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Support (Please note, this is primarily a user forum, for direct Atik support, please email support@atik-cameras.com) => Atik Infinity => Topic started by: gjasiewicz on August 26, 2016, 02:30:38 am

Title: Stacking Images
Post by: gjasiewicz on August 26, 2016, 02:30:38 am
I am very new to this camera and wonder if there is more detail manual than the version off the Atik website or on the CD.

I am sure there will be more questions with time however, for now I like to understand how the stacking works on this camera. Are the images sent to PC and the software on PC does the stacking or the stacking is done in the camera by internal software.

Also, On the Atik PC software there is a box showing how many images are stacked. Sometime this number remains at 1 (with stack box checked), sometime goes 1,2,1,2...and stops itself at 1, at other times the number goes up by one to the max I had was 11 and then the counter goes from 1 to 11 many times and when I stop it  stays at 1.
Title: Re: Stacking Images
Post by: Jo on August 26, 2016, 01:45:33 pm
The images are sent to the PC and it's the software that does the stacking. It essentially draws a kind of net around the stars in the image and uses that to align and stack them correctly.

If an image comes in that's very different from the previous image, it won't be added to the stack, but you should be able to stack far more images than you are - an indefinite number, really. Is Reject FWHM checked, and what level is it set to? Are you getting high numbers next to Rejected or to Not Stacked?

Thanks,
Jo
Title: Re: Stacking Images
Post by: KenT on August 31, 2016, 11:43:48 am
Hi,
     Try unchecking "Auto Reset Stack", down on the bottom left, it sounds as if your stack is resetting due to tracking errors. You may get a little movement , and you will see your tracking error distance, if it manages to keep up with your mount.
Good Luck, Ken
Title: Re: Stacking Images
Post by: gjasiewicz on September 03, 2016, 11:26:07 pm
Thank you very much Jo and Ken for taking time to read my post and to reply to it.

It took me a while to setup the scope and the Infinity to go through your suggestions. I looked at the Arcturus and surrounding, then at the M13.

First replying to Jo's comments:
1. I did 0.1, 0.5 and 1 sec exposure
2. Bin set to 1
3. Auto reject set to Full range
4. The images are not very different at all, I see then clearly on the screen.
5. Stack Images is checked
6. Reject FWHM is checked
7. FWHM reject level - I setup first at 10, then 5 and then 1

With all the variations above, there was one time when I saw stack # going to 45 and the stack info few seconds. I thought this was going somewhere so I left the setup for few minutes waiting for stack to go to much higher number but when I came back the stack was zero.

This brought me to Ken's suggestion to uncheck "Auto Reset Stack" on the bottom left. I could not find the exact button down the bottom and did not uncheck. Then, I was reading manual and I think Ken may have referred to "Auto Range" and "Auto Range Type" however, the manual clearly states this is for black level setting. As I mentioned above, I do not see "Auto Reset Stack".
Is it possible I have an old version? Looks to me that you have the same on the web site.

If you find time, please review and provide more advices.

Also, is it possible to experiment with infinity punching few pinholes in the plastic cover?

Best Regards,
George
Title: Re: Stacking Images
Post by: elpajare on September 04, 2016, 08:18:28 am
Hello gj

I suggest you do this:

Start the session choosing a light star or a open cluster. Not a bright one or a globular cluster.

Choose " Finder mode"

Set exposure at 1" and binnig to 4

Focuse your target >> "Show image quality" >>"numbers only" a big red number will appear on your screen. Focuse  until this number is no more high than 2

Move the histogram white bar to the right to decrease light the maximum possible.

Switch to "Video mode" and increase exposure to 5" and binning to 1

Start stacking.


Example of Markab at Pegasus. 26 exp. x 5" each

Title: Re: Stacking Images
Post by: gjasiewicz on September 04, 2016, 07:01:15 pm
Elpajare,

Thank you for the procedure with recommendations. I will follow it tonight, step by step and will share with you and with all others who are reading this thread.
I will work on Markab if I can see it from my observation point or if not, I will use Polaris that is only slightly brighter than Markab. Will try similar settings to your sample.

Question, why you do not recommend globular cluster or bright star? I understand they pose different challenges but for the sake of experiments would M13 be better than darker objects?
I am pretty good with DSLR use for astrophotos, but have no experience whatsoever with specific astro-cameras.

Take care,
George
Title: Re: Stacking Images
Post by: elpajare on September 04, 2016, 08:20:54 pm
Hello George

In order to have a exact focus you need to use faint objects. You will see that the red numbers go down just 2 that is a good focusing.

With bright objects you never will achieve it.
Title: Re: Stacking Images
Post by: gjasiewicz on September 05, 2016, 04:31:28 am
Thank you Elpajare.

I just came back inside from experimenting with your procedure and it worked. There are still many combination of parameters that I need to work with but I think I understand your procedure and also the focusing explanation.
With exactly the parameters you recommended I was getting too many rejected frames, roughly 1:1. I did get similar picture though to yours.
With the focusing by number, I did get down to zero. I do not quite understand yet the FWHM setting.

As an experiment I swung the scope from the Markab to M13 and started stacking. I tried 5 secs bin 1, and with FWHM set to 3, 6, 9 the stacking did not work showing zero and rejects one. This was not changing for close to 5 minutes. I turned the FWHM Reject off and stacking went flawlessly up to 45 exposures. After that I turned it off.

I will appreciate any other comments and recommendations.

Best Regards,
George
Title: Re: Stacking Images
Post by: elpajare on September 05, 2016, 08:09:15 am
Reject FWHN, rejects all the frames whose number ( the red number) is higher than the limit you have put in.

When I take a picture of a bright object, the red numbers are higher than a faint objet so you can do 2 things:

Increase the level number of rejection or turn off the automatic FWHM rejection.

If you are sure that you have good focus ( done as I have explained before ) you can turn off automatic reject off FWHM without problem.

With bright objects, my RED NUMBER never is low than 6 or 7- Even I have a good focus. If you have put the rejection FWHM nº lower, you can't stack any picture..... :(





Title: Re: Stacking Images
Post by: gjasiewicz on September 06, 2016, 02:32:25 am
Elpajare,

I appreciate you finding time to educate me. I have learned what the FWHM is but did not find any explanation what to do with it. Your comment is straight down to the practical bottom and I will let you know what I find. I am getting ready to experiment some more tonight.
Couple questions again:
1. after saving your stack, where you find the details like how many images stacked, exposure time and all other info
2. when stacking some faint object, do you see live improvement with progressing number of stacks? My understanding is yes but I did not notice it yet.

Best Regards,
George
Title: Re: Stacking Images
Post by: elpajare on September 06, 2016, 08:28:53 am
Thanks George. We are all learning here and is nice to share experiences.

More about FWHM, after saved the picture I think that all parameters uses are lost. You must annotate when you are saving the picture.

When you are saved the first object, you wil have the tree histogram bars ( black, orange and white ) in a particular position, the best for have a good image.

If you go to another object, without touching the bars position and you make a zoom over the object you will se how the picture are changing every time a new stack image comes on.

It would not be a bad idea that someone of ATIK give us some practical and theoretical classes on FWHM, ja,ja,ja...
Title: Re: Stacking Images
Post by: gjasiewicz on September 06, 2016, 03:53:32 pm
Elpajare,

I am glad that's how you look at that. Right now I don't think I contributed very much but I own the Infinity for about 1/2 year but started using it only about 3 weeks back and that not full time. I hope I will contribute some experiences perhaps not for the sake of advanced users but for more juniors than I am.

Starting from the back of your post, yes, I agree that Atik could present users with some more details of what is in the manual at the very high level. Jo, are you following and can you help with that?

I had a feel that there is no way to retrieve info from the stack but have not tried to record and play sessions. That may show what you do.
Perhaps in the next release Atik can incorporate metadata with stacks or even individual images. Again, Jo may want to take a note.

I did some more experiments with the Atik last night and to avoid worrying of tracking/guiding accuracy I set up the night with Altais and ended with Polaris.
So, this is what I found:
1. Altais - Started with 5sec BIN1, Auto range off, Stack and Reject FWHM checked, FwHM level 10.5. Stacking stopped at about 80 images (400s)
2. Altais- same as above but Reject FWHM unchecked, same happened.
3. Polaris - started with 5 then 8 and then 10 secs exposure, Bin 1, Auto Range off, stack and Reject FWHM checked and set to 10.5. The stack resets around 105 images.

Jo mentioned that you should be able to stack indefinitely and KenT recommended to uncheck Auto Reset Stack. None seems to work for me.

More to come.

Regards,
George
Title: Re: Stacking Images
Post by: elpajare on September 06, 2016, 06:45:42 pm
I never exceed 300 s per image and never have had a problem of stopping stacking.

Infinity hasn't cooling and I fear strange effects in the chip because temperature, so I never do it.

In my limited experience 300 seconds is enough to fill completely the chip. I have photographed galaxies of mag 14,5 without problem.

May be Jo has another explanation......
Title: Re: Stacking Images
Post by: gjasiewicz on September 06, 2016, 11:27:44 pm
Elpajare,


Actually in response to my original question starting this thread Jo had mentioned that I should be able to stack infinite number of images. I really think this is theoretical capacity and you are right, 300 secs should be sufficient for anything that I would like to do. This would be perfect if it always worked. My problem is that with some settings where I understand all should work, I get resets after 3-12 images. I did not write all the settings but next time I will test it and document.  Not sure when for it looks cloudy today and forecast is for thunderstorms over the next few days/nights.

I agree with you that the chip is not cooled and this may cause some issues that will be more pronounced in warmer climates. I am near Toronto, Canada and daily we are having 30-32C and nightly low to mid 20s. The last two nights though it was 15 and 18 degrees what should be very reasonable.

Anyway, I will focus on finding settings allowing me a min 250-300 secs stack.

I am not sure what you mean that 300 secs will fill the chip............ As Jo explained, the images are sent to your PC where the stacking happens. So, the camera handles really one image at the time and unless you go to 300 secs exposure, the camera handles only 5-10 secs at once. Am I wrong?

I will be sharing my future experiences whenever I make them happen.

Regards,
George
Title: Re: Stacking Images
Post by: elpajare on September 07, 2016, 11:28:11 am
You are right about "fill the chip", if as Jo saids, is the PC the one who stacks the images, the light captured by the chip is the exposure seconds of each photo.

This night I try to minimize the noise of the picture, and these are some results taking pictures of galaxies mag. 12 and starfields adjacents:

10" exposure to 300 " total, when I did a high zoom in a bright point of the image, I can see some colored dots ( green, blue,red)

10" exposure to 400" total, the colored points dots  almost disappears !!

So, increase light means reduce noise, and for deep sky objects like faint galaxies a 40x10" exposure may be good.
Title: Re: Stacking Images
Post by: gjasiewicz on September 07, 2016, 07:14:05 pm
Thanks Elpajare.

I am glad to see your images and the parameters. I will be sending you mine when I get better hold of that.

I attach the stack of 30 10 secs exposures with 6" F/10 Nexstar 6SE, 2"0.63 reducer, star diagonal and 0.50 reducer before the infinity. So, the FOV is about 47 mins by 1 deg and 3 mins.

I noticed the image may be better with white bar on the histogram about 1/2 way to the right. That is my next experiment and I will try to find a galaxy of mag 10-12.

I think perhaps for this kind of exchange we should move to our personal mails and use the forum rather for technical questions we have.
My address: gjasiewicz@rogers.com

Take care,
George
Title: Re: Stacking Images
Post by: gjasiewicz on September 12, 2016, 11:44:35 pm
Hello Jo and Elpajare,

Regarding the stacking and self terminating the stack sequence after about say 300 secs total, I may be wrong but I think this is the sensor overheating issue. When I was having this happen, the temps at night were min 20C but probably 23-24C. So with an uncooled sensor the heat accumulates and eventually shuts the sensor. Not sure though why I can restart stacking right away and go for another 200-300-400 secs.
Last night the temp was only 14C and the stacking was not shutting easily. I was imaging the surroundings of M57 and I managed to stack more than 100x15 secs images. It stopped stacking after 1,500 secs before 1,600 secs.

My questions are:
1. Is it possible that the sensor overheats easy above say 24C?
2. What is the working temp range for the infinity?

Now, unrelated question is why there is no obvious difference between 10x15 secs stack and 100x15 secs stack? Both stacks attached. Setup: 6" F/10 Nexstar 6 SE, 2" 0.63 focal reducer, 2" star diagonal, 0.5 focal reducer and Atik Infinity. The view angle is about 47 mins by 1deg and 3 mins.
I will do more testing tonight and compare single exposure with a stack of as many as I can stack.

Please provide your view on my findings described above.

Best Regards,
George
Title: Re: Stacking Images
Post by: Jo on September 13, 2016, 11:09:34 am
Hi George and Elpajare

I'm sorry I've been absent from this thread recently, but I'm glad to see you both sharing your findings and improving your results, it's great to see that happening on the forum.

To revisit some of your earlier questions, in terms of the extra details you'd like to see from us and in the manual, can I clarify that you'd like us to provide better explanations of what the FWHM is and how to use it for image rejection?

Also, I think someone else has also suggested that stacking data be recorded in the saved file, so we'll consider adding that as a feature.

With your comments about filling the chip, do you mean how long you can expose for before the sensor becomes saturated? Naturally, this really depends on your setup and what you're imaging - you can saturate a bright star very quickly, but to capture faint objects, you can go much longer - for example, our 414EX that uses the same sensor as Infinity but in a cooled camera model can be used for exposures of up to and well over 30 minutes if you have a sky and a setup that can handle it!

Also, these sensors don't overheat as such, at least not in the ambient temperature range available. What does happen though is that they'll get noisier and have more hot pixels at higher temperatures.

There should be a difference between a 10x15s stack and a 100x15s stack - I don't think the files attached properly, but I'd be interested to take a look.

I hope that begins to answer some of the questions?

Jo

Title: Re: Stacking Images
Post by: elpajare on September 13, 2016, 11:46:59 am
Thanks for your help, Jo.

Talking about noise, I have a doubt...

To Jo:

Question: Would have the same noise in a single exposition of 300 seconds that in a multiple exposition of 25 x 12 seconds = 300 seconds exposition?

Another question:  Can you explain some more things about how Histogram works in different situations of faint and bright objects ? Black bar, Orange bar and White bar. The precise regulation of these bars is the 99,9% of success of the final picture.

to George:

I'm working every night about 2 hours at 22º. I have not noticed any increment of noise ( colored dots ).

Nice to know the result of your experiment with single and multiple expositions.
Title: Re: Stacking Images
Post by: gjasiewicz on September 14, 2016, 02:49:35 am
To Jo,

Jo, when I mentioned the manual, it would be nice to provide more details how to use the camera. The manual covers very high level items that I am sure are sufficient for the experienced users but are not sufficient for newbies like me and I believe the Infinity is focusing on newbies. FWHM is just one item that would be nice to understand how to use it and what level to setup for what images. I read the FWHM theory and I understand that but it does not give me any help with understanding how to apply it and what levels to setup. Histogram that Elpajare mentioned is another example. I think every item that the user can adjust should be explained in details even if they are very basic. Various users have various knowledge and one can understand some items another different ones. There will be also users that know very little overall about astro imaging. I am very technical person and also very well experienced in photography but not in astrophoto and having problem understanding the settings.

I apologize, I simply forgot the attachments. They are attached now. One is 10x15 secs and the other 100x15 secs. That info is also in the file names. FWHM was off.

I know you mentioned the Infinity should be capable of stacking very large number of frames however for some reason mine resets randomly after some number of images. That happens regardless of FWHM setting. I tried levels one, five and 10. The stack of 100 was with FWHM off and even that it reset itself somewhere before 110. I was saving stacks every 10 frames and was hoping that it finally works but unfortunately not.
Earlier in the thread, Ken suggested to turn off Auto Reject. I think he meant to turn off WFHM for I don't see the button Auto Reject.

To answer your last question, yes, you help quite a lot. I also appreciate a lot both of you involvement in helping each other.

To Elpajare,

I did not go out since my last post and did not test single frame against a stack. When I do it I will share with you the findings. Thank you for replying to my ambient temperature concern. I would not expect the chip overheating at 24C. If that was the case the Infinity use would be significantly limited. Also, Jo explained that the heat will not shut down the sensor but will produce more noise.

All the best,
George

The attached images ate not adjusted at all.
Title: Re: Stacking Images
Post by: gjasiewicz on September 14, 2016, 02:52:21 am
sorry, for some reason only one attachment came through. Here is the second.
Title: Re: Stacking Images
Post by: Jo on September 15, 2016, 03:42:17 pm
There would be a difference in noise between these, particularly in terms of read noise because in the 25 x 12s you’re reading the sensor 25 times instead of just one. Also, you tend to get a better signal to noise ratio in longer exposures.

That said, there are other limitations such as light pollution etc. that mean every setup has a different balance.

It’s difficult to set precise instructions about how to use histogram as every different object taken with a different setup from a different sky will have a slightly different ‘best’ setting. I say ‘best’ because it also comes down to personal preference as well.

The main thing is to try and set it so you’re losing the minimum amount of data. A general piece of advice would be to set the black level a little below the peak curve at the bottom ( - though personally I quite like to go a little lower than this at the expense of a lighter background) Then set your white at a level that doesn’t blow out the image, and slide the orange around to pull out maximum detail depending on your object.

The nice bit about Infinity is how flexible it is, and I really would just say keep playing with it! Get a feel for the settings you like - there really isn't a strict right and wrong here.

I’ll have a think about how we might be able to put together a better guide for beginners explaining the more complicated settings and some far better advice on using the histogram than I may have given there…

I've attached a screenshot of the Auto Reset Stack button, is not showing in your menu? Are you on the latest version of the software?

I see what you mean about them being similar. Did you change the histogram settings between the two? If not, you may be clipping off the additional data gained by the bigger stack. Also, as it's just a star field it may be harder to see the difference - if it was the equivalent experiment on a faint object, it should be much easier to see the benefit of the additional stacking.

Thanks,
Jo
Title: Re: Stacking Images
Post by: elpajare on September 15, 2016, 07:54:35 pm
Thanks Jo. Your advice is very useful.

There are new things in the latest version that are no explained in tutorials, or I have not found:

Image quality , with the two options
Add Q to FWHM
Calc Image movement
Auto reset stack
Use Orig CB

It would be interesting to know what they mean and what are they for.
Title: Re: Stacking Images
Post by: gjasiewicz on September 15, 2016, 08:05:59 pm
Thank you Jo,

I did some more experiments last night and I took 1,10,50, 100 and 130 stacks of Polaris and about 40-50 minutes around it. I can clearly see the better contrast less noise and more clarity especially when enlarging the images. I will start playing now with galaxies, nebulas where I understand you really appreciate the infinity and the stacking.

I fully understand the flexibility of adjustments and peoples likings but for newbies it would be nice to see few simple examples showing what the adjustments do. I will do some more testing as I said and I am sure I will figure it out. Time is the essence.

Yes, I do not see the Auto Reject button so, looks I have an old version of the Atik software. On your website under Atik Resources are only drivers. I do not see Atik app. I also do not see what version I have. I am pretty sure I downloaded the drivers when I originally installed all Atik components.

Please send me a link for the most recent software and if you have newer drivers Please indicate them as well.

Regarding the likings, I did not pay attention in details where I set the bars but I definitely prefer lighter background. By lighter I mean not black but dark dark gray.
Your explanation of how you set the histogram is sufficient for me. Tells me what each bar does and the rest is up to me.

When I have a chance to go out again and do more experiments I will share with you.

Elpajare,
Please let me know if you like to see the samples I mentioned above and I will send them for you.


Best Regards to you both,
George
Title: Re: Stacking Images
Post by: gjasiewicz on September 15, 2016, 09:29:01 pm
Jo,

I found the newer software and have the autoreject button. Please do not bother sending me the link.

Thank you,
George
Title: Re: Stacking Images
Post by: elpajare on September 16, 2016, 08:08:17 am
George, you have a PM about your offer
Title: Re: Stacking Images
Post by: KenT on September 16, 2016, 08:22:55 pm
Thank you Jo,
saving for a 414, glad you got the updated software George.
As Jo said, play with the controls and see what they do, then see what they can do for you.
Enjoy,
Ken
Title: Re: Stacking Images
Post by: gjasiewicz on September 16, 2016, 09:30:20 pm
Thanks all. I will keep you posted and please keep me with your advices.

What's the PM Elpajare?
Title: Re: Stacking Images
Post by: gjasiewicz on September 17, 2016, 01:03:01 am
Elpajare, attached are my stacks I described in separate message.

Title: Re: Stacking Images
Post by: gjasiewicz on September 17, 2016, 01:06:17 am
Elpajare,

I really don't see how to attach multiple files. the attachment function below allows one file only and the button above does not seem to work. So here is the last of the sequence.

George
Title: Re: Stacking Images
Post by: gjasiewicz on September 20, 2016, 04:52:49 am
Well, I have version 1.3 of Arik Infinity software and with this all seems to work. Now I will finally start working with the camera and will share with you the findings. The stack does not get reset and finally I don't need to see when the stack resets.
I will share the findings.

George
Title: Re: Stacking Images
Post by: Jo on September 21, 2016, 11:52:57 am
Hi George,

That's great to hear, glad it's all working for you now and looking forward to seeing your findings!

Ken - excellent choice  ;)

Thanks,
Jo
Title: Re: Stacking Images
Post by: gjasiewicz on September 23, 2016, 02:43:42 am
Thank you all, Jo, Elpajare and Ken.

You all had an input into my struggle and no I think I am fine and need to practice. Unfortunately in the last couple days the weather here is not so good.

Hopefully soon...........
George