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Old 11-09-2009, 08:28 PM
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Dust UNDER chip filter.

I have some pretty bad dust under the glass filter that covers my CCD chip in the Orion Starshoot Pro DSI.

Has anyone here ever dismantled one to clean out from under the glass? Is it a simple or dangerous excersise?

Attached is a single 15minute sub. This has been on every pic since I bought the camera.

Baz.
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  #2  
Old 11-09-2009, 08:33 PM
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Gee baz that dose not look good, now I have dismantled a Canon DSLR before but not the Orion Starshoot, you would have to wonder how it all got under there in the first place.

It can however be tricky work


Leon
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Old 11-09-2009, 09:01 PM
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This does not look good Baz.What is the CCD chip #?
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Old 11-09-2009, 09:10 PM
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David, it's a Sony SuperHAD ICX413AQ colour CCD. Why's that? You know it?

Baz.
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Old 11-09-2009, 09:30 PM
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Are you sure it's dust .... maybe it's mold.

Have you kept in a dry place between uses ?
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Old 11-09-2009, 09:34 PM
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Quote:
Originally Posted by bloodhound31 View Post
David, it's a Sony SuperHAD ICX413AQ colour CCD. Why's that? You know it?

Baz.
I was going to get the PDF spec sheet and find what and how the window is mounted. I just hope it's not thermal epoxy sealed.
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Old 11-09-2009, 09:37 PM
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Quote:
Originally Posted by Ian Robinson View Post
Are you sure it's dust .... maybe it's mold.

Have you kept in a dry place between uses ?
No mate, not mould. It has been exactly the same since brand new. I originally thought it was on the outside, but after weeks of owning it and finally deciding to clean it, i found it was under. Mold changes shape and size over time. Plus it tends to multiply. This has not.
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Old 11-09-2009, 09:57 PM
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It looks like the Sony ICX413AQ CCD has a plain glass window from the factory (good) and the Orion folks put their own IR cut window over that. So it looks like your JPEG indeed shows a very closely spaced IR filter that is not sealed. There is no other way for dust to get in this space, I would have to have it infront of me to see how the IR filter bonding is done.
If it's under warranty send it back.
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Old 12-09-2009, 06:08 PM
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Any thoughts on what to do with the dusty CCD Baz ?
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Old 12-09-2009, 06:34 PM
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It looks like the Sony ICX413AQ CCD has a plain glass window from the factory (good) and the Orion folks put their own IR cut window over that. So it looks like your JPEG indeed shows a very closely spaced IR filter that is not sealed. There is no other way for dust to get in this space, I would have to have it infront of me to see how the IR filter bonding is done.
If it's under warranty send it back.
Thanks mate. I think it's out of warranty now. Not sure what to do. I think when I have finished imaging in this beautiful weather, I might pull it apart and at least investigate. If it looks too hard to do, I will leave it alone. If it is reasonably simple I will seek more advice, maybe give it a go and post a tutorial on it if appropriate.

Thanks for your input David.

Baz.
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Old 12-09-2009, 08:19 PM
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from what I can tell with my StarShoot Pro, it should be easy enough to open the camera up, although the CCD Chamber will be sealed, and I dont know how they come apart from there.. so you'll be flying blind so to speak..

If you manage to get it open, use a lens cleaning cloth to give it a quick wipe, then using a magnifying glass to get a better look at it, inspect it for dust or other odd looking spots, wipe clean using a micro fibre cloth over a Q-tip with a drop or two of 99% isopropyl alcohol on it.. this will clean it up nicely... When re-sealing it up, make sure to do so in a very low humidity area.. there are many issues that can come from moisture getting inside the camera.. Another option here is to tape a small bag of silica gel somewhere inside the camera to dry out any moisture / humidity that gets into the camera while you have it open...

Best of luck mate..
Alex.
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Old 12-09-2009, 09:11 PM
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Thanks Alex, I will keep that in mind and be very careful. I appreciate the advice fella's.

Baz.
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Old 12-09-2009, 09:27 PM
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Don't take this as gospel, but I think I read somewhere that the ccd chamber on the orion starshoots is argon filled. food for thought.

Brett
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Old 12-09-2009, 09:39 PM
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and if that is the case, opening it is NOT a good plan.. I'd email Orion regarding this If I were you Baz... Better to be safe than sorry..
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Old 12-09-2009, 09:44 PM
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Yes, I did think of that.

Already emailed the seller. Michael at Bintel is pretty knowledgeable on the subject so I thought I would ask him.

Just waiting on an answer.


At this stage I don't think i will risk doing it myself.
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Old 16-09-2009, 01:06 PM
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OK, here's where I am at so far.

Calibration with flats seems to remove it just fine.

That being said, it seems is quite normal for most camera's to have some degree of this stuck in their optical train. Within reason, that is why even the camera manufacturers recommend flats calibration. If it was particularly bad, I am sure they would be reasonable.

In a similar case, I believe it is expected in most television manufacturers QA checks to have an acceptable number of dead pixels in a brand new TV screen. They expect it and even disclose this fact in their fine-print prior to sale.

As I said, taking flats works fine in this case. If, however, the big blob in the top left was smack in the middle of my sensor, i think I would request a replacement or at least a service to remove it.

The image above is a crop of the top left third of my entire sensor, so the percentage of image it interferes with is very small indeed. (I will post a processed JPG of the full sensor tonight when I get home).

My very helpful and knowledgeable supplier is still going to send said processed image to Orion anyway, to see what they say. I will let you all know the outcome when the time comes.

It is my hope that this experience like all others can be shared with the wider astrophotographer community to help them along in similar situations. It is a good thing to be able to see this from the supplier/manufacturers perspective as well as the consumer, that we can all determine what is fair, reasonable and to be expected or not.

Baz.
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Old 16-09-2009, 05:41 PM
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That big blob Baz, is, believe it or not, a tiny, tiny piece of dust or similar spec on the filter window of the camera. Its just that big due to the distance the shadow is cast.

Problem is it may have been clean at the time of testing, but shipping causes many bumps, etc. This can dislodge a speck from somewhere else to fall on somewhere where a shadow is caused on the sensor.

Even camera lenses get dust in between them.

Theo
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Old 16-09-2009, 07:29 PM
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Quote:
Originally Posted by Gama View Post
That big blob Baz, is, believe it or not, a tiny, tiny piece of dust or similar spec on the filter window of the camera. Its just that big due to the distance the shadow is cast.

Problem is it may have been clean at the time of testing, but shipping causes many bumps, etc. This can dislodge a speck from somewhere else to fall on somewhere where a shadow is caused on the sensor.

Even camera lenses get dust in between them.

Theo
The smaller ones are, yes, Theo, but the large one appears to be a tiny inclusion in the glass. When light is shone on the chip, this tiny fault reflects back.

If a bright star is in or near this inclusion, a curved diffraction spike emanates from the point source.

As promised, here is a full frame JPG of a flat from the chip, followed by an unprocessed JPG single-sub light frame.

Baz.
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Old 17-09-2009, 01:03 PM
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The Sony CCD has no coatings or anything on the glass surface.
Unless its in the debayer film (I doubt), it may just be on the glass surface, or on the back of the filter glass.
Too bad it doesnt have a simple opening somewhere to clean the CCD surface easily.

Theo.
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