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Antiblooming cameras?

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  • pappayliou
    Rob s book categorizes cameras as either antiblooming or non-antiblooming. How does one tell which is which? I have a ZWO ASI1600MM-cool and, so far as I can
    Message 1 of 11 , May 5, 2017

      Rob's book categorizes cameras as either antiblooming or non-antiblooming. How does one tell which is which? I have a ZWO ASI1600MM-cool and, so far as I can tell, none of the literature/specs use those terms. In fact, I cannot recall any of the cameras I considered specifying that characteristic.


      Thanks for you help


      Regards, George

    • Stu Beaber
      Take a pix of a bright star...if you get a vertical spike coming off it then it s non-antiblooming...there is software to remove those spikes Stu wd4sel.com
      Message 2 of 11 , May 5, 2017
        
        Take a pix of a bright star...if you get a vertical spike coming off it then it's non-antiblooming...there is software to remove those spikes
         
        Stu
        wd4sel.com
         
        ----- Original Message -----
        Sent: Friday, May 05, 2017 4:18 AM
        Subject: [ccd-newastro] Antiblooming cameras?

         

        Rob's book categorizes cameras as either antiblooming or non-antiblooming. How does one tell which is which? I have a ZWO ASI1600MM-cool and, so far as I can tell, none of the literature/specs use those terms. In fact, I cannot recall any of the cameras I considered specifying that characteristic.


        Thanks for you help


        Regards, George

      • Ron Wodaski
        Blooming or anti-blooming are actually characteristics of the chip in the camera. If you can find out what the chip is, then you can look at the specifications
        Message 3 of 11 , May 5, 2017
          Blooming or anti-blooming are actually characteristics of the chip in the camera. If you can find out what the chip is, then you can look at the specifications for the chip to find out what type it is.

          That camera’s web page doesn’t specify the exact chip used, but it does note that it is a CMOS-type sensor, not CCD. So the question is automatically answered: CMOS chips are anti-blooming by the nature of the way they capture and move charge. The conversion to voltage happens right in the pixel; there is no charge transfer as there is on a CCD chip. (Some CCD chips have circuitry to bleed off the excess charge, and those are the anti-blooming CCD chips)

          Ron Wodaski
          rwodaski@...



          On May 5, 2017, at 2:18 AM, w3gp@... [ccd-newastro] <ccd-newastro@yahoogroups.com> wrote:


          Rob's book categorizes cameras as either antiblooming or non-antiblooming. How does one tell which is which? I have a ZWO ASI1600MM-cool and, so far as I can tell, none of the literature/specs use those terms. In fact, I cannot recall any of the cameras I considered specifying that characteristic.


          Thanks for you help


          Regards, George



        • Tim Walters
          Hi George, You wrote about Rob s book... Would you please tell me which book you re speaking of? Thanks! Tim On Fri, May 5, 2017 at 4:18 AM, w3gp@arrl.net
          Message 4 of 11 , May 5, 2017
            Hi George,

            You wrote about "Rob's book..."
            Would you please tell me which book you're speaking of?

            Thanks!

            Tim

            On Fri, May 5, 2017 at 4:18 AM, w3gp@... [ccd-newastro] <ccd-newastro@yahoogroups.com> wrote:
             

            Rob's book categorizes cameras as either antiblooming or non-antiblooming. How does one tell which is which? I have a ZWO ASI1600MM-cool and, so far as I can tell, none of the literature/specs use those terms. In fact, I cannot recall any of the cameras I considered specifying that characteristic.


            Thanks for you help


            Regards, George


          • pappayliou
            Thanks to all who replied. I new this camera had a CMOS chip and not a CCD. I didn t realize that all such chips are inherently anti-blooming. Actually there s
            Message 5 of 11 , May 5, 2017
              Thanks to all who replied. I new this camera had a CMOS chip and not a CCD. I didn't realize that all such chips are inherently anti-blooming. Actually there's quite a bit I don't realize as I've only this gear (camera, EFW and OAG/camera) a few days and have yet to set up at night. Previously I used an APS-sized DSLR and the learning curve seems pretty steep. That's why Ron book has been such a useful primer even though it appears ere has been a fair bit of technical development since it was written. As for my choice of a CMOS chip camera while I understand that it is not as capable as a CCD some astrophotographers whom I heard speak suggested that the gap was closing and that it would provide decent value for money at the entry level.

              Again thanks to all.

              Regards, George
            • stan_ccd
              CMOS (e.g. DSLR & ZWO) do not (and cannot) bloom due to readout circuitry integral to CMOS. Very few modern CCD bloom. It is really only a concern if you are
              Message 6 of 11 , May 5, 2017
                CMOS (e.g. DSLR & ZWO) do not (and cannot) bloom due to readout circuitry integral to CMOS.

                Very few modern CCD bloom. It is really only a concern if you are getting old used equipment or an expensive specialty cam. 

                Blooming is a sign of high QE (anti-bloom circuits harm QE) so it is not to be avoided if you want maximum performance. But the pretty-pic crowd cares less about real performance than prettiness. Strangely though many affix or paste phony diffraction spikes to prettify a pic but have conniption fits over blooms! <g>

                Consumer level CCDs are almost extinct. Kodak is dead, though the corpse has been partially reanimated by "TrueSense", Sony has shut down all CCD production.  It may not be long before there are no amateur CCD cams because there will be no mass produced CCDs and custom CCDs are very expensive.  This could be very unfortunate for some types of astro-imaging (esp DS).

                I'm experimenting with the ZWO 1600 and it is promising but definitely has problems with low flux (e.g. the notorious unstable "banding" that is a signature of CMOS).

                Stan
              • Lunam Seagull
                excuse my ignorance but what is this bloming/antiblooming and why is it important?Manny La unica limitante al exito es nuestra propia actitud derrotista y el
                Message 7 of 11 , May 5, 2017
                  excuse my ignorance but
                  what is this bloming/antiblooming and why is it important?
                  Manny 
                  La unica limitante al exito es nuestra propia actitud
                  derrotista y el temor a vivir la vida....
                  http://members.tripod.com/~Gandalf001/index.html

                  The only limitation to succeed is our own attitude and
                  the fear to live the life
                  http://members.tripod.com/~Gandalf001/English/index.html



                  From: "Ron Wodaski rwodaski@... [ccd-newastro]" <ccd-newastro@yahoogroups.com>
                  To: ccd-newastro@yahoogroups.com; w3gp@...
                  Sent: Friday, May 5, 2017 7:54 AM
                  Subject: Re: [ccd-newastro] Antiblooming cameras?

                   
                  Blooming or anti-blooming are actually characteristics of the chip in the camera. If you can find out what the chip is, then you can look at the specifications for the chip to find out what type it is.

                  That camera’s web page doesn’t specify the exact chip used, but it does note that it is a CMOS-type sensor, not CCD. So the question is automatically answered: CMOS chips are anti-blooming by the nature of the way they capture and move charge. The conversion to voltage happens right in the pixel; there is no charge transfer as there is on a CCD chip. (Some CCD chips have circuitry to bleed off the excess charge, and those are the anti-blooming CCD chips)

                  Ron Wodaski
                  rwodaski@...



                  On May 5, 2017, at 2:18 AM, w3gp@... [ccd-newastro] <ccd-newastro@yahoogroups.com> wrote:


                  Rob's book categorizes cameras as either antiblooming or non-antiblooming. How does one tell which is which? I have a ZWO ASI1600MM-cool and, so far as I can tell, none of the literature/specs use those terms. In fact, I cannot recall any of the cameras I considered specifying that characteristic.

                  Thanks for you help

                  Regards, George




                • Ron Wodaski
                  It’s a topic that runs right through astronomical imaging. Blooming occurs when photons accumulate to saturation level in a pixel. (Larger pixels can
                  Message 8 of 11 , May 5, 2017
                    It’s a topic that runs right through astronomical imaging.

                    Blooming occurs when photons accumulate to saturation level in a pixel. (Larger pixels can typically collect more photons before they saturate.) Once saturation occurs, the data begins to overflow (unless there is an anti blooming circuit built in, which removes the charge downward, rather than letting it leak sideways into other pixels). The brighter the star, the greater the overflow and the larger the bloom into other pixels.

                    The quick points:

                    * A camera that blooms is typically using a CCD chip. It is likely to have higher quantum efficiency than an anti blooming, for several reasons. One, CCD is a more sensitive technology. Two, many anti-blooming cameras use CMOS technology, which is inherently less sensitive (but has other advantages). 

                    * There are CCD chips that have anti-blooming circuits, but they are moving current away from pixels, and are also inherently less sensitive.

                    So one reason to get a blooming chip is that is is more sensitive. The downside are, of course, the blooms on stars that are bright enough to cause them. That’s an oversimplification; it’s  a deep topic. 

                    Ron Wodaski
                    rwodaski@...



                    On May 5, 2017, at 2:13 PM, Lunam Seagull seagull001@... [ccd-newastro] <ccd-newastro@yahoogroups.com> wrote:


                    excuse my ignorance but 
                    what is this bloming/antiblooming and why is it important?
                    Manny 
                    La unica limitante al exito es nuestra propia actitud 
                    derrotista y el temor a vivir la vida.... 
                    http://members.tripod.com/~Gandalf001/index.html 

                    The only limitation to succeed is our own attitude and 
                    the fear to live the life 
                    http://members.tripod.com/~Gandalf001/English/index.html



                    From: "Ron Wodaski rwodaski@... [ccd-newastro]" <ccd-newastro@yahoogroups.com>
                    To: ccd-newastro@yahoogroups.com; w3gp@... 
                    Sent: Friday, May 5, 2017 7:54 AM
                    Subject: Re: [ccd-newastro] Antiblooming cameras?

                     
                    Blooming or anti-blooming are actually characteristics of the chip in the camera. If you can find out what the chip is, then you can look at the specifications for the chip to find out what type it is.

                    That camera’s web page doesn’t specify the exact chip used, but it does note that it is a CMOS-type sensor, not CCD. So the question is automatically answered: CMOS chips are anti-blooming by the nature of the way they capture and move charge. The conversion to voltage happens right in the pixel; there is no charge transfer as there is on a CCD chip. (Some CCD chips have circuitry to bleed off the excess charge, and those are the anti-blooming CCD chips)

                    Ron Wodaski
                    rwodaski@...



                    On May 5, 2017, at 2:18 AM, w3gp@... [ccd-newastro] <ccd-newastro@yahoogroups.com> wrote:


                    Rob's book categorizes cameras as either antiblooming or non-antiblooming. How does one tell which is which? I have a ZWO ASI1600MM-cool and, so far as I can tell, none of the literature/specs use those terms. In fact, I cannot recall any of the cameras I considered specifying that characteristic.

                    Thanks for you help

                    Regards, George






                  • Lunam Seagull
                    Thank you so much for explaining that to me Manny ... Thank you so much for explaining that to me Manny On May 5, 2017, at 17:20, Ron Wodaski rwodaski@me.com
                    Message 9 of 11 , May 5, 2017
                      Thank you so much for explaining that to me
                      Manny

                      On May 5, 2017, at 17:20, Ron Wodaski rwodaski@... [ccd-newastro] <ccd-newastro@yahoogroups.com> wrote:

                       

                      It’s a topic that runs right through astronomical imaging.


                      Blooming occurs when photons accumulate to saturation level in a pixel. (Larger pixels can typically collect more photons before they saturate.) Once saturation occurs, the data begins to overflow (unless there is an anti blooming circuit built in, which removes the charge downward, rather than letting it leak sideways into other pixels). The brighter the star, the greater the overflow and the larger the bloom into other pixels.

                      The quick points:

                      * A camera that blooms is typically using a CCD chip. It is likely to have higher quantum efficiency than an anti blooming, for several reasons. One, CCD is a more sensitive technology. Two, many anti-blooming cameras use CMOS technology, which is inherently less sensitive (but has other advantages). 

                      * There are CCD chips that have anti-blooming circuits, but they are moving current away from pixels, and are also inherently less sensitive.

                      So one reason to get a blooming chip is that is is more sensitive. The downside are, of course, the blooms on stars that are bright enough to cause them. That’s an oversimplification; it’s  a deep topic. 

                      Ron Wodaski
                      rwodaski@...



                      On May 5, 2017, at 2:13 PM, Lunam Seagull seagull001@... [ccd-newastro] <ccd-newastro@yahoogroups.com> wrote:


                      excuse my ignorance but 
                      what is this bloming/antiblooming and why is it important?
                      Manny 
                      La unica limitante al exito es nuestra propia actitud 
                      derrotista y el temor a vivir la vida.... 
                      http://members.tripod.com/~Gandalf001/index.html 

                      The only limitation to succeed is our own attitude and 
                      the fear to live the life 
                      http://members.tripod.com/~Gandalf001/English/index.html



                      From: "Ron Wodaski rwodaski@... [ccd-newastro]" <ccd-newastro@yahoogroups.com>
                      To: ccd-newastro@yahoogroups.com; w3gp@... 
                      Sent: Friday, May 5, 2017 7:54 AM
                      Subject: Re: [ccd-newastro] Antiblooming cameras?

                       
                      Blooming or anti-blooming are actually characteristics of the chip in the camera. If you can find out what the chip is, then you can look at the specifications for the chip to find out what type it is.

                      That camera’s web page doesn’t specify the exact chip used, but it does note that it is a CMOS-type sensor, not CCD. So the question is automatically answered: CMOS chips are anti-blooming by the nature of the way they capture and move charge. The conversion to voltage happens right in the pixel; there is no charge transfer as there is on a CCD chip. (Some CCD chips have circuitry to bleed off the excess charge, and those are the anti-blooming CCD chips)

                      Ron Wodaski
                      rwodaski@...



                      On May 5, 2017, at 2:18 AM, w3gp@... [ccd-newastro] <ccd-newastro@yahoogroups.com> wrote:


                      Rob's book categorizes cameras as either antiblooming or non-antiblooming. How does one tell which is which? I have a ZWO ASI1600MM-cool and, so far as I can tell, none of the literature/specs use those terms. In fact, I cannot recall any of the cameras I considered specifying that characteristic.

                      Thanks for you help

                      Regards, George






                    • Michael Larson
                      What is Rob s Book ? Curious, if CMOS sensors don t do binning how does that affect sensitivity on faint objects? Or is stacking the cure? Mike On Fri, May 5,
                      Message 10 of 11 , May 6, 2017
                        What is "Rob's Book"?

                        Curious, if CMOS sensors don't do binning how does that affect sensitivity on faint objects? Or is stacking the cure?


                        Mike


                        On Fri, May 5, 2017 at 4:46 PM, Lunam Seagull seagull001@... [ccd-newastro] <ccd-newastro@yahoogroups.com> wrote:
                         

                        Thank you so much for explaining that to me
                        Manny

                        On May 5, 2017, at 17:20, Ron Wodaski rwodaski@... [ccd-newastro] <ccd-newastro@yahoogroups.com> wrote:

                         

                        It’s a topic that runs right through astronomical imaging.


                        Blooming occurs when photons accumulate to saturation level in a pixel. (Larger pixels can typically collect more photons before they saturate.) Once saturation occurs, the data begins to overflow (unless there is an anti blooming circuit built in, which removes the charge downward, rather than letting it leak sideways into other pixels). The brighter the star, the greater the overflow and the larger the bloom into other pixels.

                        The quick points:

                        * A camera that blooms is typically using a CCD chip. It is likely to have higher quantum efficiency than an anti blooming, for several reasons. One, CCD is a more sensitive technology. Two, many anti-blooming cameras use CMOS technology, which is inherently less sensitive (but has other advantages). 

                        * There are CCD chips that have anti-blooming circuits, but they are moving current away from pixels, and are also inherently less sensitive.

                        So one reason to get a blooming chip is that is is more sensitive. The downside are, of course, the blooms on stars that are bright enough to cause them. That’s an oversimplification; it’s  a deep topic. 

                        Ron Wodaski
                        rwodaski@...



                        On May 5, 2017, at 2:13 PM, Lunam Seagull seagull001@... [ccd-newastro] <ccd-newastro@yahoogroups.com> wrote:


                        excuse my ignorance but 
                        what is this bloming/antiblooming and why is it important?
                        Manny 
                        La unica limitante al exito es nuestra propia actitud 
                        derrotista y el temor a vivir la vida.... 
                        http://members.tripod.com/~ Gandalf001/index.html 

                        The only limitation to succeed is our own attitude and 
                        the fear to live the life 
                        http://members.tripod.com/~ Gandalf001/English/index.html



                        From: "Ron Wodaski rwodaski@... [ccd- newastro]" <ccd-newastro@yahoogroups.com>
                        To: ccd-newastro@yahoogroups. com; w3gp@... 
                        Sent: Friday, May 5, 2017 7:54 AM
                        Subject: Re: [ccd-newastro] Antiblooming cameras?

                         
                        Blooming or anti-blooming are actually characteristics of the chip in the camera. If you can find out what the chip is, then you can look at the specifications for the chip to find out what type it is.

                        That camera’s web page doesn’t specify the exact chip used, but it does note that it is a CMOS-type sensor, not CCD. So the question is automatically answered: CMOS chips are anti-blooming by the nature of the way they capture and move charge. The conversion to voltage happens right in the pixel; there is no charge transfer as there is on a CCD chip. (Some CCD chips have circuitry to bleed off the excess charge, and those are the anti-blooming CCD chips)

                        Ron Wodaski
                        rwodaski@...



                        On May 5, 2017, at 2:18 AM, w3gp@... [ccd- newastro] <ccd-newastro@yahoogroups.com> wrote:


                        Rob's book categorizes cameras as either antiblooming or non-antiblooming. How does one tell which is which? I have a ZWO ASI1600MM-cool and, so far as I can tell, none of the literature/specs use those terms. In fact, I cannot recall any of the cameras I considered specifying that characteristic.

                        Thanks for you help

                        Regards, George









                        --
                        Mike Larson

                        "Our Constitution was made only for a moral and religious people. It is wholly inadequate to the government of any other."

                        John Adams



                      • stan_ccd
                        CMOS ... gap was closing and that it would provide decent value for money at the entry level. For sure. ZWO prices are remarkable and the quality is pretty
                        Message 11 of 11 , May 6, 2017
                          "CMOS ... gap was closing and that it would provide decent value for money at the entry level."

                          For sure. ZWO prices are remarkable and the quality is pretty good. But the cameras are less than perfect. I have 3 of them and they are all problematic in some way or another though each newer one is an improvement over earlier ones.  

                          In practice, CMOS is more complicated than CCD and more difficult to optimize. They originated as video cams adapted for lunar/planetary lucky imaging.  Only the most recent are really usable for deep space (esp the cooled 1600).  It can be tricky to figure out appropriate gain and exp times. And calibration is too often unpredictable and inadequate.  But there is some real potential...

                          Stan
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