Sensor is the camera, so all that "stuff" is in the sensor. There's a lot going on in a CMOS sensor so not as simple as the a CCD nor is the answer.  There are also a lot of semiconductor techniques for cooling, sleeping and otherwise.  I have no idea how this will turn out... or how QHY is limiting "Amp glow".


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#212 Thirteen

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Posted 07 May 2016 - 01:39 PM

Well with AstroLive USB coming out very soon, and owning a C11 EdgeHD Hyperstar, I decided to order the color version of the cooled ASI1600. I also ordered the EOS adapter and the holder ring for the ASI1600 cooled so I can also use the camera with my EOS lenses for very wide field. 

 

I think that is an exciting choice and one I contemplated.  Yes it would be nice to have mono and filter wheel and could be possible, but that's a great "grab and go" option, for less than an astro modded DSLR.  You could take a lightweight system out and be going in no time.


Edited by Thirteen, 07 May 2016 - 01:41 PM.

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#213 Goofi

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Posted 07 May 2016 - 01:48 PM

 

 

Since I made the mistake of posting this question during the middle of this morning's testosterone match, I'll post it again with the hope that folks have cooled down enough to get back to a thought provoking discussion...

 

Perhaps folks can elaborate for us less experienced imagers: What indicator(s) in the spec sheet shows a more competent ability to do more/shorter subs as opposed to the fewer/longer subs?

 

 

I see the ability to use a widely variable gain, at very high gain (as little as ~0.2e-/ADU), with extremely low read noise around 1.2e-, with very low dark current around 0.0062e-/s, as well as the ability to record video (namely to uncompressed .ser) as the things that improve this camera's capability when it comes to doing higher speed imaging, lots of short subs. 

 

 

This is the first I've seen the dark current reported. Assuming Jon's numbers are good (I imagine they are), this means dark current noise will equal read noise in about 4 minutes of exposure (232 seconds:  r^2/d, 1.2*1.2/0.0062). For comparison, it's over 2 hours with my Sony 694 sensor.


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#214 FirstC8

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Posted 07 May 2016 - 02:06 PM

Well with AstroLive USB coming out very soon, and owning a C11 EdgeHD Hyperstar, I decided to order the color version of the cooled ASI1600. I also ordered the EOS adapter and the holder ring for the ASI1600 cooled so I can also use the camera with my EOS lenses for very wide field.


You could even try to ask Sam if he would let you test this setup for him, no waiting list and less cost.

#215 bobzeq25

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Posted 07 May 2016 - 02:10 PM

 

Since I made the mistake of posting this question during the middle of this morning's testosterone match, I'll post it again with the hope that folks have cooled down enough to get back to a thought provoking discussion...

 

Perhaps folks can elaborate for us less experienced imagers: What indicator(s) in the spec sheet shows a more competent ability to do more/shorter subs as opposed to the fewer/longer subs?

 

Mostly low read noise.  Read noise accumulates which each sub, if your camera has low read noise, more and shorter subs become more attractive.  With low read noise, theoretically, something like 30X30" can be equivalent to 6X150".  Many might find that easier to track with an inexpensive mount.

 

As Jon stated above, rapid download speed and low dark current also count.  A few people have been doing hundreds or thousands of subs on DSOs already, the CMOS cameras characteristics open up the possibility to a wider group of imagers.  That opens up the additional possibility of fighting seeing by throwing away a lot of subs.

 

Like most of AP, it gets complicated.  Here's a fairly simple discussion:

 

http://www.samirkhar...-exposures.html

 

And, a more complicated one.

 

http://www.cloudynig...ficiency samir


Edited by bobzeq25, 07 May 2016 - 02:16 PM.

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#216 Jon Rista

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Posted 07 May 2016 - 02:22 PM

 

 

 

Since I made the mistake of posting this question during the middle of this morning's testosterone match, I'll post it again with the hope that folks have cooled down enough to get back to a thought provoking discussion...

 

Perhaps folks can elaborate for us less experienced imagers: What indicator(s) in the spec sheet shows a more competent ability to do more/shorter subs as opposed to the fewer/longer subs?

 

 

I see the ability to use a widely variable gain, at very high gain (as little as ~0.2e-/ADU), with extremely low read noise around 1.2e-, with very low dark current around 0.0062e-/s, as well as the ability to record video (namely to uncompressed .ser) as the things that improve this camera's capability when it comes to doing higher speed imaging, lots of short subs. 

 

 

This is the first I've seen the dark current reported. Assuming Jon's numbers are good (I imagine they are), this means dark current noise will equal read noise in about 4 minutes of exposure (232 seconds:  r^2/d, 1.2*1.2/0.0062). For comparison, it's over 2 hours with my Sony 694 sensor.

 

 

For the record, that is at -20C...but even at -15C it is still very good at ~0.008e-/s. Here is my reference:

 

https://www.facebook...?type=3

 

I am also curious what the dark current in your camera is? If it is similar to other Sony's, I suspect ~0.003e-/s? The reason it takes longer to equal read noise, is read noise is a lot higher (once squared):

 

1.2^2 = 1.44e-

5^2 = 25e-

 

I am also curious what this metric, how long it takes dark current to equal read noise, actually means? (Honest question.)

 

Just thinking out loud here... Read noise is a constant addition to each frame, while dark current grows with exposure time. Dark current is then more like object signal and skyglow in that it is Poisson. It is also still likely to be completely swamped by skyglow if you expose long enough (and not yet sure how long that would be with NB using this sensor), since dark current noise at 232 seconds would only be 1.19e-. You only need a 24e- skyglow signal to sufficiently swamp that, whereas you need a 100e- signal to swamp 5e- read noise... It would seem as though it would still be better to expose for longer if that is what it took to get the skyfog level to 25e-, 30e-, even 50e-, than to stop exposing when dark current reached the same level as read noise, because otherwise you would have to add more frames together, which means you would be adding more total read noise (whereas dark current noise is going to be the same relative to other noise terms regardless of the number of frames you stack.)


Edited by Jon Rista, 07 May 2016 - 02:40 PM.


#217 JMW

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Posted 07 May 2016 - 05:30 PM

I found out today that the just released AstroLive USB is free for use with the ZWO ASI cameras. I am running it right now on my Windows 10 laptop hooked to a ASI174MM camera on a SVR90T pointed at trees across the street. It will be a couple of more days before the rain goes away and I can play with it under the stars. It may be June before I see my ASI1600 color cooled camera.

 

You can download the AstroLive USB software at:

 

astrolive.io


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#218 Thirteen

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Posted 07 May 2016 - 08:38 PM

 

 

 

 

The 1600 is not really new, it fits in the complete lineup of new CMOS and those have already produced magnificent images ...

Another ASI user beating the crap out of most CCD imagers;
http://www.astrobin....users/Thirteen/

Now that's funny! Beating the crap outta who? His planetary images are magnificent, but that's about where it ends. The tech will get there, but right now it's not ready for prime time for astroimaging. Technology, no matter how great, cannot change the laws of physics and light. Can they change the efficiency of how many photons are converted to electrons? sure, but faint detail with short exposures is no where close. There are many chips which much greater efficiency currently, but most of us can't afford them.
Aww come on, I didn't ask for this.

Come on Mike?!?! He's not selling these or pushing them on anyone. Just sharing his work and helping others out. Doesn't seem to be a need to put down his images which many people are very impressed by. Just unnecessary.

 

 

Josh,  I'm not slamming the work, I'm responding to this untrue comment "Another ASI user beating the crap out of most CCD imagers" That's simply a false statement looking at the work, and is derogatory towards others.  The planetary quality totally smoked my attempts from years past. I think there's a ton of ccd imagers that are on here not having "the crap beat out of them" by that camera. I'm not even against CMOS, I think the market will be there in 3-5 years.

 

 

In full disclosure, I'm not that sensitive.  And, thanks for the compliments on the planetary.  I'm proud to have gotten where I have with that, finally.   

 

It's important to note that I didn't claim to be beating the crap of anyone.   I've tried to politely sidestep the back-and-forth.   I don't really know why I was pulled into this, besides obviously some people think the results are worth consideration.  We all know how much the processing and acquisition has to do with your outcome, also.   I'm slowly working through those skills. 

 

I will leave you with this, though:

 

EdgeHD 8"

.7x Reducer

Moonlite 2.5" CHL

Orion TOAG with ASI120MM

ZWO LRGB and FW

ASI174MM-Cool

 

...for less cash than a new QSI683-wsg8.    

 

And yes, add a 2.5x powermate and take out the reducer and there you have my planetary setup. 


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#219 Goofi

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Posted 07 May 2016 - 10:23 PM

Jon, my Atik's dark current is about 1/2 of what you thought ... 0.0014 e-/s (at -10C, which is what I image at) when I measured using Pixinsight; that's comparable to other Sony 694's I've seen.  Oh, and I got the formula from this post (just making clear the source).

 

I think we're in agreement on your analysis of the specs. 

 

I want to repeat, I don't have a problem with CMOS sensors ... but I think some of the claims people are making are over-inflated. I image in narrowband, and I see CMOS lagging here.  I also think a test of dim targets is a better test than of a bright, easily imaged target.



#220 dr.who

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Posted 07 May 2016 - 10:55 PM

OK folks. This is the first and last warning. Any more off topic or less than polite posts and this thread will be well and done.

#221 rkayakr

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Posted 08 May 2016 - 08:41 AM

Ok new question.

If BSI is the holly grail of CMOS, despite price drop still profibitively expensive for most of us, then why isn't any of them introduce some smaller BSI chip cameras and sell more of them?

Most faint DSOs have narrow FOV, can really benefit from the high QE and low noise, while chip size can be small.

ZWO has been there and done that: ASI178mm and ASI178mc

Sony IMX178 STARVIS and Exmor R sensor. 6 million, 2.4 um, BSI pixels on a 11 mm diagonal sensor with a 14 bit ADC

I have the ASI178mc and it is a great camera for some uses.


Edited by rkayakr, 08 May 2016 - 09:58 AM.


#222 bobzeq25

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Posted 08 May 2016 - 09:08 AM

Ok new question.

If BSI is the holly grail of CMOS, despite price drop still profibitively expensive for most of us, then why isn't any of them introduce some smaller BSI chip cameras and sell more of them?

Most faint DSOs have narrow FOV, can really benefit from the high QE and low noise, while chip size can be small.

I'm a car enthusiast (used to race), and this kind of question frequently shows up on car enthusiast boards.  The default answer applies here.

 

Because they don't think it would make them enough money to bring out the product.  What some enthusiasts want (often including some enthusiasts within the company) often doesn't pass muster with the business manager.

 

By the way, don't know if this has been explicit before.  The reason the 1600 is 12 bit is that first they chose what they thought would be a good chip (high sensitivity, low noise).  Maybe one where they could easily source a mono version.  That CMOS chip has 12 bit analog to digital conversion integrated in.   They no doubt thought the compromise (a small limitation on dynamic range at low gain levels) would be acceptable to most customers, especially at this price point.  12 stops of dynamic range is a good number.  Another business decision.

 

Does CMOS always have ADC on the chip, or just usually?


Edited by bobzeq25, 08 May 2016 - 09:11 AM.


#223 FirstC8

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Posted 08 May 2016 - 12:57 PM


Ok new question.

If BSI is the holly grail of CMOS, despite price drop still profibitively expensive for most of us, then why isn't any of them introduce some smaller BSI chip cameras and sell more of them?

Most faint DSOs have narrow FOV, can really benefit from the high QE and low noise, while chip size can be small.

ZWO has been there and done that: ASI178mm and ASI178mc
Sony IMX178 STARVIS and Exmor R sensor. 6 million, 2.4 um, BSI pixels on a 11 mm diagonal sensor with a 14 bit ADC
I have the ASI178mc and it is a great camera for some uses.

You are right I forgot about the 178 BSI, we now also have the 290 BSI from both manufactures.

#224 gregj888

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Posted 08 May 2016 - 01:30 PM

Bob,

 

There's an amp and ADC per row or column, so 1k and up. This is also the primary source of Fixed Pattern Noise as well as the speed (FPS).  Also note that you never get raw data out of a CMOS sensor (without special setups anyway).  That's why I use TDN for CMOS and not "read noise"...  and why you have to be careful calibrating CMOS, discussed in other threads (solar system imaging).

 

sCMOS don't always work this way, but I'm not sure I can tell you more than that.  The sCMOS I've looked at have the sensor matrix on one chip and the ADC/Amps etc are on another.

 

There's not a lot of reason to have more bits than it takes to encode the well depth at 1e/ADU.  If you want/need more dynamic range you can simply stack more frame.  With TDN <1-2e, there isn't the penalty there was at 20e with the older sensors.  Most of the CMOS sensor go from about 4e/ADU to about 0.2e/ADU... so things are covered.

 

Most of the CMOS sensors also have imaging modes, including a HDR (High Dynamic Range) setting.  This mode will  typically takes 3 different exposures and combines the for a final image... all on sensor.  Not that useful for Astronomy, but it's there.  My Flea 3 CCD camera can do the same, but it's not done on the sensor, I don't use it there either :-).



#225 rocketdog

rocketdog

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Posted 08 May 2016 - 02:38 PM

If I had known this camera was around the corner 6 months ago I would have held back from purchasing an 8300 camera.  Also I would love the possibility of lucky imaging and planetary. But you pays your money and takes your chances. I will take heart from some of the stunning images produced with the chip in my camera, and watch in genuine anticipation of what this new camera can do in the hands of some of you guys buying it.




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