?Are these sausage shapes dust on my CCD chip?

[Chris]

Hi Guys,

I've bought a second hand mod'd Canon350D and got to have a quick play with it last night. Despite only getting a dozen short poor quality subs due to the Moon and thin cloud I still stacked them anyway just to test the camera which is when I noticed lots of dark sausage shapes all over the the image:( I think this might be dust on the sensor? Can I confirm that this is correct, and if so what should I use to clean the sensor? Also when I took my darks I noticed roughly 40 bright pixels on them scattered about the image (looks much worse on my computer than the image below) is this typical of a camera thats been around the block? Please see images below and any advice greatly appreciated as always:)

Chris

[JonH]

Hi Chris,

Yep, all that crud is on the sensor I'm afraid. As for cleaning, I use Visible Dust brushes and swabs which work really well but are horrendously expensive. I'm sure others on here will have different options for you.

If you don't fancy tackling the job yourself, you could always get it professionally cleaned. This firm Home - H. Lehmann Ltd are excellent and one I can highly recommend for all camera/lens repair jobs.

As for the hot pixels, I'm no expert but I'm guessing that yours is par for the course.

HTH.

Cheers,

Jon

[stan26]

Not the end of the world mate, just need to clean the sensor. Swabs are the best method, although there are many other ways. You could try what I did to clean my 500D but be careful!

With the 500D you can lock the mirror up for cleaning, I would assume you can do this with the 350...? (found in the settings menu) This allows access to the CMOS sensor. Make sure you have a good battery, you don't want the mirror slamming down whilst your in there cleaning! I used a vacuum cleaner to suck the dust from the sensor. Don't stick it right up against the sensor though!, I just used my hand to create a loose seal around the camera aperture and the end of the vacuum nozzle. I worked quite well for me, be careful though, to much suction may damage the fragile parts inside. Some dust won't go because is welded itself to the sensor from the static charge, this will need to be removed via swab......

HTH

Stan

[Chris]

Thanks guys:) I've locked the mirror up like you've described Stan and used a puffer to blow out the area, then I've used a pro sensor cleaning pen which has little brushes and fuzzy pads on it to gently sweep across the sensor. Not sure if its worked yet, I guess the best way to tell will be to take some flats, If this hasn't worked then I will get some swabs, are these specialist swabs with some kind of cleaning compound on them?

Thanks again, Chris

[stan26]

Chris, You can check it right now, Put on a camera lens switch to AV mode and select a small aperture i.e f22, Then get a white screen on your PC (i.e word pad etc) and take a pic of the white screen. The high "F" aperture will help show up the dust spots. this method is usually used in photography on a white cloudy sky, but a pc screen should work fine, or a well lit kitchen appliance like a fridge etc.......

This is of course assuming you have a lens....

Stan.

[Chris]

Hi Stan:) I like your adea about using the PC screen and small aperture I'll give that a go next time. I took a pic to show up dust by stretching a white baby grow over the camera lens and selected a sub-second exposure before pointing the lens at a well lit area (see below), I think I've reduced the dirt and dust by about 50%, I'll buy a sensor swab kit to remove the rest I recon. I think it might be a good idea for me to get one of those Astronomic CLS clip filters to both reduce LP and stop crud getting back on the censor:)

Cheers Stan:)