Stuck shutter?

[Earl]

I noticed my shutter was stuck this evening did it casue this?

[peter shah]

are you talking about the line coming from the star?? if you are its nothing to do with the shutter and more to do with the anti-blooming gate on the sensor....that's normal.

[Earl]

Hi Peter

I have never had it before, odd ill see what happens next session.

[ollypenrice]

As Peter says, looks like the anti blooming was defeated for some reason. A bad column could look like this but it would need an almighty coincidence for it to pass right through that bright star!

Olly

[Earl]

As Peter says, looks like the anti blooming was defeated for some reason. A bad column could look like this but it would need an almighty coincidence for it to pass right through that bright star!

Olly

A bad column would show on daks?

[davew]

I've seen an effect very similar to this due to read out happening before the shutter has fully closed. That was on a full frame chip too. What I don't remember seeing though was the line above the star as here.

The shutter prevents light hitting the pixels during transfer and read out.

When you say you noticed the shutter was stuck, what exactly do you mean ? Was it not rotating ?

Dave.

Then again, if I was a betting man, I'd back Peter over me

[Earl]

I've seen an effect very similar to this due to read out happening before the shutter has fully closed. That was on a full frame chip too. What I don't remember seeing though was the line above the star as here.

The shutter prevents light hitting the pixels during transfer and read out.

When you say you noticed the shutter was stuck, what exactly do you mean ? Was it not rotating ?

Dave.

Then again, if I was a betting man, I'd back Peter over me

The shutter was stuck open, I have ran the QSI tools and its now fixed. (the shutter that is )

Im about to run some darks to see if it shows still.

[davew]

Have you seen this effect since it was fixed or not had a chance yet ?

If the shutter is open during read out then it just isn't going to work. It has to be fully closed.

Dave.

[Earl]

Have you seen this effect since it was fixed or not had a chance yet ?

If the shutter is open during read out then it just isn't going to work. It has to be fully closed.

Dave.

Not had a chance yet, hopefully tonight if its clear, running a dark now. (attached)

Its not in the dark so that rules out a bad column?

[swag72]

Wouldn't a bad column show on a bias?

[davew]

I think a bloom would only show if the pixel was saturated and the over charge bled off down the line. A dark shouldn't have any saturated pixels.

I can't see it being a bad column and think Sara is correct.

Dave.

[Earl]

here is a flat of sorts....

[davew]

Oh dear. I've not seen one quite like that from an 8300.

How long was the exposure ?

Dave.

[Earl]

1 second, somthing noit right, Im in communication with Ian King to see what he says.

[davew]

Ian will probably know. Hope it's not the shutter again because it may be a service requirement.

I aim for 3 second minimum with mine but less doesn't show what you've got.

Good luck,

Dave.

Don't let all this affect the stress levels mate !

[swag72]

Did you see Steve's thread the other day about vertical banding on his flats? It was due to too short an exposure.

[Earl]

I have just reconnected it up on my pc and all fine............. no lines Im stumpped

[Earl]

This is a 3 second exposure with a sheet of papper over the t-port on the camera. stretched in PI

Looks fine now. i dont get....

[davew]

That looks a bit more like.

Maybe the shutter. Maybe a lead. Maybe a Gremlin.

What did Ian say ?

Dave

[Earl]

Ian said, drivers and firmware should be updated to make sure first.

One thing i have concluded the PSU is not the same from desk to obsy and the lead is also different, so there are a good number of vareiables at play here to weed out.

[davew]

Well good luck.

I hope the stuck shutter was a software Gremlin. That's the aspect in all this that I'd find the most worrying to be honest.

Dave.

[Earl]

Back in the observatory, but with the PSu from the good flat and the usb lead and the lines are back.

USB direct into the laptop fresh drivers and rebooted.... Stumped

[davew]

Can you get the camera to cycle shots IE. take a short exposure and download a few times. As it's cycling,  look down the scope and see if the wheel covers the opening as it downloads. I can see the shutter working on mine if I do that. Trouble is, you may not be able to suss a slow shutter.

Other than that, stumped as well. Sorry,

Dave.

Did you tell Ian you had to sort this shutter out ?

[ollypenrice]

Columns do show on darks.

Blooms do tend to show a little above and a lot below the source star so the line was, I'm sure, a bloom.

Don't you have to do longish flats with shutter cameras anyway, to avoid the 'wipe' of the shutter creating a gradient? Your later flat looks fine. Did you calibrate your flats with bias frames used as darks? This is a good idea. You don't need dedicated darks for flats, normally.

Olly

[Coco]

here is a flat of sorts....

Not dissimilar to Steves.. 

http://stargazerslounge.com/topic/222320-faulty-flat-frames-with-osc-camera-and-a-solution/