16 replies to this topic

[mhooper]

 

Not sure whats going on here. These spots are on my lights and flats and I cant process them out with siril. I'm new to all this but never been a problem with my WO Zenithstar 61 and 183MC Pro. The scope is an new Askar 103APO and camera is an ASI 533MC pro, the scope seems fine as far as focus. I moved the camera from my WO Zenithstar 61, which is a 183MC pro and dont have the spots. I lost the original data so I cant send it (computer error by me/had onedrive on new desktop). I shoot with lights, darks, bias and flats. The attached photo is a flat frame view from my asaiar plus. Any advise is welcome. Coudy night so cant get any new data yet.

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[Jim Waters]

IMO they are dust motes.  They are large enough to be on a corrector or something.  Correctly processing them with Flats should fix the problem.

Edited by Jim Waters, 15 April 2024 - 07:39 PM.

[bobzeq25]

You can drive yourself crazy looking at flats in isolation, and it's well nigh impossible to say if flats are good from looking at them separately..  The only thing that matters is how your calibrated lights look.

[Robert7980]

Those look pretty bad, I’d probably disassemble things and use a camera blower to dust things off… Wouldn’t usually recommend cleaning optics, but it’s probably due, I’d just use a little gentle air… 

[mhooper]

The big dark one at the bottom left was in my calibrated light frame. Everything was new and assembled right from factory packaging. I will try another session on the same target (whirlpool) and get some air duster and see if any dust gets removed. I did have a 1x flatter. I guess more calibration frames would help. I had 49 lights, 20 darks, 10 flats and bias frame. I was able to crop out the bad area and had a decent image, all I have left is the cropped fits and a JPEG. 

[mhooper]

Being everything was new I didn’t bother to look for dust. Everything came directly from a sealed package, assembled and used within a few hours. 

[Andros246]

Being everything was new I didn’t bother to look for dust. Everything came directly from a sealed package, assembled and used within a few hours. 

thats normal looks like its on the IR window

Edited by Andros246, 15 April 2024 - 08:11 PM.

[DeepSky Di]

I was worried about the line across the picture until I realized it's a reflection. I take a lot of screenshots. On iPad there's a gesture swiping up diagonally from the bottom left corner. I think it has to be enabled in settings, but it's very handy.

 

Agreed with others, these are dust motes. If they are still on the image after flat calibration then the flats are wrong.

[mhooper]

I was worried about the line across the picture until I realized it's a reflection. I take a lot of screenshots. On iPad there's a gesture swiping up diagonally from the bottom left corner. I think it has to be enabled in settings, but it's very handy.

 

Agreed with others, these are dust motes. If they are still on the image after flat calibration then the flats are wrong.

I used a double layer new white tee shirt with a trace panel about mid brightness. The ASIAIR figured the exposure time. Do you think I should raise the brightness and/or take more. 

[Jim Waters]

FYI

https://www.amazon.c...,aps,138&sr=8-1

 

or...

 

https://www.amazon.c...,aps,138&sr=8-9

[Robert7980]

The big dark one at the bottom left was in my calibrated light frame. Everything was new and assembled right from factory packaging. I will try another session on the same target (whirlpool) and get some air duster and see if any dust gets removed. I did have a 1x flatter. I guess more calibration frames would help. I had 49 lights, 20 darks, 10 flats and bias frame. I was able to crop out the bad area and had a decent image, all I have left is the cropped fits and a JPEG. 

Be careful with canned air, that’s not really what you want, you want one of the rubber squeeze bulbs meant for dusting off camera equipment. Canned air has some chemicals in the propellant that aren’t good for optics I’d avoid that, if any liquid manages to leave the can it’s game over for the coatings on the glass as the CO2 will likely dissolve it… A decent blower bulb is around $20 and will last pretty much forever… Anyone that owns any higher precision optics should have one… 

 

I’ve got this one and couple others, it’s decent quality and been with me for years… Some of the really cheap ones are terrible, it’s worth spending a couple bucks more… 

 

https://www.amazon.c...,97&sr=8-4&th=1

Edited by Robert7980, 15 April 2024 - 11:56 PM.

[DeepSky Di]

I used a double layer new white tee shirt with a trace panel about mid brightness. The ASIAIR figured the exposure time. Do you think I should raise the brightness and/or take more. 

That's how I do flats. By "wrong" I mean, either the wrong flats for the lights - for example, taken too far apart and some more dust got in - or being combined wrongly. I use APP for stacking.

[rj144]

Being everything was new I didn’t bother to look for dust. Everything came directly from a sealed package, assembled and used within a few hours. 

Dust gets in there almost immediately.

[mhooper]

Moved camera to my other scope (WO zenith star 61) and the same spots are in the same spots. If it was dust on the sensor the spot wouldn’t be bloated? Any new ideas? Could it be a camera issue?

[Tapio]

If the spots would in fact be in camera sensor the spots would be small and sharp. That is really rare.

But if they are on the cover glass they are bigger and smoother because the cover glass is some distance from the sensor.

[mhooper]

Problem solved. It was dust. First attempt to air jet dust failed. Second attempt I actually lightly wiped the camera sensor window and was successful. I would like to thank everyone for their advice!

[Tapio]

Good. But do take flats in the future. It's not just dust motes they cure.