Interference from CCD fan or download possible into a DSLR??

[tooth_dr]

I've noticed banding on my DLSR images recently.  After looking back at images taken with the DSLR earlier this year, I cant see any banding at all.  Banding is a new feature in my DSLR images.

Is it possible to introduce interference into my camera from either a Bluetooth EQMOD adapter or from the fan or download of a CCD camera image?  I don't have my powerleads or USB leads wrapped together, nor are they in the same duct. 

What do you think?  I've just attached the red channels but all channel are affected (green seems to be least affected).

1) RED CHANNEL OF IRIS - single 300s sub at ISO800

2) RED CHANNEL OF HEART - single 600s sub at ISO800

3) RED CHANNEL OF IRIS - stacked image (using multiple subs from 1) above)

 

 

 

 

 

 

[MarsG76]

I had that banding from my 40D from the beginning, I just use a banding removal filter in AstroTools... that works very well. I think that the banding is heat related... it doesn't show up on shorter subs, only on my 15 minute + subs.

Which DSLR?

 

[tooth_dr]

18 minutes ago, MarsG76 said:

I had that banding from my 40D from the beginning, I just use a banding removal filter in AstroTools... that works very well. I think that the banding is heat related... it doesn't show up on shorter subs, only on my 15 minute + subs.

Which DSLR?

 

Its the 40d MG. The 600s above shows no banding yet the recent ones at 300s show banding?

[michael8554]

Imaging on a hot night can give banding with a Canon dslr that is usually free of banding.

Compare the sensor temperatures on your good and bad images with an EXIF viewer.

Michael 

[tooth_dr]

1 hour ago, michael8554 said:

Imaging on a hot night can give banding with a Canon dslr that is usually free of banding.

Compare the sensor temperatures on your good and bad images with an EXIF viewer.

Michael 

Thanks for this suggestion. I’ll have a look. That indeed could be a very likely reason ??

[Xiga]

Hi Adam

What are you using to power your Atik and 40D?
One suggestion to try and eliminate whether or not it’s interference coming from the Atik’s power cable: on your next session, keep the Atik powered down and fire off a couple of subs with the 40D. Then power up the Atik and run your session as normal. Afterwards, compare the 40D subs immediately before and after the Atik was switched on, and see if there is a noticeable increase in noise/banding.

[tooth_dr]

46 minutes ago, Xiga said:

Hi Adam

What are you using to power your Atik and 40D?
One suggestion to try and eliminate whether or not it’s interference coming from the Atik’s power cable: on your next session, keep the Atik powered down and fire off a couple of subs with the 40D. Then power up the Atik and run your session as normal. Afterwards, compare the 40D subs immediately before and after the Atik was switched on, and see if there is a noticeable increase in noise/banding.

Thanks Ciaran.  I've attached a photo that should explain this better.  The 12v power comes off the Hitec Astro dew controller (8) and feeds into a home made power supply (9).  This contains some wiring to convert one of the inputs to 8.4V for the 40d (5), and the other input simply runs straight through to provide 12v for the Atik (4).

Could I try this without imaging the stars, even just taking darks - would the lines show up on the darks too?  It's not looking clear for a few nights.

[Xiga]

45 minutes ago, tooth_dr said:

Thanks Ciaran.  I've attached a photo that should explain this better.  The 12v power comes off the Hitec Astro dew controller (8) and feeds into a home made power supply (9).  This contains some wiring to convert one of the inputs to 8.4V for the 40d (5), and the other input simply runs straight through to provide 12v for the Atik (4).

Could I try this without imaging the stars, even just taking darks - would the lines show up on the darks too?  It's not looking clear for a few nights.

Absolutely Adam, no need to test this one under the stars, Darks should work just fine.
I’m wondering if your power supply is definitely up to the task of powering both cameras simultaneously? Just seems strange that this has only surfaced now that your power requirements have increased.
As an aside, while I was processing your LBN 468 data I did notice the strong banding in the 40D stack, but I was able to remove the vast majority of it very easily with Noel’s actions in PS. Strange that it didn’t work for you. Did you try using it directly on the 40D stack, and not on the combined Ha + OSC image? I usually run it right after stretching, and before doing any NR. In any case, it’s still better to try and get to the source of the problem.

Ps – It’s a great setup you have ?

[tooth_dr]

2 minutes ago, Xiga said:

Absolutely Adam, no need to test this one under the stars, Darks should work just fine.
I’m wondering if your power supply is definitely up to the task of powering both cameras simultaneously? Just seems strange that this has only surfaced now that your power requirements have increased.
As an aside, while I was processing your LBN 468 data I did notice the strong banding in the 40D stack, but I was able to remove the vast majority of it very easily with Noel’s actions in PS. Strange that it didn’t work for you. Did you try using it directly on the 40D stack, and not on the combined Ha + OSC image? I usually run it right after stretching, and before doing any NR. In any case, it’s still better to try and get to the source of the problem.

Ps – It’s a great setup you have ?

Thanks again Ciaran!

It did run my two Canons off this, but like you say, the power demand has increased.  I think I should run some tests and then report back!

I did try NC action on my stack after stretching, as well as before stretching.  Is there anything else to change with the action?  I normally just run the action by hitting the play button and thats it!

[Xiga]

49 minutes ago, tooth_dr said:

Thanks again Ciaran!

It did run my two Canons off this, but like you say, the power demand has increased.  I think I should run some tests and then report back!

I did try NC action on my stack after stretching, as well as before stretching.  Is there anything else to change with the action?  I normally just run the action by hitting the play button and thats it!

No it's just a one-click operation. I usually do it in it's own layer and then check that it has worked by blinking the layer on and off several times, and the difference is usually really obvious (although you will need to increase your Zoom level a bit to really see the impact, don't check the whole image at once).

Do you have APP? Try throwing the 40D Autosave tiff into it and applying an Auto DDP stretch. Then save it as a 16 bit tiff and import it straight into PS and test the action again. If you don't have APP then just do a big stretch manually in PS. Either way, try the action again after doing nothing but a stretch. If you're not seeing any impact, then the actions may have become corrupt and you might need to re-install them.

[tooth_dr]

3 minutes ago, Xiga said:

No it's just a one-click operation. I usually do it in it's own layer and then check that it has worked by blinking the layer on and off several times, and the difference is usually really obvious (although you will need to increase your Zoom level a bit to really see the impact, don't check the whole image at once).

Do you have APP? Try throwing the 40D Autosave tiff into it and applying an Auto DDP stretch. Then save it as a 16 bit tiff and import it straight into PS and test the action again. If you don't have APP then just do a big stretch manually in PS. Either way, try the action again after doing nothing but a stretch. If you're not seeing any impact, then the actions may have become corrupt and you might need to re-install them.

Great advice Ciaran, thanks again for this.