OIII stacked ... what's going on here?

[souls33k3r]

3 minutes ago, RolandKol said:

If no Reducer was used,

Camera probably,

As it has to be a really large smuggle on the scope to become visible. My 130PDS mirrors are constantly dirty as I am surrounded by trees and nothing is visible on the images or flats.

Lets hope it was just a bit of dew on the outer glass of ASI.

If it's inside.... - ASI .pdf Manual has a section how to clean it!

However, if it is still covered by warranty.... I would keep a manual aside.

I was using my Esprit 100 and was also using it's field flattener.

Camera surface was never touched but i can easily unscrew that bit to check.

If the smudge was on the sensor, do you reckon that it would be a bit more darker? 

Just trying to figure out where in the optical path this could be. 

I don't think my camera is under warranty any more

3 minutes ago, carastro said:

Hmmm, not seen anything like this before. 

Let me get my head around this.  Does this streaky pattern appear on your subs, or just when you have stacked? 

What is going on in my mind is, are faulty flats causing this problem.

How do you do your flats?

Carole 

No Carole, i can not see on the individual subs and neither do i see it on the stacked Ha and SII (maybe because if you see on the flats it appears very light) but it did appear like a sore thumb on the OIII stacks which is why i thought it was only confined to OIII filter and now flats have proven it they're not.

I've done the flats using iPad and SGP flats calibration wizard.

 

 

[carastro]

Sorry - I revised my last post while you were replying to me.  Please re read.

Carole 

[RolandKol]

9 minutes ago, souls33k3r said:

I was using my Esprit 100 and was also using it's field flattener.

Camera surface was never touched but i can easily unscrew that bit to check.

If the smudge was on the sensor, do you reckon that it would be a bit more darker? 

 

Dust would be darker 100%, I have one spot which annoys me and will send my cam to supplier in April (month before warranty ends).

But if its some humidity, which is transparent, - it may be a different story, in addition, - if ASI manual has a section for chamber cleaning, - maybe it is not a new issue at all.

So you need to run the last test... Flats - Not Cooled, No filter, No Reducer. Flats - Cooled, No filter, No reducer.

Fingers crossed!

[souls33k3r]

7 minutes ago, carastro said:

Sorry - I revised my last post while you were replying to me.  Please re read.

Carole 

It's ok Carole.

Well i haven't removed the camera. I was asking, what if i should remove to inspect it?

I have applied the flats and they do seem to work and my OIII is much much cleaner now so i'm happy with the end result but i would most certainly like to find out what this is, where can i look for and how to clean it and how it came to be?

My concern is, if it's on the sensor then i need to act upon it quickly and get this sorted, if it's on the camera AR window then i need to look in to resolving this. If it's on the FF, then i need to have it cleaned. The scope looks clean but that's another thing to consider.

1 minute ago, RolandKol said:

Dust would be darker 100%, I have one spot which annoys me and will send my cam to supplier in April (month before warranty ends).

But if its some humidity, which is transparent, - it may be a different story, in addition, - if ASI manual has a section for chamber cleaning, - maybe it is not a new issue at all.

So you need to run the last test... Flats - Not Cooled, No filter, No Reducer. Flats - Cooled, No filter, No reducer.

Fingers crossed!

I can run the tests with cooled and not cooled as soon as i possibly can. Hopefully before the weekend finishes.

[RolandKol]

I still hope you will not need it.

just in case

https://astronomy-imaging-camera.com/manuals/How_to_clean_ASI_camera_and_redry_the_desiccant.pdf

[souls33k3r]

Just now, RolandKol said:

I still hope you will not need it.

just in case

https://astronomy-imaging-camera.com/manuals/How_to_clean_ASI_camera_and_redry_the_desiccant.pdf

Cheers for that mate. Just opened up Google to search for this

[carastro]

Quote

My concern is, if it's on the sensor then i need to act upon it quickly and get this sorted, 

If this is a new camera under guarantee, then I would definitely be having talks and showing photos to your retailer, even if it turns out to be something else in the end, then at least you have established the problem existed during the warranty period.  I certainly would not be taking anything apart yourself and trying to sort it you may negate your warranty. 

In any case they should be able to give you some advice on what is causing it and how to rectify it. 

Do you have a dessicant port on this camera, because the dessicant should deal with the damp and only when that is saturated will it stop working and you need to change it/dry it out.

Carole 

[souls33k3r]

2 minutes ago, carastro said:

If this is a new camera under guarantee, then I would definitely be having talks and showing photos to your retailer, even if it turns out to be something else in the end, then at least you have established the problem existed during the warranty period.  I certainly would not be taking anything apart yourself and trying to sort it you may negate your warranty. 

In any case they should be able to give you some advice on what is causing it and how to rectify it. 

Do you have a dessicant port on this camera, because the dessicant should deal with the damp and only when that is saturated will it stop working and you need to change it/dry it out.

Carole 

It's most likely the camera is now out of warranty Carole.

It does have a chamber on the side and i must admit, i have never dried the tablet(s). The link that @RolandKol shared shows that you have to open the seal from the top to do this but i'm sure you don't have to do this for the v3 of the camera.

I have emailed the supplier i bought this from (before i made my first ever purchase from FLO). Awaiting to hear back from them.

[RolandKol]

been thinking about my camera prospects...

Decided to share with you (just in case)

https://www.firstlightoptics.com/zwo-accessories/zwo-desiccant-tablets-for-cooled-cameras.html

[souls33k3r]

2 hours ago, RolandKol said:

been thinking about my camera prospects...

Decided to share with you (just in case)

https://www.firstlightoptics.com/zwo-accessories/zwo-desiccant-tablets-for-cooled-cameras.html

Did you not get these with your camera? I certainly did. 

[RolandKol]

hmmm.... I do not recall any...

Will check boxes later on

Thanks

[david_taurus83]

I'd take all apart to see if there is any condensation anywhere. Is it the ASI1600 you have? Previous versions came with the dessicant tablets to replace should you need but the newer versions don't. The current ones have a plug on the side where you screw in a dessicant tube. The idea is to prevent dust ingress on the sensor.

Do you know that to prevent the sensor window from forming condensation you need to run the cooler hard? The excess heat from the heatsink acts like a dew heater?

[coatesg]

Has the OIII output always looked like this? I'm wondering if it's inherent to the sensor (polishing marks from the silicon on sensor).

I'd always be applying flats fwiw. The lights and flats both show the same pattern, and so may well reduce out.

My ST2000 shows quite marked diagonal lines from bond wire glints. Looks horrible on flats and lights with brighter backgrounds; reduces out well though.

[ollypenrice]

On 04/03/2019 at 18:49, souls33k3r said:

Could OIII filter really pick up thin clouds? that would be my first question.

The haziness is unforgivable but the streaks are liveable right now i suppose because i couldn't see them in the combined image so far.

I will try to get flats done and see if these still appear in that.

Also found this article on ZWO forum, worth applying this fix i suppose? But i do worry and wonder, it was never like this before so what caused it? The only thing that changed was a refractor. Coming from a WO Star 71 to SW Esprit 100.

https://bbs.astronomy-imaging-camera.com/viewtopic.php?t=7516&start=10

It isn't that the OIII filter picks up the cloud. (I've no idea how much OIII is reflected by cloud! Anyone?) It's just that the cloud blocks the OIII signal from space.

The 45 degree orientation of the pattern of light and dark bands, and my inability to think of an optical obstruction capable of producing such a regular effect, makes me think they will be of electronic origin. The Equalize filter in Photoshop is very useful for exaggerating small differences in faint signal. Running your flat through Equalize gives this:

The bands on the left are dead straight and parallel. Can they really be optical? I wouldn't rule it out completely but my hunch is for an electronic explanation. I bet if you reassemble the system differently and take flats again you'll see exactly the same thing.

Olly

 

[RolandKol]

On 04/03/2019 at 17:49, souls33k3r said:

Also found this article on ZWO forum, worth applying this fix i suppose? But i do worry and wonder, it was never like this before so what caused it? The only thing that changed was a refractor. Coming from a WO Star 71 to SW Esprit 100.

https://bbs.astronomy-imaging-camera.com/viewtopic.php?t=7516&start=10

I saw your topic on this ZWO forum also...
it looks like they are much more responsive on their official Facebook Page, - they replied me in 1 hour, probably as they are a bit more visible there...

[souls33k3r]

On 06/03/2019 at 21:31, david_taurus83 said:

I'd take all apart to see if there is any condensation anywhere. Is it the ASI1600 you have? Previous versions came with the dessicant tablets to replace should you need but the newer versions don't. The current ones have a plug on the side where you screw in a dessicant tube. The idea is to prevent dust ingress on the sensor.

Do you know that to prevent the sensor window from forming condensation you need to run the cooler hard? The excess heat from the heatsink acts like a dew heater?

I think i will have to do that for further analysis but ZWO came back to me (via Zoltan) that flats should calibrate this out and which it did but doesn't help me understanding the issue in the first place. It is the version 3 camera which has the plug on the side. Not sure if the camera within it's chamber still has desiccant tablets or not. I always do the -20 but it was relatively mild to begin with to getting colder later in the night when i was last out a few days ago.

On 07/03/2019 at 08:27, ollypenrice said:

It isn't that the OIII filter picks up the cloud. (I've no idea how much OIII is reflected by cloud! Anyone?) It's just that the cloud blocks the OIII signal from space.

The 45 degree orientation of the pattern of light and dark bands, and my inability to think of an optical obstruction capable of producing such a regular effect, makes me think they will be of electronic origin. The Equalize filter in Photoshop is very useful for exaggerating small differences in faint signal. Running your flat through Equalize gives this:

The bands on the left are dead straight and parallel. Can they really be optical? I wouldn't rule it out completely but my hunch is for an electronic explanation. I bet if you reassemble the system differently and take flats again you'll see exactly the same thing.

Olly

 

I do see the weight in your explanation Olly, but if electronically, why is it that i'm only seeing them now. But then again bands/streaks were never really present before or maybe if they were, they were super soft and hardly noticeable. The flats do take care of this but i guess you're right, i might have to take off the camera at some point and inspect.

On 07/03/2019 at 09:14, RolandKol said:

I saw your topic on this ZWO forum also...
it looks like they are much more responsive on their official Facebook Page, - they replied me in 1 hour, probably as they are a bit more visible there...

Cheers mate, that's super helpful to remember. I did wonder why i was being ignored on the forum

[david_taurus83]

FYI here's an example of my Oiii and Ha flats. Oiii being worse. Polishing artifacts on the filters or sensor I'm led to believe. They calibrate out. I haven't noticed them in my actual subs though. And I've always calibrated with flats so wouldn't have seen them on my stack either. If they calibrate out, then, carry on I suppose!

[souls33k3r]

2 minutes ago, david_taurus83 said:

FYI here's an example of my Oiii and Ha flats. Oiii being worse. Polishing artifacts on the filters or sensor I'm led to believe. They calibrate out. I haven't noticed them in my actual subs though. And I've always calibrated with flats so wouldn't have seen them on my stack either. If they calibrate out, then, carry on I suppose!

Cheers for showing us your flats mate. I suppose i'm now less worried about the banding but slightly more concerned about the smudge like feature at the bottom of my flats that is very visible in the OIII subs and how to avoid it being spreading if that.

[ollypenrice]

3 hours ago, souls33k3r said:

 

I do see the weight in your explanation Olly, but if electronically, why is it that i'm only seeing them now. But then again bands/streaks were never really present before or maybe if they were, they were super soft and hardly noticeable. The flats do take care of this but i guess you're right, i might have to take off the camera at some point and inspect.

 

I think a lot might be to do with the stretch you apply, which will always vary considerably in strength from image to image and filter to filter based on signal at low brightnesses. NB filters will suppress low signal from skyglow and take/need a harder stretch than, say, luminance.

But if flats take care of it you're up and running.

Olly

[Lead_weight]

See here: https://stargazerslounge.com/topic/330669-oiii-flats-uneven/?tab=comments#comment-3604600