Dust Bunnies

[thing]

I was having another bash at M13 last night. I tried using Dynamic Background extraction in PixInsight LE to shift the vignetting which it isn't bad actually but it doesn't shift the dust bunnies. Are flats really the only way of doing this and in fact do flats shift dust bunnies at all?

Also how do you get rid of the white background when you crop an image? Image below, out of focus but ignore that. 15x2 mins, 10x2 mins darks at ISO 800. Thanks in advance.

(click to enlarge)

[Paxo]

Dave,

The flats will also include the dust bunnies (as log as they have been taken recently while you have the same dust pattern) so when used in DSS or other software they are removed from the image (can't remember whether they are subtracted are used to divide the image). In practice though this can be difficult as the bunnies can appear at any time so regular flats are the only real answer. I once get a terrible image from the GRAS system which was riddled with DB's and was surprised when the flats removed them all!

Steve

[thing]

Thanks Steve. Isn't it possible to clean the sensor? I think I have a CCD clean option on mine but I'm not sure what it does.

[jgs001]

Dave, cleaning the sensor is a scary proposition first go, but with the correct tools, it's actually very easy. I had a horrendous sticky blob on my sensor and it wouldn't shift, so I bought me a kit from here and it had it off in a jiffy. Just make sure the battery is fully charged, mount the camera on a tripod with the lens mount pointing down, as you don't want any dust to fall in whilst everything is opened up after the clean.

[thing]

Thanks for that John.

[Psychobilly]

I have used both the wet and dry kits to clean sensors...Soemtiems you need both...epends whas on the sensor i suppose.

Having removed the Filter from my 350D I had to clean the actual sensor surface itself last week so I bought myself a new Lenspen SensorKlear kit and it did a pretty good job the only difference is taht there was no "lift off" are outside the sensor so the corners were a PITA..

I check the sensor for dust by taking pictures of an LCD monitor displaying a white screen.. just remeber when you check the the resulting images the positions off the dust on the sensor are upside down and back to front...

Billy...

[thing]

It's a never ending tale of making things work this hobby..............

[rawhead]

When clearing dust bunnies, this was the best £8 I ever spent...Quick couple of blasts will get rid of most of the blighter's!

http://www.warehouseexpress.com/product/default.aspx?sku=133

[thing]

Mmmm...looks interesting.

[jgs001]

Dave, I think that kit I referenced includes a small rocket blower. Another way to test, is to set the aperture to minimum (biggest number), set the lens to longest FL as this will often allow a smaller aperture, set the focus to manual, use the flash and take a shot of a blank white surface. Any DB's will show up as clear spots.

[thing]

I shall try that thanks John.