Date   

Re: To bin or not to bin ..

cstockies
 

Hi Rolando,


The benefits of binning depend on the camera, for example is it using on chip binning or software? Is the read noise the same when being read 2x2 as 1x1 or is it different? 


I've used 2 x SBIG ST10XME and currently use an STT3200 binned 2x2 on a CDK12.5. Both use the  KAF3200 CCD and the image scale is 0.55"/px unbinned. Additionally, chip linearity is an issue with precise photometry and binning can provide some benefits in this situation.


My testing has shown that:

1. With 2x2 binning the read noise is about 1/4 of the four reads from a 1x1 image.

2. For the KAF3200 the linearity goes off from about 19000 counts when binned 1x1 . By 35000 counts it's off by 10%. I didn't test any higher so I don't know just how far it drops off.

3. Binned 2x2 it is linear through to 64000 counts when imaging an evenly illuminated target (which a star field isn't - the star centroid will tend to be over one pixel more so than the others in the 2x2 bin - so in practice it will be somewhat less than this).

4. The images are 1/4 the storage! (which can be important for long time series work).


Interesting the ST-8XME (KAF1603) is linear through to 39,000 counts with 1x1 binning and the read noise looks to be a bit higher for a 2x2 read as opposed to a 1x1 read, still a bit less overall.


I have seen a camera based on a Sony chip (I can't recall the details) where binning is performed by the software, which really loses any advantage that binning would have provided.


It looks like for your camera that 1x1 is the way to go. What make/model camera did you use for the photos?


Regards,

Chris


Re: To bin or not to bin ..

David Pearson
 

I always like to see real data comparisons like these. I also agree that luminance should always be binned 1x1. However, for those whom are just starting out, be careful about applying this result to blindly to RGB. Whether you bin RGB depends on your seeing, image scale, camera binned characteristics, object being imaged, and personal preference. It is impossible to have only one binning guideline for all conditions or equipment. Note, there is an image scale for each seeing condition that will not cost a lot of resolution when binning 2x2. Binning 2x2 does not for every camera double the signal and may not reduce the read noise contribution to noise. Some cameras will limit the signal while binning. Also, beware when it is said that binning by itself reduces total exposure time. That is only true if you give up signal and therefore color. How much signal or color you are willing to lose is dependent on your personal preference. In the majority of cases, bin2 will have more signal then bin1. this addition signal can be traded for reduce total exposure time until the bin1 signal level is reached. Of course, you can reduce below the bin 1 signal level, but you will lose color below that obtained by using bin1. And that is personal preference to what you consider a "pretty picture".
Dave


Re: APCC Weather Station Support

Ron Kramer
 

Is there any way to get  Sky quality and seeing info in the environment tab os SGP?  (local station?)


On Fri, Nov 10, 2017 at 9:52 PM, gshaughnessy@... [ap-gto] <ap-gto@...> wrote:
 

I would also be interested in connectivity with weather underground.  I currently have my own home-built weather station with a cloud sensor and sky quality meter.  If I could push those to WU and pull them using the ASCOM driver for WU, that would make things so much easier.  


Cheers,
Gabe



Re: To bin or not to bin ..

CurtisC
 

I think the more usual question is about binning the RGB exposures.  The luminance should always be unbinned.  In my own work, everything is unbinned.


Re: Ground loops

Christopher Erickson
 

I think you have misunderstood my attempts at moderation advice on that CN
thread.

Electricity and grounding are two things that can risk life and property if
done incorrectly.

Statistically in the US, one person dies every day by electrocution and one
person dies every fours days from an electrical fire. The majority of these
deaths are caused by common 120 volt AC systems.

Handing out random electrical advice openly on the Internet without
appropriate training, credentials, liability insurance or strong disclaimers
simply isn't very prudent.

I am all for discussing electrical systems and grounding but I will always
point people to local professional assistance when things might be taken
beyond theoretical discussion.

Everyone else should too. Including electricians and electrical engineers.

I hope this helps.


-Christopher Erickson
Observatory engineer
Summit Kinetics
Waikoloa, HI 96738
www.summitkinetics.com

-----Original Message-----
From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]
Sent: Saturday, November 11, 2017 10:09 AM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] RE: Ground loops

Hi Lance,
As the original poster on the CN forum I would advise reading the CN posts
with a strong sense of caution and irony.
As previously noted, any professionals with experience in this area were
strongly discouraged from offering advice to anyone concerned with ground
loops.
That essentially left the responding field to people who think they know
what they're talking about and one or two professionals who weren't afraid
of being sued because of offering some general information on the internet.
Ground loops, though low voltage, can affect imaging results and under
certain circumstances can cause damage to electronic equipment. It's worth
it to spend the time and effort to prevent them.

dan kowall
photonhunter.com


--------------------------------------------
On Thu, 11/9/17, calypte@verizon.net [ap-gto] <ap-gto@yahoogroups.com>
wrote:

Subject: [ap-gto] RE: Ground loops
To: ap-gto@yahoogroups.com
Date: Thursday, November 9, 2017, 3:35 AM

Hi, Lance.  Greetings from a fellow Palomar Observatory docent.  You
should go over to the CN observatories forum.  Within the past few days
there has been a big discussion of grounding issues, including
participation by Chris Erickson.  Unfortunately, you may find that the more
someone knows about electrical engineering, the more reluctant they may be
to offer advice, since they haven't seen your setup, and they don't want
to be responsible for offering a recommendation that may work in some cases
but not yours.

Posted by: calypte@verizon.net




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Re: To bin or not to bin ..

Stuart Heggie <stuart.j.heggie@...>
 

Rolando, this is a very powerful argument for 1x1 binning. I don't bin ever and now I'm feeling better about that choice.

Stuart

On Sat, Nov 11, 2017 at 6:58 PM, chris1011@... [ap-gto] <ap-gto@...> wrote:
 

..that is the question (apologies to the Bard)

I had heard from various sources that 2x2 binning would result in higher signal to noise than 1x1 binning. And you could cut the exposure in half, at the cost of some loss of resolution. If the focal length is long so that you over sample, then binning should give you a leg up. Well here is the result, side by side images, for your examination.

17"F8 astrograph 0.54 arc sec/pixel @1x1 bin, 1.08 arc sec/pixel @2x2 bin, STL11K camera

https://www.astromart.com/common/image_popup.asp?image=/images/forums/836000-836999/836517.jpg&caption=

On the left is 2x2 binning 26x600sec (4.3hours total exposure)
On the right is 1x1 binned 10x1200 sec (3.3 hours total exposure)

Resolution is 22% better for the 1x1 binning. Note how much better the little galaxy shows up. Even though the 2x2 binned image has longer exposure, the sig/noise seems to be better in the 1x1 bin image.

Rolando





To bin or not to bin ..

Roland Christen
 

..that is the question (apologies to the Bard)

I had heard from various sources that 2x2 binning would result in higher signal to noise than 1x1 binning. And you could cut the exposure in half, at the cost of some loss of resolution. If the focal length is long so that you over sample, then binning should give you a leg up. Well here is the result, side by side images, for your examination.

17"F8 astrograph 0.54 arc sec/pixel @1x1 bin, 1.08 arc sec/pixel @2x2 bin, STL11K camera

https://www.astromart.com/common/image_popup.asp?image=/images/forums/836000-836999/836517.jpg&caption=

On the left is 2x2 binning 26x600sec (4.3hours total exposure)
On the right is 1x1 binned 10x1200 sec (3.3 hours total exposure)

Resolution is 22% better for the 1x1 binning. Note how much better the little galaxy shows up. Even though the 2x2 binned image has longer exposure, the sig/noise seems to be better in the 1x1 bin image.

Rolando


Re: Dither Sanity check

Matthew Hughes
 

Although I think a desired 2.0 the dither size of 2.0 in his example is actually “High”not “Very High” going by his scales


Re: Dither Sanity check

Tony Benjamin <tonybenjamin@...>
 

Thant is a good write up and clear.

 

Many Thanks

 

From: ap-gto@... [mailto:ap-gto@...]
Sent: Saturday, November 11, 2017 3:19 PM
To: ap-gto@...
Subject: RE: [ap-gto] Dither Sanity check

 

 

Hi Tony,

 

I found a post in the SGP forums from Andy (PHD2 Guru). Here it is if anyone else is interested.

 

http://forum.mainsequencesoftware.com/t/dither-scaling-between-sgp-and-phd/693/3


Re: Dither Sanity check

Matthew Hughes
 

Hi Tony,


I found a post in the SGP forums from Andy (PHD2 Guru). Here it is if anyone else is interested.


http://forum.mainsequencesoftware.com/t/dither-scaling-between-sgp-and-phd/693/3


Re: Dither Sanity check

Tony Benjamin <tonybenjamin@...>
 

Yeah, the amount of dither must be camera dependent. I know for the CMOS ASI1600 they recommend “Extreme” and if I was doing 5 min subs I would be dithering every frame.

 

From: ap-gto@... [mailto:ap-gto@...]
Sent: Saturday, November 11, 2017 2:52 PM
To: ap-gto@...
Subject: Re: [ap-gto] Dither Sanity check

 

 

Rolando and Tony,

 

Thanks. I’ll set say 9 seconds as I was using 3 sec exposures. Adjust as I change exposure length with seeing changes. 

With SGP I don’t think you can select a pixel dither amount. Just high to very high etc.

I’ll read the help file and see what it says about the levels. 

Thankyou again. Love the AE’s. I was guiding at 0.2 to 0.3 RMS last night from my wooden roof top balcony. Amazing.

Regards,

 

Matt Hughes


On 12 Nov 2017, at 09:43, chris1011@... [ap-gto] <ap-gto@...> wrote:

 

Yes, it should not take more than 2 or 3 guide pulses to settle after a dither. It all depends how far you are dithering. I normally dither between 3 and 5 pixels. When I am taking 5 sec guide exposures I set the delay at 15 seconds after a dither in order to have everything settle down.

Rolando

 

 

 

-----Original Message-----
From: matthughes77@... [ap-gto] <ap-gto@...>
To: ap-gto <ap-gto@...>
Sent: Sat, Nov 11, 2017 3:58 pm
Subject: [ap-gto] Dither Sanity check

Ok after a few months with the AP 1100 AE mount I tried dithering for the first time last night. Selected high dither in SGP Pro and after each 10 min sub. Imaging at 1.96 pix/arcs secs. Each dither took literally 2-3 secs. No time at all. I’ve read in forums it can take 2-3 mins with some mounts. So are my results normal? Is it due to no Dec back lash and quick response of the encoders? I was hesitant to use dithering till now due to the length of time I understood it took. However the response of the mount it was easy and quick. Are my results typical? Or am I missing something... should I use a high dither..? Bewler? Thanks Matt ------------------------------------ Posted by: matthughes77@... ------------------------------------ To UNSUBSCRIBE, or for general information on the ap-gto list see http://groups.yahoo.com/group/ap-gto ------------------------------------ Yahoo Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/ap-gto/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/ap-gto/join (Yahoo! ID required) <*> To change settings via email: ap-gto-digest@... ap-gto-fullfeatured@... <*> To unsubscribe from this group, send an email to: ap-gto-unsubscribe@... <*> Your use of Yahoo Groups is subject to: https://info.yahoo.com/legal/us/yahoo/utos/terms/


Re: Dither Sanity check

Matthew Hughes
 

Rolando and Tony,

Thanks. I’ll set say 9 seconds as I was using 3 sec exposures. Adjust as I change exposure length with seeing changes. 
With SGP I don’t think you can select a pixel dither amount. Just high to very high etc.
I’ll read the help file and see what it says about the levels. 
Thankyou again. Love the AE’s. I was guiding at 0.2 to 0.3 RMS last night from my wooden roof top balcony. Amazing.

Regards,

Matt Hughes

On 12 Nov 2017, at 09:43, chris1011@... [ap-gto] <ap-gto@...> wrote:

 

Yes, it should not take more than 2 or 3 guide pulses to settle after a dither. It all depends how far you are dithering. I normally dither between 3 and 5 pixels. When I am taking 5 sec guide exposures I set the delay at 15 seconds after a dither in order to have everything settle down.

Rolando




-----Original Message-----
From: matthughes77@... [ap-gto] <ap-gto@...>
To: ap-gto <ap-gto@...>
Sent: Sat, Nov 11, 2017 3:58 pm
Subject: [ap-gto] Dither Sanity check

Ok after a few months with the AP 1100 AE mount I tried dithering for the first time last night. Selected high dither in SGP Pro and after each 10 min sub. Imaging at 1.96 pix/arcs secs. Each dither took literally 2-3 secs. No time at all. I’ve read in forums it can take 2-3 mins with some mounts. So are my results normal? Is it due to no Dec back lash and quick response of the encoders? I was hesitant to use dithering till now due to the length of time I understood it took. However the response of the mount it was easy and quick. Are my results typical? Or am I missing something... should I use a high dither..? Bewler? Thanks Matt ------------------------------------ Posted by: matthughes77@... ------------------------------------ To UNSUBSCRIBE, or for general information on the ap-gto list see http://groups.yahoo.com/group/ap-gto ------------------------------------ Yahoo Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/ap-gto/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/ap-gto/join (Yahoo! ID required) <*> To change settings via email: ap-gto-digest@... ap-gto-fullfeatured@... <*> To unsubscribe from this group, send an email to: ap-gto-unsubscribe@... <*> Your use of Yahoo Groups is subject to: https://info.yahoo.com/legal/us/yahoo/utos/terms/


Re: Dither Sanity check

Matthew Hughes
 

Rolando and Tony,

Thanks. I’ll set say 9 seconds as I was using 3 sec exposures. Adjust as I change exposure length with seeing changes. 
With SGP I don’t think you can select a pixel dither amount. Just high to very high etc.
I’ll read the help file and see what it says about the levels. 
Thankyou again. Love the AE’s. I was guiding at 0.2 to 0.3 RMS last night from my wooden roof top balcony. Amazing.

Regards,

Matt Hughes

On 12 Nov 2017, at 09:43, chris1011@... [ap-gto] <ap-gto@...> wrote:

 

Yes, it should not take more than 2 or 3 guide pulses to settle after a dither. It all depends how far you are dithering. I normally dither between 3 and 5 pixels. When I am taking 5 sec guide exposures I set the delay at 15 seconds after a dither in order to have everything settle down.

Rolando




-----Original Message-----
From: matthughes77@... [ap-gto] <ap-gto@...>
To: ap-gto <ap-gto@...>
Sent: Sat, Nov 11, 2017 3:58 pm
Subject: [ap-gto] Dither Sanity check

Ok after a few months with the AP 1100 AE mount I tried dithering for the first time last night. Selected high dither in SGP Pro and after each 10 min sub. Imaging at 1.96 pix/arcs secs. Each dither took literally 2-3 secs. No time at all. I’ve read in forums it can take 2-3 mins with some mounts. So are my results normal? Is it due to no Dec back lash and quick response of the encoders? I was hesitant to use dithering till now due to the length of time I understood it took. However the response of the mount it was easy and quick. Are my results typical? Or am I missing something... should I use a high dither..? Bewler? Thanks Matt ------------------------------------ Posted by: matthughes77@... ------------------------------------ To UNSUBSCRIBE, or for general information on the ap-gto list see http://groups.yahoo.com/group/ap-gto ------------------------------------ Yahoo Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/ap-gto/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/ap-gto/join (Yahoo! ID required) <*> To change settings via email: ap-gto-digest@... ap-gto-fullfeatured@... <*> To unsubscribe from this group, send an email to: ap-gto-unsubscribe@... <*> Your use of Yahoo Groups is subject to: https://info.yahoo.com/legal/us/yahoo/utos/terms/


Re: Dither Sanity check

Tony Benjamin <tonybenjamin@...>
 

I believe some time is recommended. I have mine set at 8 sec on the advice of other SGP users.

 

From: ap-gto@... [mailto:ap-gto@...]
Sent: Saturday, November 11, 2017 2:42 PM
To: ap-gto@...
Subject: Re: [ap-gto] Dither Sanity check

 

 

0.5 pixels. Which I think was default. Should I have a time?

Regards,

 

Matt Hughes


On 12 Nov 2017, at 09:40, 'Tony Benjamin' tonybenjamin@... [ap-gto] <ap-gto@...> wrote:

 

What is your settling time set at?

 

From: ap-gto@... [mailto:ap-gto@...]
Sent: Saturday, November 11, 2017 1:59 PM
To: ap-gto@...
Subject: [ap-gto] Dither Sanity check

 

 

Ok after a few months with the AP 1100 AE mount I tried dithering for the first time last night.
Selected high dither in SGP Pro and after each 10 min sub.
Imaging at 1.96 pix/arcs secs.
Each dither took literally 2-3 secs. No time at all.
I’ve read in forums it can take 2-3 mins with some mounts.

So are my results normal? Is it due to no Dec back lash and quick response of the encoders?
I was hesitant to use dithering till now due to the length of time I understood it took. However the response of the mount it was easy and quick. Are my results typical? Or am I missing something... should I use a high dither..?
Bewler?
Thanks
Matt


Re: Dither Sanity check

Roland Christen
 

Yes, it should not take more than 2 or 3 guide pulses to settle after a dither. It all depends how far you are dithering. I normally dither between 3 and 5 pixels. When I am taking 5 sec guide exposures I set the delay at 15 seconds after a dither in order to have everything settle down.

Rolando



-----Original Message-----
From: matthughes77@... [ap-gto]
To: ap-gto
Sent: Sat, Nov 11, 2017 3:58 pm
Subject: [ap-gto] Dither Sanity check

Ok after a few months with the AP 1100 AE mount I tried dithering for the first time last night. Selected high dither in SGP Pro and after each 10 min sub. Imaging at 1.96 pix/arcs secs. Each dither took literally 2-3 secs. No time at all. I’ve read in forums it can take 2-3 mins with some mounts. So are my results normal? Is it due to no Dec back lash and quick response of the encoders? I was hesitant to use dithering till now due to the length of time I understood it took. However the response of the mount it was easy and quick. Are my results typical? Or am I missing something... should I use a high dither..? Bewler? Thanks Matt ------------------------------------ Posted by: matthughes77@... ------------------------------------ To UNSUBSCRIBE, or for general information on the ap-gto list see http://groups.yahoo.com/group/ap-gto ------------------------------------ Yahoo Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/ap-gto/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/ap-gto/join (Yahoo! ID required) <*> To change settings via email: ap-gto-digest@... ap-gto-fullfeatured@... <*> To unsubscribe from this group, send an email to: ap-gto-unsubscribe@... <*> Your use of Yahoo Groups is subject to: https://info.yahoo.com/legal/us/yahoo/utos/terms/


Re: Dither Sanity check

Matthew Hughes
 

0.5 pixels. Which I think was default. Should I have a time?

Regards,

Matt Hughes

On 12 Nov 2017, at 09:40, 'Tony Benjamin' tonybenjamin@... [ap-gto] <ap-gto@...> wrote:

 

What is your settling time set at?

 

From: ap-gto@... [mailto:ap-gto@...]
Sent: Saturday, November 11, 2017 1:59 PM
To: ap-gto@...
Subject: [ap-gto] Dither Sanity check

 

 

Ok after a few months with the AP 1100 AE mount I tried dithering for the first time last night.
Selected high dither in SGP Pro and after each 10 min sub.
Imaging at 1.96 pix/arcs secs.
Each dither took literally 2-3 secs. No time at all.
I’ve read in forums it can take 2-3 mins with some mounts.

So are my results normal? Is it due to no Dec back lash and quick response of the encoders?
I was hesitant to use dithering till now due to the length of time I understood it took. However the response of the mount it was easy and quick. Are my results typical? Or am I missing something... should I use a high dither..?
Bewler?
Thanks
Matt


Re: Dither Sanity check

Tony Benjamin <tonybenjamin@...>
 

What is your settling time set at?

 

From: ap-gto@... [mailto:ap-gto@...]
Sent: Saturday, November 11, 2017 1:59 PM
To: ap-gto@...
Subject: [ap-gto] Dither Sanity check

 

 

Ok after a few months with the AP 1100 AE mount I tried dithering for the first time last night.
Selected high dither in SGP Pro and after each 10 min sub.
Imaging at 1.96 pix/arcs secs.
Each dither took literally 2-3 secs. No time at all.
I’ve read in forums it can take 2-3 mins with some mounts.

So are my results normal? Is it due to no Dec back lash and quick response of the encoders?
I was hesitant to use dithering till now due to the length of time I understood it took. However the response of the mount it was easy and quick. Are my results typical? Or am I missing something... should I use a high dither..?
Bewler?
Thanks
Matt


Dither Sanity check

Matthew Hughes
 

Ok after a few months with the AP 1100 AE mount I tried dithering for the first time last night.
Selected high dither in SGP Pro and after each 10 min sub.
Imaging at 1.96 pix/arcs secs.
Each dither took literally 2-3 secs. No time at all.
I’ve read in forums it can take 2-3 mins with some mounts.

So are my results normal? Is it due to no Dec back lash and quick response of the encoders?
I was hesitant to use dithering till now due to the length of time I understood it took. However the response of the mount it was easy and quick. Are my results typical? Or am I missing something... should I use a high dither..?
Bewler?
Thanks
Matt


Fixed -- The APCC pro screen is out of whack - bottom truncated

steven ho
 

I reconfigured window7 pro to use a larger font and this totally screwed up the APCC UI.


Re: The APCC pro screen is out of whack - bottom truncated

steven ho
 

I should add the  -Resize to original Window Size does not fix it. I uploaded a file with a screen shot.

thanks