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One ASI impression

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#1 Sunspot

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Posted 02 February 2013 - 09:39 PM

Hi all,

I'm having a great time learning how I want to use my new ASI camera. However I'm having one little issue that I'm not sure how to deal with. It is NOT a complaint, not in any way, but I've noticed this and hopefully someone can help me. This camera attracts dust motes for me like no other planetary cam I've owned. I'll be focusing and see them show up on the screen. Maybe they won't show up when I process I haven't tried that yet. I use a squeeze blower to try to remove the dust and while it helps, they just keep showing up. Q-tips and camel hair brushes just moves them around. It makes me wonder if the cmos chips generate small amounts of static. I do live in a very dry, somewhat dusty environment which probably contributes to the issue.

Like I said, it's not a complaint, just an observation.

Paul

#2 Rankinstudio

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Posted 02 February 2013 - 09:54 PM

Paul, I noticed that as well. I wonder if the smaller pixel size is causing the little ones to show up more? I have to spend a while cleaning mine before each session. My little rocket air deal and some lint free wipes do the trick.

#3 Kokatha man

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Posted 02 February 2013 - 10:31 PM

.....join the club fellas..! :lol:

It's dry & dusty "down here" also.....using 800X640 @ 50fps on Saturn has reduced the amount of cleaning time I need to attend to - the big screen with (relatively small) Saturn means I can usually keep away from 'em....! :lol:

#4 wenjha

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Posted 03 February 2013 - 02:37 AM

Yes Its very easy become dirty.
I found it useful when use the IR-CUT filter screw to the camera body.not the 1.25" T2 adapter.
but I usually swich between all sky camera and plantery camera.so no good choose for me

#5 Chris_H

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Posted 03 February 2013 - 12:33 PM

Hell yes! I've never seen so much dirt before! I never had any problem with the DMK but the ASI seems to just attract dust! :grin: I must have spent an hour on it with swabs, lens pens and so on but nah - always some left... :( Any tips Sam? :question:

#6 RedLionNJ

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Posted 03 February 2013 - 03:00 PM

Ditto on the ASI. When I received my DMK, I thought it had an unusual propensity for attracting dust motes. But one really good cleaning-out of the housing seemed to cure that. And from then on, I always cap it when not in use AND store it in a freezer-quality Ziploc bag.

Then came the ASI120. It probably had TWICE as many initial flecks of dust on the sensor cover as the DMK came with. The blowing-out of the enclosure and repeated application of isopropyl alcohol with a Q-tip seemed to work for a bit, but then I discovered the internal threading of the 1.25" adapter was shedding and magically being attracted to the sensor cover. So I thoroughly cleaned the adapter and now follow the same process as for storing my DMK - put a 1.25" cap over the filter end of the adapter when not in use, and store in a Ziploc bag. So far, so good, but I've only had the ASI for about a month (with no good seeing, naturally).

Grant

#7 Sunspot

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Posted 03 February 2013 - 03:44 PM

Wow! At least it wasn't my imagination. I never thought about the adapter. Thanks for that heads up.

Paul

#8 Freddy WILLEMS

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Posted 03 February 2013 - 03:52 PM

Thanks for the update on that camera, Does a clear filter might work also ?

#9 Chris_H

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Posted 03 February 2013 - 03:55 PM

I never though about the threading. Will look into that!

#10 Kokatha man

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Posted 03 February 2013 - 04:49 PM

.....I should respond to my somewhat flippant first reply here: if you settle on a specific optical train/setup then the problem virtually disappears - my Mk3 setup for variable image scales is clamped into my EFW and I take this whole unit off (camera, adapter & EFW) and cap the scope end of the EFW when stowing this in a ziplock bag in a plastic container to eliminate this problem.....the soon finished Mk4 will be slimmer & lighter and be stored the same way - neither version needs to see the camera being exposed to the air/dust again and gives image amplification from 1.2X to about 3X.....more than one would need for this small-pixelled camera! :)

#11 RedLionNJ

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Posted 03 February 2013 - 08:42 PM

Agreed totally, Darryl. If you don't shake the camera about or expose the open end, you'll likely be fine. Unfortunately for me, it's not the only piece of equipment I hang off my main scope at times. When the seeing is too poor for planetary, I can sometimes get away with some DSLR photography instead...

Grant

#12 wenjha

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Posted 03 February 2013 - 08:53 PM

I think the best way is the attach a clear filter to the camera body after clear it.
And we are improving our assemble line to make the sensor as clear as possible.
thank your guys feedback

#13 Gupise

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Posted 04 February 2013 - 02:41 AM

i noticed the same, for planet imaging is not a big problem (with roi), but if you want to shoot moon or sun it's hard to have a perfecty clean sensor.

#14 dobsoscope

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Posted 04 February 2013 - 03:44 AM

Maybe you can point out the best way to carry out cleaning without causing damage?

#15 Sunspot

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Posted 04 February 2013 - 09:49 PM

I was thinking if a clear piece of flat optical glass was installed in the recessed area above the sensor, that might help. It would be similar to the Flea3. It would be much easier to keep clean and because it's away from the focal plane maybe the motes won't show up so dramatically.

Thinking out loud...
Paul

#16 JMW

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Posted 04 February 2013 - 11:34 PM

Had my ASI120MC out for a test ride tonight. Horrible seeing and transparency and eventually cloud cover. I was using it on a C11 EdgeHD at 2800 mm. I had active cooling on the scope so the problem appears to be the sky not the scope. I was happy to get a pretty good focus in the conditions but I will wait for a better seeing forecast before I try again. Didn't notice any dust.

Are there any good links to getting starting tutorials for hints on focusing, capturing and processing with a planetary cam?

#17 Eduardo PS

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Posted 13 March 2013 - 11:15 AM

Hi guys, first of all sorry about my english.
about some dust on the ASI120MC it's seeing like that
https://www.youtube....h?v=0h0HGQSTaXg
this video was taken on 03/12/13 in my house, I thought that was my IR filter but when i put the ASI in front off my lcd panel without any filter the dust appears too.

#18 PiotrM

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Posted 13 March 2013 - 12:18 PM

Blowgun is handy to clean the cover glass. Also cleaning with Baader Optical Wonder (or alike) may be handy/needed too.

#19 joelimite

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Posted 16 April 2013 - 10:44 PM

I'm having the same issue with my new ASI 120MC. Great camera, but it's a dust magnet! Any more tips on cleaning the sensor? I've tried q-tips and 91-percent rubbing alcohol, a bulb blower, and a microfiber cleaning cloth, but I can't seem to get it entirely clean. No matter what I do, a few stubborn dust motes still appear on screen, especially when imaging the moon.

#20 Bird

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Posted 18 April 2013 - 07:36 PM

My ASI camera sensor was covered in dust and spots when I received it, doesn't look like it had been handled in any sort of clean room. But after a few passes of cleaning I got rid of the most noticeable dust (a few faint ones are still there, I can see them on the flat-field if I stretch it up).

The smaller pixel size should reduce the visiblility of the dust motes, simply because you will be using a lower focal ratio, and so the depth of field is smaller. The dust will still be there, but more out of focus compared with large focal ratios used on cameras with bigger pixels.

eg on my flea3 I use f/24-ish, and on the ASI I use f/16-ish. Depth of field is quite a bit less at f/16 and so dust on the sensor is more out of focus at the image plane.

cheers, Bird

#21 Sunspot

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Posted 18 April 2013 - 10:21 PM

I've noticed that as well. When using the ASI with the Mewlon and C14 I use F/15-16 and don't see the dust motes. When I'm doing solar imaging with the EON120 I'm using F/23 and definitely see them. I would love to see the version of the ASI come with a cover glass over the sensor.

Paul


My ASI camera sensor was covered in dust and spots when I received it, doesn't look like it had been handled in any sort of clean room. But after a few passes of cleaning I got rid of the most noticeable dust (a few faint ones are still there, I can see them on the flat-field if I stretch it up).

The smaller pixel size should reduce the visiblility of the dust motes, simply because you will be using a lower focal ratio, and so the depth of field is smaller. The dust will still be there, but more out of focus compared with large focal ratios used on cameras with bigger pixels.

eg on my flea3 I use f/24-ish, and on the ASI I use f/16-ish. Depth of field is quite a bit less at f/16 and so dust on the sensor is more out of focus at the image plane.

cheers, Bird








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